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Geological Disposal

Generic Transport Safety CaseExecutive Summary

December 2010

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The Nuclear Decommissioning Authority (NDA), through its Radioactive Waste Management Directorate (RWMD), is working on a programme to implement a geological disposal facility (GDF) for higher activity radioactive wastes, as set out in the UK Government’s Managing Radioactive Waste Safely (MRWS) White Paper.

The White Paper defi nes a Baseline Inventory of materials that may need to be managed through geological disposal: high level waste (HLW), intermediate level waste (ILW), some low level waste (LLW) unsuitable for near-surface disposal, spent fuel (SF), depleted natural and low-enriched uranium (DNLEU), highly-enriched uranium (HEU) and separated plutonium (Pu).

We have produced an initial generic Disposal System Safety Case (generic DSSC). The generic DSSC explains and assesses the safety and environmental implications of all aspects associated with the geological disposal of higher activity radioactive waste in the UK.

The generic DSSC addresses the following:

• transporting the waste to a GDF – the safety arguments and assessments of this are presented in the Geological Disposal: Generic Transport Safety Case main report

• construction of and emplacement of waste within a GDF, subsequent storage and eventual backfi lling, decommissioning and closure – presented in the Geological Disposal: Generic Operational Safety Case main report

• the environmental safety of a GDF during the operational period and after closure of the facility - presented in the Geological Disposal: Generic Environmental Safety Case main report.

1. Introduction

Materials Notes Packaged volume Radioactivity (At 1 April 2040)

Cubic Metres % Terabequerels %

HLW 1,2,3,5 1,400 0.3 36,000,000 41.3

ILW 1,2,5 364,000 76.3 2,200,000 2.5

LLW (not for LLWR) 1,2,5 17,000 3.6 <100 0

Spent nuclear fuel 1,4,5 11,200 2.3 45,000,000 51.6

Plutonium 1,4,5 3,300 0.7 4,000,000 4.6

Uranium 1,4,5 80,000 16.8 3,000 0

Total 476,900 100 87,200,000 100

Baseline Inventory

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The aim of the generic Transport Safety Case (TSC) is to demonstrate that the transport operations to move radioactive waste from the waste producers’ sites to the site of a GDF can be achieved safely with radiation exposures below allowable limits and as low as reasonably practicable (ALARP). It would provide information to the regulators, the public, other stakeholders and ourselves that the transport operation is justifi ed and that exposure to ionising radiations can be limited. We aim to provide confi dence that radioactive waste transport operations will meet the regulatory requirements.

Another key element of the generic TSC main report is the emergency arrangements to cover the response to any incidents involving the transport of radioactive materials.

The generic TSC comprises the following main areas of work, each of which has its own supporting documentation:

• transport package safety (TPS). This report describes the means by which we aim to make the transport of waste packages safe

• generic Transport System Safety Assessment (TSSA). This report includes an assessment of the doses to operators from the transport operation as a whole

• safety case production and management (SCP&M). This report describes the safety principles and regulatory constraints for the safety cases as well as the management arrangements and methodologies for production of the safety case documents.

This document is drawn from the generic TSC main report, and it briefl y summarises these areas of work. Its objectives are:

• to draw together the safety arguments and evidence from the supporting documents that make up the generic TSC into a single coherent and consistent entity, and hence give assurance that radioactive waste can be transported safely

• to facilitate regulator and stakeholder involvement in developing the safety case by providing an overview of the safety case that summarises and references the more detailed documents.

Transport container

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As a GDF site has not yet been identifi ed, it is not possible at this stage to refer to site-specifi c transport factors. However, the generic TSC sets out the means by which we aim to make the transport of the wastes from producing sites in the UK to a GDF safe, effective and effi cient.

To meet the safety requirements in transport, principles have been established to ensure that material is properly contained and protected, that responsibilities are well defi ned and that the consequences of any incident are limited. For transport, these principles imply that:

• safety is ensured mainly by the engineering design of the package, thus reducing the need to depend on operational controls, such as route restrictions, speed limits and vehicle modifi cations

• transport safety is ascertained by assigning appropriate responsibilities to all parties concerned with the transport operation, including the consignor, that is a person, an organisation or the Government, who will be in charge of preparing the waste packages consignment for transport, and transport operators

• packaging and performance standards are graded according to the nature and quantity of the contents (i.e. the magnitude of the hazard and potential risk)

• the ALARP principle applies to radiological safety just as it does to conventional safety.

These requirements and principles are enshrined in the International Atomic Energy Agency (IAEA) Regulations for the Safe Transport of Radioactive Material (IAEA Transport Regulations). In addition, certain international treaty obligations apply. The transport of waste must also comply with the Health and Safety at Work Act.

2. Context

An illustration of road transport

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3. Safety strategy

In the UK, radioactive material transport through the public domain must be approved by the Department for Transport (DfT) for certain types of transport package – including those likely to be used for transport to a GDF. Regulatory control in the UK for road and rail transport is in accordance with the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations (the CDG Regulations), which incorporate the requirements of the IAEA Transport Regulations. Transport by sea is regulated by the Merchant Shipping Regulations 2009.

The IAEA Transport Regulations specify criteria that must be met by each transport package, for example, on external dose rate and fi ssile material contents. The regulations also require demonstration of the ability of transport packages to withstand certain physical challenges, and to satisfy other tests that simulate their performance under normal conditions and in potential accidents.

The generic TSC explains how approval of a transport package is granted by means of a formal process by the competent authority, which is the DfT, for Type B packages. For industrial packages (IPs), approval can be granted through an auditable process of self-approval by the package designer. However, documentary evidence of compliance of these designs with the applicable requirements is to be made available to the competent authority on request.

A Package Design Safety Report (PDSR) provides the justifi cation for safety of specifi c transport package designs, and approval of the design is provided as a Certifi cate of Approval issued by the competent authority.

Regulators’ logos

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Prior to transport, consignors are required to produce a Radiation Protection Programme (RPP). The RPP documents the controls in place to limit the doses to workers and members of the public.

Consignor shipping procedures specify the procedures and local work instructions for preparation of a waste package for despatch in accordance with the requirements set out in the Certifi cate of Approval.

At this early stage in the development of the geological disposal system, some waste packages have already been manufactured and placed in store awaiting transport to a GDF. Compliance of these packages with our own and regulators transport and disposal requirements is assessed as part of our Letter of Compliance (LoC) disposability assessment process. This process allows waste packaging to proceed now with confi dence that packages will be suitable for transport and disposal.

3. Safety strategy

Concrete tanks at Sellafi eld

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4. Assessment basis

We are responsible for providing an integrated transport system that will provide a safe, secure and effective means of delivering the waste to a GDF.

An integrated transport system for the movement of radioactive waste material consists of three basic elements:

• waste and waste packaging: information required for the assessment includes the waste type and types of packages that would be used

• transport modes (rail, road, sea): the vehicles or vessels which could be used and the transport routes

• transport operation (processes, people and places): processes include the loading, moving and unloading of the vehicles or vessels, the people are those that may be employed or affected by the transport activities and places are the sites of waste arisings.

Sea transport

Rail transport

Road transport

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5. Safety assessment

A multi-barrier approach

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5. Safety assessment

A multi-barrier approach is adopted for protecting the waste during transport. The immobilised waste, know as the wasteform is held inside a waste container, the combination of the immobilised waste and its waste container being referred to as a waste package. The more highly radioactive waste is protected by an additional reusable shielded transport container, thus forming a multi-barrier transport package.

The mode of transport that will be used for moving the waste to a GDF is uncertain at this stage, and so the generic TSC considers a number of transport scenarios based on rail, road, sea or a combination of those modes.

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5. Safety assessment

Appropriate waste package specifi cation and design is the fundamental input to the generic TSC. However, the generic TSC also incorporates the fi ndings of an early stage safety assessment that predicts doses to workers from routine operations. The results are compared with the annual limits and targets for individual doses, derived from health and safety regulation and guidance, as presented in our Radiological Protection Policy Manual (RPPM). All doses are predicted to be below the RPPM targets for worker doses. These assessments add to the assurance provided by compliance with the IAEA Transport Regulations.

A dose assessment is a prerequisite for a formal ALARP study, providing a baseline against which to evaluate potential measures to reduce dose uptake, and thus to weigh their safety benefi ts against costs. The generic TSC includes a preliminary ALARP study that identifi ed a number of dose reduction measures that will feed into the design of the transport system. It also lays a foundation by establishing a methodology for future full ALARP assessments.

The TSC will evolve to satisfy our legal and regulatory obligations and the needs of stakeholders, which will change and develop as we progress through the MRWS stages. Legal and regulatory obligations during operation differ to those required for prior permission, and we need to plan for those changes now. We will engage with stakeholders to discuss how the TSC should evolve to satisfy these changing needs.

Intermediate level waste

Low level waste

High level waste

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This generic TSC main report and its supporting documents show how we have confi dence that we will be able to provide the safe transport operation needed to move all of the waste from the various locations where it is currently held to a GDF.

The argument for radiological safety is based principally on demonstrating compliance with the IAEA Transport Regulations. The generic TSC also aims to provide confi dence that procedures and processes are, or will be, in place to ensure compliance. The LoC disposability assessment process for proposals for waste packaging not only confi rms compliance of a transport package but gives confi dence to the waste producers, stakeholders and ourselves that waste packaged now will be suitable for transport and disposal.

Beyond this work to achieve regulatory compliance, we draw on national and international experience of safely transporting radioactive materials. Over the past 50 years there have been regular movements of radioactive material through the public domain in the UK. The LLW Repository in West Cumbria has provided a disposal facility for LLW since 1959 and has accepted waste from nuclear licensed sites throughout the UK. Road and rail transport of fuel and SF to and from civil reactor sites throughout the country is a regular operation. In addition, there have also been many transfers of fuel and SF out of and into the country by sea.

Aerial view of Low Level Waste Repository

6. Conclusion

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There have been no incidents associated with these transport operations that have resulted in a release of radioactive material above and beyond routine levels of release into the environment. These transport operations have been carried out under the regulatory framework for transport described in this report and have developed the UK expertise needed to provide confi dence that it can be operated safely.

A dose assessment based on our current understanding and expectations of the transport system has provided confi dence that dose to operators will be within our targets.

At this early stage in the development of a geological disposal system, the generic TSC is of necessity an indication of how we aim to ensure the safe transport of the waste inventory. We have confi dence that the transport operation will be safe.

5. Safety assessment

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Nuclear Decommissioning AuthorityRadioactive Waste Management DirectorateBuilding 587Curie AvenueHarwell Science and Innovation CampusDidcotOxfordshire OX11 0RH

ISBN 978-1-84029-448-4

t +44 (0)1925 802820f +44 (0)1925 802932w www.nda.gov.uk

©Nuclear Decommissioning Authority 2010