REACTOR DECOMMISSIONING

International Atomic Energy Agency

REACTOR

DECOMMISSIONING

Michele Laraia, IAEA

World Outlook in Nuclear Technology, March 27-29, 2008, Istanbul, Turkey


ContentsContents

•International Context

•IAEA safety and industrial guidance

•Technological issues

•Financial issues

•Organizational and management issues

•Feedback from decommissioning experience to design and construction of new nuclear power plants


Decommissioning – a safety-oriented IAEA Decommissioning – a safety-oriented IAEA definitiondefinition

The administrative and technical actions taken to allow the removal of some or all of the regulatory controls from a nuclear facility (except for a repository or for certain nuclear facilities used for the disposal of residues from the mining and processing of radioactive material, which are ‘closed’ and not ‘decommissioned’).


A broader vision of decommissioningA broader vision of decommissioning

• The two main objectives of decommissioning are to render the site permanently safe and to recover it, as far as practicable, for reuse (TRS # 444, WNA 2006)


Status of the Decommissioning of Nuclear Status of the Decommissioning of Nuclear Facilities around the World*Facilities around the World*

• Nuclear Power Plants• Operating: 446

• Under construction: 45

• Shutdown, under decommissioning: 107

• Decommissioned: 14

• Research reactors and critical assemblies• Operating: 288

• Under construction: 9

• Shutdown, under decommissioning: 119

• Decommissioned: 404

* various IAEA sources, 2004-2005


Status of the Decommissioning of Nuclear Status of the Decommissioning of Nuclear Facilities around the World*Facilities around the World*

• Fuel cycle facilities (uranium milling, uranium conversion/recovery, uranium enrichment, fuel fabrication/heavy water production, fuel reprocessing)• Operating: 423• Under construction: 19• Shutdown, under decommissioning: 297• Decommissioned: 192

• Medical, research and industrial facilities: ~ 320 000

• Cold war legacy

• Total decommissioning liability for the period up to 2050 of about $ 1000 billion ($ 1 trillion) !!!

*various IAEA sources 2004-2005

• * various IAEA sources, around 2004


BackgroundBackground•IAEA Statute:

•Develop safety standards

•Promote activities cost-effectively and consistent with Safety Standards

Nuclear Safety

Radiation Safety

Waste Safety

Transport Safety

Peer reviewsTechnical cooperationTrainingExchange/disseminate information (technical reports/docs)Research and development


DECOMMISSIONING


The Decommissioning The Decommissioning Programme of the IAEA: Programme of the IAEA: Safety-related AspectsSafety-related Aspects


Safety Guides

Safety Requirements

Safety Fundamentals

Safety Reports

Safety Standards Hierarchy


Safety Requirements Safety Requirements (selection)(selection)

•The preferred decommissioning strategy shall be immediate dismantling. The decision to undertake the deferred dismantling or entombment options shall be justified on a facility-by-facility basis.


Safety Requirements (cont‘d)Safety Requirements (cont‘d)

•States shall include provisions in their national legal framework for establishment of funding mechanisms for decommissioning


Safety RequirementsSafety Requirements• A decommissioning plan shall be developed since the design

and construction stage and submitted by the operator as part of the application for an authorization to operate the facility

• and regularly reviewed to reflect changes in:

• operation

• regulatory requirements

• technological improvements, etc.

• It shall demonstrate:

• that the selected decommissioning option is safe

• no undue burdens to future generations• dismantling and decontamination techniques minimising

waste generation and airborne contamination


The Decommissioning The Decommissioning Programme of the IAEA: Programme of the IAEA:

Strategic and Technological Strategic and Technological AspectsAspects



Explosive dismantling of a stackExplosive dismantling of a stack


Brookhaven Reactor Decommissioning : Brookhaven Reactor Decommissioning : Work Begins in South Duct 12/27/03 Work Begins in South Duct 12/27/03

(underground)(underground)


Building wall clearance

through ISOCS (Vandellos NPP,

Spain)

Building wall clearance

through ISOCS (Vandellos NPP,

Spain)


CONSTRUCTION

OPERATION

DECOMMISSIONING

SITING

AND NOW ?

REDEVELOPMENT!

CLOSING THE NUCLEAR LOOP


The “Vaporsphere” at ANL, USA, a former nuclear facility, now a warehouse


Journalists watching

decommissioning activities at

Vandellos NPP, Spain

Journalists watching

decommissioning activities at

Vandellos NPP, Spain


Handheld mechanical cutting equipment for small contaminated pipes (decommissioning

with limited resources)


IAEA’s Technical Assistance IAEA’s Technical Assistance Projects on Decommissioning Projects on Decommissioning

(selection)(selection)


SLOVAKIA (2000, ongoing)SLOVAKIA (2000, ongoing)

Robotic, Remote Viewing Technologies for D&D of A-1 NPP (e.g. IGRIP, laser scanner,

gamma camera).


A1 NPP Slovakia, Aladin gamma cameraA1 NPP Slovakia, Aladin gamma camera


A1 Slovakia Graphic

simulation (IGRIP)



LITHUANIA ( 2000, ongoing)LITHUANIA ( 2000, ongoing)

Planning for Decommissioning of Ignalina NPP (e.g. upgrading of national infrastructure,

review of draft docs., workshops)


Technology IssuesTechnology Issues


Introduction: Introduction: Decommissioning can and has been doneDecommissioning can and has been done

• Total dismantling of prototype facilities and commercial NPPs has been done up to “green field”, like:• KKN, Shippingport NPP, JPDR

• Maine Yankee, Trojan

• More NPP are currently being decommissioned (Stade, Wuergassen etc)

• From 1990 until 2000 the technology has been improved and the major basis have been set up

• The D&D “market” is now growing rapidly, expected to peak around 2015-2020


Development of the technology Development of the technology (a piece of history)(a piece of history)

• A view of some of the pilot projects

WAGR

BR3-PWR

KRB-A

EWN

AT-1


Development of the technology Development of the technology (a piece of history)(a piece of history)

• Today, the US has carried out many times the one piece removal of RPV...


Is technology mature?Is technology mature?

• Current technology is able to carry out most decommissioning activities and operations

• Nevertheless, improvements can be done for improving the operations

• The incentives to improve technology are rather important:• reduce the costs

• limit the waste production

• reduce operator exposure

• reduce contamination hazard

• improve the industrial safety

• reduce the industrial and financial risk

• be able to react to unforeseen situations


Some overview of the available technologySome overview of the available technology

• Let us separate it in three main categories:• characterization techniques

• before dismantling

• during dismantling

• after dismantling

• decontamination techniques• for metal

• for concrete

• dismantling techniques• for activated metal

• for contaminated metal

• for concrete


Characterization before dismantling : a Characterization before dismantling : a difficult job but a lot of possibilitiesdifficult job but a lot of possibilities

• Before dismantling:

• by direct measurement on site

• by sampling & measurement (lab or radiochemistry)

• by remote monitoring (e.g. ISOCS)

• by calculation (improvements in activation codes and even contamination models)


Characterization & measurement during Characterization & measurement during D&D: a hard job D&D: a hard job

• Some measurements have to be carried out during the dismantling to allow sorting the material or defining the route to follow


Characterization after decommissioning: Characterization after decommissioning: an important step an important step

• For radwaste management or material free release, the needs for characterization are important!• Gross gamma counting

• Gamma spectrometry

• Alpha spectrometry

• Use of isotopicvector

• ....


Decontamination: Decontamination: this concept covers a very broad spectrum of activitiesthis concept covers a very broad spectrum of activities

• Metal decontamination:

• before dismantling

• after dismantling

• Concrete decontamination

• Site or soil decontamination


Example of application of thorough chemical decontamination: the Medoc workshop at BR3


Material after decontaminationMaterial after decontamination


Another example: Another example: Projection of COProjection of CO22 ice or water ice ice or water ice

• CO2 ice pellets are projected at high speed against the surface

• The CO2 pellets evaporate and remove the contamination

• The operator works in ventilated suit inside a ventilated room to remove CO2 and contamination

• Needs some decontamination tests before selecting the process (not efficient for deep contamination)


New techniques are currently developed to New techniques are currently developed to improve the efficiency and reduce the effluentsimprove the efficiency and reduce the effluents

• Methods based on laser ablation

• Increasing the pressure of the water jetting

• New chemical or electrochemical methods; new effluents treatment methods

• Other methods...

• But they are still under development!


Examples of Hand scabblingExamples of Hand scabbling(labour intensive)(labour intensive)

Courtesy from Belgoprocess


Automatic wall shaverAutomatic wall shaver


Close up view

of the machineUse on a reprocessing cell wall


Remote controlled jackhammerRemote controlled jackhammer



Some other shots...Some other shots...

Brokk and jackhammer Diamond centerless saw

Shaver


Some views Some views of the very large number of processesof the very large number of processes

Laser Cutting

Explosive Cutting

Pipe cutter

Plasma Cutting


The cut pieces must match the material handling The cut pieces must match the material handling and removal requirementsand removal requirements

Output dismantling = Input material management

e.g. Belgian standard : 400-l drum


Secondary waste generatedSecondary waste generated

• The secondary waste generated depends on the piece being cut and the cutting techniques as well

• The final volume of the secondary waste is the main determining economical factor

• Size and size distribution are from first importance in order to allow collection of the generated secondary waste. Eventually, different physical forms of waste can be generated (solid and gaseous…)


Conventional safety aspectConventional safety aspect

• Dismantling techniques are close linked with the following hazards:• Heat generation (plasma torch)

• Piece falling down

• Sharp edges

• Projection of material

• Working at heights

• Noise

• Working in a continually different environment

• …


What are the most important factors What are the most important factors to look at when selecting a process?to look at when selecting a process?

• Keep it simple ! complex technologies are often difficult to repair and to maintain, mainly in nuclear (D&D) environment....

• Use only proven technology: do not use industrial D&D projects to make R&D; new technologies are often subject to infant mortality...



• The reliability of the technology is an important factor!



• Radioprotection aspects:

• Most of the technologies evolved from industrial processes adapted for usein nuclear environment

• But the radioprotection aspects are not always well understood by technology suppliers



• Industrial safety is a very important factor in decommissioning:• combination of industrial

hazard with radiological hazard

• presence of corrosive ortoxic chemicals and gas

• risk of fire, of fall, of wounds,of shocks etc...


Concluding remark:Concluding remark:the best way to select a process...the best way to select a process...

• Processes are existing for decommissioning nuclear installations

• Some innovative techniques are needed for difficult operations or to improve the efficiency of today technology

• Go visit and check with operators having used the method or process!

• Do not believe catalogues, vendors or commercials...

• Do not focus on one aspect (like e.g. cutting or cleaning speed)


Financial issuesFinancial issues


Identification ofIdentification ofDecommissioning CostsDecommissioning Costs

• In the mid-1990s, three groups compiled elements of decommissioning costs for the phases of a project for virtually any type of facility

• The groups:• OECD/NEA Task Group

• IAEA Consultants Group on Decomm. & WM

• Comm. of European Communities Nuclear Fission Safety Program

• A single comprehensive list of cost items was adopted. “A Proposed Standardized list of Items for Costing Purposes in the Decommissioning of Nuclear Facilities,” available from the OECD/NEA website


Types of Cost EstimatesTypes of Cost Estimates

• Association for the Advancement of Cost Engineering International (AACEI) Definitions

• Order of Magnitude CE -30% to +50% • Without detailed engineering data (scaling factors/ratios)

• Scope not well defined

• Budgetary CE -15% to +30

• Scope defined – Have site plans/drawings/equip. • Definitive CE -5% to +15%

• Accurate site drawings/records available(Examples - plot plans/elevations, piping & instrument diagrams, equipment data sheets)

• Scope well defined/characterization/approach


Developing the Cost EstimateDeveloping the Cost Estimate

• Costs may be estimated in several ways

• Bottoms-up – site specific and most accurate

• Specific analogy – based on known cost of an activity in prior estimates

• Parametric – based on historical databases of similar systems and structures

• Cost review and update – based on previous estimates of same or similar project

• Expert opinion – based on consensus of several specialists in an iterative process


Cost Estimate DefinitionsCost Estimate Definitions

• Activity-dependent costs – decontamination, removal, packaging, shipping and disposal – repetitive activities

• Period-dependent costs – program management, engineering, licensing, health & safety, security, energy, & QA

• Collateral costs – dismantling equipment, site prep, insurance, taxes, HP supplies, liquid radwaste processing, verification surveys

• Contingency – specific provision for unforeseeable elements of cost within project scope – delays, weather, tool breakdown, changes in plant conditions


Cost Estimate Definitions Cost Estimate Definitions (Cont.)(Cont.)

• Scrap – clean material that may be recycled as raw materials – copper, steel, aluminum, etc.

• Salvage – clean materials that can be reused in their current form – pumps, tanks, motors, diesels, generators, etc.

• Work Breakdown Structure (WBS) – categorization of cost elements into logical groupings directly related to each other

• WBS levels – hierarchal format similar to a company’s organization chart

• Chart of accounts – individual cost items of labor, capital equipment, consumables, transportation, and disposal are tracked by project management or accounting software relative to the available budget – OECD/NEA Standardized List of Cost Items


Collection and Management of FundsCollection and Management of Funds

• Decommissioning is inseparable from waste management

• Funding must include disposal of radioactive (and other) wastes

• Countries without waste disposal facilities may include the cost of developing a waste disposal facility (particularly for developing nations with few nuclear facilities)

• The liability requires legal requirements to ensure funding will be sufficient and available


Collection andCollection andManagement of Funds Management of Funds (Cont.)(Cont.)

• The funds need to meet the following criteria:

• Contributions to be made by facilities using radioactive material during their operation

• Funding to be in line with estimated service life of the facility, including decommissioning, waste management and spent fuel disposition

• Funds are to be managed and reviewed periodically to ensure liquidity until needed

• Funds are to be used only to cover the costs of decommissioning in line with the strategy (under a legal framework)



• Collection of funds differs from country to country.

• Some require funds to be accumulated year-by-year over the life of the facility

• Others require accumulation over a much shorter period, or to make a down payment as a condition for obtaining the first license

• This latter case is a hedge against premature shutdown



• Growth of the fund is dependent on the investment strategy

• Greatest possible return – investment in equities (stocks) – higher risk

• Lowest risk – government securities/certificates of deposit, etc.



• Example of NPV:

• Decommissioning cost = €500 million

• Cost escalation =3% per year

• Timing =40 years

• Expected future cost =€1,631 million

• Discount rate =5%

• NPV =€232 million• Net present value (NPV)

• Discounted costs taking into account the expected expense schedule

• Requires an estimate of discount rate and expected timing of decommissioning

• The later the expense is incurred, the lower the net present value

• NPV approach can be deceiving as it assumes escalation rate and discount rate are unchanged over long periods of time.



• Internal management - licensee/owners are allowed to accumulate and manage their funds that remain in their own accounts

• Potential risk that the monies may not be there when needed

• May require governmental oversight to ensure availability

• External management - licensee/owners are required to collect funds and deposit them in external trusts

• Disbursement may be tied to specific milestones of decommissioning

• Special cases – licensee/owners contributing to fund are allowed to borrow back up to 75% of the capital against company full securities at a defined interest rate. The government has the right to borrow the rest of the capital (Belgium)



• In the U.S. the concern for liquidity of funds and potential poor trust fund performance has favored low risk, low return securities.

• These funds have been given favorable tax treatment, and are called qualified funds

• Higher risk investments (equities – stock), are considered nonqualified funds, and are taxed at the higher corporate tax rate

• Usually, the nonqualified funds generate sufficient returns to offset the higher tax rate


Social-Economic Development and Stakeholder Social-Economic Development and Stakeholder RelationsRelations

• Decommissioning and facility closure will have both direct and indirect costs and social impacts on the surrounding community• Direct costs include:

• Job training for decommissioning

• Retention funds for key employees

• Severance funds for redundant employees

• Job re-training for employees for future opportunities


Social-Economic Development and Stakeholder Social-Economic Development and Stakeholder Relations Relations (Cont.)(Cont.)

• Indirect costs include:

• Loss of town tax income from relocated employees

• Drop in employment levels in the community

• Reduced market value of homes vacated by relocated employees

• Loss of income to local businesses

• Higher cost per capita to maintain town services – town government, schools, fire and police brigades, hospitals, recreational facilities, libraries, road maintenance, etc.


Social-Economic Development and Stakeholder Social-Economic Development and Stakeholder Relations Relations (Cont.)(Cont.)

• Direct costs are usually factored into the budget for decommissioning the facility

• Indirect costs are not, and can contribute to a downward spiraling of the local economy

• The importance of pre-planning the socio-economic impacts cannot be understated

• Work with the local government

• Attract new businesses with large employment needs

• Construct a new power generation facility

• Town may offer low initial tax incentives to new businesses

• Banks may offer low cost construction loans to attract new businesses


Organization and Management Organization and Management IssuesIssues


Cultural changes between operation (left) Cultural changes between operation (left) and decommissioning (right)and decommissioning (right)

• Relying on permanent structures

• Safety management based on routine operations

• Management objectives are production oriented

• Permanent employment with routine objectives

• Established regulations

• Introduce temporary structures

• Safety management based on decom tasks

• Management objectives are project completion oriented

• Visible end of employment -refocus work goals of staff

• Changing regulatory focus


Cultural changes between operation (left) Cultural changes between operation (left) and decommissioning (right)and decommissioning (right)

• Predominant nuclear and radiological risk

• Repetitive activities

• Working environment well known

• Routine communications with external parties

• Reduction of nuclear risk, changed nature of radiological risk, significant industrial risk

• One-time activities

• Unknowns possible

• New communication requirements


Project ManagementProject Management• Decommissioning is not operations or a plant

outage – do not manage it as such

• Early and frequent on-going dialogue with the regulator is essential to project success especially when agreeing upon site clean-up criteria

• Dialogue with other stakeholders to keep everyone informed and a part of the process

• Invest in the project staff – provide good strong training program to persons on the decommissioning team


Project Management (ctd)Project Management (ctd)

• Look closely at your own operations for ways to improve it as work progresses

• Be alert for technologies that may appear to be very user friendly but in the end may generate large quantities of secondary waste in their use – ex - water jet cutting

• Be aware of the limitations of dismantling and decontamination technologies – speed, costs & schedule, training, regulatory issues, etc


CharacterizationCharacterization

• Do not overlook this critical aspect of any decommissioning activity – do not rush into showing ‘visible progress’ before a thorough characterization can be performed

• Become familiar with the details of the facility – review available records, old photos, interview former or current workers


Characterization ConcernsCharacterization Concerns

• Some common pitfalls:

• Inadequate documentation and planning for characterization

• Not accounting for natural radioactivity background of construction materials

• Use of techniques with sensitivities that are not capable of achieving release criteria activity levels

• Poorly documented construction activities during periods of inactivity at a site/facility


Project Management Project Management

• Cannot overemphasize the need to communicate with all involved parties in the decommissioning:

• Management / funding sponsors

• Project team members

• Regulators

• Technical community

• General public

• Community groups


Waste ManagementWaste Management

• The project is a hostage to the waste management facility – work closely with their staff to facilitate timely disposal/storage of your waste materials

• Allocate and commit adequate time to fully characterize your waste streams to the satisfaction of the disposal/storage site – including the non-radiological waste as well as the radiological waste

• Prior to final facility shutdown, minimize the volumes of legacy operational radioactive waste – this project is now radwaste


Waste Management (ctd)Waste Management (ctd)

• Closely evaluate (cost/benefit analysis) any and all opportunities to decontaminate material for release

• Rancho Seco saved $10 M USD by free releasing material

• Evaluate options for large intact component removal versus size reducing larger items as well as using a radioactive waste processor

• Understand the packaging and disposal requirements - the first time

• Maintain detailed and accurate records on the contents of your waste packages


Project Management StrategiesProject Management Strategies

• Licensee serves as Decommissioning Operations Contractor (DOC) and integrates others onto team as appropriate

•May maximize use of outside firms

(Maine Yankee NPP)

•Minimize use of outside firms to only highly specialized functions (Trojan NPP)


Use of ContractorsUse of Contractors

• Financial considerations may impact the selection of and the use of contractors – however, the licensee always maintains responsibility for any and all decommissioning activities

• While supporting a need in performing decommissioning, an appropriate level (a strong level) of contractor control, supervision and training is required

• Use of contractors is most likely to occur when deferred dismantlement is the selected decommissioning option or the operating staff do not have the required expertise to perform the decommissioning activities


Local complicating factorsLocal complicating factors

• Local purchasing and socio-economic objectives

• Workforce reduction issues

• Labor agreement requirements


A DECOMMISSIONING LESSONS LEARNED PROGRAMME AND ITS APPLICATIONS TO

DESIGN/CONSTRUCTION OF A NEW NUCLEAR FACILITY


INFORMATION SOURCES INFORMATION SOURCES

• Experienced technical and management staff members that have performed decommissioning of nuclear facilities – regulators, operators and contractors

• Often lessons learned are detailed in project final reports and in some instances specific reports on lessons learned

• Site visits to units or facilities in decommissioning is another useful way to learn what others have done in similar situations


INFORMATION SOURCES (CTD)INFORMATION SOURCES (CTD)

• Dedicate resources to track projects as they are happening

• In addition, there are some sources of lessons learned available on the Internet –

• Important: do not re-invent the wheel !


A BASIC PROBLEM IN TRANSFERRING A BASIC PROBLEM IN TRANSFERRING DECOMMISSIONING LESSONS LEARNED TO DECOMMISSIONING LESSONS LEARNED TO

DESIGNERS AND BUILDERS OF NEW FACILITIESDESIGNERS AND BUILDERS OF NEW FACILITIES

• Decommissioners and designers/builders belong to different categories, well distinct in space, time, organizations, professional / contractual interests and motivations

• A conscious effort is needed by an independent / overarching authority to establish and enforce the link


A FEW SELECTED CRITERIA TO REVIEW A FEW SELECTED CRITERIA TO REVIEW DESIGN/CONSTRUCTION IN THE LIGHT OF DESIGN/CONSTRUCTION IN THE LIGHT OF

DECOMMISSIONINGDECOMMISSIONING

• Decide on scope of decommissioning e.g. what is going to be left behind following decommissioning (foundations, discharge pipes, etc.)

• Avoid considering unproven decommissioning technologies – let someone else test or evaluate and ready the new technology. Keep it simple ! Do not re-invent the wheel !

• Maintain a strong document control system including effective retrieval and prompt disposition of unneeded records. “Flag “ decommissioning-related records !



DECOMMISSIONING (CTD)DECOMMISSIONING (CTD)

• Become familiar with the details of the facility

• Account for natural radioactivity background of construction materials

• Be alert for co-mingling of systems with adjacent facilities

• Plan ahead for adequate equipment lay-down space and movement paths




• ‘As built’ drawings are often not accurately ‘as built’ and other documentation may be lacking

• Time is money – tackle a problem with the biggest equipment space constraints allow to be used

• Facility maintenance is a critical activity also for eventual decommissioning

• Do not overlook the issues of:• Groundwater contamination• Soil contamination• Know what is underground




• Evaluate options for large intact component removal versus size reducing larger items

• Understand the packaging and disposal requirements even at the design stage

• Make provisions to maintain detailed and accurate records on the contents of your waste packages




• Take benefit of the return of experience of other similar projects


Documents

REACTOR DECOMMISSIONING