AMEC - Overview of Knowledge Coverage for Geological Disposal

Technical Report

Overview of Knowledge Coverage for Geological Disposal

Bill Miller

AMEC Report Reference: 200094

Client Reference: ONR158

Issue Number: 1.1

Date of Report: 13th January 2015

Office for Nuclear Regulation (ONR) Page i

DOCUMENT ISSUE RECORD (Engineering Documents)

Document Title: Overview of Knowledge Coverage for Geological Disposal

Project Reference: ONR158

Purpose of Issue: Submission of final report to client prior to publication

Security Class: No classification

Issue Description of Amendment

Originator / Author

Reviewers Approver Date

1.0 Final report Bill Miller Timo Saanio Peter Hufschmied Tim McEwen

Bill Miller 19/12/13

1.1 Minor amendments prior to publication

Bill Miller William Turner Bill Miller 13/01/15

Previous issues of this document shall be destroyed or marked SUPERSEDED © Amec Foster Wheeler UK Limited 2015

This report was prepared exclusively for ONR (the “Company”) by Amec Foster Wheeler UK Limited (“AMEC”). This report must be read as a whole and is subject to, and limited by, (i) the information available at the time of preparation of the report; (ii) the data supplied by the Company and outside sources; (iii) the assumptions, methodology and procedures that have been agreed as the scope of work to be conducted by AMEC in connection with this report; (iv) the assumptions, conditions and qualifications set forth in this report; and (v) the terms and conditions of the agreement under which this report was prepared between the Company and AMEC, together with any subsequent amendments.

To the extent permitted by law, this report shall not be used or relied upon by any person other than the Company without the express written consent of AMEC, and, absent any such consent, AMEC disclaims any liability or responsibility for the use of or reliance on this report or any information contained in this report by any third party.

Office for Nuclear Regulation (ONR) Page ii

Contacts For further information please contact the following:

Contact Person

Title Address Contact Number

Bill Miller Repository Director

AMEC The Renaissance Centre 601 Faraday Street Birchwood Park Warrington WA3 6GN United Kingdom

TEL: +44(0)7931 256288 Email: [email protected]

Office for Nuclear Regulation (ONR) Page iii

Contents

1 Introduction ........................................................................................................ 1

1.1 Background ............................................................................................................... 1

1.2 Objectives of this report............................................................................................. 2

1.3 Method of working ..................................................................................................... 2

2 UK context and open questions........................................................................ 5

2.1 Inventory of wastes ................................................................................................... 5

2.2 Ongoing waste conditioning and packaging operations ............................................ 6

2.3 Site selection ............................................................................................................. 6

2.4 Geological disposal concepts.................................................................................... 7

2.5 Co-disposal of wastes ............................................................................................... 8

2.6 Retrievability and reversibility.................................................................................... 8

2.7 Significance............................................................................................................... 9

3 The regulatory framework ............................................................................... 13

3.1 Health, safety and security regulation ..................................................................... 13

3.2 Environmental regulation......................................................................................... 15

3.3 Other regulations..................................................................................................... 15

3.4 Significance............................................................................................................. 16

4 Balancing risks during GDF implementation................................................. 18

4.1 Significance............................................................................................................. 21

5 Stages in the GDF programme........................................................................ 23

5.1 Stages in the MRWS process ................................................................................. 23

5.2 An outline programme for the GDF and key activities............................................. 24

5.3 Significance............................................................................................................. 26

6 Main activities during the GDF programme stages....................................... 28

6.1 Format of discussion and definitions ....................................................................... 28

6.2 Stage A: Programme planning and site selection ................................................... 32

6.3 Stage B: Surface investigations .............................................................................. 37

6.4 Stage C: Access shaft / tunnel construction............................................................ 40

6.5 Stage D: Phased underground excavations............................................................ 44

6.6 Stage E: Inactive and active commissioning ........................................................... 48

6.7 Stage F: Phased waste emplacement..................................................................... 50

6.8 Stage G: Closure and sealing ................................................................................. 53

7 Underpinning knowledge and understanding ............................................... 55

7.1 Significant projects and publications ....................................................................... 56

Office for Nuclear Regulation (ONR) Page iv

8 Knowledge coverage for geological disposal................................................ 99

8.1 Organisational structure and planning................................................................... 100

8.2 Inventory and waste packaging............................................................................. 101

8.3 Concept development and design optimisation..................................................... 103

8.4 Characterisation and monitoring of the site........................................................... 106

8.5 Construction, installation and testing..................................................................... 108

8.6 Operations and waste emplacement..................................................................... 110

8.7 Backfilling and closure........................................................................................... 111

8.8 Waste retrieval ...................................................................................................... 113

8.9 Safety cases and permitting .................................................................................. 114

9 References ...................................................................................................... 117

10 Appendix: Project workshop......................................................................... 119

Office for Nuclear Regulation (ONR) Page v

Executive Summary This contractor report may be used by the UK’s nuclear and environmental regulators as one input when developing a Nuclear Research Needs (NRN) for the UK’s planned geological disposal facility (GDF). Nonetheless, the information and opinions expressed in this report represent the views of the author and do not, necessarily, reflect the position of the regulators.

The UK Government’s ‘Managing Radioactive Waste Safely’ (MRWS) policy sets out a staged approach to implementing the geological disposal of higher activity radioactive wastes (HAW). A volunteer siting process is underway that might lead to a GDF being constructed in any of the potentially available rock types and geological environments in the UK. The Radioactive Waste Management Directorate (RWMD) of the Nuclear Decommissioning Authority (NDA) has been identified by Government as the implementer for the GDF.

The Office for Nuclear Regulation (ONR) is responsible for regulating the nuclear, radiological and industrial safety of the GDF during all stages of its implementation. In parallel, the relevant environment agency (depending on where the GDF may be sited) has responsibility to ensure protection of people and the environment. Jointly, the ONR and the relevant environment agency (the ‘regulators’) will ensure safety and environmental protection by undertaking critical scrutiny and evaluation of the proposed GDF design, operational procedures and periodic safety assessments submitted by the implementer.

This report is intended to support the regulators by reviewing the underpinning knowledge base relevant to geological disposal (e.g. technical publications, research studies, development work etc.) available internationally and in the UK. Note that it is not the intention of this report to undertake a detailed peer review of the research and other technical work performed by RWMD. To structure the review of the knowledge base, the main phases of the GDF implementation programme were considered, along with their associated key activities (e.g. excavation of disposal tunnels, emplacement of waste etc). Possible knowledge gaps and open questions were identified which might require further research and development (R&D) to support their understanding, assessment or mitigation.

Although the review focussed on geological disposal, many (but not all) aspects of this study will also be relevant to proposals for near-surface and surface disposal facilities for certain types of low-level and short-lived radioactive wastes.

The review identified a number of high-level issues that may be significant for the design and operation of the GDF, and consequently for its safety and environmental performance:

1. The GDF implementation programme is subject to many variables such as the choice of site, the inventory of wastes to be disposed, the design of the facility, its operation and closure methods, and the possible need for retrievability. Many of these variables are inter-dependent. For example, the design of the GDF cannot be decided until after the site has been chosen and a decision has been made on the wastes to be disposed. The large number of variables makes it difficult to plan for and design the GDF, and to account for all of the possible safety and environmental implications. It may not be feasible to progress far with implementation whilst keeping all variables open. Evaluating different options in the early stages of implementation will, however, provide useful information that can inform later decisions on which option is ultimately preferred.

Office for Nuclear Regulation (ONR) Page vi

2. Wastes continue to be generated during routine operations and decommissioning activities, and these wastes need to be conditioned and packaged to be made passively safe for interim storage. There is a risk that wastes packaged now may not be in a physical or chemical form that is optimal for disposal in the GDF, once a site and design are chosen. The RWMD Letter of Compliance (LoC) process is intended to mitigate this risk but it currently applies only to intermediate-level wastes. Several other waste types such as vitrified high-level wastes (HLW) and some potential waste materials (e.g. uranium and plutonium-bearing fissile materials) do not have LoCs.

3. Government has expressed a preference for a single GDF for disposal of both cementitious ILW, and vitrified HLW and spent fuels, in co-located but physically separated underground areas. No other national disposal programme plans to dispose of such a diverse range of waste types, with such a large total volume, in a single co-located facility. The closest comparison is with the planned French repository which is also intended to dispose of both HLW and ILW, but the UK ILW inventory is approximately five times greater than the French ILW inventory. There is, therefore, limited international experience of co-location to draw upon. Maintaining physical and chemical separation of the different waste types in a co-located facility is essential to avoid undesirable interactions and corrosion process occurring. This places important constraints on the requirements and suitability of the host rock. It is not yet known whether a suitable rock volume will be available within any volunteered site and, consequently, it remains a possibility that more than one geological disposal facility may need to be sited in the UK.

4. Deciding upon the disposal concept for the GDF is not a straightforward process, and many different safety, environmental, technical, financial and stakeholder issues will need to be taken into consideration. Optimisation of the GDF design and its operational practices will require appropriate balancing of full life-cycle operational safety (i.e. risk to site workers and current generations) against post-closure safety (i.e. risk to future generations), and against the other non-safety attributes. The process and methodology to be used for decision making and optimisation has yet to be agreed. This process will need to be transparent, auditable and acceptable to all key stakeholders, including the regulators and the local communities at the volunteer site.

There has now been over five decades of detailed research into geological disposal. The bulk of this work has focussed on understanding and modelling the long-term evolution of disposal systems, and on assessing the post-closure consequences of radionuclide releases and exposures to people. Reviewing the underpinning knowledge, it is apparent that, at a high level, there is relevant knowledge applicable to all of the stages and activities anticipated in the GDF programme. Certain topics are very well researched and understood internationally, and it might be argued that no further fundamental research is required on aspects such as:

HLW and spent fuel long-term stability, and radionuclide release processes in chemically reducing, low groundwater flow geological systems;

packaging concepts for solid, chemically and physically inert wastes;

long-term behaviour and containment properties afforded by compressed bentonite as a buffer material; and

radionuclide release and transport modelling, and associated dose/risk consequence analysis for environmental safety cases.

Much of the available knowledge comes from overseas HLW and spent fuel disposal programmes that have already chosen sites and are nearing full implementation (e.g. Finland, Sweden, France).

Office for Nuclear Regulation (ONR) Page vii

This knowledge can be translated to disposal in the UK, provided allowances are made for any key differences in waste materials and the geological conditions at any volunteered site etc.

Less emphasis has typically been given to research into methods for the construction and operation of geological disposal facilities, or to aspects of nuclear safeguards and security. This is despite the obvious hazards associated with handling large and heavy radioactive waste packages in confined spaces underground. This situation is now changing with several international collaborative projects ongoing in underground research laboratories that involve testing and demonstrating the equipment and methods that may be used for construction and operations, such as full-scale waste emplacement trials. The UK participates in some of these projects but the implementation methods that may be applied in the GDF cannot be fully developed until after a site has been chosen, and a disposal system designed that is consistent with the characteristics of the host rock.

This review identified a number of potential knowledge gaps and open questions that will need to be addressed as the GDF programme moves forward. Not all of these knowledge gaps need to be addressed now, but a plan should be developed to ensure that key information is available at the time it is needed, and at the appropriate level of detail. In some cases, this may mean work needs to start soon to obtain the information that will be needed during later stages of implementation, especially where long-term research or development of technology may be required.

Some of these open questions relate to the high-level issues of waste inventory, disposal concept design and decision making processes, described earlier. Questions such as:

How should wastes continue to be processed and packaged without foreclosing options, given uncertainty regarding the site, geology and design of the facility?

What disposal concepts and engineering designs are suitable for UK wastes and geological environments (both established concepts and promising but less well developed alternatives)?

How will decisions (on site, inventory, design etc.) be closed out and banked, to enable the programme to move forward through each stage of implementation in the light of new information as it is gathered?

Many other questions relate to specific technical, engineering, design and operational aspects of the GDF during later stages of implementation, such as:

How will the ‘as built’ design be recorded and input to the nuclear and environmental safety cases?

How can active and non-active areas of the GDF be separated from each other?

What will be the procedure and techniques for managing any waste package that might have degraded or leaked?

What wastes and disposal areas will need to be backfilled at the time of waste emplacement?

None of the open questions identified in this report are ‘show stoppers’ and none of them would mean that the GDF programme could not move forward to the next stages of implementation. Several of them will, however, need to be answered with sufficient detail before embarking on MRWS Stage 6 (Underground operations) which marks a fundamental change in the programme from performing largely desk-based studies, to undertaking practical construction and engineering activities. Questions such as:

Office for Nuclear Regulation (ONR) Page viii

What are the factors affecting the choice of primary access route to the underground parts of the GDF (e.g. shaft or inclined tunnel)?

What are the safety critical posts in the implementing organisation, and what competence does the implementer need to manage the design and construction of the access shaft / tunnel?

What site characterisation and baseline monitoring information must be collected before shaft / tunnel construction can commence?

What information is needed to determine whether the access needs to be designed to allow retrievability?

Their inclusion in this report does not imply that these open questions have not, or cannot, be answered at this time. It will be through the continuing process of scrutiny, that the regulators may come to a view that these questions have, or have not, been answered to their satisfaction, at a level of detail appropriate to the current stage of the GDF implementation programme.

It is stressed that it is not the intention of this report to peer review the work of RWMD, and the list of open questions in this report does not imply any deficiency in their technical and research programmes.

Clarification for publication

This report was written in 2013, and presents the findings of a study that was carried out in the period 2012 - 2013. It is being published in 2015 and so may not fully reflect more recent developments in Government policy (MRWS), or the updated programmes and working arrangements of the organisations mentioned herein.

Office for Nuclear Regulation (ONR) Page 1

1 Introduction

1

.1 Background

In 2001 the UK Government and devolved administrations initiated the Managing Radioactive Waste Safely (MRWS) programme with the aim of finding a practicable solution for the UK’s higher activity radioactive wastes (HAW). As part of the MRWS programme, Government appointed the independent Committee on Radioactive Waste Management (CoRWM) and charged them with making recommendations for how HAW should be managed. In 2006, CoRWM published their findings and recommended that geological disposal, supported by an integral programme of safe and secure interim storage, was the best available approach for the long-term management of HAW (CoRWM, 2006).

The Government1 accepted this recommendation and it is now policy in England, Wales and Northern Ireland that HAW will be disposed of in a geological disposal facility (GDF) at some future time and at a site yet to be identified. The policy and regulatory framework underpinning geological disposal was set out in a White Paper (Defra et al., 2008) that specified that the Nuclear Decommissioning Authority (NDA) is the body responsible for planning and implementing a GDF, through its Radioactive Waste Management Directorate (RWMD). The policy in Scotland is that the long-term management of HAW should be in near-surface facilities located as near to the site where the waste is produced as possible (Scottish Government, 2011).

The implementation of a GDF will be a complex undertaking that will need to address many conventional and radiological hazards to people and the environment during its design, construction and operation, and also into the very far-future after it has been closed. The Office for Nuclear Regulation (ONR) has a statutory duty to regulate nuclear, radiological and industrial safety on nuclear sites in the UK, and so has a primary interest in all safety relevant aspects of the GDF throughout all stages in its lifecycle. The 2008 White Paper makes clear that the GDF will require a Nuclear Site Licence under the Nuclear Installations Act 1965.

In parallel, the relevant environment agency2 will have responsibility to ensure protection of people and the environment during construction and operation of the GDF, and also into the far-future after the facility has been closed. Jointly, the ONR and the relevant environment agency will ensure safety and environmental protection by undertaking critical scrutiny and evaluation of the proposed GDF design, operational procedures and periodic safety assessments submitted by the implementer.

Although the primary focus of the report is on geological disposal, many (but not all) aspects of this study are also likely to be relevant to near-surface and surface disposal facilities (such as those considered in the Scottish policy for management of HAW), provided consideration is given to possible consequences for safety and environmental performance due to the depth of the disposal facility.

1 In this report, the term ‘Government’ refers to the UK Government unless the context indicates otherwise. 2 Environmental regulation is a devolved matter. Consequently, either the Environment Agency (EA), Natural Resources Wales (NRW) or the Northern Ireland Environment Agency (NIEA) will be the relevant environment agency for the GDF, depending on whether it is sited in England, Wales or Northern Ireland. For the purposes of this project, the EA has taken the lead on behalf of all the environment agencies.


1.2 Objectives of this report

This contractor report will be used by the regulators to underpin a Nuclear Research Needs (NRN) for the GDF. Nonetheless, the information and opinions expressed in this report represent the views of the author and do not, necessarily, reflect the position of the regulators.

The purpose of this report is to take a high-level overview of the GDF implementation programme and its associated activities, and to consider the extent of the underpinning knowledge base (e.g. research studies, development work etc). This review will help to identify any outstanding aspects that may affect the safety and environmental performance of the GDF, and associated knowledge gaps, which might require further research and development (R&D) to support their understanding, assessment or mitigation.

At this stage in the GDF programme, the primary aim is to ensure there is sufficient knowledge to move forward to the next steps of implementation and there are no obvious ‘show stoppers’. Not all knowledge gaps need to be addressed now, but a plan should be developed to ensure that key information is available at the time it is needed, and at the appropriate level of detail. In some cases, this may mean work needs to start soon to obtain the information that will be needed during later stages of implementation, especially where long-term R&D may be required.

It is understood that certain design features and operational practices have implications in terms of nuclear, environmental and conventional safety and security. There may, consequently, be a tension when meeting the totality of regulatory requirements. An additional specific purpose of this report is to examine how ‘operational safety’ may be appropriately balanced against ‘post-closure safety’ through optimisation of the facility design and its operational practices.

It is not the purpose of this report to review RWMD’s implementation programme for the GDF nor is the aim to peer review RWMD’s technical publications. Other reports have recently addressed those topics (e.g. CoRWM, 2012, 2013; ONR & EA, 2011, 2013). This report may, however, be used as one input to the regulators continuing process of scrutiny and evaluation of RWMD. Through the continuing process of scrutiny, the regulators may seek to establish whether the open questions raised in this report have been, or are planned to be, answered by RWMD at a level of detail appropriate to the current stage of the GDF implementation programme. These open questions may then be tracked through the issues management processes already established by both the regulators and RWMD.

1.3 Method of working

To help structure the project and ensure the objectives were met, the work was undertaken in a number of steps, as shown in Figure 1.1.

This method of working was adopted because it was considered sensible to discuss the questions associated with geological disposal in the context of the most important activities that will be undertaken by the implementer in each of the main stages of GDF implementation (construction, operation etc.), and then to consider what are the potential high-level safety and environmental implications of those activities. These implications are phrased as possible questions that the regulators may wish to ask as part of their scrutiny of the GDF programme.


Step 1:Review the Government policy and

regulatory framework

Step 3:Identify the key stages in the implementation programme

Step 4:Consider implications of activities

and associated ‘questions’

Step 5:Identify the underpinning

knowledge for key activities

Step 2:Consider balancing operational and

post-closure safety

Identify programme drivers, open issues with safety and environmental implications

Determine what are the most significant activities that will be undertaken in the programme

Develop a set of questions the regulators may wish to ask as part of scrutiny of the programme

Review published international research, development work and collaborative projects

Consider available methods to optimise the design accounting for all key decision attributes

Sections 2 and 3

Section 5

Section 6

Section 7

Section 4

Step 6:Identify any potential gaps in

knowledge and need for new R&D

Align international knowledge to GDF programme activities and identify any potential gaps

Section 8

Figure 1.1: The steps in the project leading to fulfilment of the project objectives, and the sections in the report in which each step is described.

For example, during construction, an important activity will be the design and excavation of the primary access route for waste transport to the underground parts of the GDF (e.g. vertical shaft or inclined tunnel). This access has obvious safety implications for construction and removal of excavated rock, routine waste handling operations, and potential accident scenarios. Additionally, the access might provide a pathway for post-closure radionuclide releases in the far-future. The regulators may wish to ensure all factors are taken into account in its design and so might ask the question:

What information is needed to make the decision on the choice of the primary access route and what is the decision making process?

An important step in the project was to consider the status of current knowledge relevant to the most important activities. When identifying the knowledge base, consideration was given to the international context and the experience from those national disposal programmes that are at a more advanced stage of implementation than the UK (e.g. Finland, Sweden, France).

No assumptions have been made for the likely host rock type or concept design for the GDF, and international knowledge relevant to all possible options has been


gathered, including some disposal concepts that have not been considered in detail within previous phases of R&D into geological disposal in the UK. This helps to identify what relevant knowledge could be applied to the GDF programme, and also where there may be key knowledge gaps due to the unique nature of the UK’s radioactive wastes and its disposal programme.

Within the resource constraints of the project, it was not feasible to identify all published research etc. but a concerted effort was made to identify the most recent and applicable sources of information. Particular attention was paid to the outputs from large-scale international collaborative projects (e.g. those led by the EC and IAEA) because these tend to be planned specifically to support knowledge transfer. Reports published by the UK regulators or the UK implementing body (RWMD) were not included in this review.

To help identify the most important activities and associated high-level questions, a workshop was held at the beginning of the project that involved experts drawn from the regulators (ONR and EA) plus the following independent experts to provide additional knowledge and ensure an international perspective to the review.

John Whyatt from the Health and Safety Executive’s Mines Inspectorate (UK)

Tim McEwen from McEwen Consulting Ltd (UK)

Timo Saanio from Saanio & Riekkola Oy (Finland)

Peter Hufschmied from ExTechNa GmbH (Switzerland)

In addition to participating in the workshop, these experts also peer reviewed a draft of this report.

The Appendix provides a full list of the workshop participants, together with a summary of the main points and questions that arose during discussions.


2 UK context and open questions

2.1 Inventory of wastes

The UK has a wide array of radioactive wastes and materials that are likely to be sentenced for disposal in the GDF, the most significant being vitrified high-level waste (HLW) and a broad range of intermediate-level wastes (ILW) generated during routine plant operations and decommissioning. Collectively, HLW and ILW form the bulk of wastes that are defined as HAW. In addition, HAW may also include a small volume of low-level waste (LLW) that cannot be disposed to the national LLW repository (LLWR) due to high concentrations of certain long-lived radionuclides that exceed the LLWR nuclide-specific waste acceptance criteria.

In addition to HAW, there are large volumes of other radioactive materials that are not currently classified as wastes but may, subject to changes in Government policy, be reclassified as wastes and be sentenced for disposal in the GDF. These include:

spent nuclear fuels that are not subject to existing reprocessing contracts, such as those from any new power reactors that may be built in the UK;

depleted, natural and low-enriched uranium (DNLEU) stockpiles, generated during fuel manufacture and processing; and

stockpiles of plutonium and highly-enriched uranium, held for strategic purposes.

The quantities of the HAW wastestreams and their anticipated future arisings are provided in the 2010 UK Radioactive Waste Inventory (DECC & NDA, 2011a), whilst quantities of the other radioactive materials not classed as wastes are reported separately (DECC & NDA, 2011b). Those documents report ‘conditioned volumes’ making assumptions for how each waste stream will or may be processed. For planning purposes, Government set out in the 2008 White Paper a Baseline Inventory for wastes that may be disposed to the GDF and this is summarised in Table 2.1.

Table 2.1: The Baseline Inventory expressed as total packaged quantities of radioactive wastes and materials potentially to be disposed of in the GDF.

Baseline Inventory Packaged volume Radioactivity Material

m3 % TBq %HLW 1,400 0.3 36,000,000 41.3ILW 364,000 76.3 2,200,000 2.5LLW 17,000 3.6 < 100 < 0.1Spent fuel 11,200 2.3 45,000,000 51.6Plutonium 3,300 0.7 4,000,000 4.6Uranium 80,000 16.8 3,000 < 0.1Totals 476,900 100 87,200,000 100

The large total conditioned waste volume, the diversity of individual waste streams and the times of their arising will place certain requirements on the design of the GDF


and also requirements of the host site. These relate to aspects such as the minimum necessary excavated rock volume, the need to operate the GDF over many years, and a requirement to separate different wastes from each other, and to coordinate parallel construction and operation activities.

2

2

.2 Ongoing waste conditioning and packaging operations

To date, approximately 25,000 m3 of the ILW identified in Table 2.1 (c. 7% of the total) has already been produced, conditioned and encapsulated into some 47,000 waste packages (DECC & NDA, 2011a). This was done against Letters of Comfort/ Compliance (LoCs) previously issued by Nirex on the assumption that these wastes would be disposed of using the Phased Geological Disposal Concept (PGRC) that was developed by Nirex during the 1980s and 1990s. ILW continues to be generated and packaged following the LoC process (under RWMD), and it is likely that a substantial additional volume of packaged waste will exist by the time construction of the GDF begins. Similarly, vitrified HLW is being produced at Sellafield without an LoC although discussions with RWMD, and other related developments, are in progress. There is, nonetheless, widespread international consensus on the suitability of vitrified wastes for geological disposal.

Given that there is, as yet, no site or host rock selected and, therefore, no agreed design concept for the GDF, there is a risk that some or all of the existing packaged wastes might not be in a form that is optimal for disposal. The LoC process is intended as a pragmatic means to mitigate this risk, and allow ongoing ILW management to continue until such time as a site and concept for the GDF have been agreed. The LoC process involves RWMD undertaking comprehensive ‘disposability assessments’ of the waste producers’ proposals for conditioning and packaging each ILW waste stream against RWMD’s generic waste package specifications.

.3 Site selection

The UK Government takes the view that a site for the GDF should be selected using a step-wise approach based on voluntarism and partnership. Following publication of the 2008 White Paper there has been an open invitation to communities to express an interest and engage with Government in the siting process. At the time of writing, however, no community has yet made a formal ‘Decision to Participate’ and so no preferred location for the GDF has been identified.

The White Paper recognises that the design and layout of the GDF (both above and below ground) must be tailored to the geological characteristics of the chosen host site, and the inventory to be disposed. Given that the volunteer siting process does not exclude any areas of the country or geological environments, disposal might occur in any of the potentially available geological environments and rock types, including hard (crystalline) rocks, clay (argillaceous) rocks and salt formations. These rock types have significantly different physical, chemical and hydraulic characteristics and, consequently, the detailed design of the GDF cannot be determined until after a site has been chosen (NDA, 2008).

In late 2013, Government consulted on proposals to amend the volunteer siting process. The proposed changes would affect some aspects of how volunteerism would work, and how land-use planning decisions may be made, but would not materially change any of the conclusions or recommendations in this report.


2.4 Geological disposal concepts

The UK Government’s policy is for deep geological disposal. The 2008 White Paper does not specifically define ‘deep’ but suggests that disposal might occur at a depth somewhere between 200 and 1000 m below the surface, depending on the geology at the site in question. The general intent of geological disposal is that the facility is constructed at a depth sufficient to isolate it from the dynamic natural process and man-made activities that occur at or near the ground surface.

Similarly, the White Paper does not mandate any aspect of the GDF design, other than it should be based on the multi-barrier principle, comprised of both engineered and natural barriers. As illustration, the White Paper makes reference to a number of multi-barrier designs that have been developed internationally, including:

the operating WIPP facility constructed in bedded salt in the USA for the disposal of transuranic bearing ILW;

the KBS-3V design for spent fuel disposal that is being implemented in both Sweden and Finland; and

the cementitious repository design for ILW that was proposed by Nirex in the 1980s and 1990s, before the current Government policy was initiated.

These well developed disposal concepts are not, however, the only design concepts that could be adopted for the GDF. Several other alternative concepts (some less developed but potentially promising) are possible based around design features such as large caverns in which waste packages can be stacked; long tunnels in which waste packages can be emplaced horizontally; and very deep boreholes in which waste packages can be emplaced vertically. In very broad terms, these concepts are all based on an engineered barrier system (EBS) that comprises multiple barriers including (from the inside out) a solid waste form, a robust waste package, a buffer or backfill material, and then the host rock.

In some advanced overseas disposal programmes, disposal concept designs and operational methods have been subject to practical testing using half-scale and full-scale mock-ups in underground research laboratories (URLs). In some cases, this practical experience has led to significant design changes and design variants to simplify waste emplacement operations. One such example is the development of ‘supercontainer’ designs which, in simple terms, change the order of the barriers by including buffer materials inside the canister overpack. One supercontainer design has now been adopted as the preferred concept in the Belgian HLW/SF programme (ONDRAF/NIRAS, 2011) and other supercontainer designs have been investigated in France, Switzerland, Sweden and Finland.

In some national programmes, certain wastes with short half-lives (that would be considered HAW in the UK) are considered for near-surface instead of geological disposal. This strategy is based on radioactive decay significantly reducing the radiological hazard during the likely period of institutional control (usually taken to be around 100 to 300 years). For example, in Belgium ‘Category A’ wastes are planned to be disposed of in a near-surface vault-type facility at Mol-Dessel. Category A wastes are defined as short-lived LLW and ILW containing radionuclides with half-lives < 30 years and trace amounts of long-lived radionuclides (Sumerling & Vermariën, 2007).


International experience illustrates that designing a disposal facility is a complex task that requires consideration of many different (and sometimes opposing) aspects, and must take account of the need to balance the practical aspects of constructing and operating the facility against the requirement to ensure long-term safety.

2.5 Co-disposal of wastes

Although the 2008 White Paper does not mandate the design of the GDF, it does express a preference for co-locating disposal facilities for different types of waste at the same site. This essentially means having separate disposal areas beneath ground but sharing the same access tunnels and surface facilities, provided the necessary safety, security and environmental requirements can be met. In broad terms, a co-located facility would have (as a minimum) two disposal areas, one for ILW/LLW, and a second for HLW/SF.

Co-location introduces significant requirements for an acceptable site and host rock, such as the availability of a sufficiently large volume of suitable rock, the ability to achieve the necessary minimum physical separation distances between disposal areas and predictable groundwater flow patterns. A co-located disposal facility would need to be designed to ensure different disposal areas were physically, chemically and hydrogeologically separated, so far as is reasonably practicable, because some wastes are chemically incompatible with each other, in particular the vitrified HLW is susceptible to corrosion in the high-pH leachates that will arise from cemented ILW.

In a volunteer siting process, it is possible that a community may set restrictions during discussions with Government and RWMD on what wastes they are prepared to accept in a GDF. This is similar to the role communities have in decisions regarding retrievability as described in the White Paper, and so might influence the need for co-located facilities. As an example, in Canada, Ontario Power Generation (OPG) has a hosting agreement with the Municipality of Kincardine near the Bruce nuclear power station which specifically states the planned geological repository would only be used for the disposal of L/ILW from OPG reactors and specifically would not accept spent fuel (Municipality of Kincardine, 2004).

Until the chemical, physical and radiological inventory of the wastes to be disposed has been determined, it is not possible to define at any level of detail what are the minimum physical requirements of a site to support co-location. Consequently it remains an open question whether or not co-location will be achievable at a site chosen through the MRWS process.

2.6 Retrievability and reversibility

Many stakeholders favour disposal designs that would enable wastes to be taken back out of a disposal facility. This is generally referred to as retrievability but there are variants on the retrieval concept, depending on whether or not the facility remains open or has been partially or fully closed at the time waste recovery is considered. CoRWM used the following terminology:

reversibility: designed into the option to facilitate the recovery of material by reversing the original emplacement process;

retrievability: designed into the option to facilitate the physical retrieval of waste through means other than reversing the process, such as ensuring


access to the waste and having (or being able to have) the retrieval mechanism in place;

recoverability: addressing retrievability by demonstrating that the waste is technically recoverable through mining or other means.

The concept of retrievability is particularly important for the ‘phased disposal concept’, in which wastes are emplaced in the disposal facility but the facility is explicitly designed and planned to then be left open to allow futures generations the option to either retrieve the waste or to finally close and seal the facility.

Although members of the public often have a preference for phased disposal, many technical experts (and CoRWM itself) take the opposite view on the basis that leaving a facility open, possibly for centuries after waste has been emplaced, increases the risks disproportionately to any gains. In the 2008 White Paper, Government expressed its view that the decision about whether or not to keep the GDF open for an extended period of time after waste emplacement, to allow for retrievability, can be made at a future time and in consultation between the regulators and the host community. In the meantime the planning, design and construction of the GDF is to be carried out in such a way that the option of extended retrievability is not excluded.

This policy requirement introduces complexities in the GDF implementation programme, not least because the extent of ‘retrievability’ that should be designed for has not been specified. Furthermore, the safety and environmental consequences of incorporating retrievability into the GDF design (and in different rock types) are not yet well established. From an engineering perspective, multiple options and requirements need to be designed and maintained until such time as the question of retrievability is finally decided, and options can be down-selected.

It should be noted that retrievability is also a requirement in some other national disposal programmes (notably France and Switzerland) but, because this requirement is clearly defined at the outset, not so many options need to be carried forward. In these programmes, retrievability is often linked to the concept of monitoring. For example, in the Swiss concept of ‘monitored long-term geological disposal’ there is a legal requirement to include an underground pilot facility containing a small number of waste packages that will be monitored to provide representative information on the functioning of the entire disposal facility (Nagra, 2009).

2.7 Significance

There are a number of observations relevant to this project that arise from this discussion of the UK context. These are set out below, together with some related questions with safety and environmental implications that the regulators may wish to ask.

1. The GDF implementation programme is subject to many variables that relate to aspects such as the choice of site, the inventory, the engineered design, its operation and closure methods, and the potential need for retrievability. These variables are all coupled, to a certain extent, and therefore it may not be feasible to progress far with implementation whilst keeping all of them open. Evaluating different options in the early stages of implementation (e.g. as done by RWMD in the gDSSC) will, however, provide useful information that can inform later decisions on which option is ultimately preferred.


What is the minimum level of protection (e.g. containment and isolation) required for each of the main waste types, and what are the essential design requirements of the GDF necessary to provide that level of protection to ensure the safe disposal of each waste type?

What are the additional design features that may be desirable or add value, and what is the process for deciding which of these features should be included in the GDF design?

What are the key variables that affect GDF implementation and what weighting is placed on them during decision making?

What safety or environmental factors, other than those related to geological and surface conditions, might cause a site to be considered or eliminated during the site selection process?

2. The fact that the inventory is not fixed in terms of either materials or quantities introduces large uncertainties that affect all subsequent GDF design and implementation activities. In particular, the dimensional requirements for a host site and volume of rock suitable for the disposal of all wastes may be restrictive.

What are the potential safety and environmental implications of different inventory boundary conditions, and is it realistic and feasible to plan for a single GDF for all HAW?

3. The potential inclusion of certain fissile materials (e.g. plutonium stocks) in the inventory of materials to be disposed to the GDF increases the importance of safeguards and security considerations. Depending on how these materials may be conditioned and packaged will affect the effort required to ensure safeguards and security in the design and operation of the GDF.

What measures would need to be taken to ensure all safeguards and security requirements are met if fissile materials are disposed in the GDF?

4. The need to continue to condition and package wastes as they arise raises the potential risk that they might not be optimal for disposal in the GDF. ILW has been (and will continue to be) conditioned and packaged using RWMD’s LoC process. It is not known how different the actual GDF design and site characteristics will be from those assumed in current disposability assessments, and the consequences of those differences is also unknown. In any case, the GDF must be capable of disposing all of the legacy wastes currently in storage, and still being produced, which sets a requirement for a broad envelope for waste acceptance, and flexibility in its design and operation.

How should wastes continue to be processed and packaged without foreclosing options, given uncertainty on the site, geology and design of the facility?

5. The many permutations of host rocks, generic disposal concepts and their design variants means that there may be several engineered designs that could be implemented at a volunteered site. It is likely that there will be differences in the level of knowledge and understanding of these alternatives. The down-selection of designs to a preferred option will need to be done carefully to avoid bias in favour of the better understood options. The process will also need to be transparent and be consistent with all regulatory and stakeholder expectations.


What disposal concepts and engineering designs (both well established and promising but less well developed alternatives) are suitable for UK wastes and geological environments?

What is the process for comparing and contrasting alternative disposal concepts to identify reference designs, and for justifying the exclusion of others?

How will local communities be involved in the process for comparing and down-selecting options during the volunteer process? And what other aspects of the GDF can they influence (e.g. site selection, facility design, allowable inventory, retrievability etc)?

6. International experience from underground testing and demonstration projects suggests that disposal system designs may need to be significantly modified to simplify emplacement activities. This experience has shown that it is not until underground tests have been attempted that a real appreciation of the nature and scale of the practical difficulties can be gained. Potential modifications ideally should be identified as early as possible to minimise the knock-on consequences for other aspects of the implementation of the GDF, and for the implementation schedule.

What demonstration studies are needed to assess the safety and practicability of proposed designs, and how will this feed into design optimisation?

7. Some national programmes plan to dispose of short-lived ILW in near-surface facilities separately from long-lived wastes in geological disposal facilities. Segregating and managing wastes in the UK by half-life rather than by total activity may allow for additional disposal strategies to be considered.

Is deep geological disposal the only appropriate option for all HAW?

What might be the potential safety and environmental implications of segregating and disposing of short-lived ILW in near-surface facilities?

8. The incompatibility between different wasteforms means that it is essential to ensure a high degree of physical, chemical and hydrogeological separation between co-located disposal areas and their wastes, and this places important constraints on the suitability of the host rock. This is particularly important because of the very large volumes of cementitious ILW in the UK inventory. It is not yet known whether a suitable rock volume will be available within any volunteered site and, consequently, it remains a possibility that more than one geological disposal facility may need to be sited in the UK.

What are the minimum requirements to ensure physical, chemical and hydrogeological separation of co-located disposal facilities? And what are the risks if separation were to fail?

What are the potential safety and environmental implications of operating a single co-located facility compared to two entirely separate facilities?

9. The fact that retrievability remains an open question that is not due to be closed-out until a site has been chosen and there has been dialogue with the host community introduces large uncertainties that affect all subsequent GDF design and implementation activities. In particular, the extent of reversibility / retrievability


that might need to be designed for has not been specified, meaning that there are likely to be significant differences between the expectations of some stakeholders in this regard. There is currently only limited understanding from underground tests and demonstration projects of the practical constraints on the extent to which retrievability may actually be possible.

What are the potential safety and environmental implications of incorporating different extents of retrievability into the GDF design for each possible host rock?

Are there wastes with a higher likelihood of being retrieved than others, for whatever reason, and how will this affect the design of the facility and the waste emplacement strategy?

What are the likely safety and environmental consequences if retrievability were to be carried out for whatever reason?

Would the need for retrievability rule out certain disposal concepts? For example, boreholes.

10. The GDF implementation programme will take many decades and, in this time, new technology will be developed and new knowledge is likely to be gained. It is important that all new information is taken into consideration but key decisions need to be banked to enable the programme to maintain momentum.

How will decisions (on site, inventory, design etc.) be closed out and banked, to enable the programme to move forward through each stage of implementation in the light of new information as it is gathered?


3 The regulatory framework The regulatory framework that applies to the development of the GDF has evolved somewhat since the publication of the 2008 White Paper. Under the current framework, the GDF will be regulated jointly by the ONR and either the Environment Agency (EA), Natural Resources Wales (NRW) or the Northern Ireland Environment Agency (NIEA), depending on whether it is sited in England, Wales or Northern Ireland. Note that the policy in Scotland is for the long-term management of HAW in near-surface facilities located as near to the site where the waste is produced as possible (Scottish Government, 2011).

To date, the EA has taken the lead on developing understanding and guidance on geological disposal, in collaboration with the other environmental agencies. For simplicity during the remainder of this report, reference to the EA can be taken to mean the relevant environment agency for wherever the GDF is finally sited.

In simple terms, the ONR has responsibility for regulating the GDF to ensure safety and security throughout all aspects of its design, construction and operational phases (including waste transport aspects). The EA will have parallel responsibility to ensure protection of people and the environment during construction and operation of the GDF, and also into the far-future after the facility has been closed.

Neither regulator has any formal role in selecting a site for the GDF but they will help the siting process by advising and commenting on safety and environmental matters. RWMD is voluntarily submitting to regulatory scrutiny through a ‘process by agreement’ with both ONR and EA. This scrutiny is intended to help RWMD to progress implementation and to develop the applications that will be necessary for licensing and permitting processes.

The regulatory framework is broadly the same for both geological and near-surface disposal and so would apply if, for example, some short-lived wastes were considered for disposal in shallow disposal facilities.

3.1 Health, safety and security regulation

The principle regulations that the ONR will apply to regulation of the GDF are:

Nuclear Installations Act 1965 (NIA).

Ionising Radiations Regulations 1999 (IRRs)

Nuclear Industries Security Regulations 2003 (NISR)

Health and Safety at Work Act 1974 (HSWA)

Although disposal is not a prescribed activity in NIA, Government has indicated in the 2008 White Paper that the GDF will become a licensed facility. The point in the GDF development programme at which the site will become licensed has not yet been established but it is reasonable to expect that the GDF might become a licensed site before significant underground construction begins, in line with ONR guidance that “A nuclear site licence must be granted to a developer before they may undertake


construction work which could, if inadequately conceived or executed, affect nuclear safety when the plant is operational” (ONR, 2012).

Neither the standard Licence Conditions nor the Safety Assessment Principles (SAPs) were developed with the GDF in mind, and so these will need to be reviewed and modified as necessary to take account of the unique nature of the GDF and its operations.

For the GDF (as with any other planned new nuclear facility) iterative nuclear safety cases will be required at key stages in its development. The number, timing and content of these nuclear safety cases have not yet been decided. For the purposes of this report, it is assumed that the following nuclear safety cases will need to be produced by the implementer and evaluated by the ONR as part of a staged licensing process:

Preliminary Nuclear Safety Case, once a preferred site has been chosen and characterised, to be used as the basis for the application for the site licence;

Pre-Construction Nuclear Safety Case (Access), to demonstrate that the GDF access (vertical shaft or inclined tunnel) is capable of being constructed and operated safely on the basis of a site-specific design;

Pre-Construction Nuclear Safety Case (First phase), to demonstrate that the first phase of the disposal tunnels and vaults are capable of being constructed and operated safely on the basis of a site-specific design;

Pre-Commissioning Nuclear Safety Case, once the first phase excavations are complete to demonstrate that the as-built GDF meets relevant safety criteria and can be operated safely;

Pre-Operational Nuclear Safety Case, once active commissioning has been completed to demonstrate that all necessary pre-operational actions and modifications are completed, validated and implemented;

Post-Operational (Pre-Closure) Nuclear Safety Case, after all wastes have been emplaced to demonstrate that the GDF can be backfilled, closed and sealed safely.

Due to the GDF having separate (co-located) but differently designed disposal areas for the various wastes, plus the likelihood of the facility being developed in phases, most of these nuclear safety cases may need to be produced for each separate disposal area and each phase of development.

One important objective of the iterative nuclear safety cases produced during the early stages of GDF design and implementation will be to demonstrate how concept and design options and alternatives are progressively reduced, and how the final as-built engineering design is chosen and optimised (e.g. to ensure the ALARA principle is upheld). Optimisation of design is one activity that will need carefully to balance operational safety with post-closure safety, as discussed in Section 4.

Another important objective of these iterative nuclear safety cases is to identify all outstanding issues which need to be resolved (e.g. through further R&D), their importance and the work required to resolve them (with timescales). Later iterations will need to demonstrate that outstanding issues have been closed out by the further work.


3

3

.2 Environmental regulation

The EA will regulate the GDF under the Radioactive Substances Regulation (RSR) framework largely using Schedule 23 of the Environmental Permitting Regulations 2010 (EPR) which sets out the requirements for the safe handling of radioactive substances, and for the disposal and discharges of radioactive wastes.

Schedule 23 provides the necessary powers for the EA to grant an environmental permit for the GDF under a ‘staged regulation’ process, beginning from the point that intrusive investigation work is planned to be carried out. As with nuclear safety cases, iterative environmental safety cases will be required at key stages during the development of the GDF. The number, timing and content of these environmental safety cases has not yet been decided but the EA has published specific guidance on the requirements for authorisation (the ‘GRA’) for geological disposal (EA & NIEA, 2009; EA, 2012). This sets out the EA’s preliminary expectations for environmental safety cases that would show how the GDF will protect people and the environment, and the following would be expected:

Initial Site Evaluation, before any intrusive site investigations can commence to give a largely qualitative view on the feasibility of constructing the GDF at the site;

Preliminary Environmental Safety Evaluation, after the site has been characterised to provide a preliminary assessment that the GDF will be safe before underground excavations can begin;

Initial Environmental Safety Case, before the significant underground excavations begin to provide enough evidence to inform EA’s decision on whether to grant a permit for disposal in principle;

Pre-Operational Environmental Safety Case, before waste emplacement to provide a sound scientific and technical basis to inform EA’s decision on whether to grant a permit for disposal;

Post-Operational (Pre-Closure) Environmental Safety Case, after all wastes have been emplaced to demonstrate that the GDF can meet its post-closure safety requirements.

In addition to Schedule 23 of the EPR, the EA will also regulate the GDF under several other parts of EPR and other applicable regulations where they may be relevant to the construction and operation of the facility, such as the Conservation (Natural Habitats) Regulations 1994 and the Water Resources Act 1991. Since these are not primarily concerned with safety, they are not discussed further here but the GRA provides a summary of the other sets of legislation that will apply.

.3 Other regulations

The development of the GDF will be subject to other regulation, in addition to those described above to ensure health, safety and environmental protection. In particular, any proposal to develop a GDF at a particular site will be subject to land use planning regulation and the associated requirements for Strategic Environmental Assessment (SEA) and Environmental Impact Assessment (EIA).


These regulations fall outwith the responsibilities of the ONR and environment agencies, and so are not discussed any further in this report, although it is worth noting that the environment agencies have responsibilities as statutory consultees under SEA and EIA legislation.

3.4 Significance

There are a number of observations relevant to this project that arise from this summary of the regulatory framework. These are set out below, together with some related questions with safety and environmental implications that the regulators may wish to ask. Note that some of these questions will need to be considered by the regulators themselves, and would not be directed at the implementer.

1. The point at which the GDF will become a licensed facility has not been decided. This introduces a level of uncertainty that affects planning and preparations for performing regulatory oversight and scrutiny of the safety relevant aspects of its design and operation. Licence Condition 14 implies that licensing should occur early in the implementation process, before any significant decisions are made concerning the design of the GDF. In practice this is likely to mean before any access shafts or tunnels as constructed. The ongoing joint ONR and EA scrutiny programme can influence RWMD’s plans now and before licensing.

What is the regulatory process to be applied during the pre-construction phases of the GDF programme, and at what point should a site licence be granted?

2. Clear decisions will also be required in terms of deciding ‘what’ is actually licensed, recognising that the GDF will effectively be an integration of engineered structures and the host geological environment. The physical boundaries of the GDF are, therefore, ambiguous in a way that is not the case for a conventional nuclear facility or site that is regulated under NIA.

What will be the physical (3D) extent of the licensed site, and how does this relate to the above and below ground parts of the GDF?

How is co-location defined in terms of site licensing? Should the entire disposal complex be licensed as a single facility or as two or more separate facilities?

3. The GDF may be regulated under existing sets of legislation that were never intended to be applied to geological disposal. Care will be required when developing guidance to explain how existing legislation will be applied to the GDF, and in developing licence conditions and safety assessment principles, to avoid difficulties in later stages of implementation. Similarly, the standard set of nuclear safety cases required for the development of a new nuclear facility (and their scope) should be evaluated to determine which of these is appropriate for the GDF.

4. Joint regulation implies that the regulators should integrate their requirements for safety and environmental cases, so that a single set of documents can be produced by RWMD to meet the expectations of both regulators. The environment agencies have published their requirements in the form of the GRA. ONR is currently in discussions with Government clearly to establish its regulatory vires in respect of the GDF, and determine what additional guidance is needed.


What new (or modified) guidance is required to set out the safety principles and regulatory requirements that will be applied to each stage of the development of the GDF?

5. Although the ONR and the environment agencies will regulate the GDF under different sets of legislation, it is important to understand that there is no ‘hierarchy of importance’ between them. All regulations will apply equally at all times to the GDF (at times and places when they are relevant) and, consequently, it is not the case that one regulation has primacy over another. This will necessitate the development of an optimal design for the GDF, and plan its operation, that ensures all requirements are met to protect the health and safety of people, and protection of the environment. Similarly, clear justifications will need to be made to explain how the GDF was optimised to ensure all regulatory requirements have been appropriately addressed and balanced.

What is the process for design optimisation, and how are safety and environmental considerations taken into account in the process?

6. The GDF will need to be designed so as to be consistent with the characteristics of a volunteer site and its geology. This may have knock-on consequences for the safety and environmental performance of the GDF during its construction, operation and in the post-closure period. It may also mean that greater emphasis will be placed on the safety performance of the engineered barriers than the host rock. In simple terms, the GDF will need to be designed to work within the geological constraints imposed by whatever site is made available through the volunteer siting process.

What isolation performance will be required from the EBS in different possible host rocks, and how will the EBS be designed to overcome possible inadequacies in the host rock isolation capacity?


4 Balancing risks during GDF implementation Depending on the outcome of the volunteer siting process, a preferred site may need to be chosen from several different areas around the country, or from various locations within a single area. In either case, it is possible that there will be a number of geological environments and/or host rocks to be compared. In addition to identifying a preferred site, a reference disposal concept will need to be developed for the GDF excavations (tunnels, vaults, boreholes etc.) and the engineered barriers (canisters, backfills, seals etc.) that is consistent with the geology of the preferred site.

Over time, as more information on the preferred site is obtained, the reference disposal concept will be progressively refined to develop a detailed system design which ultimately will need to be optimised. In simple terms, as shown in Figure 4.1, there will be a hierarchy of decision making events that starts with an “optioneering case” to evaluate potential sites and concepts, and leads on to a series of progressively more detailed “safety cases” that evaluate and balance the operational and post-closure safety of alternative system designs and operational methods.

Figure 4.1: An illustrative example of how decision making for the GDF will need to be hierarchical and begin with sites and concepts, and move to detailed designs.

Many of the optioneering and design decisions to be made for the GDF will have significant implications for the balance between operational and post-closure risks. Illustrative examples of some of these are given in Table 4.1. In this context, it is important to recognise that the overall operational safety of a GDF design concept is the sum of the risks associated with the totality of all of the design components and operating practices, over the full life-cycle of the GDF from initial shaft sinking or access tunnel excavation, through to final closure.

It is evident from this, that certain design decisions may be made that could impose a real increase in occupational risks (both conventional and radiological) to present-day workers so as to achieve a reduction in the conditional (hypothetical) risk to people in


the far future. In no case, however, would the GDF be allowed to be built if the risks to workers were considered by the regulators to be unacceptable in comparison with whatever limits are applicable at the time. Similarly, a GDF would not be built if the calculated post-closure doses and risk to people were deemed unacceptable. Nonetheless, it is probable that there will be some safety ‘headroom’ due to robust engineering design and conservatism in the safety assessments. Optimisation of the GDF design may, consequently, allow some of the post-closure safety ‘headroom’ to be reduced to achieve an increase in worker safety, or vice versa. This is consistent with the environmental regulators’ own guidance (the GRA) which makes clear that optimisation does not necessarily demand the choice of the option with the lowest possible radiological risk to the public (EA & NIEA, 2009).

Table 4.1: Illustrative examples of design decisions that require careful balancing of operational and post-closure risks.

Design aspect

Potentially ‘best’ option for post-closure safety

Potentially ‘best’ option for operational safety

Primary access route design

Vertical shaft: Smallest volume of rock to be excavated, and potentially provides simplest design for sealing. Increased risk of conventional accidents during construction. High consequence if hoists fail during operations. Shortest flowpath to surface.

Inclined tunnel: Potentially more difficult to excavate and seal, depending on the rock type. More flexibility for waste handling, and lower consequence from mechanical failure during operations.

Geometry of disposal tunnels

Long, blind tunnels: Limits the potential for post-closure convective groundwater flow, and so reduce releases to the surface environment. Increases hazards to construction workers (e.g. rock collapse) and limits escape routes.

Double entry tunnels: Increases the potential post-closure flowpath routes for released radionuclides. Offers greater flexibility during operations, and multiple escape routes for workers in case of accidents.

Waste package dimensions

Supercontainers: Provide post-closure durability and corrosion resistance. Large weight and dimensions make them difficult to handle in restricted underground space, especially if waste handling systems fail.

Small containers: Potentially less overpack may mean shorter post-closure containment period. Lighter weight and smaller dimensions means waste handling systems can be simplified, and refurbishment made easier.

Optimisation of the GDF design will require appropriate balancing of the full life-cycle operational safety (risk to site workers and current generations) against the post-closure safety (risk to future generations), and against the other non-safety attributes. As a minimum, this will require a method for balancing risks to workers and to members of the public, and risks to the current generation and to future generations. Assuming two different GDF design options and their associated operating practices (A and B in Figure 4.2), it might be that their respective distribution of risk to people is fundamentally different to each other. A similar assessment can be made for benefits arising from the GDF, and to the community to which they accrue.


Figure 4.2: An illustration of how two different GDF concepts (A and B) might lead to skewed distributions of risks and benefits to certain populations.

A ‘balanced decision making process’ is, therefore, necessary to ensure decisions on GDF design and operations are not disproportionately skewed in favour of any one particular potentially impacted group of people. Although it is common for safety-critical industries to balance different risks in their decision making processes (e.g. optimisation in the nuclear sector), the disposal of long-lived wastes introduces particular complexities because of the potential for exposing populations in the very far future. In addition, concepts like BAT are usually applied in a much more technical context (e.g. to decide on a discharge abatement method for a permit under EPR) and do not typically take into consideration the much wider socio-economic factors that will apply to the GDF.

At present, there is no agreed process for how design decisions and options selection for the GDF (at either a conceptual design or detailed engineering level) will be made. Whatever process is adopted, it will need to:

take account of all important decision attributes including conventional and radiological risks to workers, and post-closure radiological risks to people, in addition to a range of other factors (e.g. technical viability, conventional environmental impacts, cost and affordability etc.);

be understandable, transparent and auditable;

be acceptable to both regulators, given that the GDF will be regulated under several sets of regulations with varying requirements;

be acceptable to all other key stakeholders, including a local host community that reserves the right to withdraw from the siting process and to be involved in certain design decisions, including those related to retrievability; and

balance risks to all potentially exposed groups and to the environment, in all stages of implementation (pre-construction, construction, operation and post-closure).

In this decision making context, the term ‘optimisation’ is often used but this has different meanings to different stakeholder groups which can lead to confusion. In engineering, optimisation usually refers to the refinement of a design to achieve particular goals, such as to meet a specific functional requirement (e.g. load, capacity,


throughput, operating lifetime etc.) or to construct a system within a certain timeframe or below a certain cost target etc.

In relation to radiological protection, ‘optimisation of protection’ is one of the ICRP’s basic principles and is directly linked to the ALARA principle. In terms of the GDF, however, there is the added complexity of deciding whether ALARA should apply equally to both current and future generations to reduce their respective risks (and, if so, how), as shown in Figure 4.2.

For the GDF, both the engineering and radiological protection meanings of ‘optimisation’ are relevant, and the decision making process applied to its design will need to take account of both.

4.1 Significance

There are a number of aspects relevant to this project that arise from this discussion of balanced decision making. These are set out below, together with some related questions with safety and environmental implications that the regulators may wish to ask.

1. There is no agreed decision making process for down selecting GDF concepts and design alternatives. Existing MADA processes such as BAT/BPEO were not developed to be applied to facilities such as the GDF that have such wide ranging potential impacts in terms of space, time and exposed populations.

What is the decision making process for comparing disposal concepts that will be applied to down select the preferred GDF concept design, once a site has been selected, and for justifying the exclusion of others?

What are the key drivers / variables that affect decisions on the GDF design and implementation programme, and what weighting is placed on them during decision making?

2. Different GDF design alternatives are likely to place proportionately different burdens of risk on workers and members of the public, and on current and future generations. The ALARA principle does not make any clear distinction or recommendation concerning which potentially exposed population should be most protected when all groups cannot be equally protected.

In the decision making process, what emphasis is placed on balancing risks to workers and the public, and current and future generations?

What occupational risk target will be applied to conventional hazards during construction and operation of the GDF?

3. The terminology used for expressing the process of GDF design development is ambiguous, particularly in terms of the word ‘optimisation’ that has different meanings to different stakeholders.

What is the optimisation process, and how will engineering optimisation be integrated with radiological optimisation (ALARA)? Specifically how will proportionality be addressed in relation to ensuring exposures will be kept as low as reasonably achievable, economic and social factors taken into


account, given that there may be significant differences in the costs and impacts to local communities associated with alternative GDF concepts?

How does the application of conservatism differ in nuclear and environmental safety cases, and how does this affect optimisation and the balancing of risk to workers and future generations?


5 Stages in the GDF programme

5.1 Stages in the MRWS process

The 2008 White Paper set out, at a very high level, a staged process for the MRWS programme, as shown in Figure 5.1. This deliberately did not include any milestone dates or durations because of public and stakeholder considerations.

Figure 5.1: The MRWS site selection stages. From Defra et al. (2008).

The MRWS process is largely focussed on the ‘front-end’ site selection activities. The bulk of the actual construction and operation activities associated with the GDF all occur within MRWS Stage 6 and, therefore, a more detailed programme is required against which research can be planned.

To enable them to plan and prepare for their work, RWMD developed a ‘preliminary implementation plan’ (NDA, 2010) that set-out the main phases they considered necessary, as shown in Figure 5.2. This preliminary plan includes an indicative timeline, although it should be noted that the dates given are simply planning assumptions and do not reflect any formal decisions made.


Figure 5.2: Indicative timeline for the GDF implementation programme. All dates and durations shown are purely for preliminary planning purposes. From NDA (2010).

One important aspect in RWMD’s planning is that the construction and operation stages overlap each other because it is considered to be highly inefficient and potentially unsafe to excavate the entire GDF before first waste emplacement takes place. This pragmatic approach is consistent with the planning assumptions made for geological repositories in other countries, such as Finland, Sweden and the USA.

5.2 An outline programme for the GDF and key activities

As with all large projects, the GDF development programme will be broken down into key stages, with associated project ‘gates’ or ‘decision points’ separating them. These decision points represent an opportunity for the GDF programme to be reviewed, and for all necessary safety cases and applications to be submitted to the regulators for the necessary formal authorisations and permits to operate in the next stage.

It is not possible for the GDF development programme to be set out in detail at the present time because many important decisions have yet to be made, not least the choice of site and design of the facility. Nonetheless, the main stages in a generic programme are broadly known because they are independent of the site and design. Solely for the purposes of this project, an outline programme for the development of the GDF is set-out in Figure 5.3, starting from the point that a preferred site has been identified in Stage 4 of the MRWS volunteer siting process.

This outline programme identifies the main stages in the programme, and the probable nuclear and environmental safety cases that will need to be submitted by the developer at each key decision point (see Section 3). It should be noted that this is a simplified and indicative programme solely for the purposes of this report.

For simplicity, it is assumed in this report that each stage starts with its associated planning work but it should be understood that, in reality, there will be some overlap between stages because, for pragmatic reasons, some planning and preparation work for the next stage(s) will begin before the current stage is completed. So, for example, design and testing work on closure systems will be needed considerably in advance of reaching the closure stage. Similarly, the organisation structure and competences required by the implementer will need to be put in place before each stage commences to enable work to be planned efficiently.

It should also be noted that this outline programme does not include an explicit stage for performing underground investigation before underground operations begin. This is because no such stage is included in the MRWS process (Figure 5.1) which represents Government policy. If it did, it would fall between Stages 5 and 6 of the MRWS process.


Stage B:Surface investigations

Stage C:Access shaft / tunnel construction

Stage D:First phase excavations

Stage E:Active commissioning

Stage F:First phase waste emplacement

Second phase excavations

Stage G:Closure and sealing

Post-closure activities

Site Licence Granted

Authorisation to Dispose

Preferred Site(s) Selected

Preliminary Environmental Safety Evaluation

Preliminary Nuclear Safety Case

Initial EnvironmentalSafety Case

Pre-Operational Environmental Safety Case

InitialSite Evaluation

Pre-Construction Nuclear Safety Case (First phase)

Pre-Commissioning Nuclear Safety Case

Pre-Operational Nuclear Safety Case

Post-Operational Nuclear Safety Case

Authorisation to Close

First underground excavation

Post-Operational Environmental Safety Case

MRWS Stage 6:

Underground operations

MRWS Stage 5:

Surface investigations

MRWS Stage 4:

Desk studies

Key Decision Point

Stage A:Programme planning

Site selection

First nuclear material on site

Pre-Construction Nuclear Safety Case (Access)

Figure 5.3: A simplified and indicative programme for the GDF, showing the main stages in the programme, and the probable nuclear and environmental safety cases that will need to be submitted by the developer at each key decision point.


This is a different approach to that adopted in some other programmes. For example, in Finland, Posiva has been operating the ONKALO rock characterisation facility at the site of the planned spent fuel repository since 2004, and so has gathered nearly a decades’ worth of site-specific information which was used to underpin their construction licence application submitted to the regulator in 2012. There are potential complexities that will arise from undertaking underground investigations in parallel with construction (e.g. perturbations to measured conditions) that cannot be fully predicted until the underground conditions are known.

In Section 6, for each stage in the programme, the main activities that will be performed and the associated questions are discussed.

5.3 Significance

There are a number of aspects relevant to this project that arise from this discussion of repository programme planning. These are set out below, together with some related questions with safety and environmental implications that the regulators may wish to ask.

1. Planning is obviously necessary for many reasons, such as to provide an estimate of the resources required, but is subject to many uncertainties not least because the site and host-rock is unknown. Planning must therefore be done considering a broad range of possible scenarios for all likely combinations of site, rock type and concept design. Nonetheless, uncertainties and assumptions propagate through any preliminary programme, meaning that the identification of activities and research requirements associated with the later stages (e.g. Stage E waste emplacement) can only be described at a general level at this time.

How are uncertainties in the design and operating methods for the GDF accounted for when assessing safety and environmental performance in later stages of the implementation programme?

2. The lack of an explicit stage in the MRWS process for performing site-specific underground investigations will mean that those investigations will necessarily have to be performed in parallel with construction of the facility. Whilst this might reduce the overall lifetime of the GDF programme, this approach introduces the risk that certain measurements of the hydrogeochemical system at depth may be compromised by the impacts of the excavation work and associated groundwater pumping etc.

Given international experience, is it reasonable to plan for GDF implementation without a specific stage for performing underground investigations?

How will long-term underground investigations be planned and implemented without being compromised by the impacts of excavation work?

3. Planning to perform excavation work in parallel with waste emplacement operations is a pragmatic approach intended to reduce the overall lifetime of the GDF but this approach will, however, introduce other hazards and complexities into the programme that will need to be managed, such as coordinating the movement of workers, waste rock and nuclear materials to keep them separated at all times.


What information is need to ensure that it is safe to undertake parallel disposal and tunnelling operations, and how can active and non-active areas of the facility be separated from each other?

4. Even applying best practice, it will not be possible to predict all of the geological conditions and features that will be met in advance of excavating the GDF. There is a risk that conditions might be significantly different to those anticipated and, possibly, beyond those considered in the pre-construction safety cases. In this case, the design of the facility will need to be modified during construction to take account of conditions as they are encountered.

What measurements would be made and what criteria would be applied to determine whether actual conditions were within the ‘design basis’ assumed in the safety cases?

What actions would be taken if actual geological conditions and features were beyond the design basis?


6 Main activities during the GDF programme stages

6.1 Format of discussion and definitions

In this section, the main activities that will need to be performed by the implementer in each stage of the GDF programme (see Figure 5.3) are identified, together with the areas of potential greatest regulatory interest and examples of questions regulators may wish to ask. Much of this information is provided in tabular form, under headings with the following definitions:

Main Activities: The most important activities that will be performed during the programme stage being discussed. These may be technical, desk-based or management related. This list is indicative and should not be taken to be comprehensive of all activities that will be undertaken.

Future Regulatory Expectations at that Stage: The generic activity areas (see below) on which regulators might expect to focus their attention during future stages of the repository programme, when they are reached. These are simply categorised in terms of likely regulatory interest:

– Red, indicates areas of potentially greatest regulatory interest.

– Amber, areas of lesser regulatory significance.

– Green, areas of least regulatory significance (but this should not be taken to suggest there will be no regulatory interest).

Current Regulatory Expectations of that Stage: The generic activity areas related to future stages of the repository programme on which the regulators may focus their attention now (during the current stage) with a view to ensuring appropriate preliminary work is being undertaken and/or appropriate efforts are being made in the planning and preparation of future work. These are categorised in the same manner as described above.

Examples of Current Questions about that Stage: These are examples of the questions regulators may wish to ask now (during the current stage) about each stage of the repository programme, consistent with their ‘current regulatory expectations’. The questions asked about future stages are generally at a high-level reflecting how current work related to future activities is likely to be at a preliminary stage. This list of questions is indicative and should not be taken to be comprehensive of all questions the regulators may choose to ask.

It should be noted that it is not the intention of this report to peer review the research and other technical work performed by RWMD. As a consequence, there is no implication that the ‘current questions’ have not, or cannot, be answered by an implementer at this stage in the GDF implementation programme. As indicated in Section 7, there is a great deal of relevant information that relates to the main activities and the current questions. The ‘current questions’ may be used by the


regulators as one input to their own process of critical scrutiny of the GDF programme and, it is through that process, the regulators may come to a view that the questions have, or have not, been answered to their satisfaction.

To simplify the description of regulatory expectations, the wide range of activities that will need to be performed to implement the GDF have been grouped in the following ‘generic activity areas’, although it is recognised that there will be some overlap between these areas, and different activities may be needed for the disposal of the different wastestreams, at different times. The generic activity areas considered here are:

1. Organisational Structure and Planning: All activities necessary to put in place a competent organisation capable of implementing the repository programme. This includes its structure, working procedures, suitability qualified and experienced personnel (SQEP), and intelligent customer capability to manage the supply chain etc. This also includes activities necessary to maintain and evolve the capability of the organisation over time to reflect the changing activities that will need to be performed in future stages of the programme.

2. Inventory and Waste Packaging: All activities necessary to establish the inventory of wastes to be disposed, and to ensure wastes are conditioned and packaged so that they are suitable for disposal in the facility as it will be finally designed and constructed. This includes setting appropriate packaging requirements for waste producers, taking account of current uncertainties related to the site conditions and geology, disposal concept and design, and operating practices etc. It also includes setting formal waste acceptance criteria once the site and concept design have been decided.

3. Concept Development and Design Optimisation: All activities related to the design of the disposal facility including the surface installations, underground excavations, engineered barriers and waste handling infrastructure etc. This includes work progressively to identify suitable concepts and design options, to down select options and justify the choice of a preferred option(s), and to optimise the final engineered design taking account of geological conditions at the chosen site, mitigation and balancing of risks, operational plans etc.

4. Characterisation and Monitoring of the Site: All activities to gather geoscientific information on the chosen site and its hydrogeochemical characteristics etc.

– Characterisation is the gathering of information about the natural, undisturbed conditions of the site to ensure its suitability prior to construction, and to provide site-specific inputs to all safety and environmental assessments.

– Monitoring is the gathering of data during and after excavation to understand how the site responds to the construction work. It also includes gathering data after waste emplacement operations to understand how the disposal system evolves and to confirm its behaviour is consistent with assessment predictions.

5. Construction, Installation and Testing: All activities to build the disposal facility, including to excavate the underground shafts, tunnels and vaults; and to install and test the waste handling and emplacement infrastructure plus all other safety equipment and services (e.g. ventilation). Due to phased


construction/operations, this also includes activities to ensure construction will not adversely impact on wastes already emplaced or being handled.

6. Operations and Waste Emplacement: All activities to dispose of waste in the facility, including the handling and transport of waste packages from their receipt on site to their emplacement underground. Depending on the design of the facility, this may also include progressive backfilling of some excavations as certain waste packages are emplaced. Due to phased construction/operations, this also includes activities to ensure waste handling operations are coordinated with other underground movements (e.g. removal of excavated rock). A waste emplacement strategy will be needed to plan waste movements and optimise disposal activities.

7. Backfilling and Closure: All activities to emplace any tunnel/vault backfills, seals, plugs etc. that form part of the engineered design, and to perform any final closure operations as well as to undertake any necessary post-closure institutional control arrangements. Where there is co-location of disposal areas for different wastes in the facility, some parts of the facility may be backfilled before others and so closure may be a sequential process.

8. Waste Retrieval: All activities necessary to plan and prepare for waste retrieval for as long as this remains a potential design requirement, and to undertake waste retrieval at any time in the future should circumstances demand it.

9. Safety Cases and Permitting: All activities necessary to prepare and submit formal applications to regulators for authorisations to proceed through each stage of the programme. This includes submission of nuclear and environmental safety cases, as well as preparation of EIA’s for land-use planning applications etc.

Certain of the generic activity areas are aligned with specific stages in the GDF (e.g. waste emplacement), but others will continue throughout several stages (e.g. safety cases and permitting). This is shown illustratively in Figure 6.1. This figure is useful because it shows which of the activity areas begin in the early stages of the GDF programme, and so should be the topics of immediate interest to ensure there is sufficient underpinning knowledge.

In the following sections, the main activities, generic areas of potential regulatory interest and examples of the questions the regulators may choose to ask are described for each stage in the GDF implementation programme as illustrated in Figure 5.3.

Figure 6.1: The alignment of the generic activity areas against the timeline of the key stages in the GDF implementation programme.

Stage B:Surface

investigations

Stage C:Access shaft /

tunnel construction

Stage D:First phase excavations

Stage E:Active

commissioning

Stage F:First phase waste

emplacement

Stage G:Closure and

sealing

Stage A:Planning

Site selection

7) Backfilling and closure

8) Waste retrieval (if required)

9) Safety cases and permitting

1) Organisational structure and planning

2) Inventory and waste packaging

3) Concept development 3) Design optimisation

4) Site characterisation 4) Monitoring and continued site characterisation

5) Construction, installation and testing

6) Waste emplacement



6.2 Stage A: Programme planning and site selection

This is the current stage in the GDF implementation programme.

A considerable amount of programme planning and desk based work is required to underpin later stages in the GDF development programme. This is in parallel to the ongoing MRWS site selection process which is led by Government. The regulators have no formal role in selecting a site for the GDF but they will help the siting process by advising and commenting on safety and environmental matters.

The main activities, regulatory expectations and current questions associated with this stage are shown in Table 6.1. These mostly relate to the following topics:

Ensuring suitable management arrangements are in place so that site selection and the next stages of the GDF development programme can be implemented.

Ensuring waste arisings can continue to be managed (conditioned and packaged) in the absence of a known site or host geology for the GDF, and an agreed disposal concept, without unduly foreclosing options.

Scoping and understanding the implications for the GDF programme of the main technical uncertainties and policy considerations, such as changes to inventory boundary conditions.

Understanding the potential differences in safety and environmental performance of different host rocks and geological environments, and establishing a process for choosing between sites if more than one becomes available through the MRWS process.

Identifying all reasonable alternative GDF concept and design options (including those established internationally but also including those that show promise but are less well developed) and evaluating them for suitability in a UK context.

Establishing a robust process for comparing and contrasting alternatives for progressive down-selection of design alternatives once a site(s) has been identified, in a way that balances operational and post-closure safety.

In addition to the work of the implementer, the regulators have a key activity in this stage to establish the necessary (joint) regulatory process and guidance. As part of this activity, they may need to address the following questions:

How can regulators ensure a suitable site is selected if they have no formal role in the initial site selection process?

What is the regulatory process to be applied during the pre-construction phases of the GDF programme, and at what point should a site licence be granted?

What will be the physical (3D) extent of the licensed site, and how does this relate to the above and below ground parts of the GDF?


How is co-location defined in terms of site licensing? Should the entire disposal complex be licensed as a single facility or as two or more separate facilities?

What new (or modified) guidance is required to set out the safety principles and regulatory requirements that will be applied to each stage of the development of the GDF?

The decision point at the end of this stage will mark a decision on which site(s) will be taken forward for surface investigations. An Initial Site Evaluation (report) will need to be prepared and issued to the EA before any intrusive site investigations can commence in Stage B.


Table 6.1: Main activities of the implementer, regulatory expectations and current questions associated with Stage A: Programme planning and site selection.

Future Regulatory Expectations at that Stage

Current Regulatory Expectations of that Stage

Main Activities during Stage A: Programme planning and site selection

(See Section 6.1)

Examples of Current Questions about that Stage

Note: all activities are desk-based and generic – Establish competent implementer

organisation – Provide packaging advice to waste

producers – Develop design basis for disposal

and potential disposal concepts – Develop transparent process for the

down-selection of alternative design options and sites

– Identify potential site(s) through the MRWS process for investigation

– Preparation of generic safety cases – Working with communities

N/A

1, 2, 3, 9 4 5, 6, 7, 8

Aa. What are the safety critical posts in the implementing organisation and what competence does the implementer need to manage site selection? [1]

Ab. How will decisions (on site, inventory, design etc.) be closed out and banked, to enable the programme to move forward through each stage of implementation in the light of new information as it is gathered? [1,2,3,9]

Ac. What safety or environmental factors, other than those related to geological and surface conditions, might cause a site to be considered or eliminated during the site selection process? [1,3,4,9]

Ad. How should wastes continue to be processed and packaged without foreclosing options, given uncertainty regarding the site, geology and design of the facility? [2]

Ae. Which wastes pose the greatest risks at each stage in the GDF implementation programme? [2,3,9]

Af. What is the minimum level of protection (e.g. containment and isolation) required for each of the main waste types, and what are the essential design requirements of the GDF necessary to provide that level of protection to ensure the safe disposal of each waste type? [2,3,9]

Ag. What are the additional design features that may be desirable or add value, and what is the process for deciding which of these features should be included in the design? [2,3]

Ah. Is deep geological disposal the only appropriate option for


all HAW? [2] Ai. What are the potential safety and environmental implications

of different inventory boundary conditions, and is it realistic and feasible to plan for a single GDF for all HAW? [2]

Aj. What might be the potential safety and environmental implications of segregating and disposing of short-lived ILW in near-surface facilities? [2,3]

Ak. What are the minimum requirements to ensure physical, chemical and hydrogeological separation of co-located disposal facilities? And what are the risks if separation were to fail? [2,3]

Al. What are the potential safety and environmental implications of operating a single co-located facility compared to two entirely separate facilities? [2,3]

Am. What disposal concepts and engineering designs are suitable for UK wastes and geological environments (both established and promising but less well developed alternatives)? [3]

An. What is the process for comparing and contrasting alternative geological environments / sites to identify a preferred site(s) to be investigated, and for justifying the exclusion of others? [3,4]

Ao. When is a decision made on the need for a co-located facility, and what issues inform this decision? [3]

Ap. What is the decision making process for comparing disposal concepts that will be applied to down select the preferred GDF concept design, once a site has been selected, and for justifying the exclusion of others? [3]

Aq. What are the key drivers / variables that affect decisions on the GDF design and implementation programme, and what weighting is placed on them during decision making? [3]

Ar. In the decision making process, what weighting is placed on balancing risks to workers and the public, and current and future generations? [3,9]


As. How will local communities be involved in the process for comparing and down-selecting options during the volunteer process? And what other aspects of the GDF can they influence (e.g. site selection, facility design, allowable inventory, retrievability etc)? [3,9]

At. Would the need for retrievability rule out certain disposal concepts? [3,7,8]

Au. What extra knowledge is necessary to bring understanding of clay and salt rocks up to the level of understanding of hard rock, to enable comparison in the UK context? [4]

Av. What level of understanding of the construction and operational aspects of the facility are needed to plan site investigations to ensure a site is suitable? [5,6]

Aw. What are the relevant safety functions for different potential rock types, and how are these used in site selection? [9]


6.3 Stage B: Surface investigations

Surface investigations are intended to provide the geoscientific information necessary preliminarily to establish the suitability of a site to host a GDF, and to enable comparison of sites if more than one is under consideration, to support a decision to progress with underground excavations and investigation.


Ensuring suitable management arrangements are in place so that appropriate surface investigations can be planned and implemented.

Ensuring waste arisings can continue to be managed (conditioned and packaged) in the absence of a known site or host geology for the GDF, and an agreed disposal concept, without unduly foreclosing options.

Establishing a robust process for site characterisation that identifies all of the necessary safety and environmental parameters to be measured/monitored, and the most appropriate means to do so.

Establishing a preliminary integrated geological/hydrogeological/geochemical site model as the basis for developing a preliminary GDF design and supporting safety cases. Understanding the significance of uncertainties on the model and alternative interpretations, and their implications.

Making a decision on whether the investigated site is suitable to host a co-located facility for all wastes, or only a proportion of the inventory (and which wastes). Evaluating whether a co-located facility represents the safest design approach, even if it is technically feasible.

If more than one site has been investigated and compared, make a transparent and defensible decision on which site is finally selected for construction of the GDF.

Down-selecting GDF concepts and designs on the basis of the geological conditions at the site identified through surface investigations.

Developing preliminary nuclear and environmental safety cases, based on the information from surface investigations, which provide an appropriate level of confidence in the site conditions and preliminary design, to enable a site licence to be issued.

Ensuring sufficient information is gathered to inform a robust decision on the design of the GDF access (vertical shaft or inclined tunnel) and support the necessary nuclear and environmental safety cases.

The decision point at the end of this stage will mark decisions on (1) whether a site licence is granted, and (2) whether authorisation is given to commence construction of the GDF access shaft or tunnel. A Preliminary Nuclear Safety Case will need to be prepared and issued to the ONR to support and application for a site licence. A Pre-Construction Nuclear Safety Case (Access) and a Preliminary Environmental Safety


Evaluation will need to be prepared and issued to the ONR and EA, respectively, before underground excavations can commence in Stage C.


Table 6.2: Main activities, regulatory expectations and current questions associated with Stage B: Surface investigations.



Main Activities during Stage B: Surface investigations

(See Section 6.1)


Note: some activities and methods are site and rock dependent – Evolve organisational structure to

manage stage B – Provide packaging advice to waste

producers – Geological mapping (local and

regional) – Geophysical investigations (seismic,

gravity, EM etc.) – Drilling and testing of shallow

boreholes – Drilling and testing of deep boreholes – Groundwater sampling and

hydrotesting in boreholes – Surface environmental surveys – Site baseline monitoring – Develop geological model of site – Comparing and contrasting sites if

more than one is investigated – Develop site-specific disposal

concept and preliminary design – Preparation of safety cases and

permit applications – Working with communities

1, 2, 3, 4, 9 5 6, 7, 8

1, 2, 3, 4, 9 5 6, 7, 8

Ba. What are the safety critical posts in the implementing organisation and what competence does the implementer need to manage site characterisation? [1]

Bb. How should wastes continue to be processed and packaged without foreclosing options, given uncertainty regarding the site, geology and design of the facility? [2]

Bc. What inventory is suitable for disposal at the site being investigated? [2,3]

Bd. What information is needed to determine whether a site is suitable to host a co-located GDF? [3]

Be. What disposal concepts/designs are suitable for UK wastes in the geological environment being characterised? [3,4]

Bf. Is it possible to assess the potential suitability of the rock mass at depth for construction and operation of the GDF before going underground? [4]

Bg. What site characterisation and baseline monitoring information must be collected before any boreholes are sunk? [4]

Bh. What site characterisation and baseline monitoring information must be collected before shaft / tunnel construction can commence? [4]

Bi. What site characterisation data is needed as input to nuclear and environmental safety cases at this stage? [4,9]

Bj. What other information is needed (e.g. facility design and operational plans) as input to nuclear and environmental safety cases at this stage? [4,5,6,7,8,9]


6.4 Stage C: Access shaft / tunnel construction

This stage represents the first significant underground work in the GDF programme. There are two main options for providing the primary access route from the surface to the below ground areas of the GDF:

vertical shaft(s) fitted with appropriate lifting equipment; and

an inclined tunnel (possibly spiral) enabling the use of a road or rail system.

In both cases, transport will be required in both directions, to remove excavated rock from depth to the surface, and to transport packaged wastes from the surface to the disposal areas.

The design of the access will have significant consequences for logistical arrangements and safety during routine operations, and in accident scenarios, and potentially also for post-closure behaviour of the GDF.

Note that if an inclined tunnel is used for the primary access route, other shafts are likely to be required to provide for ventilation, emergency evacuation routes etc. but their purpose would not be for waste handling.


Ensuring suitable management arrangements are in place so that the access can be design and constructed, and all design authority and intelligent customer responsibilities are clearly defined. Importantly, the respective roles and responsibilities of the implementer, the companies undertaking the actual construction work and other key stakeholders need to be fully established and understood.

Ensuring waste arisings can continue to be managed (conditioned and packaged) in the absence of a finally agreed disposal concept, without unduly foreclosing options.

Adopting appropriate access design features and excavation/construction technologies that ensure the safety of workers without unduly compromising later nuclear operations (e.g. waste package movements) and the long-term isolation performance of the rock mass.

If not already done, make a decision on whether the site is suitable to host a co-located facility for all wastes, or only a proportion of the inventory (and which wastes).

Making a decision on whether the access needs to be designed so as to facilitate retrievability (and when and to what extent), and determining what requirements and constraints this places on the design of the access and its waste handling infrastructure.

Refining the site model and the design of the GDF disposal vaults and tunnels on the basis of additional geoscientific information gathered during excavation of the access shaft / tunnel.


Ensuring sufficient information is gathered to inform a robust decision on the design of the first phase of disposal excavations, and support a Pre-Construction Nuclear Safety Case (First phase) that provides sufficient confidence that the design is capable of being constructed and operated safely on the basis of site-specific knowledge.

The decision point at the end of this stage will mark a decision on whether authorisation is given to commence construction of the first phase of disposal tunnels and vaults. A Pre-Construction Nuclear Safety Case (First phase) and an Initial Environmental Safety Evaluation will need to be prepared and issued to the ONR and EA, respectively, before underground excavations can commence in Stage D.


Table 6.3: Main activities, regulatory expectations and current questions associated with Stage C: Access shaft / tunnel excavation.



Main Activities during Stage C: Access shaft / tunnel excavation

(See Section 6.1)


Note: some activities and methods are site and design dependent – Evolve organisational structure to

manage Stage C – Continue to provide packaging advice

to waste producers – Make decision on access design

(vertical shaft or inclined tunnel) – Shaft sinking – Tunnel excavation – Blasting / tunnelling – Fixing rock supports / shotcrete – Rock spoil removal – Ventilation and dust suppression – Groundwater pumping – Underground / confined space

working – Underground geological

characterisation – Underground research and testing – Site baseline monitoring – Continued development of site-

specific disposal concept and preliminary design

– Preparation of safety cases and permit applications

– Working with communities

1, 3, 4, 5, 9 2, 6, 7, 8

2, 3, 5 1, 4, 9 6, 7, 8

Ca. What are the safety critical posts in the implementing organisation, and what competence does the implementer need to manage the design and construction of the access shaft / tunnel? [1]

Cb. What capability and experience does the implementer need to act as the design authority / intelligent customer to proceed with shaft / tunnel construction? [1]

Cc. What is the process, and who has responsibility, for implementing design changes when adapting quickly to underground conditions during excavation? [1,5]

Cd. How should wastes continue to be processed and packaged without foreclosing options, given uncertainty on the final design of the facility? [2]

Ce. What are the factors affecting the choice of the primary access route to the underground parts of the GDF (e.g. inclined tunnel or shaft)? [3]

Cf. What site-specific and other information is needed to make the decision on the choice of primary access route and what is the decision making process? [3]

Cg. What site monitoring needs to be performed to quantify perturbations caused by excavation of the access, and how will it be achieved? [4]

Ch. What underground investigations will need to be performed during shaft / tunnel construction and completed before excavation of the disposal tunnels can commence? [4,5]

Ci. What are the factors affecting the choice of construction method (e.g. blasting or TBM)? [5]


Cj. What information is needed to make the decision on the choice of construction method and what is the decision making process? [5]

Ck. How can geological studies be performed safely before the shaft / tunnel is lined? [5,9]

Cl. What features need to be included in the shaft / tunnel design at the time of construction to ensure the facility can be backfilled and sealed at closure? [7]

Cm. What information is needed to determine whether the access needs to be designed to allow retrievability? [3,8]

Cn. What site specific information is needed as input to nuclear and environmental safety cases at this stage? [4,9]

Co. What other information is needed (e.g. updated facility design and operational plans) as input to nuclear and environmental safety cases at this stage? [4,5,6,7,8,9]


6.5 Stage D: Phased underground excavations

This stage involves the excavation at depth of the disposal tunnels and vaults, and all of the necessary connecting tunnels, plus the installation of the infrastructure needed to transport and emplace waste packages etc. It is probable that the GDF will be excavated in phases, starting with the first separated disposal areas for HLW/SF and ILW (assuming the selected site was suitable to host a co-located facility). Subsequent underground excavations will continue in a phased manner to extend the GDF, in parallel with waste disposal operations (see Section 6.7).


Ensuring suitable management arrangements are in place so that the access can be design and constructed, and all design authority and intelligent customer responsibilities are clearly defined.

Optimise the final design of the GDF layout (tunnels and vaults) for the first (and subsequent) phases of construction, the EBS and the waste emplacement methods.

Adopting appropriate excavation designs and excavation/construction technologies that ensure the safety of workers without unduly compromising later nuclear operations (e.g. waste package movements) and the long-term isolation performance of the rock mass.

Determining what are the appropriate conventional risk targets (occupational risks) when planning excavation work underground in a nuclear licensed facility.

If not already done, make a decision on whether the site is suitable to host a co-located facility for all wastes, or only a proportion of the inventory (and which wastes).

Making a decision on whether the disposal tunnels/vaults needs to be designed so as to facilitate retrievability (and when and to what extent), and determining what requirements and constraints this places on the design of the excavations and its waste handling infrastructure.

Refining the site model on the basis of additional geoscientific information gathered during excavation.

Establishing and recording the as-built design of the GDF disposal vaults and tunnels, and all supporting infrastructure, and using this to update the nuclear and environmental safety cases.

The decision point at the end of this stage will mark a decision on whether authorisation is given to commence active commissioning of the facility and to bring on site the first nuclear materials. A Pre-Commissioning Nuclear Safety Case will need to be prepared and issued to the ONR before commissioning can commence in Stage E.

Table 6.4: Main activities, regulatory expectations and current questions associated with Stage D: First phase excavations.



Main Activities during Stage D: First phase excavations

(See Section 6.1)


Note: some activities and methods are site and design dependent – Evolve organisational structure to

manage Stage D – Continue to provide packaging advice

to waste producers – Optimise site-specific design and

layout of GDF, and design of disposal tunnels and vaults (size, connections, dead-end tunnels etc)

– Make decision on design of the EBS in each disposal area

– Training of operators and staff in underground working and excavations

– Tunnel excavation (TBM / blasting) – Fixing rock supports / shotcrete – Rock spoil removal – Ventilation and dust suppression – Groundwater pumping – Underground / confined space

working – Underground characterisation and

testing – Site baseline monitoring – Emergency evacuation procedures – Installation of services (power,

ventilation, fire, pumps)

1, 3, 4, 5, 9 2, 6, 7, 8

3, 5 1, 4, 6, 9 2, 7, 8

Da. What are the safety critical posts in the implementing organisation and what competence does the implementer need to manage construction of the disposal tunnels and vaults? [1]

Db. What capability and experience does the implementer need to act as the design authority / intelligent customer to proceed with construction? [1]

Dc. What is the process, and who has responsibility, for implementing design changes when adapting quickly to underground conditions during excavation? [1,5]

Dd. What uncertainties remain about waste conditioning and packaging for the GDF design? [2]

De. What are the TRLs for each item waste handling equipment and other safety relevant infrastructure? [3,5,9]

Df. What work is necessary to configure ‘off the shelf’ equipment for safe use in the GDF? [3,5,9]

Dg. What demonstration studies are needed to validate the safety and practicability of proposed designs, and how will this feed into design optimisation? [3,5]

Dh. What is the process for GDF design optimisation and how are safety and environmental considerations taken into account in the process? [3]

Di. How will the ‘as built’ design be recorded and input to the nuclear and environmental safety cases? [3,5,9]

Dj. What isolation performance will be required from the EBS in the host rock, and how will the EBS be designed to overcome possible inadequacies in the host rock isolation capacity? [3]



– Installation of waste handling equipment (lifts, cranes, train etc.)

– Nuclearisation design of all systems and equipment

– Inactive commission (testing equipment, methods and procedures)

– Preparation of safety cases and permit applications

– Working with communities

Dk. Given international experience, is it reasonable to plan for GDF implementation without a specific stage for performing underground investigations? [4]

Dl. How will long-term underground investigations be planned and implemented without being compromised by the impacts of excavation work? [4]

Dm. What measurements would be made and what criteria would be applied to determine whether actual conditions were within the ‘design basis’ assumed in the safety cases? [4,9]

Dn. What actions would be taken if actual geological conditions and features were beyond the design basis? [4,9]

Do. How will TBM and blasting be handled in the construction of short and long tunnel sections? [5]

Dp. What are the safety implications of long blind tunnels with single access? [5,9]

Dq. What is the necessary design, spacing and operation of ‘safe havens’ for workers? [5]

Dr. How would you recover people from a safe haven in the event of a tunnel collapse or fire? [5]

Ds. What is the mitigation in case of facility shut-down due to accidents, and what will be the impact on the integrity of the excavations in the case of a long shut-down? [5]

Dt. At what point does the retrievability question get closed out? [8]

Du. What are the potential safety and environmental implications of incorporating different extents of retrievability into the GDF design? [3,8]

Dv. What is the optimisation process, and how will engineering optimisation be integrated with radiological optimisation (ALARA)? [3,5,6,7,9]

Dw. How does the application of conservatism differ in nuclear and environmental safety cases, and how does this affect optimisation and the balancing of risk to workers and future generations? [3,5,6,7,9]

Dx. What occupational risk target will be applied to conventional


hazards during construction and operation of the GDF? [5,9] Dy. What features need to be included in the GDF design at the

time of construction to ensure the facility can be backfilled and sealed at closure? [7]

Dz. What information is needed to determine whether the GDF needs to be designed to allow retrievability? [3,8]

Daa. What site specific information is needed as input to nuclear and environmental safety cases at this stage? [4,9]

Dbb. What other information is needed (e.g. updated facility design and operational plans) as input to nuclear and environmental safety cases at this stage? [4,5,6,7,8,9]


6.6 Stage E: Inactive and active commissioning

Commissioning will begin with inactive trials using dummy waste packages, and then progress to active trials. Active commissioning represents the first time nuclear material will be on site, albeit in restricted amounts as a small number of waste packages are used to test and verify all waste handling equipment and procedures etc.


Development of a commissioning schedule for all parts and systems in the GDF, taking account of the planned phasing of excavation and disposal operations over several decades.

Confirming Technology Readiness Levels (TRLs) for each system and component needed for the full waste handling infrastructure in the GDF, and the work needed to ensure system viability. Note that a TRL of 9 is defined as suitable for actual system operations (NDA, 2011).

Commissioning of multiple waste handling routes and infrastructure systems for the different waste types and disposal areas.

Potential benefits for testing of mock-up systems before first phase excavation work begins to capture early lessons learned in design.

Determining procedures and means to reverse steps in the case of system failure in testing (including means to return waste packages to the surface, if necessary).

Bringing on site the first nuclear materials used for active commissioning.

The decision point at the end of this stage will mark a decision on whether authorisation is given to commence full scale waste disposals in the phase 1 excavations. A Pre-Operational Nuclear Safety Case and a Pre-Operational Environmental Safety Case will need to be prepared and issued to the ONR and EA, respectively, before waste emplacements begin in Stage F.

Given that there may be multiple and different disposal areas in the GDF that share some common facilities (e.g. the main access and waste handling infrastructure), and also some parts of the facility may interact (e.g. impacts of parallel construction on disposal operations), it will be important to clarify what part of the facility and what systems are commissioned, and at what stage.

Multiple commissioning activities and disposal permits may be required for each of the different waste disposal vaults and tunnels.

Table 6.5: Main activities, regulatory expectations and current questions associated with Stage E: Inactive and active commissioning.



Main Activities during Stage E: Inactive and active commissioning

(See Section 6.1)


Note: some activities and methods are site and design dependent – Bringing on site the first nuclear

materials – Multiple inactive and active

commissioning of each part of the facility (HLW, SF, ILW) and respective waste handling equipment

– Excavations may be ongoing in parts of the facility

1, 4, 5, 6, 9 6, 7, 8 2, 3

3, 5, 6 1, 4, 6, 8, 9 2, 7

Ea. What are the safety critical posts in the implementing organisation and what competence does the implementer need to manage nuclear materials and active commissioning? [1]

Eb. Is it necessary to develop a separate underground test facility ahead of the GDF for active trials? [3,5]

Ec. Are industrial mock-ups adequate for replicating underground conditions for commissioning? [3,5]

Ed. Will active commissioning also test waste retrieval and reversibility systems? [3,5,8]

Ee. What is the procedure in the event that active commissioning reveals a flaw that requires design modifications? [3,5]

Ef. What is the procedure in the event that active commissioning reveals a substantial design failure? [3,5]

Eg. Will construction of parts of the facility still be ongoing during active commissioning? [5]

Eh. What level of evidence of safe working is needed in a pre-operation safety case? [9]

Ei. What site specific information is needed as input to nuclear and environmental safety cases at this stage? [4,9]

Ej. What other information is needed as input to nuclear and environmental safety cases at this stage? [4,5,6,7,8,9]

Ek. Does the whole facility get commissioned and permitted, or will commissioning and permitting be phased as each waste disposal vault / tunnel is completed? [9]



6.7 Stage F: Phased waste emplacement

This stage represents the first full-scale disposal operations in the GDF. Depending on the emplacement strategy chosen, disposal may occur in either the HLW/SF or ILW areas, or both, simultaneously.

It is likely that first phase disposal operations will be performed in parallel with second phase excavations. In practice, it is very likely that there will be many more than just two phases of excavation, and the issues identified here will recur for each phase. As a consequence, all of the activities and questions associated with Stage D will also occur in this stage. The additional main activities, regulatory expectations and current questions associated with this stage are shown in Table 6.6. These mostly relate to the following topics:

Ensuring isolation of active from inactive areas in the GDF, in terms of ventilation, worker access, vehicle movements etc.

Coordinating movements in the common areas, particularly to separate movements of waste packages (surface to depth) with the removal of excavated rock spoil (depth to surface) in the main access route.

Determining safe separation distances between excavations and disposal operations, and mitigating any influences between construction and operations.

Establishing the procedures and methods for radiation monitoring throughout the entire GDF, and package condition monitoring in the disposal areas.

Deciding whether to backfill disposal areas immediately or to delay backfilling until later (where that is an option), and establishing the procedures and methods for performing backfilling operations. In practice, this decision is likely to be made earlier but considerations of retrievability may mean that this decision will need to be revisited at the point backfilling can first take place.

The decision point at the end of this stage will mark a decision on whether to authorise final closure of the GDF after all wastes have been emplaced. A Post-Operational Nuclear Safety Case and a Post-Operational Environmental Safety Case will need to be prepared and issued to the ONR and EA, respectively, before the GDF can be closed and sealed in Stage G.


Table 6.6: Main activities, regulatory expectations and current questions associated with Stage F: First phase waste emplacement.



Main Activities during Stage F: First phase waste emplacement Second phase excavations.

(See Section 6.1)


All questions from Stage D apply here. Additional activities include: – Concurrent emplacement of wastes

with continued facility construction – Coordinating movements of waste,

people and rock spoil removal in common areas / tunnels

– Separation of active and inactive zones in underground excavations

– Radiation monitoring of all areas – Monitoring of waste package

condition – Waste retrievals and operation of

recovery cell (if needed) – Backfilling of tunnels as wastes are

emplaced (if needed)

1, 4, 5, 6, 7, 9 8 2, 3

2, 3, 4, 6 1, 5, 9 7, 8

All questions from Stage D apply here. Additional questions include: Fa. What are the safety critical posts in the implementing

organisation and what competence does the implementer need to manage nuclear materials and waste emplacement operations? [1]

Fb. What measures would need to be taken to ensure all safeguards and security requirements are met if fissile materials are disposed in the GDF? [1,6]

Fc. What is the holistic plan needed to ensure mining, nuclear and conventional safety? [1,6,9]

Fd. What site baseline monitoring will be needed, and how will it be achieved? [4]

Fe. What package condition and radiation monitoring will be needed, and how will it be achieved? [4]

Ff. What measurements and records will be required after each package (or group of packages) is emplaced while they remain accessible? [4]

Fg. How can active and non-active areas of the facility be separated from each other? [6,9]

Fh. What information is needed to ensure that it is safe to undertake parallel disposal and tunnelling operations? [6,9]

Fi. What wastes and disposal areas will need to be backfilled at the time of waste emplacement? [6,7]

Fj. What will be the procedure and techniques for managing any waste package that might have degraded or leaked? [4,6,8]


Fk. What would trigger the retrieval of any waste packaged and how would that be achieved? [8]

Fl. What site specific information is needed as input to nuclear and environmental safety cases at this stage? [4,9]

Fm. What other information is needed as input to nuclear and environmental safety cases at this stage? [4,5,6,7,8,9]


6.8 Stage G: Closure and sealing

This stage will occur only when (and if) a decision is made permanently to close and seal the GDF after last waste emplacement. Depending on the timing of last waste arisings and the final closure strategy, different parts of a co-located GDF may be closed at different times.


Establishing the decision making process and authority for final closure and sealing.

Determining what installed infrastructure needs to be removed prior to closure, and the means to do this safely.

Determining the closure strategy, and finalise the design of the seals, plugs and other closure systems to be consistent with the ‘as built’ GDF design.

Determining what may be appropriate post-closure monitoring objectives and targets, and establishing the best means to perform monitoring.

Establishing the needs and objectives for any additional institutional control over the surface site and footprint, and the organisational responsibilities.

Determining when and how the site licence and disposal permits should finally be revoked.

The main regulatory end-point following final closure of the GDF is currently unknown, and will be dependent on future Government policy decisions regarding any requirements for post-closure institutional control. Note that the GDF is designed to provide for passive safety and, consequently, any post-closure institutional controls are likely to be for reassurance purposes only.

Table 6.7: Main activities, regulatory expectations and current questions associated with Stage G: Closure and sealing.



Main Activities during Stage G: Closure and sealing

(See Section 6.1)


Note: some activities and methods are site and design dependent – Removal of waste handling

equipment and services – Removal of tunnel supports and

shotcrete (depends on concept) – Emplacement of tunnel backfills – Installation of tunnel and borehole

seals and plugs – Installation of remote monitoring

equipment – Cessation of groundwater pumping – Removal of surface infrastructure – Post-closure institutional controls – Final site delicensing

1, 7, 9 4, 8 2, 3, 5, 6

3, 7 4, 5, 6, 8, 9 1, 2, 7

Ga. What are the safety critical posts in the implementing organisation and what does the implementer need to close and seal the facility? [1]

Gb. What is the process for ending institutional controls and revoking the site licence? [1,9]

Gc. What are the likely objectives of any post-closure monitoring, and how will it be achieved? [4]

Gd. How could post-closure monitoring distinguish between system failure and inadequate prediction of system evolution? [4,9]

Ge. Will closure be a single activity or will the GDF be closed in stages (e.g. co-located disposal areas)? [6,7]

Gf. What work is needed to develop designs for seals and plugs and backfills needed for closure? [3,7]

Gg. If done in stages, how will closure affect fire safety, ventilation, drainage etc. in the remaining open tunnels? [6,7]

Gh. What are the safety implications of strip out of rock supports and infrastructure? [6,7]

Gi. Can sacrificial rock supports be used to avoid the need for strip out? [3,6,7]

Gj. Are there wastes with a higher likelihood of being retrieved than others, for whatever reason, and how will this affect the design of the facility and the waste emplacement strategy? [8]

Gk. What are the likely safety and environmental consequences if retrievability were to be carried out for whatever reason? [8]



7 Underpinning knowledge and understanding Both implementers and regulators need to have confidence that the intended design, infrastructure, operating practices and management systems for the GDF are underpinned by robust knowledge and understanding, appropriate to the relevant stage of the programme. This knowledge should increase in scope and detail as the programme moves forward. In the early planning and generic design stages, there will be gaps in knowledge and consequently additional R&D work must be planned to fill those gaps. By the time actual construction and operations begin, the level of knowledge must be sufficient to substantiate the safety of the GDF, and all its component parts and processes, taking account of any significant remaining uncertainties. Using NDA’s ‘Technology Readiness Level (TRL) terminology, before full implementation, all components of the GDF should have a TRL of 8 (i.e. the GDF system should be “completed and qualified through test and demonstration”). The development of knowledge will be presented in the nuclear and environmental safety cases produced iteratively by the implementer throughout the GDF programme.

At the current time, there is a considerable baseline of knowledge and understanding relevant to geological disposal that has been developed through several decades or more of work in the UK and international nuclear communities. It is important to recognise that knowledge can be gathered from sources wider than what is often simply referred to as ‘research’, such as:

research specifically to support geological disposal (e.g. radionuclide solubility and speciation experiments);

research to support other aspects of the nuclear industry (e.g. occupational dose assessments and mitigation methods);

relevant generic research in other scientific disciplines (e.g. materials science);

transfer of information from other industries and applications (e.g. mining);

practical testing and verification studies (e.g. full-scale scale mock-ups);

international comparison exercises to identify best practice (e.g. NEA expert groups);

etc.

In the following tables, examples are provided of the current underpinning literature and knowledge base from different sources, in the form of published documents or links to international projects etc. For each item listed, a brief commentary is provided together with a correlation to the relevant generic activity areas (1-9, Section 6.1) and GDF development stages (A-G, Figure 5.3). This correlation should be taken as indicative because overseas programmes do not necessarily follow the same activity areas and development stages described in this report.

Within the resource constraints of the project, it was not feasible to identify all published research etc. but a concerted effort was made to identify the most recent (post-2000) and applicable sources of information. Particular attention was paid to the outputs from international agencies and projects (e.g. those led by the EC and IAEA) because these tend to be planned specifically to support knowledge transfer.


7.1 Significant projects and publications

The following tables provide details of the significant projects and publications from the following organisations and national disposal programmes:

Table 7.1: European Commission (EC)

Table 7.2: International Atomic Energy Agency (IAEA)

Table 7.3: Nuclear Energy Agency (NEA)

Table 7.4: Finland (Posiva)

Table 7.5: Sweden (SKB)

Table 7.6: Switzerland (Nagra)

Table 7.7: France (Andra)

Table 7.8: Belgium (ONDRAF/NIRAS and SCK)

Table 7.9: Germany (BfS and GRS)

Table 7.10 Japan (NUMO and JAEA)

Table 7.11: USA (DOE)

Table 7.12: UK (NDA, RWMD and Nirex)

Table 7.1: Significant projects and documents published by the EC that provide knowledge that is relevant to the GDF programme.

Knowledge source or reference

Commentary Generic activity areas / GDF development stages

European Commission: The EC funds international collaborative research intended to develop knowledge and information transfer. Research in the last decade has been performed under the 5th, 6th and 7th Frameworks (FP5, FP6, FP7). Recently the EC has changed its emphasis from ‘research’ to supporting practical engineering and demonstration projects for geological disposal. EC (2010) The Joint EC/NEA Engineered barrier system project: Synthesis report (EBSSYN). Report EUR 24232.

FP7. EBSSYN. Joint EC and NEA project to develop state of the art understanding of engineered barriers.

3, 5, 6, 7 F, G

Grambow, B. et al. (2010) Model uncertainty for the mechanism of dissolution of spent fuel in nuclear waste repository. Report EUR 24597.

FP6. MICADO. Project to model uncertainty for the mechanism of dissolution of spent fuel in a nuclear waste repository.

2, 9 F, G

FUNMIG (2009) Final scientific and technical report of the integrated project “Fundamental processes of radionuclide migration”. Unnumbered Report.

FP6. FUNMIG. Project to improve understanding in the fundamental understanding of radionuclide migration.

9 F, G

Van Geet, M. et al. (2009) A large-scale in situ demonstration test for repository sealing in an argillaceous host rock – Phase II. Report EUR 24161.

FP5. RESEAL II. Project to perform large scale in situ demonstration test for repository sealing in an argillaceous host rock.

3, 5, 6, 7 F, G

CARD (2008) A co-ordination action on research, development and demonstration priorities and strategies for geological disposal. Report EUR 24442.

FP6. CARD. Project for the co-ordination of R&D priorities and strategies for geological disposal. This led to the IGD-TP project in FP7.

1 A, B

Martell, M. et al. (2008) European Observatory for long-term governance on radioactive waste management. Publishable final Activity Report. Unnumbered Report.

FP6. OBRA. Project to identify and promote appropriate forms of interaction with experts, and help plan how research, training and development in radioactive waste is formulated and managed.

1 A, B

NF-PRO (2008) Understanding and physical and numerical modelling of the key processes in the near field and their coupling for different host rocks and repository strategies. Report EUR 23730.

FP6. NF-PRO. Project to improve physical and numerical modelling of the key processes in a repository near-field.

4, 9 F, G

Borgermans, S. et al. (2007) Safety and operational monitoring of nuclear waste repositories with fibre-optic sensing systems. Report EUR 22384.

FP5. SOMOS. Project to develop sensors for safety and operational monitoring of a GDF with fibre optic sensing systems.

4, 5, 6 D, E, F


Knowledge source or reference Commentary Generic activity

areas / GDF development stages

Oversby, V.M. (2007) Rates and mechanisms of radioactive release and retention inside a waste disposal canister. Unnumbered Report.

FP5. IN CAN. Project to assess the rates and mechanisms of radioactive release and retention inside a waste disposal canister.

2, 9 F, G

Ribet, I. et al. (2007) Long-term behaviour of glass: improving the glass source term and substantiating the basic hypotheses. Unnumbered Report.

FP5. GLASTAB. Project to improve understanding of long term waste glass behaviour.

2, 9 F, G

Van Iseghem, P. et al. (2007) A critical evaluation of the dissolution mechanisms of high-level waste glasses in conditions of relevance for geological disposal. Report EUR 23097.

FP5. GLAMOR. Project to critically evaluate dissolution mechanisms of HLW glass in disposal conditions.

2, 3, 9 F, G

Gobel, I. et al. (2006) Heater experiment: rock and bentonite thermo-hydro-mechanical (THM) processes in the near-field of a thermal source for development of deep underground high level radioactive waste repositories. Report EUR 22586.

FP5. HE. Project to perform heater experiments in rock and bentonite.

2, 3, 6, 7, 9 F, G

Li, X. et al. (2006) TIMODAZ final activity report. Unnumbered Report.

FP6. TIMODAZ. Project to assess the thermal impact on the damaged zone around a repository.

5, 6, 9 F, G

Miller W. et al. (2006) Network to review natural analogue studies and their applications to repository safety assessment and public communication. Report EUR 21919.

FP5. NaNET. Project to review application of natural analogues in environmental safety cases and public communication.

9 D, F, G

Mutadis (2006) Cooperative research on the governance of radioactive waste management. Final synthesis report. Unnumbered Report.

FP6. COWAM in Practice. Project to help develop governance approaches to radioactive waste management in Europe.

1 A, B

Mutadis (2006) Cooperative research on the governance of radioactive waste management. COWAM2. Report EUR 23186.

FP6. COWAM2. Project to improvement governance of radioactive waste disposal in Europe.

1 A, B

Andersson, C. et al. (2005) Full-scale testing of the KBS-3V concept for the geological disposal of high-level radioactive waste. Report EUR 21924.

FP5. PROTOTYPE REPOSITORY. Project to undertake full scale testing of the KBS-3 concept for high-level radioactive waste at the Äspö hard rock laboratory.

3, 5, 6, 7, 9 D, F, G

Andra et al. (2005) Effects of cement on clay barrier performance – Phase II. Report EUR 21921.

FP5. ECOCLAY. Project to evaluate the effects of cement on clay barriers.

3, 6, 7 F, G




Degnan, P. et al. (2005) PADAMOT: project overview Report. Unnumbered Report.

FP5. PADAMOT. Project to develop methods for palaeohydrogeological data analysis and model testing in support of site understanding.

4, 9 A, B

Huertas, F. et al. (2005) Full-scale engineered barriers experiment for a deep geological repository for high-level waste in crystalline host rock – phase II. Report EUR 21922.

FP5. FEBEX. Project to experiment and demonstrate full-scale engineered barrier systems in crystalline host rock.

3, 5, 6, 7 D, E, F, G

Major, J. et al. (2005) Ventilation experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories. Report EUR 21926.

FP5. VE. Project to validate consequences of thermally driven ventilation and desaturation in consolidated clay formations.

3, 5, 6, 9 D, E, F

Mayor, C. et al. (2005) Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories. Report EUR 21920.

FP5. EB. Project to demonstrate the feasibility for emplacing a clay barrier consisting of a base of highly-compacted bentonite blocks.

3, 6, 7 F, G

Pettit, W. et al. (2005) Development of the tools and interpretation techniques for ultrasonic surveys to monitor the rock barrier around radioactive waste packages in geological repositories. Report EUR 21923.

FP5. OMNIBUS. Project to develop tools and interpretation techniques for ultrasonic surveys to monitor the rock barrier around radioactive waste packages.

4, 6 F, G

RETROC (2005) Treatment of radionuclide transport in geosphere within safety assessments. Report EUR 21230.

FP5. RETROC. Project to develop a common basis for incorporating geosphere retention phenomena in environmental safety cases for disposal.

9 A, B, D, F, G

Stephansson, O. et al. (2005) Guidance document on THM coupled processes in performance assessment. Report EUR 21226.

FP5. BENCHPAR. Project to benchmark tests and guidance on coupled processes for performance assessment of nuclear repositories.

9 A, B, D, F, G

Dutton, M. et al. (2004) The comparison of alternative waste management strategies for long-lived radioactive wastes. Report EUR 21021.

FP5. COMPAS. Project to compare alternative waste management strategies for long-lived radioactive wastes.

1, 2, 3 A

ESDRED (2004) Final summary report and global evaluation of the project. Unnumbered Report.

FP6. ESDRED. Project by European implementers to establish a sound technical basis for demonstrating the safety of geological disposal.

3, 5, 6, 7 C, D, F, G

Kursten, B. (2004) State-of-the-art document on the corrosion behaviour of container materials. Unnumbered Report.

FP5. COBECOMA. Project to provide state of the art (at the time) review on the corrosion behaviour of container materials.

2, 3, 6 F, G




Nirex et al. (2004) Thematic network on the role of monitoring in a phased approach to geological disposal of radioactive waste. Report EUR 21025.

FP5. TN on Monitoring. Project to examine the role of monitoring in a phased approach to disposal.

4, 5, 6, 7 B, C, D, E, F, G

Smailos, E. et al. (2004) Long-term performance of candidate materials for HLW/spent fuel disposal containers. Unnumbered Report.

FP5. CONTAINER CORROSION. Project to evaluate the long-term performance of candidate materials for HLW / spent fuel disposal containers.

2, 3, 6, 9 F, G

Andersson, K. et al. (2003) Transparency and public participation in radioactive waste management RISCOM II Final report. SKI Report 2004:08.

FP5. RISCOM. Project to enhance transparency and public participation in nuclear waste management.

1 A, B, G

Bechthold, W. & Hansen, F.D. (2003) Backfilling and sealing of underground repositories for radioactive waste in salt, Phase II. Report EUR 20621.

FP5. BAMBUS. Project to evaluate backfill and material behaviour in underground salt repositories.

3, 5, 6, 7 D, E, F, G

BENIPA (2003) Bentonite barrier in integrated performance assessment. Final technical report. Unnumbered Report.

FP5. BENIPA. Project to evaluate bentonite barriers in integrated performance assessment.

3, 6, 7 F, G

Mutadis (2003) COWAM Network. Nuclear waste management from a local perspective, reflections for a better governance. Unnumbered Report.

FP5. COWAM. Project to compare decision-making processes at the local and regional community level.

1 A, B

Rodwell, W. et al. (2003) A thematic network on gas issues in safety assessment of deep repositories for radioactive waste. Unnumbered Report.

FP5. GASNET. Project to evaluate gas issues in safety assessment of deep repositories for nuclear waste.

5, 6, 9 D, F, G

Wickham, S. et al. (2003) Building confidence in deep disposal: The borehole injection sites at Krasnoyarsk-26 and Tomsk-7 (BORIS). Report EUR 20615.

FP5. BORIS. Project to assess confidence in deep disposal examining the borehole injection sites in Russia.

3, 6, 9 A, F, G

Becker, D. et al. (2002) Testing of safety and performance indicators. Report EUR 19965.

FP5. SPIN. Project to test a variety of safety and performance indicators used in performance assessments.

9 F, G

http://www.carbowaste.eu/ No final reports yet published.

FP7. CARBOWASTE. Project to evaluate treatment and disposal of irradiated graphite and other carbonaceous waste.

2, 3 A

http://www.insotec.eu/ Landström, A. & Bergmans, A. (2011) Socio-technical challenges to implementing geological disposal: a synthesis of findings from 14 countries. Unnumbered Report.

FP7. INSOTEC. Project exploring international socio-technical challenges for implementing geological disposal.

1 A, B


http://www.carbowaste.eu/

http://www.insotec.eu/



http://www.modern-fp7.eu/ No final reports yet published.

FP7. MODERN. Project examining monitoring developments for safe repository operation and staged closure.

4, 7, 8 D, F, G

http://www.bgs.ac.uk/forge/ Norris, S. (2009) Summary of gas generation and migration.

State‐of‐the‐art. Unnumbered Report.

FP7. FORGE. Project to understand the fate of repository gases. Ongoing Project.

6, 9 F, G

http://www.posiva.fi/dopas No summary reports yet published.

FP7. DOPAS. Project to provide full scale demonstration of repository plugs and seals in different rock types. Ongoing Project.

3, 7 F, G

http://www.skb.se/lagerbladet____33716.aspx No summary reports yet published.

FP7. BELBAR. Project to examine the effects of bentonite erosion on the long term performance of the EBS. Ongoing Project.

7, 9 F, G

http://www.sitexproject.eu/ No summary reports yet published.

FP7. SITEX. Provision of technical and regulatory expertise for geological disposal, and development of competence. Ongoing Project.

1 A, B

http://www.lucoex.eu/ No summary reports yet published.

FP7. LUCOEX. Project for joint collaboration regarding large underground concept experiments in URLs etc. Ongoing Project.

3, 5, 6 C, D, F

http://www.pebs-eu.de/PEBS/EN/Home/PEBS_node_en.html PEBS (2011) Long-term performance of engineered barrier systems. Project periodic report. Unnumbered Report.

FP7. PEBS. Project to evaluate the sealing and barrier performance of the EBS over long periods of time, by experiment and modelling. Ongoing Project.

3, 6, 7 F, G

http://www.igdtp.eu/ IGD-TP (2011) Implementing geological disposal of radioactive waste technology platform strategic research agenda. Unnumbered Report.

FP7. IGD-TP. Major technology platform for testing and implementing methods for the geological disposal of radioactive waste. Ongoing Project.

3, 5, 6, 7 B, C, D, F, G


http://www.modern-fp7.eu/

http://www.bgs.ac.uk/forge/

http://www.posiva.fi/dopas

http://www.skb.se/lagerbladet____33716.aspx

http://www.sitexproject.eu/

http://www.lucoex.eu/

http://www.pebs-eu.de/PEBS/EN/Home/PEBS_node_en.html

http://www.pebs-eu.de/PEBS/EN/Home/PEBS_node_en.html

http://www.igdtp.eu/

Table 7.2: Significant projects and documents published by the IAEA that provide knowledge that is relevant to the GDF programme.



IAEA: The International Atomic Energy Agency (IAEA) undertakes R&D in relation to geological disposal through its Waste Technology Section. The IAEA publishes many reports and guides on the management and safety assessment of nuclear facilities. Many of these are generic for all types of facilities. Only those with specific relevance to geological disposal are listed below. IAEA (2013) The safety case and safety assessment for the predisposal management of radioactive waste. General safety guide GSG-3. STI/PUB/1576.

Guidance on the development and review of safety cases and safety assessment for a predisposal waste management facility or activity (e.g. characterisation and storage).

9 A

IAEA (2012) The safety case and safety assessment for the disposal of radioactive waste. Specific safety guide SSG-23. STI/PUB/1553

Latest international guidance on the principles and practice of undertaking post-closure environmental safety cases for geological disposal.

9 A, F

IAEA (2012) Monitoring for compliance with remediation criteria for sites. Safety reports series 72.

Guidance on monitoring contaminated land. Potentially useful when planning post-closure monitoring of the GDF.

4, 7 G

IAEA (2012) Spent fuel performance assessment and research: Final report of a coordinated research project (SPAR-II). IAEA TECDOC 1680.

The results of an IAEA coordinated research project on the integrity and degradation of spent fuel during storage.

2 A

IAEA (2011) Disposal of radioactive waste. Specific safety requirements SSR-5. STI/PUB/1449.

High level international guidance with specific requirements for safety to be included in the siting, design and operation of a geological disposal facility.

1, 3, 6, 9 A, B, C, D, F, G

IAEA (2011) The management system for the development of disposal facilities for radioactive waste. Nuclear energy series NW-T-1.2. STI/PUB/1496.

Guidance on management system requirements, planning, and establishment of procedures and methodologies relevant to the development (design/construction) and operation of geological disposal facilities.

1, 3, 6, 9 A

IAEA (2011) Geological disposal facilities for radioactive waste. Specific safety guide SSG-14. STI/PUB/1483.

Guidance on the implementation of geological disposal, covering organisation structures, safety approach and assessment, facility siting and step-wise implementation plans.

1, 3, 4, 6, 9 A, B, C, D, E, F, G




IAEA (2010) Technological implications of international safeguards for geological disposal of spent fuel and radioactive waste. Nuclear Energy Series NW-T-1.21. STI/PUB/1414.

Discussion of application of safeguards for HAW during geological disposal, covering requirements, practical methods and technical implications.

1, 6 A, C, D, E, F, G

IAEA (2009) Geological disposal of radioactive waste: technological implications for retrievability. Nuclear Energy Series NW-T-1.19. STI/PUB/1378

Discussed the technological implications of retrievability when developing designs for geological disposal. Considers concepts currently being developed by some countries for the retrieval of emplaced waste.

8 A, F, G

IAEA (2009) Policies and strategies for radioactive waste management. Nuclear Energy Series NW-G-1.1. STI/PUB/1396.

High-level guidance on planning policies to establish a national strategy for the management of spent fuel and radioactive waste.

1 A

IAEA (2009) Classification of radioactive waste. General safety guide GSG-1. STI/PUB/1419.

Guidance on the classification schemes for all types of radioactive waste. Some discussion on consequences for management of different wastes.

1, 2 A

IAEA (2009) Borehole disposal facilities for radioactive waste. Specific safety guide SSG-1. STI/PUB/1418.

Specific guidance on the implementation of disposal of HAW by boreholes and associated safety strategy.

3, 5 A, D

IAEA (2008) The management system for the disposal of radioactive waste. Safety standards series GS-G 3.4. STI/PUB/1330.

Guidance on management systems, policies, responsibilities and processes for geological implementation organisations.

1 A

IAEA (2007) Factors affecting public and political acceptance for the implementation of geological disposal. TECDOC-1566.

Emphasis on public and stakeholder engagement in decision making for geological disposal. National cases studies presented.

1, 9 A, B

IAEA (2007) Cost considerations and financing mechanisms for the disposal of low and intermediate level radioactive waste. TECDOC-1552.

Summary report on options for the financing of disposal and legal responsibilities of organisations.

1 A

IAEA (2006) Geological disposal of radioactive waste safety requirements. Safety Requirements WS-R-4. STI/PUB/1231

Original safety requirements document. This has been superseded by SSR-5 (IAEA, 2011).

1, 3, 4, 6, 9 A, B, C, D, E, F, G

IAEA (2006) Release of sites from regulatory control on termination of practices. Safety guide WS-G-5.1. STI/PUB/1244.

Most relevant for nuclear surface facilities but also relevant for closure of the GDF.

7, 9 G




IAEA (2004) Application of the concepts of exclusion, exemption and clearance. Safety Guide RS-G-1.7.

Guidance on radionuclide specific levels below which wastes may be considered to be radiologically clean. Applicable to LLW disposal volume minimisation.

2 A

IAEA (2004) Developing multinational radioactive waste repositories: Infrastructural framework and scenarios for cooperation. TECDOC-1413.

Focus on shared international disposal options in host countries. Not directly relevant to UK but provides international background.

1, 3 A

IAEA (2003) Scientific and technical basis for the geological disposal of radioactive wastes. Technical report series 43. STI/DOC/010/413.

High-level international guidance on geological disposal covering aspects of suitable site characteristics, isolation by the host rock, and containment by the engineered barriers.

2, 3, 4, 7, 9 A, B, C, D

IAEA (2003) Predisposal management of low and intermediate level radioactive waste. Safety guide WS-G-2.5. STI/PUB/1150.

Guidance on management of waste, largely related to storage of ILW.

2 A

IAEA (2003) Predisposal management of high level radioactive waste. Safety guide WS-G-2.6. STI/PUB/1151.

Guidance on management of waste, largely related to storage of HLW

2 A

IAEA (2001) The use of scientific and technical results from underground research laboratory investigations for the geological disposal of radioactive waste. TECDOC-1243.

Detailed summary, at time of publication, of work performed in URLs for learning on site characterisation, construction techniques, EBS designs and design optimisation. Provides annex descriptions of work done in several URLs.

3, 4, 5 C, D

IAEA (2001) Monitoring of geological repositories for high level radioactive waste. TECDOC-1208.

Discusses the purposes for monitoring in the different stages of a repository programme, the use that may be made of the information obtained and possible techniques.

4 B, C, D, F, G

IAEA (2000) Multi-purpose container technologies for spent fuel management. TECDOC-1192.

Status report, at the time, on the design and requirements for multi-purpose storage and disposal casks for spent fuel.

2, 3 F

IAEA (1999) Hydrogeological investigation of sites for the geological disposal of radioactive waste. Technical Report Series 391. STI/DOC/010/391

Status report, at the time, of the requirement and methods for performing site characterisation.

4 B

IAEA (1999) Maintenance of records for radioactive waste disposal. TECDOC-1097.

Status report, at the time, of the requirement and methods for long-term records management for geological disposal

1, 9 A, G

http://www.iaea.org/OurWork/ST/NE/NEFW/WTS-Networks/URF/overview.html IAEA Underground Research Facilities Network (URF)

International collaboration research network in which existing underground research facilities are made available for training in and demonstration of waste disposal technologies and the sharing of knowledge.

3, 4, 5, 6, 7 A, D, E, F, G


http://www.iaea.org/OurWork/ST/NE/NEFW/WTS-Networks/URF/overview.html

http://www.iaea.org/OurWork/ST/NE/NEFW/WTS-Networks/URF/overview.html



http://www.iaea.org/OurWork/ST/NE/NEFW/WTS-Networks/DISPONET/overview.html IAEA LLW Disposal Network (DISPONET)

International collaboration research network to provide assistance and learning in LLW and short-lived ILW disposal.

2, 3, 5, 6 A


http://www.iaea.org/OurWork/ST/NE/NEFW/WTS-Networks/DISPONET/overview.html

http://www.iaea.org/OurWork/ST/NE/NEFW/WTS-Networks/DISPONET/overview.html

Table 7.3: Significant projects and documents published by the NEA that provide knowledge that is relevant to the GDF programme.



NEA: The Nuclear Energy Agency (NEA) coordinates R&D in relation to geological disposal mostly through its Radioactive Waste Management Committee (RWMC) that comprises regulators, disposal agencies and research organisations drawn from NEA member countries. The NEA publishes many reports and guides on the management of radioactive materials. Many of these are generic for all types of facilities. Only those with specific relevance to geological disposal are listed below. NEA (2013) Stakeholder confidence in radioactive waste management. NEA Report 6988.

Review from the NEA Forum on Stakeholder Confidence (FSC) of concepts central to societal decision making about radioactive waste management.

1, 9 A, G

NEA (2013) Preparing for construction and operation of geological repositories. Challenges to the regulator and the implementer. NEA Report NEA/RWM/RF(2012)2.

NEA workshop report to consider construction and operational issues taking into account the constraints on design concept from long-term safety, operational safety, and feasibility.

1, 3, 5, 6, 9 C, D, F, G

NEA (2013) The nature and purpose of the post closure safety cases for geological repositories. NEA Report 78121.

State of the art review that defines and discusses the purpose and general contents of post-closure environmental safety cases for geological disposal.

9 A, B, F, G

NEA (2013) Underground research laboratories (URLs). NEA Report 78122.

Documents and integrates recent URL literature and gives a strategic outlook of URLs internationally.

3, 5, 6, 7 C, D, F

NEA (2013) The preservation of records, knowledge and memory (RK&M) across generations. Improving our understanding. Workshop Proceedings. NEA Report NEA/RWM/R(2013)3.

Interim report on a project (2011-2014) aimed at long-term and intergenerational records management.

1, 9 A, B, C, D, E, F, G

NEA (2012) Thermodynamic Sorption Modelling in Support of Radioactive Waste Disposal Safety Cases. NEA Report 6914.

Guidelines for thermodynamic sorption model development as well as their application in repository performance assessments.

9 F, G

NEA (2012) Cementitious materials in safety cases for geological repositories for radioactive waste: role, evolution and interactions. NEA Report in preparation.

NEA workshop report to assess current understanding on the use of cementitious materials in radioactive waste disposal.

2, 3, 5, 6, 7 D, F, G

NEA (2012) Indicators in the Safety Case. NEA Report NEA/RWM/R(2012)7.

State of the art report on use of indicators other than dose and risk in safety and performance assessment.

9 A, F, G




NEA (2012) Methods for safety assessment of geological disposal facilities for radioactive waste. NEA Report 6923.

Outcomes and recommendations from the NEA Methods for Safety Assessment for Geological Disposal Facilities for Radioactive Waste (MeSA) project on post-closure environmental safety cases.

9 F, G

NEA (2012) Geological disposal of radioactive waste: national commitment, local and regional involvement. NEA Report 7082.

Collective statement by the NEA Radioactive Waste Management Committee on issues associated with technical and stakeholder confidence building.

1, 9 A, G

NEA (2011) Reversibility and retrievability (R&R) for the deep disposal of high-level radioactive waste and spent fuel. Final report of the NEA R&R project (2007-2011). NEA Report NEA/RWM/R(2011)4.

Reversibility and Retrievability (R&R) Project (2007-2011) aimed at understanding the issues associated with retrievability, and which led to the establishment of the International Retrievability Scale.

8 E, F, G

EC (2010) The Joint EC/NEA Engineered Barrier System Project: Synthesis Report (EBSSYN). EUR 24232 EN.

Summary report and recommendations from international project on EBS system designs and assessments in geological disposal.

2, 3, 5, 6, 7, 9 C, D, F, G

NEA (2010) Geoscientific information in the radioactive waste management safety case. NEA Report 6395.

Key messages from the Integrating Geological Information in the Safety Case (AMIGO) project on incorporating geoscience data in post-closure environmental safety cases.

4, 9 B, F, G

NEA (2010) Regulation and guidance for the geological disposal of radioactive waste. NEA Report 6405.

Review of international regulations on geological disposal, covering dose/risk and environmental protection.

9 A, F, G

NEA (2010) Towards transparent, proportionate and deliverable regulation for geological disposal. NEA Report 6825.

Workshop review by NEA Regulators’ Forum covering timescales for regulation, stepwise decision making, roles of optimisation and best available techniques (BAT), multiple lines of reasoning, safety indicators, recognition of uncertainties and stakeholder interactions.

1, 3, 5, 9 A, B, D, F, G

NEA (2010) Self-sealing of fractures in argillaceous formations in the context of geological disposal of radioactive waste. NEA Report 6184.

Review by the NEA ‘Clay Club’ of the evidence and mechanisms for self-sealing properties of clays rocks.

4, 7, 9 A, B, F, G

NEA (2010) Optimisation of Geological Disposal of Radioactive Waste. NEA Report 6836.

Review of concepts relevant to “optimisation” of geological disposal systems as outlined in national and international guidance. Includes observations and key open questions.

3, 5, 6, 9 C, D, F, G




NEA (2009) Approaches and challenges for the use of geological information in the safety case for deep disposal of radioactive waste.

Recommendations from the NEA Approaches and Methods for Integrating Geological Information in the Safety Case (AMIGO) project on post-closure environmental safety cases.

9 F, G

NEA (2009) A Common Objective, a Variety of Paths. Synthesis and Main Lessons. NEA Report 6385.

Third international conference on geological repositories with recommendations to assist future developments in national radioactive waste management programmes.

1 A, B

NEA (2009) Considering timescales in the post-closure safety of geological disposal of radioactive waste. NEA Report 6424.

Review of issues associated with assessing geological disposal safety over long-time periods.

9 F, G

NEA (2009) International experiences in safety cases for geological repositories. NEA Report 6251.

Outcomes and recommendations from the NEA project on International Experiences in Safety Cases for Geological Repositories (INTESC) for post-closure environmental safety cases.

9 A, B, F, G

NEA (2009) Stability and buffering capacity of the geosphere for long-term isolation of radioactive waste: application to crystalline rock. NEA Report 6362.

NEA IGSC workshop report on geosphere stability for deep geological disposal.

3, 5, 9 A, B, G

NEA (2008) Regulating the long-term safety of geological disposal of radioactive waste: practical issues and challenges. NEA Report 6423.

NEA workshop report on regulatory processes; the basis for assuring long-term protection; ethical responsibilities; and regulatory processes over long time frames.

1, 9 A, B, F, G

NEA (2007) Fostering a durable relationship between a waste management facility and its host community. NEA Report 6176.

Identifies design elements (functional, cultural and physical features) that help relationships with a host community by improving prospects for quality of life across generations.

1, 9 A, B, F, G

NEA (2007) Engineered barrier systems (EBS) in the safety case: design confirmation and demonstration. NEA Report 6257.

NEA workshop report on experiments and methods to demonstrate that EBS designs will meet long-term safety, engineering feasibility and quality assurance requirements.

2, 3, 5, 6, 9 C, D, E, F

NEA (2007) Engineered barrier systems (EBS) in the safety case: the role of modelling. NEA Report 6118.

NEA workshop report on EBS modelling in the safety case for deep disposal.

2, 3, 5, 6, 9 C, D, E, F

NEA (2007) Cultural and structural changes in radioactive waste management organisations. NEA Report 6180.

Review of changes in radioactive waste management organisations, and lessons learned from experiences.

1 A, B

NEA (2006) The roles of storage in the management of long-lived radioactive waste. NEA Report 6043.

Considers the role of storage in radioactive waste management programmes.

1, 2 A




NEA (2005) Clay Club catalogue of characteristics of argillaceous rocks. NEA Report 4436.

Catalogue of key geoscientific characteristics of argillaceous formations that have been studied in various countries.

4, 9 A, B, F, G

NEA (2005) Geological repositories: political and technical progress. NEA Report 5299.

NEA workshop status report (at that time) on technical, regulatory and stakeholder issues associated with disposal.

1, 9 A, B

NEA (2005) International peer reviews for radioactive waste management. NEA Report 6082.

Guidelines for when an international peer review is requested, organised or carried out.

1, 9 A, B

NEA (2005) Management of uncertainty in safety cases and the role of risk. NEA Report 5302.

NEA workshop report approaches to treating uncertainties in safety cases, and how concepts of risk can be used in both post-closure safety cases and regulatory evaluations.

9 A, B, F, G

NEA (2005) The regulatory function and radioactive waste management. NEA Report 6041.

Synopsis of the regulatory control of radioactive waste management in various countries.

1 A, B, F, G

NEA (2004) Engineered barrier systems (EBS): design requirements and constraints. NEA Report 4548.

NEA workshop report on the integration needed for design of the EBS, and to clarify the role that an EBS can play in the overall safety case for a repository.

2, 3, 5, 6, 7 D, F, G

NEA (2004) Geological disposal: building confidence using multiple lines of evidence. NEA Report 4309.

NEA AMIGO workshop to support the safety case using multiple lines of evidence and integrating the work of geoscientists and safety assessors.

1, 3, 9 F, G

NEA (2004) Stepwise approach to decision making for long-term radioactive waste management. NEA Report 4429.

Review of stepwise decision making: current status and recommendations, implementation issues from both the point of view of social research and RWM practitioners

1, 9 A, B, C

NEA (2004) The role of monitoring in a safety case. NEA Report NEA/RWM/IGSC(2005)3.

NEA workshop report concerning the objectives and place of monitoring in the context of safety cases.

4, 9 B, C, F, G

NEA (2003) Engineered barrier systems and the safety of deep geological repositories. NEA Report 3615.

NEA EBS project report to clarify the role that an EBS can play in the overall safety case for a deep geological repository.

2, 3, 5, 6, 7 D, F, G

NEA (2001) Reversibility and retrievability in geologic disposal of radioactive waste. NEA Report 3140.

Concepts of reversibility and retrievability as they may apply to the planning and development of engineered geologic repositories

3, 6, 8 E, F, G

NEA (2001) The role of underground laboratories in nuclear waste disposal programmes. NEA Report 3142.

Overview of URLs in disposal with international examples. Timing of a URL within a programme and benefits of international co-operation in relation to URLs.

1, 3, 4, 6 B, C, F


Table 7.4: Significant projects and documents published in Finland that provide knowledge that is relevant to the GDF programme.



Finland: Posiva publishes many documents on their website, including technical and research plan reports. Since 2000, they have published approximately 100 technical reports and 1000 working (progress) reports. The majority of these relate to aspects of their post-closure environmental safety case for the planned spent fuel repository, but others address practical implementation. Some of the most recent technical reports are listed below, together with a number of others with more design, operational and safety relevance to illustrate the breadth of publications available from Posiva. The majority of reports are written in English. All reports can be searched at http://www.posiva.fi/en/databank/search_of_material Nordbäck, N. (2013) Outcome of the geological mapping of the ONKALO underground research facility. Chainage 3116-4986. Working Report 2013-11.

Detailed update of the geological mapping work in a certain section of the ONKALO URL, explaining methods used for mapping rock types and geological features.

4, 5 A, B, C

Posiva (2013) Nuclear waste management at Olkiluoto and Loviisa power plants: review of current status and future plans for 2013-2015. Report YJH-2012.

Latest in a series of three-yearly reports setting out Posiva’s plans for management of wastes, and the programme for implementation of the planned spent fuel repository at Olkiluoto.

1, 3, 5, 6 B, C, D, E, F, G

Saanio, T. et al. (2013) Design of the disposal facility 2012. Report 2013-17.

Desciption of the construction, operation and closure of the Finnish KBS-3 spent fuel disposal facility at Olkiluoto.

2,3,5,6,7,8 C,D,E,F,G

Alterio, I & Siren, T. (2012) Results of monitoring at Olkiluoto in 2011 - Rock mechanics. Working Report 2012-47.

Detailed update of monitoring at the site of the planned spent fuel repository, geological stresses.

4 A, B

Fox, A. et al. (2012) Geological discrete fracture network model for the Olkiluoto site, Eurajoki, Finland. Report 2012-27.

Describes the methods, analyses and conclusions of the geological modelling for the site of the planned spent fuel repository at Olkiluoto.

4, 9 A, B, C

Juvankoski, M. et al. (2012) Buffer production line 2012. Report 2012-17.

One of a series of reports that underpins the plan for implementation of the repository. Detailed design and means to install the buffer.

3, 5, 7 F, G

Keto, P. et al. (2012) Backfill production line 2012. Report 2012-18.

One of a series of reports that underpins the plan for implementation of the repository. Detailed design and means to install the tunnel backfill.

3, 5, 7 F, G

Kirkkomäki, T. (2012) Design and stepwise implementation of the final repository 2012. Working Report 2012-69.

Update report on the current stepwise implementation plan for excavation of the repository and phased disposal operations.

3, 5, 6, 7 C, D, E, F


http://www.posiva.fi/en/databank/search_of_material



Kukkonen, K. (2012) Radiation protection in Posiva's encapsulation plant and disposal facility. Working Report 2012-89.

Discussion of the practices and implementation of means to reduce radiation exposures to workers during waste handling in the packaging plant and disposal in the repository.

2, 3, 6, 9 F

Kuutti, J., et al. (2012) Analyses of disposal canister falling accidents. Report 2012-36.

Scale engineering and modelling assessment of canister drop scenarios, including if the canister falls while being lowered into the shaft

2, 3, 6, 9 F

McEwen, T. et al. (2012) Rock suitability classification - RSC 2012. Report 2012-24.

Work to develop a scheme for ensuring the suitability of the host rock, and to avoid areas of weak rock when excavating the disposal tunnels and emplacing individual waste packages.

3, 4, 5 A, B, C, D, F

Peltokorpi, L. et al. (2012) Keskus- ja loppusijoitustunneleiden palotarkasteluja APROSilla. Working Report 2012-73. In Finnish (Translation: Fire analyses in central and disposal tunnels).

Detailed analysis of fire scenarios in the spent fuel repository and response procedures in the case of a fire.

6, 9 F

Pere, T. et al. (2012) Layout determining features, their influence zones and respect distances at the Olkiluoto site. Report 2012-21.

Work to determine how the layout of the repository will need to be optimised to fit in areas of competent rock between large fracture zones.

3, 4, 5 A, B, C, D, F

Pimenoff, N. et al. (2012) Climate and sea level scenarios for Olkiluoto for the next 10,000 years. Report 2012-26.

Climate change predictions as basis for assessing long-term evolution of the repository site.

4, 9 A, B

Posiva (2012) Monitoring at Olkiluoto – a programme for the period before repository operation. Report 2012-1.

Report setting out the monitoring plan for the site that will be continued from previous studies and progress through all construction work before waste emplacement.

4, 5, 9 A, B, C, D

Posiva (2012) Safety case for the disposal of spent nuclear fuel at Olkiluoto - Design basis 2012. Report 2012-3.

Report summarising the basis for the design and requirements for the repository intended to be constructed at Olkiluoto.

3, 5, 6 C, D, F, G

Posiva (2012) Safety case for the disposal of spent nuclear fuel at Olkiluoto - Description of the disposal system 2012. Report 2012-5.

Report summarising the design of the disposal system intended to be constructed at Olkiluoto.

2, 3, 4, 5, 6, 7, 9 B, C, D, F, G

Posiva (2012) Safety case for the disposal of spent nuclear fuel at Olkiluoto - Synthesis 2012. Report 2012-12.

Report summarising the safety case submitted to underpin the construction licence application for the planned spent fuel repository at Olkiluoto.

2, 3, 4, 5, 6, 7, 9 B, C, D, F, G




Raiko, H. et al. (2012) Canister production line 2012. Report 2012-16.

One of a series of reports that underpins the plan for implementation of the repository. Detailed design and means to emplace canisters.

2, 3, 6 F, G

Rossi, J. & Suolanen, V. (2012) Operational safety analysis of the Olkiluoto encapsulation plant and disposal facility. Working Report 2012-71.

Assessment of occupational and public doses from normal operations and accident scenarios for the encapsulation plant and the spent fuel repository.

2, 3, 6, 9 F

Schatz, T. & Martikaonen, J. (2012) Laboratory tests and analyses on potential Olkiluoto backfill materials. Working Report 2012-74.

Description of laboratory tests on the physical properties of alternative backfill materials for the spent fuel repository.

3, 6, 7 F, G

Sievänen, U. et al. (2012) Design, production and initial state of the underground disposal facility closure. Report 2012-19.

One of a series of reports that underpins the plan for implementation of the repository. Detailed design and means to install plugs and seals for closure.

3, 5, 7 F, G

Vaittinen, T. et al. (2012) Results of monitoring at Olkiluoto in 2011 - Hydrology. Working Report 2012-43.

Detailed update of monitoring at the site of the planned spent fuel repository, surface hydrology.

4 A, B

Posiva (2011) Olkiluoto site description 2011. Report 2011-2.

Detailed update of the geological and site characteristics of the area around the proposed spent fuel repository.

4 A, B, C

Siren, T. et al. (2011) Assessment of the potential for rock spalling in the technical rooms of the ONKALO. Working Report 2011-35.

Assessment of rock spall and potential collapse in the research areas of the underground research laboratory.

4, 5, 7 C, D, F

Toropainen, V. (2011) Core drilling of drillholes ONK-KR13, ONK-KR14 and ONK-KR15 in ONKALO at Olkiluoto 2010 – 2011. Working Report 2011-39.

Review of the methods and results from boreholes drilled at ONKALO for confirming site characterisation results.

4, 5 A, B, C

Laine, H. & Karttunen, P. (2010) Long-term stability of bentonite- a literature review. Working Report 2010-53.

State of the art report on the long-term performance of bentonite as a buffer material in the repository.

3, 7 F, G

Pitkänen, J. (2010) Inspection of bottom and lid welds for disposal canisters. Report 2010-4.

Methods for inspecting and verifying welds in the spent fuel canister.

2, 3, 4 E, F

Nolvi, L. (2009) Manufacture of disposal canisters. Report 2009-3.

Summary of the development work carried out to verify means to manufacture the copper disposal canisters.

2, 3 E, F

Antilla, P et al. (2008) KBS-3H design description 2007. Report 2008-1.

Detailed design of the alternative horizontal design variant of the KBS-3 concept, to support decision making.

3, 5, 9 C, D, F




Posiva (2008) Horizontal deposition of canisters for spent nuclear fuel. summary of the KBS-3H Project 2004-2007. Report 2008-3.

Summary of the work undertaken to date to evaluate the alternative horizontal design variant of the KBS-3 concept, to support decision making.

3, 5, 9 C, D, F

Pitkänen, P. et al. (2007) Quality review of hydrochemical baseline data from the Olkiluoto site. Report 2007-5.

Report setting out the importance of QA in the collection and analysis of geochemical data from the site characterisation programme.

4, 9 A, B, C

Smith, P. et al. (2007) Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto – Summary report. Report 2007-6.

Detailed environmental safety case calculation results for the alternative horizontal design variant of the KBS-3 concept, to support decision making.

3, 5, 9 C, D, F

Pastina, B. & Hellä, P. (2006) Expected evolution of a spent nuclear fuel repository at Olkiluoto (revised). Report 2006-5.

Detailed qualitative description of the expected long-term evolution of the spent fuel repository, from waste emplacement into the far future.

6, 7, 9 F, G

Ikonen, K. (2005) Thermal analysis of repository for spent EPR-type fuel. Report 2005-6.

Calculation of the heat output from EPR fuel and its implications for the spent fuel repository.

2, 3, 6, 9 F, G

Posiva (2003) Programme of monitoring at Olkiluoto during construction and operation of the ONKALO. Report 2003-5.

Description of the monitoring programme needed to identify disturbances to the hydrogeological conditions of the site during shaft sinking.

3, 4, 5 B, C, D

Posiva (2003) ONKALO underground characterisation and research programme (UCRP). Working Report 2003-5.

Description of the R&D work planned in the ONKALO underground research laboratory.

3, 4, 5, 6, 7 C, D, E, F, G

Vieno, T et al. (2003) Assessment of disturbances caused by construction and operation of ONKALO. Report 2003-6.

Description of the effects of construction of ONKALO shaft on the hydrogeological conditions of the site.

3, 4, 5 B, C, D


Table 7.5: Significant projects and documents published in Sweden that provide knowledge that is relevant to the GDF programme.



Sweden: SKB publishes many documents on their website, including technical and research plan reports. Since 2000, they have published approximately 300 reports. The majority of these relate to aspects of their post-closure environmental safety case for the planned spent fuel repository, but others address practical implementation. Some of the most recent technical reports are listed below, together with a number of others with more design, operational and safety relevance to illustrate the breadth of publications available from SKB. The majority of reports are written in English. All reports can be searched at http://www.skb.se/Templates/Standard____17139.aspx Anunti, A. et al. (2013) Decommissioning study of Forsmark NPP. SKB R-13-03.

A review of decommissioning methods, costs and waste arisings from future closure of the NPP

1, 2 A

Bengtsson, A. et al. (2013) Development of a method for the study of H2 gas emission in sealed compartments containing canister copper immersed in O2-free water. SKB TR-13-13.

Investigation into the possibility that copper may corrode in pure water, in contradiction to normal thermodynamic model assumptions. Significant for long-term containment of the copper canister.

2, 3, 9 F, G

Johannesson, L. & Jensen, V. (2013) Effects of water inflow into a deposition hole. Influence of pellets type and of buffer block manufacturing technique. Laboratory tests results. SKB P-13-09.

Assessment of the water uptake of bentonite buffer around the canister, with different bentonite structures (pellets and blocks).

3, 5, 7, 9 F, G

Rosborg, B. (2013) Recorded corrosion rates on copper electrodes in the Prototype Repository at the Äspö HRL. SKB R-13-13.

Results of in-situ copper corrosion rates measured in the underground research laboratory.

2, 3, 5, 9 F, G

Jaquet, O. et al. (2012) Groundwater flow modelling under ice sheet conditions in Greenland. SKB R-12-14.

Evaluation of sub-ice groundwater flow, and likely consequence for long-term climate change on the KBS-3 repository.

3, 4, 7 A, B, D

Luterkort, D. et al. (2012) Closure of the spent fuel repository in Forsmark. Studies of alternative concepts for sealing of ramp, shafts and investigation boreholes. SKB TR-12-08.

Design development work for final closure and sealing of the KBS-3 repository.

3, 5, 7 F, G

SKB (2012) Äspö Hard Rock Laboratory. Annual report 2011. SKB TR-12-03.

One of a series of annual reports summarising all of the research, development and demonstration work performed in the Äspö underground research laboratory.

3, 4, 5, 6, 7, 9 B, C, D, E, F, G


http://www.skb.se/Templates/Standard____17139.aspx



Svensson, D. et al. (2012) Alternative buffer material. Status of the ongoing laboratory investigation of reference materials and test package 1. SKB TR-11-06.

Design development work to underpin the choice of the preferred material for the buffer in the KBS-3 repository.

3, 5, 7 E, F, G

Gómez, J. et al. (2011) Assessment of the importance of mixing in the Yucca Mountain hydrogeological system. SKB TR-11-02.

Modelling studies to understand complexity of groundwater systems in unsaturated conditions, as analogue for possible Swedish climate change.

3, 4, 9 F, G

SKB (2011) Long-term safety for the final repository for spent nuclear fuel at Forsmark. Main report of the SR-Site project. Updated 2012-12. SKB TR-11-01.

The main report from one of the environmental safety cases that underpinned the construction licence application for the planned spent fuel repository at Forsmark.

9 C, G

Stepinski, T. et al. (2011) Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Algorithms for ultrasonic imaging. SKB TR-10-70.

Development of instrumentation methods to verify the integrity of welds and containment provided by the copper canister.

2, 4, 9 A

Åkesson, M. et al. (2010) SR-Site Data report. THM modelling of buffer, backfill and other system components. SKB TR-10-44.

One of a series of reports that underpins the safety case for the KBS-3 repository. Data and models report on coupled thermo-hydro- mechanical process.

3, 5, 7 F, G

Karnland, O (2010) Chemical and mineralogical characterization of the bentonite buffer for the acceptance control procedure in a KBS-3 repository. SKB TR-10-60.

Work to develop QA methods for checking the quality of materials that will be used for buffer and backfill in the KBS-3 repository.

3, 4, 7 E, F

Salas, J. et al. (2010) SR-Site - hydrogeochemical evolution of the Forsmark site. SKB TR-10-58.

Detailed description of the work undertaken to perform and model the hydrogeological characteristics of the proposed site for the KBS-3 repository.

4, 9 A, B

SKB (2010) RD&D Programme 2010. Programme for research, development and demonstration of methods for the management and disposal of nuclear waste. SKB TR-10-63.

The latest in a series of three-yearly reports that set out SKB’s plans for performing research, development and demonstration work in support of the disposal programme.

1, 3, 4, 5, 6, 7, 9 B, C, D, F

SKB (2010) Geosphere process report for the safety assessment SR-Site. Updated 2011-10. SKB TR-10-48.

One of a series of reports that underpins the safety case for the KBS-3 repository. Detailing the approach to assessing long-term evolution of the host rock in response to climate change etc.

3, 4, 7 E, F

SKB (2010) Buffer, backfill and closure process report for the safety assessment SR-Site. Updated 2011-10. SKB TR-10-47.

One of a series of reports that underpins the safety case for the KBS-3 repository. Detailing the approach to closure and sealing.

3, 5, 7 G




SKB (2010) Fuel and canister process report for the safety assessment SR-Site. Updated 2013-01. SKB TR-10-46

One of a series of reports that underpins the safety case for the KBS-3 repository. Detailing the approach to assessing long-term spent fuel evolution.

2, 3, 9 G

SKB (2010) Design, production and initial state of the canister. Updated 2011-12. SKB TR-10-14.

One of a series of reports that underpins the safety case for the KBS-3 repository. Detailing the design requirements for the copper canister.

2, 3, 6 F, G

SKB (2010) Design, construction and initial state of the underground openings. Updated 2013-01. SKB TR-10-18.

One of a series of reports that underpins the safety case for the KBS-3 repository. Detailing the design and excavation methods for the repository.

3, 5 C, D, F

SKB (2010) Design, production and initial state of the backfill and plug in deposition tunnels. SKB TR-10-16. SKB TR-10-16.

One of a series of reports that underpins the safety case for the KBS-3 repository. Detailing the design requirements for backfill, plugs and seals.

3, 7 F, G

SKB (2010) Design and production of the KBS-3 repository. SKB TR-10-12.

One of a series of reports that underpins the safety case for the KBS-3 repository. Detailing the overall design requirements for the disposal system.

3, 5, 7 C, D, F


Table 7.6: Significant projects and documents published in Switzerland that provide knowledge that is relevant to the GDF programme.



Switzerland: Nagra publishes many documents, including technical and research plan reports. These used to be available for download from their website but are currently listed, although many can still be found using the search function. Since 2000, they have published approximately 90 reports. The majority of these relate to aspects of their post-closure environmental safety case for the planned HLW repository, but others address practical implementation and the work in the Swiss underground research laboratories (Grimsel and Mont Terri). Some of the most recent technical reports are listed below, together with a number of others with more design, operational and safety relevance to illustrate the breadth of publications available from SKB. Many of the reports are written in English. The list of Nagra reports can be found here http://www.nagra.ch/en/shopengl.htm Nagra (2012) Annual report. Unnumbered report. Non-technical overview of Nagra’s organisation, its

programme and future plans. 1, 3 A, B

Nagra (2012) Mont Terri rock laboratory. Unnumbered report http://www.nagra.ch/data/documents/database/dokumente/%24default/Default%20Folder/Publikationen/Broschueren%20Themenhefte/e_bro_fmt2012.pdf

Nagra operates an underground research laboratory at Mont Terri in the Opalinus Clay, where it performs a great deal of research, development and demonstration work. Nagra makes the URL available for international collaborative projects.

3, 5, 6, 7 C, D, E, F

Patel, R. et al. (2012) Canister design concepts for disposal of spent fuel and high level waste. Nagra NTB 12-06.

Summary of latest work on alternative canister designs for HLW and ILW.

2, 3, 9 F, G

Bradbury, M. & Baeyens, B. (2011) Physico-chemical characterisation data and sorption measurements of Cs, Ni, Eu, Th, U, Cl, I and Se on MX-80 bentonite. Nagra NTB 09-08.

Detailed report on thermodynamic data used for modelling sorption in environmental safety case calculations.

9 F, G

Nagra (2011) Grimsel test site. Unnumbered report. http://www.nagra.ch/data/documents/database/dokumente/%24default/Default%20Folder/Publikationen/Broschueren%20Themenhefte/e_bro_flg10.pdf

Nagra operates an underground research laboratory at Grimsel in crystalline, where it performs a great deal of research, development and demonstration work. Nagra makes the URL available for international collaborative projects.

3, 5, 6, 7 C, D, E, F

Nagra (2011) Sachplan geologische Tiefenlager Etappe 2. Nagra NTB 11-01. In German. (Translate: Sectoral plan for deep geological repositories Stage 2)

The proposed new siting programme for HLW and ILW repositories based on the Swiss sectoral plan strategy. Nagra proposed geological siting regions based on criteria relating to safety and engineering feasibility

1, 3, 4 A, B


http://www.nagra.ch/en/shopengl.htm

http://www.nagra.ch/data/documents/database/dokumente/%24default/Default%20Folder/Publikationen/Broschueren%20Themenhefte/e_bro_fmt2012.pdf



http://www.nagra.ch/data/documents/database/dokumente/%24default/Default%20Folder/Publikationen/Broschueren%20Themenhefte/e_bro_flg10.pdf





Kelokaski, M. et al. (2010) Grimsel test site investigation phase IV. Pore space geometry project characterisation of pore space geometry by 14C-MMA impregnation. Nagra NTB 05-03.

Technical assessment of in-situ experiments for assessing the distribution of porosity in hard rocks.

4, 9 A, B, C

Nagra (2010) Klärung der Notwendigkeit ergänzender geologischer Untersuchungen. Nagra NTB 10-01. In German. (Translate: Clarification of the need to take additional geological investigations)

Strategy for the need for new geological investigations as part of siting to support safety assessment.

1, 3, 4, 9 A, B

Pike, S. et al. (2010) Critical review of welding technology for canisters for disposal of spent fuel and high level waste. Nagra NTB 09-05.

Latest research results into sealing of waste canisters. 2, 3 A, D

Landolt, D. et al. (2009) A review of materials and corrosion issues regarding canisters for disposal of spent fuel and high-level waste in Opalinus Clay. Nagra NTB 09-02.

Technical assessment of alternative materials for waste canisters for disposal in clay host rocks.

2, 9 A, D

Nagra (2009) The Nagra research, development and demonstration (RD&D) plan for the disposal of radioactive waste in Switzerland. Nagra NTB 09-06.

Latest summary report on the Swiss plans for implementation and supporting research for their HLW and ILW repositories.

1, 2, 3, 4, 5, 9 A, B, C, D, F

Turnbull, A. (2009) A review of the possible effects of hydrogen on lifetime of carbon steel nuclear waste canisters. Nagra NTB 09-04.

Technical assessment of steel corrosion processes. 2, 9 A, D

Blümling, P. & Adams, J. (2008) Grimsel test site investigation phase IV. Borehole sealing. Nagra NTB 07-01.

Update on long-term, in-situ experiments for borehole sealing in hard rocks.

3, 7 B, G

Marschall, P. & Lunati, I. (2006) Grimsel test site investigation Phase V. GAM – Gas migration experiments in a heterogeneous shear zone of the Grimsel test site. Nagra NTB 03-11.

Update on long-term, in-situ experiments for assessing gas migration in hard rocks.

4, 5 A, B, F, G

Smith, P. et al. (2006) Grimsel Test Site investigation Phase V. The CRR Final Project Report Series III: Results of the supporting modelling programme. Nagra NTB 03-03.

Final report on long-term, in-situ experiments for assessing colloid and radionuclide retention (CRR) in hard rocks.

4, 5 A, B, F, G

Nagra (2005) Spent fuel evolution under disposal conditions. Synthesis of results from the EU spent fuel stability (SFS) project. Nagra NTB 04-09.

Summary report from Nagra’s involvement in the international project on spent fuel stability.

2, 9 A




Gimmi, T. & Waber, H. (2004) Modelling of tracer profiles in pore water of argillaceous rocks in the Benken borehole. Stable water isotopes, chloride and chlorine isotopes. Nagra NTB 04-05.

Technical assessment of field experiments to perform groundwater flow / tracer studies.

4, 5, 9 A, B

Jakob, A. (2004) Matrix diffusion for performance assessment. experimental evidence, modelling assumptions and open issues. Nagra NTB 04-07.

Technical overview report on the significance of matrix diffusion for radionuclide transport.

4, 9 B, F, G

Nagra (2004) Effects of post-disposal gas generation in a repository for spent fuel, high-level waste and long-lived intermediate level waste sited in Opalinus Clay. Nagra NTB 04-06.

Technical overview report on the significance of gas generation on long-term repository performance.

2, 9 D, F, G

Kosakowski, G. & Smith, P. (2004) Grimsel test site investigation phase V. Modelling the transport of solutes and colloids in a water-conducting shear zone in the Grimsel test site. Nagra NTB 04-01.

Update on long-term, in-situ experiments for assessing colloid migration in hard rocks.

4, 5 A, B, F, G

Nagra (2002) Project Opalinus Clay. Safety report. Demonstration of disposal feasibility for spent fuel, vitrified high-level waste and long-lived intermediate-level waste (Entsorgungsnachweis). Nagra NTB 02-05.

Final and summary report of Nagra’s safety case to prove the viability of HLW disposal in clay rocks.

2, 3, 4, 5, 6, 7, 9 A, D, F, G

Nagra (2002) Project Opalinus Clay. Models, codes and data for safety assessment. Demonstration of disposal feasibility for spent fuel, vitrified high-level waste and long-lived intermediate-level waste (Entsorgungsnachweis). Nagra NTB 02-06.

One of a series of supporting documents underpinning the viability assessment and safety case for HLW disposal in clay.

2, 9 F, G

Pfingsten, W. (2001) Indications for self-sealing of a cementitious repository for low and intermediate-level waste. Nagra NTB 01-05.

Technical assessment of the potential processes for closure of fractures in cement backfills used for ILW disposal.

2, 3, 4, 9 D, F, G

Smith P. (2000) Grimsel Test Site Investigation Phase IV. The Nagra–JNC in situ study of safety relevant radionuclide retardation in fractured crystalline rock. Overview 1990–1996. Nagra NTB 00-09.

Summary report on long-term, in-situ experiments for assessing radionuclide migration in hard rocks. Jointly between Nagra and JNC (Japan).

4, 9 F, G


Table 7.7: Significant projects and documents published in France that provide knowledge that is relevant to the GDF programme.



France: Andra publishes research documents, although these are not readily listed and available on its website. The majority of these are general overview reports published in French, although the more significant ones are sometimes also available in English. The majority of these relate to the planned repository (Cigéo) at Meuse Haute-Marne. Unlike SKB, Posiva etc., Andra tends not to make all of its detailed technical reports widely available. Some reports are available here http://www.andra.fr/index.php?id=edition_1_5_2&recherche_thematique=all and also at http://www.xn--cigo-dpa.com/ Andra (2013) The Cigeo project Meuse/Haute-Marne reversible geological disposal facility for radioactive waste. Andra 504VA.

Semi-technical overview of the ongoing work to construct the French HLW repository, covering design and operations.

1, 2, 3, 4, 5, 6, 8, 9 A, B, C, D, F, G

Andra (2012) National inventory of radioactive materials and waste. Synthesis report. Andra 467VA.

Detailed report of current and anticipated future arisings of wastes and their types, including those planned to be disposed in the French HLW repository.

2, 3 A

Andra (2011) Annual sustainable development and activity report. Andra 478VA.

Non-technical overview of the French programme and ongoing work to construct the HLW repository.

1, 2, 3, 4, 5 A, B, C, D

Andra (2010) 2006 - 2009, 4 ans de recherches scientifiques à l'Andra pour les projets de stockage. Andra 383.

Summary of research performed in support of the implementation of the HLW disposal programme.

2, 3, 5 A, B

Aparicio, L. (2010) Making nuclear waste governable. Deep underground disposal and the challenge of reversibility. Andra 381VA.

Detailed review of the policy decisions leading to the French decision to make the HLW repository reversible, and the technical challenges.

2, 3, 4, 6, 8 F, G

Andra (2009) Stockage réversible profond. Etape 2009. Options de conception du stockage en formation géologique profonde. Andra 394. In French (Translation: Design options storage in deep geological formations).

Detailed design options for the planned French HLW repository.

3, 7 A, B, C, D

Andra (2009) Stockage réversible profond. Etape 2009. Proposition d'une zone d'intérêt pour la reconnaissance approfondie et de scénarios d'implantation en surface. Andra 391. In French (Translation: Survey of the surface area for installations).

Report on surface investigations at the site of the planned HLW repository.

4, 5 A, B,


http://www.andra.fr/index.php?id=edition_1_5_2&recherche_thematique=all

http://www.cig%C3%A9o.com/

http://www.cig%C3%A9o.com/



Andra (2009) Stockage réversible profond. Etape 2009. Options de réversibilité du stockage en formation géologique profonde. Andra 393. In French (Translation: Options to reverse disposal in deep geological formations).

Detailed design options for implementing reversibility in the planned HLW repository.

2, 3, 8 F, G

Andra (2009) Stockage réversible profond. Etape 2009. Options de sûreté du stockage en formation géologique profonde. Andra 392. In French (Translation: Options for safe disposal designs in geological formations).

Detailed designs for the safe operation of the planned HLW repository.

2, 3, 5, 6, 7, 8, 9 C, D, E, F, G

Andra (2008) The initial environmental state of the Meuse/Haute-Marne underground research laboratory. Andra 178VA.

Summary of the environmental conditions of the site of the planned HLW repository.

4 A, B

Andra (2008) Technical demonstrators. Andra 310VA. Non-technical overview of the research and demonstrations studies performed by Andra to prove the viability of HLW disposal.

2, 3, 5, 6, 8 A, B, C, D, F

Andra (2006) The HAVL project for high-level and intermediate-level long-lived waste. Andra 306VA.

Summary overview of the French HLW disposal programme.

1, 2, 3, 8 A, B, C

Andra (2006) Dossier 2005 Argile. Andra research on the geological disposal of high-level long-lived radioactive waste. Results and perspectives. Andra 265VA.

English summary of the Andra’s safety case to prove the viability of HLW disposal in clay rocks.

2, 3, 4, 5, 6, 7, 9 A, D, F, G

Andra (2005) Dossier 2005 Argile. Evaluation of the feasibility of a geological repository in an argillaceous formation. Synthesis. Andra 266VA.

English translation of the final and summary report of Andra’s safety case to prove the viability of HLW disposal in clay rocks.

2, 3, 4, 5, 6, 7, 9 A, D, F, G

Andra (2005) Dossier 2005 Argile. Architecture and management of a geological repository. Tome. Andra 268VA.

English translation of the detailed design and operational plans for the planned HLW repository in clay rocks.

3, 5, 6, 8 B, C, D, F

Andra (2005) Dossier 2005 Argile. Phenomenological evolution of a geological repository. Tome. Andra 269VA.

English translation of the anticipated long-term evolution of the planned HLW repository in clay rocks.

6, 7, 9 F, G

Andra (2005) Dossier 2005 Argile. Safety evaluation of a geological repository. Tome. Andra 270VA.

English translation of the operational and post-closure safety assessments for the planned HLW repository in clay rocks.

1, 5, 6, 7, 9 C, D, F, G




Andra (2005) Dossier 2005 Granite. Assets of granite formations for deep geological disposal. Synthesis. Andra 267VA.

English translation of the final and summary report of Andra’s safety case to prove the viability of HLW disposal in granite.

2, 3, 4, 5, 6, 7, 9 A, D, F, G

Andra (2005) Dossier 2005 Granite. Architecture and management of a geological repository. Tome. Andra 285VA.

English translation of the detailed design and operational plans for the planned HLW repository in granite.

3, 5, 6, 8 B, C, D, F

Andra (2005) Dossier 2005 Granite. Phenomenological evolution of a geological repository. Tome. Andra 288VA.

English translation of the anticipated long-term evolution of the planned HLW repository in granite.

6, 7, 9 F, G

Andra (2005) Dossier 2005 Granite. Safety analysis of a geological repository. Tome. Andra 287VA.

English translation of the operational and post-closure safety assessments for the planned HLW repository in granite.

1, 5, 6, 7, 9 C, D, F, G


Table 7.8: Significant projects and documents published in Belgium that provide knowledge that is relevant to the GDF programme.

Knowledge source or reference Commentary Generic activity areas / GDF development stages

Belgium: ONDRAF/NIRAS publishes some of their documents on their website, including some technical and research plan reports. The majority of these relate to aspects of their post-closure environmental safety case for the planned category B&C waste repository, but a few address practical implementation. Some of the most recent technical reports are listed below, together with a number of others with more design, operational and safety relevance to illustrate the breadth of publications available from ONDRAF. The majority of reports are written in Flemish and French, although the more significant ones are also available in English. All reports can be searched at http://www.ondraf.be/content/publications-par-th%C3%A8mes Note that much of the Belgian R&D work is done as part of wider EC collaboration in the EURIDICE programme (European Underground Research Infrastructure for Disposal of nuclear waste In Clay Environment) in the HADES underground research laboratory (URL) which involves ONDRAF and the SCK (the Belgian Nuclear Research Centre). There are several hundred technical reports available for downloaded from http://publications.sckcen.be/dspace/ and http://www.euridice.be/eng/06publicaties2012.shtm Ferrand, K. (2013) Topical report on tests on vitrified (V)HLW waste in Supercontainer disposal conditions. SCK report ER-195.

Latest summary of the design and performance of the concrete supercontainer design for HLW.

2, 3, 6 F

Vandersteen, K. et al. (2012) Transient model of the confined aquifers below the Boom Clay: 2011 update. Regional Hydrogeological Modelling of the Mol Site. SCK report ER-199.

Detailed review of the hydrogeological characteristics at Mol, around the HADES URL.

4, 9 A, B

Yu, L. & Weetjens, E. (2012) Estimation of the gas source term for spent fuel, vitrified high-level waste, compacted waste and MOSAIK waste. SCK report ER-162.

Investigation of gas release from MOSAIK cast iron containers for HLW / ILW.

2, 3, 9 F, G

Chen G. et al. (2011) ATLAS III in situ heating test in boom clay: Field data, observation and interpretation. Computers and Geotechnics, 38:5, 683-696.

Detailed modelling results of full scale heater tests in the HADES URL.

3, 4, 6, 9 E, F

Craeye B. et al. (2011) Closure of the concrete supercontainer in hot cell under thermal load. Nuclear Engineering and Design, 241:5, 1352-1359.

Discussion of the closure of the concrete supercontainer design for high active wastes.

2, 3, 5 E, F

EURIDICE (2011) Activity report 2011. Doc 12-118. Overview of all of the R&D work performed in the HADES URL and labs.

1, 3, 4, 5 B, C, D


http://www.ondraf.be/content/publications-par-th%C3%A8mes

http://www.ondraf.be/content/publications-par-th%C3%A8mes

http://publications.sckcen.be/dspace/

http://www.euridice.be/eng/06publicaties2012.shtm



ONDRAF (2011) Notre mission : vous protéger Rapport annuel 2011. In French. (Translation: Annual report 2011)

General overview of ONDRAF’s programme, including non-technical discussion of the planned repository design and work in URLs.

1, 2, 3, 5, 6, 7, 9 A, B, C, D, F

ONDRAF (2011) Waste plan for the long-term management of conditioned high-level and/or long-lived radioactive waste and overview of related issues. NIROND 2011-02 E.

Detailed description of ONDRAF’s programme to dispose of Category B&C wastes (high active wastes).

1, 2, 3, 5, 6, 7, 9 A, B, C, D, F

Yu, L. & Weetjens, E. (2011) Integration of TIMODAZ results within the safety case and recommendations for repository design. SCK report ER-188.

Investigation of thermal damaged zones around waste containers in Boom clay, and implications for repository design.

2, 3, 5, 6, 7 D, F, G

Marivoet, J. (2010) Testing safety and performance indicators for a geological repository in clay. SCK report ER-125.

Assessment of non-dose/risk indicators that can be applied in a environmental safety case.

9 F, G

ONDRAF (2010) Strategic environmental assessment (SEA) pour le plan déchets de l’ONDRAF. Report 5249-506-073. In French. (Translation: SEA for the waste plan).

Detailed conventional SEA and EIA assessments for the Belgian disposal programme.

4, 9 A, B, C, F

ONDRAF (2009) The long-term safety strategy for the geological disposal of radioactive waste. NIROND-TR 2009-12.

Overview of the design concept and safety strategy for the disposal of high activity wastes in Boom clay.

2, 3, 6, 7, 9 F, G

Smith P. et al. (2009) The long-term safety assessment methodology for the geological disposal of radioactive waste. NIROND 2009-14.

Detailed discussion of the environmental safety case methodology to be applied for Category B&C wastes.

1, 2, 9 F, G

Yu, L. & Weetjens, E. (2009) Summary of gas generation and migration. current state-of-the-art. SCK report ER-106.

Overview of the concepts and theories, current treatment and existing uncertainties in PA regarding gas generation and migration in deep geological repository.

2, 7, 9 F, G

Druyts, F. & Kursten, B. (2008) SACNUC. Sulphur-assisted corrosion in nuclear waste disposal systems. SCK report BA-24.

Evaluation of sulphur impact on container corrosion and containment performance.

2, 9 F, G

ONDRAF (2008) Rapport de gestion. Situation actuelle de la gestion des déchets radioactifs en Belgique. NIROND 2008-02. In French. (Translation: Current management plan for radioactive waste in Begium).

Overview of the Belgian management activities and future plans for all radioactive wastes, including discussion of ongoing R&D work, and URL studies.

1, 2, 3, 4, A, B




ONDRAF (2007) Evolution of the near-field of the repository concept for category c wastes: First full draft report. NIROND 2007-07.

Description of the expected long-term evolution of the disposal system for high activity wastes in Boom clay.

1, 2, 9 F, G

Van Geet, M. et al. (2005) RESEAL II. A large scale in situ demonstration test for repository sealing. Final report on laboratory tests. SCK report ER-1.

Results of a large-scale, in-situ test on sealing of shafts and disposal galleries in the HADES URL.

6, 7 F, G

Van Marcke, P. & Laenen, B. (2005) The Ypresian clays as possible host rock for radioactive waste disposal: an evaluation. NIROND 2005-01.

Detailed geological description of the potential host clay rocks based on site characterisation studies.

4, 9 A, B

NEA (2003) SAFIR 2: Belgian R&D programme on the deep disposal of high-level and long lived radioactive waste: An international peer review. Unnumbered report.

NEA peer review of the Belgian disposal programme and safety assessment SAFIR2.

1, 3, 9 F, G

ONDRAF (2001)Technical overview of the SAFIR 2 report: Safety assessment and feasibility interim report 2. NIROND 2001-05.

Summary of the SAFIR2 safety assessment and feasibility study for the disposal of high activity wastes in Boom clay.

2, 3, 6, 7, 9 A, C, F, G

ONDRAF (2001) SAFIR 2: Safety assessment and feasibility interim report 2. NIROND 2001-06.

Detailed description of the SAFIR2 safety assessment and feasibility study for the disposal of high activity wastes in Boom clay.

2, 3, 6, 7, 9 A, C, F, G


Table 7.9: Significant projects and documents published in Germany that provide knowledge that is relevant to the GDF programme.

Knowledge source or reference Commentary Generic activity areas / GDF development stages

Germany: Research for geological disposal is split between many organisations. The Federal Office for Radiation Protection (BfS) is responsible for geological disposal, including the Gorleben exploration mine (URL) and the Morsleben and Asse repositories both in rock salt. These are both are to be closed and decommissioned, with wastes retrieved from Asse. Publications from the BfS can be found at http://www.bfs.de/en/endlager/publika The Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) is a major research organisation that is involved in many German R&D projects for disposal http://www.grs.de/en/content/waste-management Much German R&D is done in the context of collaborative NEA and EU Framework projects. Almost all publications are in German although some are translated in English, and some research is summarised in English journal and conference papers. Beuth, T. et al. (2013) Untersuchungen zum menschlichen Eindringen in ein Endlager, Bericht zum Arbeitspaket 11, Vorläufige Sicherheitsanalyse für den Standort Gorleben. GRS-280. In German (Translation: Studies on human intrusion into a repository. Preliminary analysis for the Gorleben site).

Preliminary Safety Analysis of the Gorleben Site (VSG) project. Post-closure safety case and assessment of human intrusion at Gorleben.

3, 7, 9 F, G

Bracke, G. (2013) Consideration of hydrocarbons at the Gorleben salt dome in a preliminary safety assessment. In GRS (2013).

Overview of the potential hazards and consequences for oil and gas seepages into an operational repository in salt.

3, 4, 6, 9 C, D, F, G

Ellouz, M. et al. (2013) BAM challenges for design testing of waste containers for the final repository Konrad. ICEM 2013 conference paper, ICEM2013-96258.

Design of disposal canisters intended for non-heat generating wastes planned to be disposed in the German Konrad repository.

2, 3 E, F

GRS (2013, in preparation) Natural analogues for safety cases of repositories in rock salt.

Proceedings of a joint GRS/NEA workshop on geoscientific aspects of disposal in rock salt.

3, 6, 7, 8, 9 C, D, F, G

Kallenbach-Herbert, B. (2013) Public involvement on closure of Asse radioactive waste repository in Germany. ICEM 2013 conference paper, ICEM2013-96090.

Summary of the decision process to close the Asse mine, and the involvement of local stakeholders.

1, 3, 6, 7, 8 F, G

Noseck, U. et al. (2013) Geotechnical barriers in the repository concept for HLW disposal in rock salt. In GRS (2013).

Overview of the plugs and seals planned to be used for the closure of a German repository design in salt.

3, 7, 9 F, G


http://www.bfs.de/en/endlager/publika

http://www.grs.de/en/content/waste-management



Bracke, G. et al. (2012) Berücksichtigung der Kohlenwasserstoffvorkommen in Gorleben in der VSG. Bericht der Arbeitsgruppe Kohlenwasserstoffe. GRS-285. In German (Translation: Consideration of the hydrocarbon deposits in Gorleben).

Preliminary Safety Analysis of the Gorleben Site (VSG) project. Overview of the potential hazards and consequences for oil and gas seepages into an operational repository in salt.

3, 4, 6, 9 C, D, F, G

Bollingerfehrm W. et al. (2012) Endlagerauslegung und -optimierung. Bericht zum Arbeitspaket 6, Vorläufige Sicherheitsanalyse für den Standort Gorleben. GRS-281. In German (Translation: repository design and optimization).

Preliminary Safety Analysis of the Gorleben Site (VSG) project. Description of the design concept and optimisation of design.

3, 5, 6, 9 C, D, F, G

Eickemeier, R. et al. (2012) Preliminary safety analysis of the Gorleben site: thermo-mechanical analysis of the integrity of the geological barrier in the Gorleben salt formation. WM’13 Conference paper.

Assessment of the strength and self-closure properties of the Gorleben salt dome.

4, 5, 6 A, B, C, F, G

Mönig, J. et al. (2012) Sicherheits- und Nachweiskonzept. Bericht zum Arbeitspaket 4, Vorläufige Sicherheitsanalyse für den Standort Gorleben. GRS-277. In German (Translation: Safety and verification concept).

Preliminary Safety Analysis of the Gorleben Site (VSG) project. Post-closure safety case and assessment, safety concept for disposal at Gorleben.

3, 7, 9 F, G

Brennecke, P. (2010) Anforderungen an endzulagernde radioaktive Abfälle Endlager Konrad. BfS Bericht SE-IB29/08-REV-1. In German (Translation: Radioactive waste disposal requirements for the Konrad repository).

Summary of the legal requirements for waste disposal in the Konrad repository.

1, 9 A, F, G

BMU (2010) Safety requirements governing the final disposal of heat-generating radioactive waste, Federal Ministry for the Environment.

Regulatory requirements for geological disposal in Germany.

1, 9 A, B, F, G

Rothfuchs, T. et al. (2010) Long-term safety analysis and model validation through URL research. Journal of Rock Mechanics and Geotechnical Engineering, 2, 32–38.

Summary of R&D in German URLs and links to post-closure safety cases.

3, 4, 5, 6, 9 C, D, F

BMWI (2008) Final disposal of high-level radioactive waste in Germany. The Gorleben project. Federal Ministry of Economics and Technology.

Non-technical overview (at the time) of R&D for the development of the proposed Gorleben repository in salt.

2, 3, 4, 5, 6, 7 A, B, C, D


Table 7.10: Significant projects and documents published in Japan that provide knowledge that is relevant to the GDF programme.



Japan: The Nuclear Waste Management Organization of Japan (NUMO) is the implementer and undertakes research and publishes some reports in English on their website https://www.numo.or.jp/en/publications/ Other research is undertaken and published by the Japan Atomic Energy Agency (JAEA) http://jolisfukyu.tokai-sc.jaea.go.jp/ird/english/index.html and some commercial organisations that support the Japanese disposal programme. The most recent publications (mostly in English) are listed below and a selection of other publications related to implementation of the HLW disposal programme. Conner et al. (2013) Spatial and temporal distribution of future volcanism in the Chugoku Region. A partial application of NUMO's ITM and Topaz probabilistic tectonic assessment methodology. NUMO-TR-13-03

One report in a series exploring methods to predict future distribution of volcanic activity in Japan.

3, 4 A, B

Kawamura, H. & McKinley, I. (2013) Tailoring of the CARE concept for practicality, safety and robustness. ICEM 2013 conference paper, ICEM2013-96067.

Review of the CAvern REtrievable (CARE) concept, and its possible use in Japan for underground storage of spent fuels and HLW.

2, 3, 4, 7 D, E, F, G

Nishio, K. & Shimada, A. (2013) Proceedings of Information and Opinion Exchange Conference on Geoscientific Study, 2012. JAEA Review 2012-049.

Japanese conference on establishing the scientific and technological basis for the geological disposal of HLW.

3, 4, 5, 6, 7, 9 A, B, F, G

NUMO (2013) Safety of the geological disposal Project 2010. Safe geological disposal based on reliable technologies. English Summary. NUMO-TR-13-05

Summary overview of the Japanese HLW disposal project, covering safety strategies, concept design and technologies for construction, operation and closure.

1, 2, 3, 4, 5, 6, 7, 9 A, B, D, F, G

Sakai, R. et al. (2013) Study on evaluation methodology for groundwater flow based on geochemical data. 2; Case study for Horonobe area. JAEA Technology 2013-006.

Discussion of the use of palaeohydrogeological and hydrochemical information to model long-term groundwater flow patterns and rates.

3 A, B

Yoshimura, K, et al. (2013) The role of large scale demonstration experiments in supporting the implementation of a high level waste programme. ICEM 2013 conference paper, ICEM2013-96048.

Summary of Japanese - Swiss joint demonstration projects for geological implementation.

2, 3, 5, 6, 7 C, D, E, F

Ebashi, T. et al. (2012) Collaboration on strategies for the development of a repository program. NUMO-TR-12-01

Overview of the collaboration between the Japanese and Swiss disposal programmes in concept development and site selection / characterisation.

3, 4 A, B


https://www.numo.or.jp/en/publications/

http://jolisfukyu.tokai-sc.jaea.go.jp/ird/english/index.html



Iijiri, Y. et al. (2012) Study on engineering technologies in the Mizunami underground research laboratory. JAEA Technology 2012-018.

Summary of engineering studies in the URL on design and construction methods, and for disposal operations.

3, 5, 6, 9 D, F, G

Kunimaru, T. et al. (2012) Mizunami underground research laboratory project plan for fiscal year 2012. JAEA Review 2012-028.

Summary of work underway and planned in the Honorobe URL in crystalline rock.

3, 5, 6, 9 D, F, G

Nakayama, M. et al. (2012) Horonobe Underground Research Laboratory Project; Investigation report for the 2011 fiscal year. JAEA Review 2012-035.

Summary of work underway and planned for the next 20 years in the Horonobe URL.

3, 5, 6, 9 D, F, G

Inagaki, M. (2011) Preliminary study on development of a methodology for evaluating the performance of host rock for geological disposal based on surface-based investigations. JAEA Research 2011-056.

Evaluation of geological conditions to determine the usable volume of rock with specific performance characteristics.

3, 4, 5 A, B, C

NUMO (2011) RMS 2010 requirements management systems (RMS): Status and recent developments. Information exchange meeting report. NUMO-TR-10-07

Report on international workshop on requirements management for geological disposal.

2, 3, 5, 6 A, B, D, F

Sanada, M. et al. (2011) Studies on the design method of multi tunnels in geological disposal facility. JAEA Research 2011-055.

Study on the effects of excavating multiple tunnels and the impact on the extent of the engineered damaged zone.

5, 9 C, D, F

Shibata, M. et al. (2012) Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage. JAEA Research 2012-032.

Progress report on a project to enhance the methodology of repository design and performance assessment in preliminary investigation phase.

2, 3, 9 A, B, F

Hayashi, K. et al. (2010) A Study on the technology for reducing cement-type materials used for tunnel supports at high-level radioactive waste disposal sites. JAEA Research 2010-057.

Study to reduce the quantity of cement materials that cause highly alkaline environments in a HLW disposal system.

3, 5, 6, 7 C, D, F

Nakatsuka, N. et al. (2010) Research on engineering technology in the full-scale demonstration of EBS and operation technology for HLW disposal. JAEA Research 2010-060.

Summary of engineering technology studies for equipment to be used for emplacement of wastes in the HLW repository.

3, 5, 6, 7 C, D, F




Kurikami, H. et al. (2009) Study on strategy and methodology for repository concept development for the Japanese geological disposal project. NUMO-TR-09-04

Overview of how disposal concept development is influenced by iterative site characterisation and post-closure performance assessment, in the Japanese programme.

3, 4, 5, 9 A, B, D, F, G

NUMO (2007) The NUMO structured approach to HLW disposal in Japan. Staged project implementation at volunteer sites utilising a requirements management system. NUMO-TR-07-02

Description of the staged siting approach in Japan and the supporting requirements management system.

3, 4 A, B

JNC (2005) H17: Development and management of the technical knowledge base for the geological disposal of HLW. JNC TN 1400 2005-022.

Overview of the plans (at the time) for the disposal of HLW in Japan, design of facility and future R&D requirements.

2, 3, 5, 6, 7, 9 A, B, C, D, F, G

NUMO (2004) Evaluating site suitability for a HLW repository (scientific background and practical application of NUMO's siting factors), NUMO-TR-04-04

Description of the geological site suitability criteria being applied in the Japanese disposal programme.

3, 4 A, B

NUMO (2004) Development of repository concepts for volunteer siting environments. NUMO-TR-04-03.

Description of alternative disposal concepts for HAW that may be applied in different Japanese geological environments and host rocks.

3, 4 A, B

AEC (2000) Long-term program for research, development, and utilization of nuclear energy. Unnumbered report (In Japanese).

Overview of the Japanese R&D programme to support geological disposal.

1, 2, 3, 5 A, B, D, F

JNC (2000) H12: Project to establish the scientific and technical basis for HLW disposal in Japan. Project overview report. JNC TN1410 2000-001.

Detailed report providing discussion on the design and implementation of a HLW repository, and the results of a post-closure safety case.

2, 3, 5, 6, 7, 9 A, B, C, D, F, G


Table 7.11: Significant projects and documents published in the USA that provide knowledge that is relevant to the GDF programme.



USA: The Department of Energy (DoE) is the implementer for geological disposal in the US. Key reports are listed and can be searched at http://energy.gov/search/site/geological%20disposal?gid=1 and older documents related to Yucca Mountain Project (YMP) repository are listed at http://energy.gov/list-yucca-mountain-archival-documents Since closure of YMP work has looked at alternative disposal concepts including disposal in salt, potentially adding spent fuel to the TRU wastes being disposed at WIPP, as part of the “Used Fuel Disposition Campaign” research project. DOE (2013) Strategy for the management and disposal of used nuclear fuel and high-level radioactive waste. Unnumbered report.

Overview of new US policy, including plans for new siting process for a spent fuel repository.

1, 2, 3 A, B

Freeze, G. et al. (2013) Generic deep geological disposal safety case. SAND2013-0974P.

Review of different disposal concept designs and their safety assessment, with an emphasis on post-closure (environmental) safety cases.

2, 3, 6, 7, 9 C, D, F, G

Hansen, F. et al. (2013) Proceedings of 3rd US/German workshop on salt repository research, design and operation. FCRD-UFD-2013-000100.

Summary of an ongoing programme of collaboration on geological disposal in salt between USA and German agencies.

2, 3, 4, 5, 6, 7, 9 A, B, C, F, G

Sevougian, S. et al. (2013) RD&D study plan for advancement of science and engineering supporting geologic disposal in bedded salt. March 2013 workshop outcomes. FCRD-UFD-2013-000161.

Report detailing RD&D activities to support disposal of heat generating radioactive waste in a generic bedded salt repository, given the current state of knowledge.

1, 2, 3 A, B, D, F

Blue Ribbon Commission (2012) Blue Ribbon Commission on America’s nuclear future. Report to the Secretary of Energy. January 2012.

The US equivalent of the original CoRWM recommendations, that the US needs a new siting strategy after the ending of the YMP.

1, 2, 3 A, B

DOE (2012) Used fuel disposition campaign disposal research and development roadmap. FCR&D-USED-2011-000065.

Highly detailed technical report describing R&D that may be needed to underpin a new spent fuel and HLW disposal programme in the US, assuming YMP is closed.

1, 2, 3, 4, 5, 6, 9 A, B, C, D, F, G

Kuhlman, K. et al. (2012) Review and evaluation of salt R&D data for disposal of nuclear waste in salt. FCRD-UFD-2012-000380.

Examination of knowledge and gaps associated with geological disposal in salt.

1, 2, 3 A, B, D, F


http://energy.gov/search/site/geological%20disposal?gid=1

http://energy.gov/list-yucca-mountain-archival-documents



MacKinnon, R. (2012) Towards a defensible safety case for deep geologic disposal of DOE HLW and DOE SNF in bedded salt. SAND2011-6032.

Examination of the possible scenario for the disposal of spent fuel that was intended to be disposed of at YMP in the WIPP repository (or other salt repository).

1, 2, 3 A, B, D, F

DOE (2011) Draft environmental impact statement for the disposal of greater-than-class C (GTCC) low-level radioactive waste and GTCC-like waste. DOE/EIS-0375-D.

Review of options for the disposal (including near-surface disposal) for short-lived ILW equivalent wastes.

2, 3, 9 A, B

Hansen, F. & Leigh, C. (2011) Salt disposal of heat-generating nuclear waste. SAND2011-0161.

Detailed assessment of concepts for the disposal of spent fuels and HLW in rock salt.

2, 3, 6, 9 A, B, C, G

Nuclear Waste Technical Review Board (2011) Technical advancements and issues associated with the permanent disposal of high activity wastes, lessons learned from Yucca Mountain and other programs. Unnumbered report.

Summary of lessons learned etc. from US and other national disposal programmes. Recommendations for a new siting programme and R&D.

2, 3, 4, 5, 6, 9 A, B, C, D, E, F, G

Rechard, R. et al. (2011) Basis for identification of disposal options for research and development for spent nuclear fuel and high-level waste. SAND2011-3781P.

Outcome of the ‘used fuel disposition’ study in the US to examine alternatives to YMP, including various disposal concepts in different rock types.

2, 3, 5, 6, 9 A, B, C

Winterle, J. et al. (2011) Regulatory perspectives on deep borehole disposal concepts. Report prepared for the US Nuclear Regulatory Commission, Contract NRC–02–07–006.

Review and regulations for deep borehole disposal. 2, 3, 6, 9 A, B, C, G

Apted, M. et al. (2010) EPRI review of geologic disposal for used fuel and high level radioactive waste. Volume IV Lessons learned. EPRI Report 1021057

One of a series of reports assessing YMP programme. This one summarises issues that went well and could have been done better.

2, 3, 5, 6, 7 C, D, F, G

Hansen, F. et al. (2010) Shale disposal of US high-level radioactive waste. SAND2010-2843

Detailed assessment of concepts for the disposal of spent fuels and HLW in shale.

2, 3, 6, 9 A, B, C, G

Stenhouse, M. et al. (2010) EPRI review of geologic disposal for used fuel and high level radioactive waste. Volume III Review of national repository programs. EPRI Report 1021614.

One of a series of reports assessing YMP programme. This one gives an overview of national programmes.

2, 3, 5, 6, 7 C, D, F, G

Brady, P. et al. (2009) Deep borehole disposal of high-level radioactive waste. SAND2009-4401.

Detailed assessment of deep borehole disposal concept for spent fuels and HLW.

2, 3, 6, 9 A, B, C, G

DOE (2009) Waste isolation pilot plant compliance recertification application. DOE 2009-24-34.

Latest application for periodic relicensing of the WIPP facility for disposal operations.

2, 6, 7, 9 F, G




DOE (2008) Yucca mountain repository license application. http://www.nrc.gov/waste/hlw-disposal/yucca-lic-app/yucca-lic-app-safety-report.html

The whole (very large) suite of documents for the license application for the planned spent fuel repository at Yucca Mountain. Note this was never reviewed by NRC because of ending of YMP.

2, 3, 4, 5, 6, 9 A, B, C, D, E, F, G

DOE (2008) Transportation, aging and disposal canister system performance specification. DOC ID: WMO-TADCS-000001

Detailed specifications for selected system components of the transportation, aging and disposal (TAD) canister-based system.

2, 3 A

Hansen, F. (2003) The disturbed rock zone at the waste isolation pilot plant. SAND2003-3407.

Assessment of the engineered damaged zone due to construction in salt at WIPP.

5, 6, 9 C, D, F

DOE (2002) Final environmental impact statement for a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste at Yucca Mountain, Nye County, Nevada. DOE/EIS-0250.

Detailed environmental assessment of the impacts of construction and operation of YMP, including transport.

2, 3, 4, 5, 6, 9 A, B, C, D, E, F, G

DOE (2002) Yucca Mountain science and engineering report. Technical information supporting site recommendation consideration. DOE/RW-0539-1.

Highly detailed technical report describing aspects of the YMP disposal system design and safety assessment.

2, 3, 4, 5, 6, 9 B, C, D, F

DOE (1998) Viability assessment of a repository at Yucca Mountain. DOE/RW-0508. (Five volumes and overview).

Detailed report setting out viability assessment for disposal of spent fuel at YMP, covering facility design, and safety assessment etc.

2, 3, 4, 5, 6, 9 B, C, D, F


http://www.nrc.gov/waste/hlw-disposal/yucca-lic-app/yucca-lic-app-safety-report.html

http://www.nrc.gov/waste/hlw-disposal/yucca-lic-app/yucca-lic-app-safety-report.html

Table 7.12: Significant projects and documents published in the UK by NDA, RWMD and Nirex that provide knowledge that is relevant to the GDF programme. Note that it is not the intention of this project to peer review RWMD’s work programme or their technical publications. The reports listed below are provided for information only.



UK: RWMD publishes some of their documents on their website, including some technical and research plan reports, and many of the previous Nirex documents. Note most of the recent reports are identified as NDA reports, not RWMD. The most recent reports relate to the gDSSC but others provide information on RWMD plans. RWMD has commissioned many contractor project reports but these typically are not published as NDA or RWMD documents. Some of the most recent NDA / RWMD technical reports are listed below. There is no simple listing of reports but they can be searched by keyword at http://www.nda.gov.uk/documents/biblio/ Harvey, E. et al. (2013) Geological disposal concept options for vitrified HLW. Galson Sciences Report 1150b-3.

Review of concept options for the disposal of HLW. 2, 3, 9 F, G

NDA (2013) Geological disposal. RWMD approach to issues management. NDA Report NDA/RWMD/081 Version 3.

Management of outstanding issues and questions, linked to the research programme.

1, 2, 3, 9 A, B, C, D

White, M. et al. (2013) Geological disposal concept options for spent fuel. Galson Sciences Report 1150c-1.

Review of concept options for the disposal of spent fuels. 2, 3, 9 F, G

Winpenny, B. et al. (2013) Separation of co-located geological disposal facility emplacement modules: thermal, hydrogeological, mechanical, chemical and gas interactions. Galson Sciences Report 1151b1-1.

Possible methodology to determine the minimum separation distance between disposal modules in a GDF for different wastes.

3, 4, 5, 6 A, B, D

NDA (2012) Geological disposal. Concept selection process. NDA Technical Note 16764837.

Explanation of a possible process for the identification and down-selection of disposal concept options.

3 A, B, C, D

NDA (2012) Geological disposal. Technical plan. NDA Technical Note 16205026.

Report that identifies the major projects that RWMD will need to deliver as part of GDF implementation.

1 A, B

NDA (2012) Geological disposal. Upstream optioneering. Phase 2 overview. NDA Technical Note 16734027.

Summary of work to date considering opportunities to optimise the management of HAWs.

2, 3 D, F, G

Hicks, T.W. et al. (2011) The feasibility of using multipurpose containers for the geological disposal of spent fuel and high level radioactive waste. Galson Sciences Report 1107-1.

Review of the potential for using multi-purpose transport and disposal containers in the GDF.

2, 3 D, F


http://www.nda.gov.uk/documents/biblio/



NDA (2011) Geological disposal. Site characterisation for a geological disposal facility. Status Report March 2010. NDA Report NDA/RWMD/057.

Overview of preliminary plans for how site characterisation will be performed on sites volunteered in the MRWS process.

4 A, B

NDA (2011) Geological disposal. Proposed strategy for the geoscientific aspects of site characterisation. NDA Report NDA/RWMD/017.

Report summarising the developing strategy that is intended to be applied to gathering of geoscientific information during site characterisation.

4 A, B

NDA (2011) Geological disposal. Review of options for accelerating implementation of the geological disposal programme. NDA Report NDA/RWMD/083.

Presentation of alternative approaches for the accelerated implementation of the GDF.

1, 3, 5, 6 A, B, C

NDA (2011) Geological disposal. R&D programme overview. Research and development needs in the preparatory studies phase. NDA Report NDA/RWMD/073.

Overview of RWMD’s research plan to underpin the GDF implementation programme.

1, 2, 3, 9 A, B, C, D

Towler, G. et al. (2011) Optimisation of deep geological disposal of graphite wastes. Quintessa Report QRS-1378ZO-R1.

Overview of options to optimise the design of a GDF for graphite disposal, from a post-closure safety case perspective.

2, 3, 9 D, F, G

NDA (2010) Geological disposal. Permissions schedule for geological disposal of higher activity radioactive waste. NDA Technical Note 13395068.

Overview of the anticipated permissions and authorisations needed during the GDF implementation programme.

1, 9 A, B, C, D

NDA (2010) Geological disposal. Proposed approach to optioneering. NDA Technical Note 12860687.

Report setting out key drivers and issues that impact optioneering and describes the approach that RWMD intends to use during development of the GDF.

3, 5, 9 A, C, D, F

NDA (2010) Geological disposal. An overview of the generic disposal system safety case. NDA Report NDA/RWMD/010.

Summary and general non-technical overview of the generic disposal system safety case.

1, 2, 3, 4, 5, 6, 7, 9 B, C, D, F, G

NDA (2010) Geological disposal. Generic environmental safety case main report. NDA Report NDA/RWMD/021.

One the series of reports from the gDSSC. Considers the environmental safety of a GDF during the operational period and after closure of the facility

5, 6, 7, 9 C, D, F, G

NDA (2010) Geological disposal. Generic post-closure safety assessment. NDA Report NDA/RWMD/030.

One the series of reports from the gDSSC. Explains RWMD’s approach to assessing post-closure safety over very long timescales (e.g. a million years).

2, 3, 7, 9 F, G

NDA (2010) Geological disposal. Generic operational environmental safety assessment. NDA Report NDA/RWMD/029.

One the series of reports from the gDSSC. Outlines how an operational environmental safety assessment could be undertaken for the GDF.

5, 6, 7 D, F




NDA (2010) Geological disposal. Generic transport safety case main report. NDA Report NDA/RWMD/019.

One the series of reports from the gDSSC. Gives an overview of how safety would be demonstrated for individual packages, and a summary of safety of the transport system.

2, 3, 9 F

NDA (2010) Geological disposal. Operational safety case main report. NDA Report NDA/RWMD/020.

One the series of reports from the gDSSC. Presents an illustrative safety case for normal operation and under fault conditions based on three illustrative disposal concepts.

5, 6, 7 D, F

NDA (2010) Geological disposal. Geological disposal. Generic operational safety assessment volume 1. Construction and non-radiological safety assessment. NDA Report NDA/RWMD/025.

One the series of reports from the gDSSC. Presents an illustrative assessment of conventional safety of the construction and operation of the GDF.

5, 6, 7, 9 C, D, F, G

NDA (2010) Geological disposal. Geological disposal. Generic operational safety assessment volume 2. Normal operations operator dose assessment. NDA Report NDA/RWMD/026.

One the series of reports from the gDSSC. Presents an illustrative assessment of worker dose during routine disposal operations and the direct shine doses to the public from normal operations.

5, 6, 7, 9 C, D, F, G

NDA (2010) Geological disposal. Package evolution status report. NDA Report NDA/RWMD/031.

One the series of reports from the gDSSC. Describes the evolution of wastes, waste forms and waste containers.

2, 3 F

NDA (2010) Geological disposal. Generic disposal system functional specification. NDA Report NDA/RWMD/031.

One the series of reports from the gDSSC. Describes the iterative process by which the disposal system specification is developed.

2, 3, 5 D, F

NDA (2010) Geological disposal. Generic disposal system technical specification. NDA Report NDA/RWMD/044.

One the series of reports from the gDSSC. Gives the technical requirements that must be satisfied, including the number, masses and sizes of waste packages to be assumed for the disposal system design.

2, 3, 5 D, F

NDA (2010) Geological disposal. Generic disposal system designs. NDA Report NDA/RWMD/048.

One the series of reports from the gDSSC. Describes illustrative geological disposal facility designs developed for the three example host rocks.

2, 3, 5 C, D, F

NDA (2010) Geological disposal. Radioactive wastes and assessment of the disposability of waste packages. NDA Report NDA/RWMD/039.

One the series of reports from the gDSSC. Explains how the transport, operational and environmental safety cases are used to assess plans to package waste for disposal.

2, 3 F

NDA (2010) Retrievability of Waste Emplaced in a Geological Disposal Facility. Document RWMDPP03.

NDA position paper on the potential for retrieving waste packages from the GDF.

2, 8 F, G




NDA (2010) Geological disposal. Steps towards implementation. NDA Report NDA/RWMD/013.

Sets out preliminary plans for the implementation of the GDF, subject to siting decisions.

1, 3, 4, 5 A, B

NDA (2010) Geological disposal. Feasibility studies exploring options for storage, transport and disposal of spent fuel from potential new nuclear power stations. NDA Report NDA/RWMD/060.

Consideration of potential new spent fuel arisings from new build and the impact on the GDF

2, 3 F, G

Jacobs (2009) An approach to characterising a site for a co-located geological disposal facility. Unnumbered report.

Summary of the geoscientific information needs and characterisation methods that might be needed when siting a co-located GDF.

3, 4 A, B, C

Baldwin, T. et al. (2008) Geological disposal options for high-level waste and spent fuel. Unnumbered Galson Sciences Report.

Review of concept options considered internationally for the disposal of HAW.

2, 3 F, G

Nirex (2005) The viability of a phased geological repository concept for the long-term management of the UK’s radioactive waste. Nirex Report N/122.

Key Nirex report that explain the understanding (at the time) for why geological disposal was considered to be the most viable management option.

3, 4, 5, 6, 7, 9 A, D, F, G

Nirex (2004) A review of the deep borehole disposal concept for radioactive waste. Nirex Report N/108.

State of the art review (at the time) for concepts for deep borehole disposal of certain wastes.

2, 3, 6 A, B, C

Nirex (2003) Generic repository studies. The Nirex phased disposal concept. Nirex Report N/074.

Overview of Nirex’s preferred (at the time) disposal concept and strategy for disposal, based on phased periods of disposal and underground storage prior to closure.

3, 5, 6, 7 D, E, F, G




8 Knowledge coverage for geological disposal The significant projects and documents listed in the tables in Section 7 provide a snap-shot of the current scope of international R&D that can be aligned to the main stages in GDF implementation and the generic activity areas.

When comparing the UK situation with other national disposal programmes, however, it is important to understand that the GDF programme is unique. The Government’s siting policy is deliberately intended to be flexible but this means that no disposal options can yet be discounted. One consequence of this flexibility is that it requires generic R&D to address all reasonable alternatives and combinations of inventory, disposal concepts, host rocks and geological environments. No other national programme needs to gather knowledge from across such a wide range of areas. Depending on progress made in site selection, fewer options will need to remain open over time as the number of potential host sites and geological environments is progressively reduced.

It is evident from Section 7 that, at a generic or high level, there is relevant knowledge applicable to all stages and activity areas of the GDF programme. Certain topics are very well researched and understood internationally, such as:

shaft sinking and tunnel excavation using blasting and tunnel boring machines;

HLW and spent fuel long-term stability, and radionuclide release processes in chemically reducing, low groundwater flow geological systems;

packaging concepts for solid, chemically and physically inert wastes;

long-term behaviour and containment properties afforded by compressed bentonite as a buffer material; and

radionuclide release and transport modelling, and associated dose/risk consequence analysis for environmental safety cases.

Much of this knowledge comes from analogous industries (mining and tunnelling) and, in particular, from overseas HLW and spent fuel disposal programmes that have already chosen sites and disposal concept designs, and are nearing full implementation (e.g. Finland, Sweden, France). This international knowledge can be translated to disposal of HLW and spent fuel in the UK, provided allowances are then made for any key differences in fuel materials and burn-up, and geological disposal conditions.

Nonetheless, at a more detailed level, it becomes clear that there are significant aspects of the UK’s GDF that have much less international R&D coverage. These include:

large volumes of potentially gas generating ILW (especially where this requires gas vents in waste packages and gas permeable engineered barriers);

the potential for chemical interactions between cementitious and bentonite based disposal systems);


disposal of large quantities of Pu and U materials that do not feature in most other national programmes (especially the additional Safeguards concerns that these materials introduce); and

the need to optimise the design of a facility to address all three of these aspects in the same disposal environment.

These inventory related aspects have arisen because of the UK’s fuel reprocessing and nuclear defence strategies. As such, these aspects do not arise in disposal programmes in countries that adopt a ‘once through’ fuel strategy. Of the advanced overseas disposal programmes, only France intends to dispose of large quantities of both HLW and ILW [c. 70,000 - 80,000 m3 of ILW and 2,500 - 6,300 m3 of HLW] in the same facility (Andra, 2005). Note that this volume of ILW is substantially less than is anticipated in the UK [364,000 m3, Table 2.1]. Furthermore, France has already chosen a site and host rock (clay) and so does not need to investigating co-disposal in the same context as the UK which has no site.

In the following sections, the knowledge relevant to each of the generic activity areas is discussed in more detail, and any significant gaps in knowledge are identified. At this stage in the GDF programme, the primary objective is to ensure there is sufficient knowledge and understanding to move forward to the next steps of implementation and there are no obvious ‘show stoppers’. As such, not all of the knowledge gaps identified below need to be addressed now, but a plan should be developed to ensure that key information is available at the time it is needed, and at the appropriate level of detail. In some cases, this may mean work needs to start soon to obtain information that will be needed at a later stage of implementation, where long-term R&D may be required.

8.1 Organisational structure and planning

There is international guidance on how radioactive waste management organisations (WMOs) may be structured, and on their roles and responsibilities for planning and implementing disposal. Most of this guidance is published by the IAEA and NEA, with some from the EC, most recently:

IAEA (2011) The management system for the development of disposal facilities for radioactive waste. Nuclear energy series NW-T-1.2. STI/PUB/1496.

IAEA (2009) Policies and strategies for radioactive waste management. Nuclear Energy Series NW-G-1.1. STI/PUB/1396.

IAEA (2008) The management system for the disposal of radioactive waste. Safety standards series GS-G 3.4. STI/PUB/1330.

NEA (2012) Geological disposal of radioactive waste: national commitment, local and regional involvement. NEA Report 7082.

NEA (2010) Towards transparent, proportionate and deliverable regulation for geological disposal. NEA Report 6825.

NEA (2007) Cultural and structural changes in radioactive waste management organisations. NEA Report 6180.


Mutadis (2006) Cooperative research on the governance of radioactive waste management. COWAM2. Report EUR 23186.

Dutton, M. et al. (2004) The comparison of alternative waste management strategies for long-lived radioactive wastes. Report EUR 21021.

Much of this international guidance is generic and aimed at countries starting to develop a disposal programme. In addition to this generic guidance, more specific guidance is focussed on themes such as strategy development, financing, regulation, stakeholder engagement, record keeping etc. In its generic form, however, the available guidance does not provide much detail for how a WMO should operate and does not specifically address some of the key questions identified in Section 6, such as:

Aa. What are the safety critical posts in the implementing organisation and what competence does the implementer need to manage site selection? [and the other subsequent stages]

Cb. What capability and experience does the implementer need to act as the design authority / intelligent customer to proceed with shaft / tunnel construction? [and the other subsequent stages]

Fc. What is the holistic plan needed to ensure mining, nuclear and conventional safety during construction? [and the other subsequent stages]

These do not represent knowledge gaps, as such, but there is an open question of how to determine that the implementer can evolve its SQEP capability through all of the main stages of GDF development to meet certain licence conditions e.g. LC12 “Duly authorised and other suitably qualified and experienced persons”, LC17 “Management systems” and LC36 “Organisational capability”.

The knowledge base reported in Section 7 covers much of the significant work undertaken in the last decade. Older reports are often still valid but they tend to lose their relevance over time, as new information is gathered and technological developments move forward. This introduces a problem for planning because, over the decades long implementation programme, a process will need to be agreed for making decisions stick to allow progress to be made.

Ab. How will decisions (on site, inventory, design etc.) be closed out and banked, to enable the programme to move forward through each stage of implementation in the light of new information as it is gathered?

There is no clear international guidance on this question but the answer needs to be set into the UK legislative and regulatory context, and so represents a potential knowledge (process) gap for the UK.

8.2 Inventory and waste packaging

There is generic international guidance on inventory and waste classification, and pre-disposal management (e.g. interim conditioning and storage requirements) such as:

IAEA (2009) Classification of radioactive waste. General safety guide GSG-1. STI/PUB/1419.


IAEA (2004) Application of the concepts of exclusion, exemption and clearance. Safety Guide RS-G-1.7.

Most of this guidance is not, however, directly relevant to the GDF because of the specific way that UK radioactive wastes and nuclear materials are classified. Note that many other countries segregate and manage wastes by half-life, rather than by total activity, and this allows enables certain disposal options such as near-surface disposal of short-lived ILW. In addition, the UK has a much broader range of waste and material types than most other countries that arise from fuel fabrication and reprocessing operations.

There is considerable uncertainty regarding the inventory to be disposed of in the GDF (e.g. U stocks). This uncertainty may only be removed by Government policy decisions, and so does not itself represent a knowledge gap to be resolved by R&D. Nonetheless, there are related knowledge gaps that arise from this uncertainty because the GDF implementation programme needs to progress on the basis of a maximum inventory, meaning that the scope of the necessary R&D is substantially increased. The sooner the inventory uncertainty is resolved, the sooner the implementation work can begin to narrow down on preferred design options.

Given the broad range of UK wastes and uncertainty in the GDF programme, there is a potential knowledge gap related to the key questions:

Ad. How should wastes continue to be processed and packaged without foreclosing options, given uncertainty regarding the site, geology and design of the facility?

Af. What is the minimum level of protection (e.g. containment and isolation) required for each of the main waste types, and what are the essential design requirements of the GDF necessary to provide that level of protection to ensure the safe disposal of each waste type?

Ah. Is deep geological disposal the only appropriate option for all HAW?

Bc. What inventory is suitable for disposal at the site being investigated? [After the site has been chosen through the volunteer MRWS process]

Dd. What uncertainties remain about waste conditioning and packaging for the GDF design? [after the site has been chosen but before the design is finalised]

In the absence of a GDF design, the final disposal packages (and overpacks) for each waste stream have not yet been established. There is relevant international work on waste conditioning, packaging and storage, particularly for HLW and spent fuel, such as:

NEA (2006) The roles of storage in the management of long-lived radioactive waste. NEA Report 6043.

IAEA (2003) Predisposal management of high level radioactive waste. Safety guide WS-G-2.6. STI/PUB/1151.

Raiko, H. et al. (2012) Canister production line 2012. Posiva Report 2012-16.

SKB (2010) Design, production and initial state of the canister. Updated 2011-12. SKB TR-10-14.


Patel, R. et al. (2012) Canister design concepts for disposal of spent fuel and high level waste. Nagra NTB 12-06.

Nonetheless, there is limited international work that is specific to some UK wastes, and in particular the more chemically reactive ILW. Given that an operating GDF is probably at least 20 years in the future, there is a possible knowledge gap related to the need for reworking and repackaging. The need for reworking might be reduced if robust multi-purpose casks were available, for both storage and disposal, which would be suitable for a wide range of the UK’s wastes and nuclear materials. Such casks have been designed for spent fuels, but limited work has been done in relation to their application for the GDF and for other UK wastes except for some ion exchange resins e.g.:

RWMD (2011) Packaging of ion exchange materials at Bradwell using Type II ductile cast iron containers (Interim stage). Summary of assessment report. 18th October 2011.

Hicks, T.W. et al. (2011) The feasibility of using multipurpose containers for the geological disposal of spent fuel and high level radioactive waste. Galson Sciences Report 1107-1.

RWMD (2010) Magnox care and maintenance preparation wastes in ductile cast iron containers (Conceptual stage) Summary of assessment report. 19 May 2010

RWMD (2010) Geological disposal. Feasibility studies exploring options for storage, transport and disposal of spent fuel from potential new nuclear power stations. NDA Report NDA/RWMD/060.

The uncertainty on waste packaging is linked to the overall uncertainty concerning the site, geology and design for the GDF. This uncertainty will continue until a site is selected. It is recognised that the LoC process is intended as a pragmatic means to mitigate this risk, and allow wastes to continue to be packaged until such time as a site and concept for the GDF have been agreed. The LoC process applies, however, only to ILW and not to the other wastes that might be disposed of to the GDF (such as HLW and spent fuels).

8.3 Concept development and design optimisation

There is considerable knowledge about specific design concepts that have been addressed internationally and are under development in other countries or evaluated in international collaborative projects, e.g.:

Saanio, T. et al. (2013) Design of the disposal facility 2012. Posiva Report 2013-17.

ONDRAF/NIRAS (2011) Waste plan for the long-term management of conditioned high-level and/or long-lived radioactive waste and overview of related issues. NIROND 2011-02 E.

SKB (2010) RD&D Programme 2010. Programme for research, development and demonstration of methods for the management and disposal of nuclear waste. SKB TR-10-63.



Andra (2006) Dossier 2005 Argile. Andra research on the geological disposal of high-level long-lived radioactive waste. Results and perspectives. Andra 265VA.

There is, however, significantly less knowledge about some of the less well developed concepts that might show promise and potentially could be applied in the UK, such as deep borehole disposal and cavern retrievable storage (CARE) concepts, e.g.:

Kawamura, H. & McKinley, I. (2013) Tailoring of the CARE concept for practicality, safety and robustness. ICEM conference paper, ICEM2013-96067.

McKinley I.G. et al. (2007). Development of geological disposal concepts. In Alexander W.R. & McKinley L.E. (Eds) Deep geological disposal of radioactive waste, Elsevier, pp. 41-76.

Chapman, N. & Gibb, F. (2003) A truly final waste management solution. Is very deep borehole disposal a realistic option for high-level waste or fissile materials? Radwaste Solutions, 10, 26-37.

A potential knowledge gap relates to these less well developed disposal concepts given that the UK has not yet selected a design, and all reasonable alternative disposal concepts should be considered. Similarly, there is less knowledge in the UK programme about clay and salt host rocks, compared to hard rocks which were the focus of the Nirex programme. Additional knowledge on these alternative disposal concepts and potential host rocks may be needed to ensure that when a decision is made regarding a preferred concept, there is no bias in favour of the better understood concepts and rock types, and to answer key questions such as:

Am. What disposal concepts and engineering designs are suitable for UK wastes and geological environments (both established and promising but less well developed alternatives)?

Au. What extra knowledge is necessary to bring understanding of clay and salt rocks up to the level of understanding of hard rock, to enable comparison in the UK context?

At. Would the need for retrievability rule out certain disposal concepts?

The questions about design alternatives cannot, for the most part, be answered at the current time. Concept development is very closely dependent on the inventory to be disposed and the host rock type. In the UK, neither of these parameters are yet fixed and, consequently, R&D has to progress on a generic basis. This uncertainty may only be removed by a positive out turn from the volunteer siting process and Government policy decisions, and so does not represent a knowledge gap to be resolved by R&D.

In addition to technical information on rock types and disposal concepts, there is a key knowledge gap related to the process for how decisions on sites and concepts will actually be made, related to the key questions:


Ab. How will decisions (on site, inventory, design etc.) be closed out and banked, to enable the programme to move forward through each stage of implementation in the light of new information as it is gathered?

Ap. What is the decision making process for comparing disposal concepts that will be applied to down select the preferred GDF concept design, once a site has been selected, and for justifying the exclusion of others?

Aq. What are the key drivers / variables that affect decisions on the GDF design and implementation programme, and what weighting is placed on them during decision making?

Ar. In the decision making process, what weighting is placed on balancing risks to workers and the public, and current and future generations?

As. How will local communities be involved in the process for comparing and down-selecting options during the volunteer process? And what other aspects of the GDF can they influence (e.g. site selection, facility design, allowable inventory, retrievability etc)?

As mentioned previously, the UK policy preference for co-disposal of all wastes in the same facility raises key questions that are not readily addressed with information gathered internationally:

Ai. What are the potential safety and environmental implications of different inventory boundary conditions, and is it realistic and feasible to plan for a single GDF for all HAW?

Al. What are the potential safety and environmental implications of operating a single co-located facility compared to two entirely separate facilities?

Bd. What information is needed to determine whether a site is suitable to host a co-located GDF?

There is a potential knowledge gap with regard to these fundamental questions about concept that might be addressed now with some scoping R&D. In particular, it would be useful to evaluate the feasibility of co-location of the entire UK inventory and what would be the minimum site requirements to enable co-location (e.g. geometry and volume of competent rock, minimum spacing of disposal areas, necessary hydrogeological conditions etc). The latter knowledge would be useful during the site selection process to rule in or out possible sites.

Design optimisation follows from a decision on the preferred disposal concept. There has been increasing international focus on this topic and some guidance has been published e.g.:

NEA (2010) Optimisation of Geological Disposal of Radioactive Waste. NEA Report 6836.




This guidance tends to be general in nature, and does not provide detail about the decision making process that could be applied to down select alternative design concepts to identify a preferred concept, and answer key questions such as:

Ag. What are the additional design features that may be desirable or add value, and what is the process for deciding which of these features should be included in the design?

Ce. What are the factors affecting the choice of the primary access route to the underground parts of the GDF (e.g. inclined tunnel or shaft)?

Dv. What is the optimisation process, and how will engineering optimisation be integrated with radiological optimisation (ALARA)?

Aspects of the optimisation process remain important open questions for the UK, and R&D work is likely to be needed to develop an optimisation process that would be acceptable to all relevant stakeholders. Importantly, it is necessary to know how proportionality will be addressed during optimisation to balance radiological protection (the ALARA principle, with economic and social factors taken into account) given that there may be significant differences in the costs and impacts to local communities associated with alternative GDF design concepts.

8.4 Characterisation and monitoring of the site

Characterisation of the natural, undisturbed surface and subsurface conditions at a potential host site is a fundamental requirement. Following from characterisation, the ability to monitor changes in the site conditions that occur in response to construction and operational activities is important for assessing operational and post-closure safety.

There is a growing body of international guidance on site characterisation and monitoring, and also practical experience of monitoring around each of the repository sites being investigated (e.g. in Sweden and France) and also at various URLs e.g.:

EC MoDeRN Project (on monitoring developments for safe repository operation and staged closure)

EC SOMOS Project (to develop sensors for safety and operational monitoring of a GDF with fibre optic sensing systems)

Andra (2008) The initial environmental state of the Meuse/Haute-Marne underground research laboratory. Andra 178VA.

IAEA (2001) Monitoring of geological repositories for high level radioactive waste. TECDOC-1208.

NEA (2004) The role of monitoring in a safety case. NEA Report NEA/RWM/IGSC(2005)3.

Posiva (2012) Monitoring at Olkiluoto – a programme for the period before repository operation. Posiva Report 2012-1.

Posiva (2003) ONKALO underground characterisation and research programme (UCRP). Posiva Report 2003-5.


Salas, J. et al. (2010) SR-Site - hydrogeochemical evolution of the Forsmark site. SKB TR-10-58.

Borgermans, S. et al. (2007) Safety and operational monitoring of nuclear waste repositories with fibre-optic sensing systems. EC Report EUR 22384.

Pettit, W. et al. (2005) Development of the tools and interpretation techniques for ultrasonic surveys to monitor the rock barrier around radioactive waste packages in geological repositories. EC Report EUR 21923.

Nirex et al. (2004) Thematic network on the role of monitoring in a phased approach to geological disposal of radioactive waste. EC Report EUR 21025.

This knowledge is all directly applicable to the UK situation. The requirements for characterisation and monitoring will depend, in part, on the nature of the host rock and the design of the excavations. As such, a characterisation and monitoring plan for the GDF cannot be specified in detail at the current time. Nonetheless, a broad site characterisation and monitoring plan should be developed, to ensure that all of the information needs are identified at an early stage. These information needs will relate to key questions such as:

Bf. Is it possible to assess the potential suitability of the rock mass at depth for construction and operation of the GDF before going underground?

Bg. What site characterisation and baseline monitoring information must be collected before any boreholes are sunk?

Bh. What site characterisation and baseline monitoring information must be collected before shaft / tunnel construction can commence?

Bi. What site characterisation data is needed as input to nuclear and environmental safety cases at each stage in the GDF programme?

Cg. What site monitoring needs to be performed during excavation of the access, and how will it be achieved?

Ch. What underground investigations will need to be performed during shaft / tunnel construction and completed before excavation of the disposal tunnels can commence?

Dm. What measurements would be made and what criteria would be applied to determine whether actual geological conditions were within the ‘design basis’ assumed in the safety cases?

Dn. What actions would be taken if actual geological conditions and features were beyond the design basis?

A potential knowledge gap relates to the characterisation and monitoring plans that will be necessary to provide the information to inform the preliminary nuclear and environmental safety cases that will be required before construction of the access (shaft or inclined tunnel) can commence.

It is noted that the MRWS process (Figure 5.1) does not include an explicit stage for performing underground investigation before underground operations begin. This is a different approach to that adopted in some other programmes such as Finland where


Posiva has been operating the ONKALO rock characterisation facility at the site of the planned spent fuel repository since 2004. Given this, a number of important questions should be considered:

Dk. Given international experience, is it reasonable to plan for GDF implementation without a specific stage for performing underground investigations?

Dl. How will long-term underground investigations be planned and implemented without being compromised by the impacts of excavation work?

In the later operational stages of the GDF programme, monitoring of emplaced wastes will be required to answer questions such as:

Fe. What package condition and radiation monitoring will be needed, and how will it be achieved?

Ff. What measurements and records will be required after each package (or group of packages) is emplaced while they remain accessible?

Gc. What are the likely objectives of any post-closure monitoring, and how will it be achieved?

Gd. How could post-closure monitoring distinguish between system failure and inadequate prediction of system evolution?

The tools and equipment needed for such operational and post-closure monitoring may require development and, although it is some time in the future, preliminary planning may be warranted, considering some of the unique aspects of the UK inventory (e.g. monitoring methods for gas generation and release in the near-field).

8.5 Construction, installation and testing

The practicalities of constructing a geological repository have become a major focus of international collaborative projects, and there is a growing body of international guidance and practical experience of excavation from each of the repository sites being investigated (e.g. in Finland and France) and also at various URLs e.g.:


NEA (2013) Underground research laboratories (URLs). NEA Report 78122.

Vieno, T et al. (2003) Assessment of disturbances caused by construction and operation of ONKALO. Posiva Report 2003-6.

SKB (2012) Äspö Hard Rock Laboratory. Annual report 2011. SKB TR-12-03.

SKB (2010) Design, construction and initial state of the underground openings. Updated 2013-01. SKB TR-10-18.

Posiva (2008) ONKALO main drawings in 2007. Posiva Working Report 2008-01.


Andra (2005) Dossier 2005 Argile. Safety evaluation of a geological repository. Tome. Andra 270VA.

Broadly, excavation of a repository will adopt standard mining methods and practices, but these will need to be tailored to the specific safety requirements (both conventional and radiological) of the GDF design and for working in a nuclear licensed facility. Additional R&D will be required to answer some of the key questions:

Ci. What are the factors affecting the choice of construction method (e.g. blasting or TBM)?

Cj. What information is needed to make the decision on the choice of construction method (blasting or TBM) and what is the decision making process?

Ck. How can geological studies be performed safely before the access shaft / tunnel is lined?

Dp. What are the safety implications of long blind tunnels with single access?

Dq. What is the necessary design, spacing and operation of ‘safe havens’ for workers?

Ds. What is the mitigation in case of facility shut-down due to accidents, and what will be the impact on the integrity of the excavations in the case of a long shut-down?

Construction safety has been addressed in some international projects but generally this has featured less in published documents than post-closure safety, presumably because it is assumed to be routine, based on standard mining and tunnelling experience.

Installation of equipment (particularly the waste handling equipment) and its testing is an area where additional knowledge will be required, to answer questions such as:

Eb. Is it necessary to develop a separate underground test facility ahead of the GDF for active trials?

Ec. Are industrial mock-ups adequate for replicating underground conditions for commissioning?

Ed. Will active commissioning also test waste retrieval and reversibility systems?

Ee. What is the procedure in the event that active commissioning reveals a flaw that requires design modifications?

Ef. What is the procedure in the event that active commissioning reveals a substantial design failure?

As with construction, there is limited knowledge from the published studies on the subject of active commissioning of a disposal facility, and this is a topic that will require work to address the specific requirements of the site licence and nuclear safety cases.


Given that the GDF will have a long operational life and not all parts will become operational at the same time, and also that any co-located facilities may need to share common facilities (e.g. the main access and waste handling infrastructure), it is important to clarify what part of the facility and what systems are commissioned, and at what stage. Multiple commissioning activities and disposal permits may be required for each of the different waste disposal vaults and tunnels. This raises the question:

Ek. Does the whole facility get commissioned and permitted, or will commissioning and permitting be phased as each waste disposal vault / tunnel is completed?

The active commissioning process and how this is linked to formal permitting processes for operation has not been considered in detail, and this remains an important open question that should be considered.

8.6 Operations and waste emplacement

As with construction, the practicalities of operating a geological repository and emplacing wastes underground have become a major focus of international collaborative projects, and there is now a large experience base from demonstration studies and associated international guidance e.g.:

EC IGD-TP project on implementing geological disposal

EC MODERN project examining monitoring developments for safe repository operation and staged closure.

EC ESDRED project to establish a sound technical basis for demonstrating the safety of geological disposal

EC FEBEX project to experiment and demonstrate full-scale engineered barrier systems

EC PROTOTYPE REPOSITORY project to undertake full scale testing of the KBS-3 concept for HLW

EC (2010) The Joint EC/NEA Engineered Barrier System Project: Synthesis Report (EBSSYN). EC Report EUR 24232 EN.




IAEA (2011) Geological disposal facilities for radioactive waste. Specific safety guide SSG-14. STI/PUB/1483.

Some relevant knowledge comes from the operation of interim waste stores but there is limited practical experience of actual waste emplacement operations underground other than from the operating facilities such as WIPP in the US and the SFR in


Sweden. These facilities can provide important knowledge but there are a number of important UK specific questions that will need to be considered, particularly with regard to the handling of very large numbers of diverse waste packages in a co-located facility that will operate for many decades:

Fg. How can active and non-active areas of the facility be separated from each other?

Fh. What information is need to ensure that it is safe to undertake parallel disposal and tunnelling operations?

Fi. What wastes and disposal areas will need to be backfilled at the time of waste emplacement?

Fj. What will be the procedure and techniques for managing any waste package that might have degraded or leaked?

Many of the questions related to construction (Section 8.5) also apply here because it is likely that the construction and operational activities will overlap in time, due to the phases construction programme. It is clear that safe operation of the GDF will require development of a waste emplacement strategy and the careful choreography of all movements of people, waste and excavated rock waste.

Fc. What is the holistic plan needed to ensure mining, nuclear and conventional safety?

There is some relevant international knowledge in the operational plans and safety cases developed for those disposal facilities in operation or closer to implementation that the UK.

Posiva (2012) Safety case for the disposal of spent nuclear fuel at Olkiluoto - Description of the disposal system 2012. Report 2012-5.

SKB (2010) Design and production of the KBS-3 repository. SKB TR-10-12.

Andra (2005) Dossier 2005 Argile. Architecture and management of a geological repository. Tome. Andra 268VA.

It remains the case, however, that the majority of published ‘safety’ reports relate to the long-term assessment of post-closure safety and less is published on operational safety aspects. This is probably because operational safety has generally not been considered an area needing research, but rather the development and translation of operational experience from other nuclear facilities. Nonetheless, it is evident that handling large and heavy waste packages in the confined spaces in a GDF present risks that are generally not faced in other places, and so there remains an open question as to whether or not additional work is necessary to plan for routine operations and to handle accident scenarios.

8.7 Backfilling and closure

Backfilling and closure are fundamental to the long-term safety performance of the GDF because these are the activities that ensure isolation of the waste from the accessible environment.


As with construction and operations, several international collaborative projects have undertaken full-scale trials and demonstration projects on backfilling and closure in underground laboratories in different rock types. Many of these demonstration projects examine both waste emplacement and operations, and so several of the references listed in Section 8.6 are also relevant here in addition to:

EC BAMBUS project to evaluate backfill material behaviour in underground salt repositories.

EC RESEAL I and II projects to perform large scale in-situ demonstration test for repository sealing in an argillaceous host rock.

EC EB project to demonstrate the feasibility for emplacing a clay barrier consisting of a base of highly-compacted bentonite blocks.

EC DOPAS project to provide full scale demonstration of repository plugs and seals in different rock types.

EC PEBS project to evaluate the sealing and barrier performance of the EBS over long periods of time, by experiment and modelling.


NEA (2003) Engineered barrier systems and the safety of deep geological repositories. NEA Report 3615.

Juvankoski, M. et al. (2012) Buffer production line 2012. Posiva Report 2012-17.

Keto, P. et al. (2012) Backfill production line 2012. Posiva Report 2012-18.

Sievänen, U et al. (2012) Design, production and initial state of the underground disposal facility closure. Posiva Report 2012-19.

Karvonen, T. (2012) Closure of the investigation boreholes. Posiva Working Report 2012-63.

Luterkort, D. et al. (2012) Closure of the spent fuel repository in Forsmark. Studies of alternative concepts for sealing of ramp, shafts and investigation boreholes. SKB TR-12-08.

SKB (2010) Design, production and initial state of the backfill and plug in deposition tunnels. SKB TR-10-16.

This knowledge is all applicable to the UK situation, although how the GDF will actually be backfilled and sealed will depend on the nature of the host rock and the facility design. As such, a closure plan for the GDF cannot be specified at the current time. Nonetheless, broad strategies for backfilling and closure need to be developed for each of the reference disposal concepts to inform key questions such as:

Cl. What features need to be included in the shaft / tunnel design at the time of construction to ensure the facility can be backfilled and sealed at closure?

Dy. What features need to be included in the GDF design at the time of construction to ensure the facility can be backfilled and sealed at closure?


Fi. What wastes and disposal areas will need to be backfilled at the time of waste emplacement?

Ge. Will closure be a single activity or will the GDF be closed in stages (e.g. co-located disposal areas)?

Gf. What work is needed to develop designs for seals and plugs and backfills needed for closure?

Gg. If done in stages, how will closure affect fire safety, ventilation, drainage etc. in the remaining open tunnels?

Gh. What are the safety implications of strip out of rock supports and infrastructure?

An important aspect of the GDF is the potential for co-located facilities with radically different physico-chemical backfill designs (cement and clay based). Clay materials may react with cement leachates, and so the potential interactions between these materials both during the operational and post-closure periods are of key safety significance, leading to the important question:

Ak. What are the minimum requirements to ensure physical, chemical and hydrogeological separation of co-located disposal facilities? And what are the risks if separation were to fail?

Of the major national programmes, only France has similar questions regarding co-disposal using both cementitious and clay backfills. Interactions between clay and cement is, however, a concern in all programmes because small amounts of cement will feature as a construction material in all repository designs. These interactions have been considered in several studies:

EC ECOCLAY project to evaluate the effects of cement on clay barriers.

NEA (2012) Cementitious materials in safety cases for geological repositories for radioactive waste: role, evolution and interactions. NEA Report in preparation.

Andra (2005) Dossier 2005 Argile. Phenomenological evolution of a geological repository. Tome. Andra 269VA.

8.8 Waste retrieval

The possible means to enable retrievability (and reversibility) at different stages in the lifetime of a disposal facility has been the subject of international research, and several reports and guidance documents address the subject. In addition, reversibility is a design requirement in the French disposal programme, and it is discussed in several Andra reports.

NEA (2011) Reversibility and retrievability (R&R) for the deep disposal of high-level radioactive waste and spent fuel. Final report of the NEA R&R project (2007-2011). NEA Report NEA/RWM/R(2011)4.

IAEA (2009) Geological disposal of radioactive waste: technological implications for retrievability. Nuclear Energy Series NW-T-1.19. STI/PUB/1378.


Andra (2013) The Cigeo project Meuse/Haute-Marne reversible geological disposal facility for radioactive waste. Andra 504VA.

Aparicio, L. (2010) Making nuclear waste governable. Deep underground disposal and the challenge of reversibility. Andra 381VA.

Andra (2009) Stockage réversible profond. Etape 2009. Options de réversibilité du stockage en formation géologique profonde. Andra 393. In French (Translation: Options to reverse disposal in deep geological formations).

It is not intended that wastes will be retrieved from the GDF but the 2008 White Paper allows local communities to decided whether or not they wish retrievability to form part of the design requirements for the facility. The question as to whether or not the GDF should be designed to facilitate retrieval is an open question but one that cannot be answered solely by R&D because of the social and ethical dimensions to the question. Nonetheless, the fact that retrievability remains an open question does drive several other key questions that need to be addressed by R&D.

At. Would the need for retrievability rule out certain disposal concepts?

Cm. What information is needed to determine whether the access needs to be designed to allow retrievability?

Dt. At what point does the retrievability question get closed out?

Du. What are the potential safety and environmental implications of incorporating different extents of retrievability into the GDF design?

Dz. What information is needed to determine whether the GDF needs to be designed to allow retrievability?

Fk. What would trigger the retrieval of any waste package (during operations) and how would that be achieved?

Gj. Are there wastes with a higher likelihood of being retrieved than others, for whatever reason, and how will this affect the design of the facility and the waste emplacement strategy?

Gk. What are the likely safety and environmental consequences if retrievability were to be carried out for whatever reason?

It is important to note that for as long as retrievability remains an open question, the supporting R&D work for the GDF is increased because it needs to take account of multiple scenarios for retrievability in case it is included as a design requirement.

8.9 Safety cases and permitting

The bulk of ‘safety cases’ related to geological disposal published in the last several decades have addressed aspects of long-term post-closure safety. Several international guidance documents related to environmental safety case methodologies have been published.

EC NF-PRO project to improve physical and numerical modelling of the key processes in a repository near-field.


RC FUNMIG project to improve understanding in the fundamental understanding of radionuclide migration.

IAEA (2012) The safety case and safety assessment for the disposal of radioactive waste. Specific safety guide SSG-23. STI/PUB/1553

NEA (2013) The nature and purpose of the post closure safety cases for geological repositories. NEA Report 78121.

NEA (2012) Methods for safety assessment of geological disposal facilities for radioactive waste. NEA Report 6923.

NEA (2012) Thermodynamic Sorption Modelling in Support of Radioactive Waste Disposal Safety Cases. NEA Report 6914.

NEA (2012) Indicators in the Safety Case. NEA Report NEA/RWM/R(2012)7.

NEA (2009) Approaches and challenges for the use of geological information in the safety case for deep disposal of radioactive waste.

NEA (2009) Considering timescales in the post-closure safety of geological disposal of radioactive waste. NEA Report 6424.

NEA (2009) International experiences in safety cases for geological repositories. NEA Report 6251.

In contrast, less emphasis has been given to aspects of assessing conventional and radiological safety during operations, and to aspects of nuclear safeguards and security. This situation has slowly changed in the last few years as several international collaborative projects have undertaken full-scale trials and demonstration projects to support implementation, and these have raised the profile of operational safety. Similarly, recent construction licence applications (e.g. in Finland and Sweden) have addressed both post-closure and operational safety. Several relevant documents are now available.

IAEA (2013) The safety case and safety assessment for the predisposal management of radioactive waste. General safety guide GSG-3. STI/PUB/1576.


IAEA (2010) Technological implications of international safeguards for geological disposal of spent fuel and radioactive waste. Nuclear Energy Series NW-T-1.21. STI/PUB/1414.

Kukkonen, K. (2012) Radiation protection in Posiva's encapsulation plant and disposal facility. Working Report 2012-89.

Rossi, J. & Suolanen, V. (2012) Operational safety analysis of the Olkiluoto encapsulation plant and disposal facility. Working Report 2012-71.

Peltokorpi, L. et al. (2012) Keskus- ja loppusijoitustunneleiden palotarkasteluja APROSilla. Working Report 2012-73. In Finnish (Translation: Fire analyses in central and disposal tunnels).


These are relevant to the UK but there remain several safety related open questions. It is clear that both nuclear and environmental safety cases will be required to support decisions on whether or not to allow the GDF programme to progress between each stage of implementation (Section 5). At present, however, it is not precisely known what is the number, timing, structure and content of the nuclear safety cases that will be required during the GDF implementation programme. This leads to several questions.

Bi. What site characterisation data is needed as input to nuclear and environmental safety cases? [during site characterisation and at each subsequent stage of implementation]

Bj. What other information is needed (e.g. facility design and operational plans) as input to nuclear and environmental safety cases? [during site characterisation and at each subsequent stage of implementation]

Di. How will the ‘as built’ design be recorded and input to the nuclear and environmental safety cases?

Dv. What is the optimisation process, and how will engineering optimisation be integrated with radiological optimisation (ALARA)?

Dx. What occupational risk target will be applied to conventional hazards during construction and operation of the GDF?

Eh. What level of evidence of safe working is needed in a pre-operation safety case?

Ek. Does the whole facility get commissioned and permitted, or will commissioning be phased as each waste disposal vault / tunnel is completed?

Although these questions apply to many stages of implementation, clarity is needed soon on the scope of nuclear safety cases necessary to progress from Stage B (Surface investigations) to Stage C (Access shaft / tunnel construction), and also to support site licensing.


9 References Andra (2005) Dossier 2005 Argile. Phenomenological evolution of a geological repository. Tome. Andra 269VA.

CoRWM (2013) Ninth annual report. 2012-13. CoRWM Doc 3107.

CoRWM (2012) Assessment of the generic disposal system safety case. CoRWM Position Paper. CoRWM Doc 2994.

CoRWM (2006) Managing our radioactive wastes safely. CoRWM’s recommendations to Government. CoRWM document 700.

DECC & NDA (2011a) The 2010 UK radioactive waste inventory. Main Report. DECC Report URN 10D/985 and NDA Report NDA/ST/STY(11)0004.

DECC & NDA (2011b) Radioactive materials not reported in the 2010 UK radioactive waste inventory. DECC Report URN 10D/988 and NDA Report NDA/ST/STY(11)0007.

Defra, BERR & Devolved Administrations for Wales and Northern Ireland (2008) Managing radioactive waste safely. A framework for implementing geological disposal. The Stationery Office. Cm 7386.

EA & NIEA (2009) Geological disposal facilities on land for solid radioactive wastes. Guidance on requirements for authorisation. GEHO0209BPJM-E-E.

EA (2012) Guidance note for developers and operators of radioactive waste disposal facilities in England and Wales. Geological disposal facilities on land for solid radioactive wastes: guidance on requirements for authorisation. Supplementary guidance related to the implementation of the Groundwater Directive. Number LIT 8033, Version No. 1.

Municipality of Kincardine (2004) Being a by-law to authorize the signing of an agreement with Ontario Power Generation Inc. for the management of low and intermediate level nuclear waste within the Municipality of Kincardine. By-Law 2004-157.


NDA (2011) Technical baseline and underpinning research and development (TBuRD) Requirements. NDA Document EGG 10 (Revision 4).

NDA (2010) Geological disposal. Steps towards implementation. NDA Report NDA/RWMD/013.

NDA (2008) Letter of compliance (LoC) assessment process. NDA Waste & Nuclear Materials Unit Position Paper, W&NM/PP/011.


ONDRAF/NIRAS (2011) Waste plan for the long-term management of conditioned high-level and/or long-lived radioactive waste and overview of related issues. NIROND 2011-02 E.

ONR & EA (2011) Joint regulatory scrutiny of RWMD’s work relating to geological disposal of higher activity radioactive waste. Regulatory review of the generic disposal system safety case. Report GENW1211BVDX-E-E.

ONR & EA (2013) Regulatory scrutiny of RWMD’s work relating to geological disposal of radioactive waste. Summary of work (April 2010 to March 2012). Unnumbered report.

Sumerling, T. & Vermariën, E. (2007) The long-term safety of disposal of Category A waste: ONDRAF/NIRAS safety strategy and safety concept. Project near surface disposal of Category A waste at Dessel. NIROND TR-2007-06E.

Scottish Government (2011) Scotland’s higher activity radioactive waste policy 2011. Unnumbered report.


10 Appendix: Project workshop A project workshop was held at the ONR offices in Bootle on 12th June 2013 to discuss issues associated with geological disposal. The following participants were drawn from regulatory bodies and industry, including experts from Finland and Switzerland to provide an international perspective.

Chris Fisher (ONR) Paul Abratis (EA) Frans Boydon (ONR) Robert Smith (EA) Mick Bacon (ONR) Doug Ilett (EA) Dave Glazbrook (ONR) Louise Paul (EA) Lyn Westwood (ONR) Tim McEwen (McEwen Consulting) Anne Foster (ONR) Timo Saanio (Saanio & Riekkola Oy) John Whyatt (HSE) Peter Hufschmied (ExTechNa GmbH) Simon Goodwin (ONR) Bill Miller (AMEC) Simon Morgan (ONR)

At the workshop, participants were divided into three groups and asked to brainstorm issues with potential safety relevance under the broad headings of:

balancing operational and post-closure safety (Group A), and

R&D to support the key stages in the GDF life-cycle (Groups B and C).

To aid discussions, the participants were provided with a simplified breakdown of the key stages in the GDF programme and their associated main practical activities. The participants were invited to think about these stages and activities, and to consider where there may be potential conflicts between them that would need resolution, and what ‘open questions’ might need to be answered before implementation could commence.

The focus of the discussions was on the identification of questions related to conventional, nuclear and radiological safety during construction, operation and closure of the GDF (rather than post-closure safety), and with an emphasis on ‘broad-brush’ issues that might need to be addressed in the early stages of a GDF programme, prior to submission of a pre-construction safety case.

The discussions were wide-ranging and benefitted from the breadth of expertise in the group, encompassing safety assessment, engineering, geology and mining, regulation and policy etc. The key discussion points and the open questions identified were summarised by each group in bullet-point fashion on flipcharts, and these are reproduced in the tables below (as written on the day and without subsequent rephrasing or rewording). The discussion points were then grouped into a number of high-level themes:

Concept and design options. An important objective during early stages of the implementation programme will be to down-select first broad disposal concepts, and then specific designs for the engineered barriers, the excavations, and associated operating methods. Several open questions relate to whether there is adequate knowledge of all of the reasonable alternative options to allow them to be compared and contrasted on a level playing field, and the down-selection decisions to be justified.


Viability and implementability. Multiple systems, tools and procedures will be required to construct and operate the GDF. Many of the open questions relate to whether existing equipment (e.g. heavy lifts) and operating procedures are viable and could be implemented in the GDF, and whether clear specifications for all components of the GDF infrastructure will be established, and Technology Readiness Levels (TRLs) known, at the time key decisions need to be made.

‘Nuclearisation’. Related to the identification of TRLs, much of the infrastructure used in the GDF may be adapted from other industries, such as mining and tunnelling, but the unique nature of operating them in a licensed nuclear facility may require them to be substantially modified. Some of the open questions related to the level of effort, and time, needed to qualify ‘off the shelf’ equipment for use under nuclear regulations.

Parallel construction work and disposal activities. The likely operating schedule for the GDF will require parallel excavation / construction work and disposal activities. Several of the open questions related to whether all of the potential conventional, nuclear and radiological safety relevant hazards (and programme constraints) due to parallel working are understood, and appropriate plans can be developed for their mitigation.

In addition to the technically-focussed open questions, several over-arching observations arose during the discussions, and which potentially impact widely across the GDF programme. These include:

Balanced decision making processes. A properly optimised GDF design and implementation plan will need to strike a balance between the requirements of multiple sets of regulation and the expectations of multiple stakeholders. There are many different facets to be balanced, and many of these are likely to be conflicted, such as the risks and hazards:

– both conventional and radiological in nature: – to workers and public – to current generations and future generations – arising during operations and in the far-future – arising whilst waste remains on the surface and when emplaced

underground – etc., etc.

Balanced decisions will need to be made at various points in the GDF programme, particularly as alternative concepts and design options are down-selected and others rejected. Each decision will need to be clear, logical and justified, and this will require a transparent decision making process. It is an open question as to whether or not a suitable method (and the necessary tools) exists to support this unique decision making process.

Whole life-cycle safety assessment: When considering safety, it is the cumulative risk arising from all conventional and radiological hazards during the entire waste disposal life-cycle that need to be assessed to determine which strategy option is ALARA - including transport, storage, the emplacement operations etc. It is an open question as to whether or not adequate methods and tools exist to allow the cumulative life-cycle risks for


alternative disposal strategy options (and their implementation plans and schedules) to be calculated and compared.

Retrievability and reversibility: There are many potential safety relevant consequences arising from the policy requirement to maintain retrievability and reversibility as possible concept options, particularly if the GDF remains open for an extended period of time post waste emplacement but before a final decision to close or retrieve is made. Many aspects of the design of the excavations and of the waste handling infrastructure will need to be adapted to facilitate retrievability and reversibility, and these might potentially increase both the conventional and radiological hazards to workers. For example, by substantially increasing the requirement for worker access to ensure reliability and to perform maintenance. It is an open question as to whether or not the full consequences for both worker and public safety have been fully identified and evaluated.

Group A (Balanced decision making process)

It was hard to get a handle on the issue.

Need to decide the balance between what and who. e.g. between: – different generations (current and future), – groups that profit (current generation gets benefit from nuclear power) and groups

that have the burden (future generations to deal with waste) – operational and post-closure safety – site safety and transport – treat waste or foreclose options – social requirement to retrieve waste v. safe design – mine design v. post-closure safety

We need to design for post-closure safety and this needs hard research but then all we can do for design/operations is stick with appropriate codes/standards and ensure they do not compromise post-closure safety.

Can we (regulators) justify the choice of a ‘best’ site in a credible way, and explain why regulators agree with the decision made by other organisations?

What questions do ONR need to ask of RWMD (and others) in order to prepare to answer this big question and satisfy themselves that a site is ‘best’?

Is best necessary or is ‘good enough’ acceptable - is it BPEO or SFAIRP that applies?

Is there / what if there is a manifestly better site than the one chosen by volunteerism? Should regulators or others challenge? Should SEA look at alternatives beyond that considered by RWMD?

Need also to balance safety during operations in different timescales, such as surface storage and underground. This may drive for more rapid emplacement (hazard reduction).


Need to look at the “whole picture” and safety decisions should be made for the lifecycle not individual aspects - so total hazard from transport, packaging, storage and disposal etc. for different management options.

Siting process is not subject to any real options and so not balanced decision.

Are there available and appropriate decision tools to made balanced decisions? MADA is only way but participants point out this is only one input to decision making.

Different methods for decision making are needed at different stages - concepts v. designs when alternatives are narrowed down?

The activities need to be gone through rigorously to identify activities and potential conflicts (safety relevant). This is a good logical process and could be done as an R&D topic.

What kind of organisation is needed to make the ‘best’ decisions? What does RWMD need to look like, and its competencies etc.

In order to make a best balanced decision it may be necessary to reduce the “degrees of freedom” in a sensible way. There are too many variables to make decision making easy, so could simplify by e.g. fixing inventory.

Monitoring is a key issue and needs to be balanced with safety issues.

Retrievability is also a big issue and uncertainty means that this can have consequences for operational planning, design and safety to keep option open until late in programme.

Biggest question is “How do you make a decision stick?” E.g. politically to avoid stop/start programme and make progress. This requires social science research and philosophy.

Some decisions need to be revisited because current technologies become outmoded by the time we come to do things (stick to decision of what to do, keep open question of how to do it).

One priority issue is “How to explain why this is an acceptable site?” Concern that regulators are going to get involved in difficult discussion with stakeholders about issues that are not within their remit.


Group B (R&D in the GDF lifecycle stages)

This group started at the beginning of the GDF implementation programme and worked forward to later stages.

Stage A (Surface investigation):

Need to go underground to get all the necessary data (to prove safety) and don’t pepper the site with too many boreholes during surface investigations.

R&D: only need a limited borehole programme in terms of safety and constructability?

R&D: oil&gas and mining data and how can this be converted to GDF (check what is done)?

R&D shaft stability and need for refurbishment over long period of time (compared to most mines which are short lifetime) + long-term needs for support structures and rockbolts and liners. E.g. need to refurbish the supports and infrastructure may impact on operations and operational safety.

Stage B (Shaft sinking and access tunnel construction):

Optimisation, e.g. no of shafts and drifts. How do you optimise?

R&D: if retrievability is needed, how much R&D is necessary to make this realistic for all stages of the GDF programme?

R&D: Major implications of retrievability throughout, so what are these for operational safety and post-closure safety (and conflicts)?

R&D: Need to scope out the decision making process (and decision points) for retrievability to underpin the necessary R&D.

R&D: blasting, what is the safe distance between excavation work and disposal operations? And how vary by design and rock type?

R&D: Plans for design and impacts on ventilation. Blasting makes a lot of dust, so need separate ventilation system for excavation from disposal operations?

R&D: Spoil? Management, logistics, nuisance, bunding (leachate).

R&D: Nuclear and non-nuclear site logistics, movement of waste packages, people, rock spoil etc. How to separate active and non-active areas?

R&D: How to develop competency of the staff (RWMD and contractor base), and how to build capability for a complex and unique operations over a long period of time?

R&D: Geological sensitivity for long-term operations (and period of post-emplacement, pre-closure remaining open) and for maintaining the excavations and infrastructure. Availability, Reliability and Maintainability (ARM) Studies needed?

Stage C (Phase 1 disposal excavation):

TBM is only useful for longer drifts, and so blasting will be needed for all shorter tunnels.


R&D needed on mining systems. What is needed to achieve the current reference concepts (or to achieve necessary nuclear TRL?) and does RWMD have all the necessary experience to decide and to procure - intelligent customer requirement?

How much residual equipment will be left in place at closure? Realistically from mining perspective. Note that TBMs are usually driven into alcove and left in place.

Workers need safe havens in case of accidents such as fire. These need own oxygen supply / confined space.

R&D: How would you plan to recover people from safe havens after accident. E.g. after a fire and rad accident has contaminated the ventilation system, and the excavation?

R&D: How would you remediate the underground areas and emplaced wastes after accident. E.g. after a fire and rad accident has contaminated the GDF?

R&D: Need holistic planning tool and capability that combines mining, nuclear safety culture etc. This has never been done in the UK before.

People try to over engineer. You cannot engineer out all risk and the process needs to manage risk.

Mining is inherently dangerous and people are killed in many large underground excavations such as Channel Tunnel and places like ONKALO. Need to accept this may happen and plan for mitigation and post-accident impacts - avoid closing entire complex for two year safety investigation - use alternative tunnels?

Delaying the decision on retrievability has massive implications for infrastructure and design. Need to bottom out this uncertainty as early as possible.

Blind ends in tunnels are not necessarily a problem from mine safety. Not always necessary to have two escape routes (if there are safe havens). Blind tunnels may have benefits for controlling ventilation (avoid convection type cells and spread of contamination).

Group C (R&D in the GDF lifecycle stages)

This group started with the later stages of implementation and worked forward in time, to avoid duplication with Group B.

Stage F (Closure and sealing, post-closure activities):

Should you monitor? How do you make that decision (and who?) and, if so, how and so what? Need to plan for intervention levels and mitigation.

Retrievability. A thread throughout all activities. The need for (and complexity of) retrievability is different for each waste. More important for some than others.

If something ‘goes wrong’ do you plan to retrieve or to mitigate the impacts? How decide?

Note that system not behaving as expected in monitoring data is not necessarily the same as something ‘going wrong’, and may or may not have safety implications.


Only plan to do small system monitoring - e.g. Swiss monitoring of pilot area?

Need to assess the real implications and hazards to the local community and environment, and balance against hazard of retrieving waste.

Closure methods and strategy implications. E.g. impact on air flow / ventilation / drainage / fire safety as system is open and closed (progressive closure of each disposal panel and vault).

Stage E (Parallel excavation and disposal):

Support structures. Should these all be recovered before closure or can sacrificial systems be used?

Separation distances (between disposal areas) and backfill requirements in different types of host rock.

Can we specify the requirements to ‘nuclearise’ off the shelf tools and equipment (e.g. mining) to ensure they meet nuclear safety requirements. Do we understand what the system specification requirements are for GDF e.g. vertical shaft lifts to meet UK regulation?

What is the acceptable risk level for operational safety in GDF? Industrial risk is typically 10-5 but we might need to aim for higher due to GDF. What are implications for design, operations for working to tighter than normal e.g. mining safety targets?

Can we use the information from waste package aging in surface stores adequately to predict ageing underground, especially in long-term post-emplacement, pre-closure period? Note temperature and humidity etc. is controlled in store but can’t easily be underground.

Can we use the transfer the monitoring equipment and protocols from stores to GDF?

Can we specify the TRLs for monitoring equipment and identify gaps in capability?

‘Nuclearisation’ of all lifting equipment in shafts etc. Can we use off the shelf equipment?

Planning mitigation for accidents. What happens in the event of serious accident and facility is shut for extended period even from a ‘conventional accident’ - note experience of two year delay at Sellafield death due to fall from ventilation stack.

What is the organisational management structure during construction and who has decision making responsibility? Note design will need to be responsive to underground conditions “on the fly” and this has implications for design safety responsibility and intelligent customer role.

Can we specify TRLs now for all equipment, methods and tools needed for implementation? Is there something like a practicability readiness level ‘PRL’ as an equivalent to TRL given practicability is a key control on the GDF?

Security of supply for all construction materials, and sustainability considerations?

What is the likely future constraints on use of chemotoxic substances in construction materials and what impacts on availability and material performance? E.g. removal of Cr from cements. Horizon scanning R&D?


What is the decision making process / hold points for the GDF layout? What type and level of information needed for construction licence application, and ONR’s needs to determine the application? This needs to be specified soon.

What are the operational and radiological safety relevant factors and safety functions for different concept designs and geologies that will influence decisions? Are these yet specified? In similar manner for safety indicators for post-closure safety?

Stage D (Active commissioning):

Is active commissioning simply small scale handling operations of a few packages or is it intended to trial full reversibility etc?

What happens if active commissioning reveals a problem? Will commissioning waste package need to be retrieved / taken back to surface? Need one or two way waste package flows?

What circumstances in an active trial would a waste package need to be taken back to the surface? E.g. higher than anticipated dose to workers because activity took longer?

Is there a need for an operational test facility in an underground location in the UK or overseas? E.g. existing mine.

Note there are many other non-engineering benefits from parallel trials and testing. Worker experience, human factors, programme robustness etc.

Can we adequately predict equipment behaviour if there is no long-term, 1:1 testing in underground environment? What is impact on overall programme if testing is first done in GDF?

Would ONR be satisfied to approve disposal operations if justification was based purely on non-active mock-up trials? What is ONR’s level of confidence needed on trials?

What are industrial lessons to be transferred? E.g. from Cross Rail and Channel Tunnel?

Need to assess methods and viability of transferring experience for half-scale lab or engineering tests to the GDF, not very hard to replicate things like temperature, humidity etc. in lab trials that can have serious effect on practicability of operations for workers.

Bench mark international (waste handling) experience against our waste types and packages (e.g. URL tests). Where are the gaps in knowledge and full-scale trials?

Need decision making process for all activities and aspects early.

It is not just making the decision. That decision needs to be properly recorded and justified so that all decisions in the GDF programme are traceable in the future, and also justify why options were excluded. How to do?

Need to bring other disposal concepts, handling practices, and geologies up to the same level as KBS-3 etc. to make informed decision?

What is the TRL needed for alternatives to RWMD’s reference designs to make decisions?


Need to investigate technology transfers from other industries / international. What are the TRLs, need to focus on practicability issues. Do not reinvent the wheel.


11

AMEC Registered Address: Booths Park Chelford Road Knutsford Cheshire WA16 8QZ

www.amec.com Page 129