dungeness a site summary - folkestone & hythe district · 6 dungeness a - site summary 2006/07...

Dungeness ASite Summary

Lifetime Plan PSWBS Site Ref: 232006/07 Lifetime Plan

2 Dungeness A - Site Summary

2006/07 Lifetime Plan Rev. B 21-04-2006 - 23 Dungeness A

Lifetime Plan OverviewThe Lifetime Plan 2006 (LTP), describes the proposals for Dungeness A site over itslifetime while giving both the customer and stakeholders a structure that clearlydescribes the scope, schedule and cost of all activities.

This LTP draws on information fromexisting plans that have been developedover many years. The Magnox operatingplan (MOP) covers the integration andmanagement of nuclear fuel from initialmanufacture to final reprocessing acrossall Magnox reactor sites. Detaileddecommissioning plans address theprocesses that will lead ultimately, to finalsite clearance.

The LTP reflects the declared strategy forgeneration, defuelling anddecommissioning of the site, in line withthe proposals that were subjected to a fiveyear review by the health and safetyexecutive (HSE) and reported by them in2002 as being “appropriate”.

This LTP incorporates the Dungeness Anear term work plan (NTWP) 2006 whichaddresses in detail the work planned to beundertaken from April 2006 to March 2009.It takes account of constraints from the UKgovernment’s latest funding review anddescribes the impact on the plan.

Work beyond April 2009 falls into the lifecycle baseline (LCBL) section of the LTP.The end of the LCBL is the completion offinal site closeout, which is currentlyscheduled for December 2111.

Appendices

LCBLDetail

Volumes

Site Summary Long Range PlanGraphic

Category Summaries

NTWP DetailedVolumes

Technical BaselineSheets 3s

Care &Maintenance andFinal SiteClearance Scopes

HQ Bundle

Figure 23-005: Dungeness A Lifetime Plan structure

ContentsLifetime Plan Overview

Site Overview

Site Key Phases/Event

Scope of work by phase:

Generation

Defuelling

C&M Preparations

Care & Maintenance

Final Site Clearance

2

3

4

6

6

8

10

12

14

NTWP Years 1 to 3

Major Assumption & Exclusions

Risk Management

Summary Milestone Schedule

Lifetime Plan Value

Reconciliation of Costs

Staffing Curve

Metrics & Key Quantity Curves

Conclusion

16

18

19

20

24

26

27

28

30


3Dungeness A - Site Summary

Site OverviewDungeness A is a nuclear licensed site with two operating MagnoxReactors. Located on Romney Marsh in Kent the site is 20 milesfrom both Ashford and Hastings.

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Facto

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Figure 23-007: Dungeness A key facts

Location:Nearby town/cities:Site area:Number of current employees:

KentLydd (3miles), Hastings (20miles)20 hectares380

Construction start:Construction end:Start operation:End operation:Defuelling start:Defuelling end:Care & Maintenance Preparations start:Care & Maintenance Preparations end:

19601965196520062007200920052017

Reactor type:Number of reactors:Number fuel channels per reactor:Number of fuel elements per channel:Number control rods:Fuel material:Reactor coolant:Number of turbo generators:Electrical output - design (net):Electrical output - current (net):Station lifetime output to date:Previous operators:

Magnox23,9327120Natural uraniumCarbon dioxide4550 MW420 MW117.2 TW/hCentral Electricity GeneratingBoard/Nuclear Electric/Magnox Electric

Adjacent nuclear power station? British Energy's Dungeness B

The area around Dungeness A is the largest shingle structure in the UK, which as aresult requires Dungeness A to continually feed its beach

The table below shows themajor current and nearfuture activities for this siteand how they relate to theNuclear DecommissioningAuthority (NDA) lednational prioritisationworking group priorityareas.

Dugeness A

This table shows the major current and nearfuture activities for Dungeness A site and howthey relate to the April 2005 output of theNuclear Decommissioning Authority (NDA) ledNational Prioritisation Working Group priority areas.

Priority area 1, Non-discretionary work is thatnecessary to maintain legal compliance andprescribed levels of safety and security.

Priority area 2, Relates to Operations relatedtasks. Within this area lies electricity generationand defuelling and any projects specificallyenabling these activities.

Priority area 3, Discretionary work is that whichwill allow achievement and acceleration ofdecommissioning and all clean-up activities.

Current site focus/priority indicates the prioritythat each focus area will have when funds arebeing allocated.



1. Key Phase/Event

GenerationMarch 2006 to December 2006

The plan is to operate both reactorscontinuously until December 31st 2006. Asafety case has been agreed by theNuclear Installations Inspectorate (NII), thatno outage is required on reactor R1 thisyear. A letter from the NII allowing bothreactors to operate past March 2006 isexpected and this will put all safety casesin place.

In the period January 2007 to March 2007,a number of reactor fuel channels will havethe fuel removed as part of a provingprogramme for both new and modifieddefuelling equipment.

2. Key Phase/Event

Defuelling2007 to 2009

Lessons learnt from other stations in termsof having a flexible safety case to allowdefuelling of the fuel channels in any orderhave been taken on board. Arrangementswill be in place to verify that all the fuel hasbeen removed.

There have been problems with fuel chutesnot operating when they are cold and toovercome this, four new charge chuteswith greater tolerances to allow operationswhen cold have been made.

The defuelling staffing structure is agreedand will allow for acceleration of the MOP ifrequired.

Dungeness ALTP Key Phases/Event

• Construction began in August 1960

• Both reactors started operation in 1965.

• The plant was originally designed for an output of 550MW

• Current nominal output is 420MW.

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030NTWP

2035



3. Key Phase/Event

Care and Maintenance Preparations2009 to 2017

Work in this period covers dismantling,demolition and waste management. Workwill be undertaken to remove mostradioactive and non-radioactive plant andbuildings. The reactor buildings will be putinto a safe and secure state for anextended period of time.

The majority of waste generated in thisperiod will be retrieved, processed andpackaged. Intermediate level waste (ILW)will be packaged and stored in a purpose-built store for disposal at a later date.

4. Key Phase/Event

Care and Maintenance2017 to 2102

During this period buildings remaining onsite will be routinely maintained, inspectedregularly and undergo surveys to confirmthat they remain in a safe and secure stateduring this prolonged period.

No further decommissioning work will takeplace during this period although in thelatter stage, the planning and installationwork necessary for the implementation ofFSC will start.

5. Key Phase/EventFinal Site Clearance 2102 to 2111

FSC is the period when the site iscompletely cleared of all remainingbuildings, structures and fencing. However,the site infrastructure will need to bereinstated to achieve this and a wastemanagement facility (WMF) will be requiredto deal with the waste produced.

The final state will be an unlicensed sitethat will have been returned to a naturalshingle beach and will be designated a siteof special scientific interest (SSSI).

Dungeness A’s life cycle can be described interms of five time based phases

• Generation

• Defuelling

• Care and Maintenance Preparations (C&MP)

• Care and Maintenance (C&M)

• Final Site Clearance (FSC)

2045 2050 2055 2060 2065 2070 2075 2080 2085 2090 2095 2100 2105 21102040

59,557

167,679

499,325

149,224

288,418



Scope of Work:GenerationDuring Generation, key objectives at Dungeness A are to maximise income fromelectricity sales while maintaining a safe and secure working environment and toprepare for a smooth transition into the defuelling phase.

It is a requirement for Dungeness A to:

• generate until the end of 2006

• maximise the value of generation

• maintain nuclear, industrial & public safety

• maintain environmental protection

• target output during 2006 is 2.20 TWhr.

The MOP covers the management ofnuclear fuel from initial manufacture to finalreprocessing across all Magnox reactorsites. Meeting the UK’s treaty obligationsunder the Oslo-Paris (OSPAR) agreementis critical, as this impacts on the allowabledischarges from the reprocessing plants atSellafield.

Spent fuel transport flasks will bedespatched promptly and the site willmaintain the flexibility to take extra flasks ifother sites are unable to do so. Thenumber of fuel elements in each flask willbe maximised to reduce the handling

workload, which is on the critical path.

Continuing the high standards of operationwill ensure that the spent fuel pondsremain in excellent condition. This willminimise operational dose and make apositive contribution to safety duringdecommissioning.

Following an enhanced outage in 2004,arrangements have been made with theregulator for no outage on R1, in 2006. In agenerating year over 25,000 separatemaintenance activities are completed. Thisensures plant and systems remaincompliant with nuclear and environmentalmaintenance schedules and other statutoryobligations. Effective maintenanceincreases plant reliability so that theforecast output is achieved withoutinterruption and this supports generation ofincome for the NDA to discharge itsliabilities.

Also, the periodic safety review (PSR) for

both reactors expires in March 2006 andthe safety case is expected to be agreedshortly with the NII to extend operation ofboth reactors to December 2006.

Programmes for site improvement havebeen implemented to ensure a smoothtransition from generation into defuelling.

Waste produced during generation will bedisposed of using currently available routese.g. low level waste (LLW) will be sent tothe Drigg repository in Cumbria andasbestos to a licensed disposal site. Fuelelement debris (FED) is an ILW bi-productof the fuel elements and most is dissolvedin a unique plant developed at DungenessA. The result is minimal waste forsubsequent storage on site. There is nodisposal route for non-dissolvable ILW andthis will be retained on site until a nationalrepository becomes available.

Non-hazardous wastes (NHW) areremoved. Dungeness A has rigorous

Generation April 2006 to December 2006Generation at Dungeness A helps to provide the National Grid with sufficient electricity to fulfil its commitmentto the general public as well as seeking to optimise the economic return to the owner of the Site's assets.

Figure 23-021: Generation scope of work



Type/Activity Generation

Figure 23-027: Generation - key phase summary Work Programme

2006

Work force restructuring23.10

Miscellaneous site wide services23.11

Plant Enhancements 23.11

Final Safe Shutdown of Reactor 2

2007

Generation23.12Maintenance23.12Plant Enhancements23.12

Waste processing facilities23.14

Technical and project support23.15

Turbine hall plant and buildings23.13

Licence condition consent for defuelling structure

Off load discharge chute project complete

Turbine hall approval to start asbestos removal

Commence turbine hall hazard reduction

Admin building demolition complete

EIADR decision to decommission

TCPA-2 submission of application and environmental statement to planning authorityTCPA-1 submission of application and environmental statement to planning authority

Operations and Project Support (23.15.52)

LLW Operations(23.14.43)

Final Decommissioning (23.13.34)

Infastructure (23.11.13)

Operations (23.11.10)

Work force Restructuring (23.10.01)

Generation (23.12.20)

Interim Decommissioning (23.13.32)

Q2 Q3 Q4 Q1

Regulatory Milestone


External Constraints

Key Critical Path

Final shutdown of R1 and R2

Constant monitoring on site ensures thesafety of our workers, plant andsurrounding environment

The control of plant by the use of visualdisplay units enables remote monitoringand control 24/7 365 days a year

environmental standards and objectiveswith an ongoing campaign to reduce, reuseand recycle where practicable.

An environmental impact assessment hasbeen prepared and work already done toidentify areas of contaminated land.Revisions to existing waste consents andauthorisations will be sought and currentactive and conventional waste strategiesrevised.

5,357

4,386

6,375

12,747

2,6941,067

26,203

727

Transition (23.10)New Construction Projects (23.11)Commercial Operations (23.12)Decommissioning & Termination(23,13)Waste and Nuclear MaterialsManagement (23.14)Site Support (23.15)Support Services (23.16)Stakeholder Support (23.17)

Figure 23-029: Cost distribution by category for Generation



DefuellingThe priorities at Dungeness A during the defuelling phase will be safety and regulatorycompliance while meeting the targets for dispatch of fuel to Sellafield reprocessingplant in Cumbria.

Defuelling comprises all activities requiredfor:

• safe and compliant defuelling of the reactors

• dispatch of irradiated fuel

• maintenance of the fuel handling plant.

Defuelling at Dungeness A will be co-ordinated with:

• other defuelling sites

• operating power stations

• Sellafield reprocessing plant.

This will contribute greatly to meeting theUK’s treaty obligations under the OSPARagreement.

Plant and systems required to support thedefuelling process or needed for safety willbe maintained as necessary to:

• meet statutory requirements

• maximise plant availability

• rectify any defects that may occur.

Defuelling will remove more than 99.9% ofthe site nuclear inventory. This will enablethe reduction of the level of staffing andsystems required to maintain safety andwill be a significant step towards the safestate required for the C&M phase.

The planned defuelling rate is:

• 79 tonnes in 2006/07

• 285 tonnes in 2007/08

• 265 tonnes in 2008/09

• 65 tonnes in 2009/010

In parallel with defuelling there will be alimited amount of decommissioning workundertaken. Currently this work is limited to:

• early removal of asbestos from the turbine hall

• continued operations to dissolve FED

• installation of an alternative effluent discharge line in readiness for when the volume of discharged cooling water is significantly reduced

• installation of an electrical overlay system in readiness for safe dismantlingof redundant plant and equipment

• other plant and systems will be shutdown, isolated, placed in a secure and safe state and where necessary, segregated from operational plant in

preparation for finaldecommissioning.

• Removal of the old administration building following the construction of a temporary administration building

• The dismantling of the turbine hall plant,equipment and systems

Figure 23-031: Defuelling scope of work

2007-2009 DefuellingThe first and main task following shutdown is to defuel the reactors and empty the cooling pond, transferring all spent fuel off-site.Irradiated fuel constitutes more than 99.9% of the total site radioactivity. At this point the opportunity is also taken to conduct athorough post operational clean out (POCO).



Activity/Event Defuelling

Work Force Restructuring

2007/08

Licence Condition Consent for move to Decommissioning structure

Operations and project support

2008/09

Key Critical Path

Other Paths of Concern


Other Milestone


Technology Insertion Point (TIP)

Key Decision Points

Figure 23-037: Defuelling summary work programme

Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3

Defuelling (23.12.22)

Fuel removal

Maintenance

2009

Completion of defuelling of reactorsCommence defuelling of reactorsPonds confirmed empty of fuel

All fuel confirmed off site

Submission of Post Operation & Defuelling Safety Case final report

Approval of Post Operation & Defuelling Safety Case final report

Waste and materials management (23.11.12)

Liquid waste Mobile waste retrieval project

Infrastructure (23.11.13)



Conventional plant and buildings

Work Force Restructuring (23.10.01)

Operations and Project Support (23.15.52)

Turbine Hall Hazard Reduction

Conventional plant and buildings

Since 1962 spent fuel has travelled acrossthe country in robust nuclear ‘flasks’without a single hazardous incident

The unique Magnox Dissolution plant treatsintermediate level Magnox waste, resultingin minimal waste to be stored

10,89816,438

36,540

5,808

2,273

47,335

10,234

38,154

for

Transition (23.10)New Construction Projects (23.11)Commercial Operations (23.12)Decommissioning & Termination(23,13)Waste and Nuclear MaterialsManagement (23.14)Site Support (23.15)Support Services (23.16)Stakeholder Support (23.17)



Care and MaintenancePreparationsThe aim of C&MP is to make the site passively safe and minimise the amount ofsurveillance and maintenance required during the C&M phase.

Excluding the reactor buildings (which willbe put into a safe and secure state), mostplant and buildings will be removed duringC&MP. To accomplish this several projectswill have to be undertaken in support of thedecommissioning work.

Portable active effluent treatment plant(PAETP) project - A PAETP facility will besupplied and installed. It will be located onsite and connected to the necessaryservices and drains. It will bedecontaminated and removed from the siteupon completion of its duties.

Low Level Active Waste (LLAW) plantmodifications project - The throughput ofthe existing LLAW facility will be improvedby increasing the number of operators andmodification to the mechanical handling,size reduction and contamination controlarrangements.

Mobile waste retrieval project - ILW wastes(part solid/part liquid) will be recovered andtreated using a transportable dewateringunit and a transportable solidification plant.Both these plants are reusable and will be

decontaminated and removed from siteonce the work is complete.

Solid waste retrieval projects - Facilities forretrieving and processing non-dissolvableILW solids recovered from waste vaultsbelow the reactors will be installed.Following clearance of the vaults, theretrieval facility will be dismantled anddecontaminated for transportation to othersites if required.

ILW store will be built to provide temporarystorage (in a safe state) for all ILWprocessed during C&MP.

Reactor and building safestorepreparations - The existing shell of thereactor buildings and the boiler annexeswill be removed and replaced. The workalso covers:

• Isolation of the CO2 circulation system

• The removal of insulation materials

• Blank off and stabilise R1 and R2 heat exchangers for long term storage

• All R1 and R2 vessel outlets will have been isolated and closed off

The following facilities will be dismantled,decontaminated and demolished using:

• Low level active waste (LLAW) store.

• Active effluent treatment plant (AETP).

• Pond water treatment plant (PWTP).

• Caustic tanks.

• Oil/water separation plant.

• Reactor ancillaries building.

• Acid and caustic bulk chemical stores.

• Flask loading bay.

• Active waste vaults (AWV)

• R1 and R2 pond plant furniture

• Ponds and pond structure

• Turbine hall buildings

• Cooling water structures and systems

• Electrical systems/plant/ buildings

• Fuel route pile cap and transfer equipment

• Offices, workshops, stores, roads, hard standings

Care & Maintenance Preparations 2009-2017

Figure 23-041: Care & Maintenance Preparations scope of work

Dismantling work will be undertaken to remove both radioactive and non-radioactive plant and buildings whereradiological benefit cannot be achieved from deferral. Structures remaining during Care and Maintenance willbe put into a passively safe and secure state.



Activity/Event Care & Maintenance Preparations

Electrical systems plant and buildings23.11.13Active waste plant/systems/buildings23.11.11

2005/09

Key Key Decision Points

Figure 23-047: Care & Maintenance Preparations summary work programme

2009/13 2013/17 2017/22

Solid waste 23.11.12

Liquid waste 23.11.12

Waste store (ILW) 23.11.12

Waste processing facilities 23.11.12

Waste & Materials Management (23.11.12)

Irradiated fuel storage and dispatchequipment23.13.32

Land Remediation & Management23.13.32Reactor building23.13.32Heat exchangers and primary circuits23.13.32Turbine Hall Plant and Buildings23.13.32Auxilary plant23.13.32Final Decommissioning (23.13.34)Active waste plant/systems/buildingsActive Drains & Systems23.13.34

Turbine hall plant and buildings23.13.34Intermediate level waste (23.14.41)Liquid waste23.14.41Solid waste23.14.41

Ops and Project Support

Decommissioning Overarching SafetyCase

Complete Commissioning of Electrical Overlay system

Complete Construction of Portable AETP

Complete construction of Voids Retrieval Project

Complete commissioning of FED Retrieval Project

Completion of Mobile Waste Retrieval project

Complete Construction of ILW store

Complete commissioning LLAW Project

Pond Plant Furniture & D&D completed

Ponds & Pond Structure D&D complete

Land Remediation & Management complete

R1 & R2 Buildings Safestore Preparation complete

Reactors & Primary Ccts Safestore Preps complete

Turbine Hall Approval to start Asbestos Removal

Auxiliary Plant Asbestos Removal Approval

Active Waste Treatment Systems Decommissioning complete

Active Drains & Systems Decommissioning complete

Turbine Hall Demolition Complete

Completion of Mobile Waste Retrieval project

MXD Plant Operations Completed

FED Processing Complete

Void Retrieval Operations Complete

NII Approval of Safety Case

Critical Path



Other Milestone







Care & MaintenanceIn the C&M phase the site will remain in quiescent state for a prolonged period duringwhich, no significant dismantling work will be undertaken. This will allow reactorradiation levels to decay to facilitate dismantling.

It is assumed that C&M will be split intotwo periods. The first five years (when thesite will remain continuously staffed) will bethe ‘C&M Initial’ period and the remainderbeing the ‘C&M Main’ period (when staffingon site will be reduced to a levelappropriate to maintain safety andsecurity).

The buildings remaining on site will beroutinely maintained, inspected regularlyand undergo surveys conducted bysuitably qualified and experiencedpersonnel (SQEP), including civil engineers.Inspections will either be on a periodicbasis or following severe weather, toensure the integrity of the weather tightenvelope. Site ground maintenance willalso be undertaken.

The inspection and maintenanceprogramme will be based on derivedrelevant safety cases and the associatedsite maintenance schedule. The followingprogramme is representative and includeselements of land management:

• Weekly external inspections to identify obvious damage (loss of sheeting)

• Monthly ground maintenance (trimming of vegetation and the clearing of drains)

• Half-yearly engineering inspections and minor maintenance of:

• External building fabric

• Hard-standings, access road and boundary fence

• Manholes and out-falls

• External drainage sumps

• Yearly engineering inspections and minor maintenance:

• Primary access routes (stairs, platform etc.)

• Internal face of building fabric

• Primary building and plant structures(active plant enclosures such as concrete, pressure vessels, or boilers)

• Basement areas for water ingress

• Thirty year intervals for internal and external engineering inspections, followed by more major maintenance, as required:

• Full structural inspection of primary internal access routes, with the repair or replacement of unsafe structures

• Minor re-pointing of brickwork, etc. as required

• Side and roof sheeting repair - leaking joints or damaged sheets

• Examination of primary building and plant structures made of steel

• Examination of primary building and plant structures made of concrete at typical sample areas of main members for signs of cracking, rusting etc.

• Repair or replacement as necessary of paved hard-standings, manholes, drain-lines, out-falls and security fencing

Care & Maintenance 2017-2102

Figure 23-051: Care & Maintenance scope of work

Dungeness A will remain in a Care and Maintenance state for a prolonged period, to allow the benefits associatedwith radioactive decay to be gained. No significant dismantling work will be carried out but the site will continueto be managed, monitored and maintained.



Regulators undertake periodic site tours toensure that nuclear/ environmental safety ismaintained during this phase.

In 2040 the national repository becomesavailable and ILW stored on site sinceC&MP will be removed. For the remainderof C&M, the ILW store will be redundant.

Activity/Event Care & Maintenance

BXXD0 - Land Management - InitialC&MD0100 - Land Management - C&MMain

2021/42


Figure 23-057: Care & Maintenance summary work programme

2042/63 2084/2105 2105/2127

Critical Path



Other Milestone



2063/84

BXXB0 - Safestore & Site Maintenance -Initial C&MD0300 - Safestore & Site Maintenance -C&M MainZ0200 - Contaminated LandMonitoringD0600 - Cladding Refurbishment -Phase 1D0600 - Cladding Refurbishment -Phase 2

X0100 - Intermediate Level Waste(ILW) Store OperationsX0200 - ILW Store Emptying

D1300 - ILW Stire off Site Disposal

BXXC0 - Low Level Waste (LLW)Transport & Disposal

D0200 - Security Operations - C&MMainD0500 - Beach Feeding

BXXA0 - Security Operations - InitialC&M

BXXF0 - Site Licensee Management

D0400 - Site Licensee Management

BXXF0/D0400 - Site LicenseeManagement

Commence Store Emptying

10 Year Review of C&M Security Plan

End of Care & Maintenance

Functional Support (23.16.60)

Site Services (23.15.51)

LLW Operations (23.14.43)

ILW Operations (23.14.41)

Regulator Approval of FSC Organisational Arrangements (Submission)

Management of Change To C&M Approval, Site Safety Case Approval

Start Care & Maintenance

OCNS-Approve Site Security Plan

Care & Maintenance (23.13.33)

The sea wall that divides Dungeness A sitefrom the English Channel is essential forthe protection of site against the sea

Waste incineration is a means of reducingthe total residual volume of low level activeincinerable waste

7,1344,841

0

42,831

7,82143,243

33,160

10,193

Transition (23.10)New Construction Projects (23.11)Commercial Operations (23.12)Decommissioning & Termination (23,13)Waste and Nuclear MaterialsManagement (23.14)Site Support (23.15)Support Services (23.16)Stakeholder Support (23.17)



Final Site ClearanceOn completion of C&M, all remaining buildings will be cleared, including the reactors.Following ground remediation and landscaping the site will be de-licensed andreturned to shingle banks, becoming an SSSI.

At an early point in the FSC phase the siteinfrastructure will be reinstated and awaste management facility (WMF) will bedesigned, constructed and commissioned.

The WMF will be established to process allwaste arising from FSC. Wastes will betransferred in a controlled manner from thework face to the WMF where they will bemonitored and categorised. Active wastewill be packaged in waste disposal boxesfor off-site transport and disposal. Cleanwaste will be used for filling building voids(basements etc) or disposed of off site.

Access to the reactor building structure willalso be gained at an early stage of theprogramme in order to carry outpreliminary structural and radiologicalsurveys. An initial clean up to removeloose contamination will follow this.

A section of the reactor building roof willbe removed to allow large items of plant tobe lifted out using a 150 tonne capacity

mobile crane situated at ground level. A 50tonne capacity mobile crane will be lifted inusing the same roof opening to assist indismantling operations. Supports will beconstructed over the top of the reactors(pile caps) and a temporary, removablecover placed over the roof opening in orderto maintain a weather tight envelopethroughout the dismantling of the reactorblock.

Each reactor will be completely removedby:

• dismantling the pressure vessel

• removing active steel and concrete

• dismantling the reactor structures

• removal of inactive steel and concrete.

Following the removal of all-active plantand contamination, the reactor buildingsand central block will be demolished andvoids below ground level filled.

The ILW store that was emptied of storedwaste during C&M may be used forstorage during the earlier stages of FSCbut will be demolished before the end ofthis phase of work.

The ILW store is likely to be clean or lightlysurface contaminated. It will bedecontaminated as required anddemolished as a clean building usingconventional demolition techniques.

At the end of the FSC, all the new servicesand structures installed to support theproject will be dismantled, demolished andremoved. Remaining buildings will beremoved down to a depth of 1 metre belowground level.

Depending on the function of the buildingsbeing removed, some decontaminationmay be needed before the strip out offittings and demolition can commence.Demolition will be carried out usingconventional industrial techniques.

Final Site Clearance 2102-2111

Figure 23-061: Final Site Clearance scope of work

The final period of decommissioning involves the dismantling of the remaining structures, appropriate clearanceof any residual radioactivity and de-licensing of the site and make it available for return its natural state andbe designated a site of special scientific interest (SSSI).



Activity/Event Final Site Clearance

E16A0 - Install Site Infrastructure23.11

2101/03


Figure 23-067: Final Site Clearance summary work programme

2103/05 2107/09 2109/2112

Critical Path



Other Milestone



2105/07

Contaminated Land Remediation (23.13.36)

Waste & Materials Management (23.11.12)E20A0 - Build Waste ManagementFacility - 23.11Decommissioning (23.11.11)EAA00 - Supply/Install ReactorDismantling Facilities - 23.11

ECC00 - Reactor Vessel Dismantling23.13EDD00 - Reactor BuildingDecontamination & Demolition - 23.13X0400 - ILW Store Demolition23.13E20B0 - Waste Management FacilityRemoval - 23.13E23A0 - Site Infrastructure Dismantling23.13

Z0300 - Contaminated LandRemediation - 23.13Site Close out (23.13 37)

E20Ca - Intermediate Level Waste(ILW) Management -23.14E20Da - Low Level Waste (LLW)Management - 23.14E3300 - ILW Disposal23.14


E20Db - LLW Transport & Disposa23.14


E24A0 - Landscaping of Site23.13E24B0 - Site Radiological Clearance23.13

Site Services (23.15.51)E1800 - Health Physics Provision23.15E16B0 - Site Services Staffing &Security - 23.15Ops and Project Support (23.15.52)E16C0 - Overall Project Support23.15Functional Support (23.16.60)E2600 - Site Licensee Management23.16

Start FSC Period

ILW WMF Planning consent

Planning Permission granted

Commence Reactor Dismantling approval

Waste Store Demolition Complete

NII agreement to Final State

Project Support Contract Placed

ILW Disposal Complete

LLW Disposal Complete

EA agreement to final condition

OCNS - Approve Site Security Plan

Site Delicensing



Generation is required until the end of2006 maximising the value whilemaintaining nuclear, industrial and publicsafety and environmental protection.

Staff restructuring will follow generation.The management of change process willbe used and approvals obtained from theregulators.

Work associated with C&MP has beenstarted in parallel with generation to ensurethat facilities are in place before thedefuelling period starts.

MXD plant operations will continue todramatically reduce the volume of ILWrequiring storage. The initial dissolvingproject has been completed and aprogramme of modifications to allow thedissolving of fuel lug waste will becompleted prior to this NTWP. Theoperating throughput of fuel lugs isplanned to be 7.5 tonnes per year.

Electrical overlay is a system that can beinstalled, fully tested and commissionedbefore existing electrical supplies areremoved. This will ensure the safety ofpersonnel from electrical shock whileundertaking the dismantling anddecommissioning activities.

Alternative effluent discharge covers thework required to modify the existingdischarge lines in line with the smallervolumes of flow when generation ceases.

Mobile waste retrieval project includesmodifications to tanks and the installationof new pipe work inside existing plantrooms. The design is based on readilyavailable and proven technology.

Essential services - mechanical includering main modifications to water, steam,compressed gases and fire-fightingsystems.

Essential services – electrical covers thegeneral project management for monitoring



NTWP (Years 1 to 3)During the period from April 2006 to March 2009 the Generation phase will finish anddefuelling will be four months from completion.

NTWP Years - 2006-2009 (Generation - Defuelling)

Figure 23-071: Years 1 to 3 scope of work

The period covers the most intensive set of changes since construction in the early 1960s. Electricity generationceases at the end of 2006. Following a cool down period intensive defuelling will commence in April 2007. Thiswill take 28 months (four months beyond this NTWP) and removes over 99.9% of the radioactive materials.

systems, telecommunications, publicaddress (PA) system, informationtechnology (IT) and a general instrumentoverlay system.

LLAW plant modifications coversimprovements to the mechanical handling,size reduction and contamination controlarrangements.

Waste store (ILW) covers the design andbuild of a waste store to provide temporarystorage for all ILW processed into a safestate during the C&MP phase.

Fuel route equipment will be worked harderduring defuelling than at any time duringgeneration. Key equipment is beingrefurbished to ensure reliability.

Off load discharge chutes are beingdesigned and built for use in the workingenvironment that will follow the shut downof the reactors. The original chutes will notwork in these conditions as their designtolerances are insufficient. Prior to the startof defuelling, the reactors will be at



Ops and Project Support (23.15.52)


Activity/Event Generation

2006/07

Figure 23-077: Schedule highlight chart for years 1 to 5

2008/09

Work Force Restructuring

Plant Enhancements

Infrastructure (23.11.13)Miscellaneous site wide services

Electrical systems/plant/buildings

Generation (23.12.20)Generation

Maintenance

Plant enhancements


Turbine hall plant and buildings


Fuel removal

Maintenance

Admin buildings, offices, workshops etc

Technical and project support

Work Force Restructuring (23.10.01)

Key Key Decision PointsCritical Path



Other Milestone



Waste & Materials (23.11.12)


Liquid waste

Waste processing facilities

2007/08 2009/10


Licence Condition Consent for Defuelling Structure

Final shutdown of R1 and R2

NII formal agreement to extend PSR to 31/12/2006

Submission of Post Operation & DefuellingSafety Case and final report

Approval of Post Operation & Defuelling Safety Case final report


Mobile waste retrieval project

Alternative effluent discharge line project complete


Commence defuelling of reactors Completion of defuelling of reactors

Ponds confirmed empty of fuel

Turbine hall approval to start asbestos removal

Commence turbine hall hazard reduction

Admin building demolition complete

EIADR Decision to Decommission TCPA-2 Submission of Application and Environmental Statement to Planning AuthorityTCPA-1 Submission of Application and Environmental Statement to Planning Authority

Year 1 concentrates on the safe productionof electricity, maximising revenue for ourclient

A major focus of work for this period is onthe safe despatch of spent fuel to Sellafieldfor reprocessing

ambient temperature and during this perioda number of fuel channels will be defuelledas part of the proving process for the newequipment.

Defuelling of the reactors and emptying ofthe ponds will be completed four months

beyond this NTWP, the whole project beingcompleted in 28 months.



Work in this LTP is based on but notlimited to the following genericassumptions:

• Sufficient SQEP resource is available to undertake the NTWP scope of work

• Generation shutdowns / events / reductions do not exceed that stated in the current generation risk model.

• All necessary consents and authorisations are obtained in accordance with the regulatory schedule.

• An electrical overlay system will be installed and commissioned to provide

a safe alternative electrical supply before implementation of all related projects.

• The reactors will be dismantled using a top down approach via a major penetration through the pile cap.

• That agreement will be reached with theregulators before 31 March 2006 that the PSR is approved until 2016.

• Station lifetimes, de-fuelling windows and spent fuel flask deliveries to site willbe as assumed in the MOP and no external factors will prevent despatches from the site.

Major Assumptions& ExclusionsAssumptions provide a positive bounding to the work. They have been considered interms of scope, schedule, cost, contract approach and regulatory requirements, to allowthe planning process to continue past decisions or actions that have not yet taken place.

Figure 23-081: Major Assumptions & Exclusions by Category

Conventional building structures lower than 1m below ground level, do not need to be removed to achieve completion of sitedecommissioning and de-licensing.

Decommissioning & Termination (23.13)34.23230

32.23230

36.23250

Conventional plant and buildings are considered to be non-contaminated.

It is assumed that radioactively contaminated ground will be remediated by simple excavation and disposal at a national LLW repository with similar conditions for acceptance and charges as Drigg.

Category Asumptions Justification

No current evidence that excavation in excess of this depth will be required.

52.23210

52.23200

52.23200

Site Support (23.15)

Stakeholder Support (23.17)

The Decommissioning Overarching Safety Case is approved to allow fullstation decommissioning to plan.External consideration will not delay EIADR consent.

The support activities currently carried out by Reactor Sites Services will continue, regardless of where and by whom.

40 years of operational experience has found no evidence ofcontamination in these buildings.Based on experience at other sites.

17.71 Regulators available for advice and consultation as necessary and will continue to adopt a consistent and proportionate approach.

Informal discussions wirh regulator indicate that this will be acceptable

Current progress with Stakeholders is going well and adverse commentshave been received so far.Based on current plans

Continuation of current relationship

Category Asumptions Justification

An unrevealed plant condition does not reduce the de-fuelling rate by more than 10 channels per month or limits the capability to despatch flasks by a rate of 1 or more per month.

Commercial Operations (23.12) 20.23215 Historical Information on failures during 40 years of service

The existing, aged, fuel route plant remains capable of achieving the increased throughputs without failure to the end of de-fuelling.

Commercial Operations (23.12)20.23215 Subject to the satisfactory completion of the maintenance and

enhancement plans

Production Operations will cease on 31st December 2006.Commercial Operations (23.12)20.23280 The site is working to the Plan as directed by the executive.

Reactor 1 blower gland steam safety valves can be tested with the reactor on load.

Commercial Operations (23.12) 20.23280 Engineering judgement and plant configuration have shown this to be a

viable option

That no more than 1 fuel element per year will leak more than 1500 MBq/day into the pond.

Commercial Operations (23.12) 20.23215 Historical Information on failures during 40 years of service

Additional elements specific to the NTWP

• Inspection and maintenance of the ILW store can cease after the store has beenemptied, even though it will not be dismantled until the FSC.

• There will be no major new activities such as prosecutions or planning enquiries etc.

• The performance of the LTP is not adversely impacted by enforced changes to the security arrangements or changes in vigilance states

• An accident and its effects occurring at any nuclear installation both within the UK and overseas do not adversely impact the performance of the LTP.



Risks are uncertain events that, if theyoccur, would have an effect on achievingthe scope objectives. They are usuallydefined as achieving the project safely, tothe appropriate quality, within budget andwithin the baseline schedule.

Risks that positively affect the scope areconsidered as opportunities while thosethat adversely affect scope are consideredas threats. They arise as much from thepossibility of lost opportunities as from theprobability that threats will materialise orthat errors will be made. Both types ofrisks are recorded and managed incompliance with British Nuclear Group’sprocedure, which mirrors closely the NDA’sProgramme Control Procedure.

Risks are reviewed at the site ProgrammeControl Board and through regularengagement with the Site Project Lead

Team, Regulators and key stakeholders.Mitigation actions are recorded with therisk in the station Risk Register.

Risk ManagementIt is important that the significant cost and programme risks associated with thedelivery of work across Dungeness A are well understood, allowing effective riskmitigation activities to be developed and managed.

DescriptionNTWP

Description

Possible ImpactMitigation Activities

PSWBS 23.11 - Delays to the commissioning of the Electrical Overlay System

Figure 23-085: Risk Summary

Description Possible ImpactMitigation Activities

There is a risk that delays to the commissioning of the Electrical Overlay System could result in delays deplanting the Turbine Hall and inability to supply electricity to the new Administration Building.Delays to schedule and to follow up work.If by September the Specification is still undefined, and the decommissioning schedule not finalised, the contract will be tendered on the defined work only

There is a risk that the relocation infrastructure may not be fully in place by the schedule due date. Loss of IT systems, telecoms and effective management. Possibility of security and personnel safety issues.Manage the change-over in the holiday period and outside generation phase. Use specialist contractors for the decommissioning andcommissioning of the IT and telecom systems with firm price and schedule. Investigate the feasability of new stand alone IT and telecomsystems installed in the New Admin Building, installed and commissioned prior to the change-over.

Extended project duration.Include clause in the terms and conditions of the sub-contract.

PSWBS 23.11 - New Admin. Accommodation Building - Relocation Schedule Risk

Description Possible ImpactMitigation Activities

There is a risk that the de-planting contractor runs behind schedule. Delay to the removal of the Galbestos cladding.PSWBS 23.13 -Turbine Hall Hazard Reduction

Delays in the introduction of defuelling / decommissioning structure.Hold regular meetings with NII site inspector and furnish with information as necessary.

Regulator does not accept proposed new Emergency Scheme arrangements, indications on other sites that generic proposals may not be accepted.

PSWBS 23.16 - New emergency scheme arrangements.

Increased costs and delays to the schedule.Develop procurement strategies to minimise impact. A procurement plan has been developed and published for the Near Term Work Plan.

There is a risk that a significant change to the availability or cost of key supply chain above that allowed for or assumed in the plan could result in increased cost or delays to the schedule.

Multiple Projects - Changes to cost and availability of key supply chain

Lack of SQEP could result in inappropriate solutions, extended schedules and increased costs.Staff retention and succession management procedures. Constant attention given to regular group strategy meetings. The implementation of the Lifetime Partnership Agreement (LPA) up to 2010. Redirection of SQEP from other departments / sites. Further recruitment and trainingto release workforce for essential training. Additional incentives rolled out over the next year.

There is a risk that Suitably Qualified and Experienced Personnel (SQEP), especially of nuclear capability, are not availableto deliver the plans.

Multiple Projects - Lack of Suitably Qualified and Experienced Personnel (SQEP)

Description


Description


Description




SummaryMilestone ScheduleKey milestones for Dungeness A are shown in the tables below for this LTP. These arederived from the category summaries and based on the key performance indicators.

423Date Description Category

Figure 23-089: Key Milestones and Gantt chart

Transition (23.10)

Regulatory

Key milestones

Workforce Restructuring - Generation into Defuelling -Phase 1 Restructuring G/D

2006-2014

13 31/12/2006 Cessation of Generation

2 02/03/2007 Asbestos Removal - Gate 1Approval

New Construction (23.11)

Commercial Ops (23.12)

2024-2032

5 31/03/2101 Planning permissionGranted

6 01/07/2101 ILW WMF Planning consent8 30/06/2102 NII Consent to start9 23/03/2108 NII Consent to start10 20/08/2110 NII agreement to Final State11 17/06/2111 EA agreement to final

conditionOther

14 02/01/2007 Phase 1 Restructuringcomplete

15 01/04/2007 Defuelling Commenced16 08/11/2007 Overlay System Complete19 31/07/2009 Defuelling Complete20 01/08/2009 Phase 2 Restructuring

complete21 25/06/2010 Decommissioning Project

Finish22 17/04/2111 Removal complete23 25/07/2011 Ponds Plant Furniture D & D

complete24 27/11/2013 Ponds Structure D & D

Completed25 14/10/2014 ILW Store construction

complete26 04/01/2016 Project Finish28 16/01/2017 Portable AETP-construction

complete29 31/03/2017 Phase 3 Restructuring

complete30 27/12/2049 First Reactor Cladding

complete

12015-2023

Defuelling into Care & Maintenance Preparations -Phase 2 Restructuring D/CMP

Care & Maintenance Preparations into Care &Maintenance - Phase 3 Restructuring CMP/CM

Decommissioning - Portable AETP - Active WastePlant/Systems/Bldgs CMP (23235.35200)

Reactor Dismantling Facilities - Reactor Vessel FSC(23240.36200)

Waste & Materials Management - ILW Store/Designand Build - ILW Store CMP (23245.36600)

Waste Management Facility (WMF) -Build Waste Man Facy FSC (23245.36400.E20A0)

Infrastructure - Electrical Overlay System -Electrical Systems/Plant/Buildings G/D (23230.34600)

Generation - Production Operations G(23280.40000)

Defuelling - Decommissioning Preparations D(23215.32800)

Decommissioning & Termination (23.13)Interim Decommissioning - DecommissioningPreparations D - Irradiated Fuel Storage & DespatchEquipment D/CMP (23220.33600)Turbine Hall Plant & Buildings - Conventional Plantand Buildings D/CMP (23230.34800)R1 & R2 Boiler House & Circulator Halls Decomm.and Buildings - Auxilary Plant D/CMP (23240.35900)R1 & R2 Buildings Safestore Preparation - AuxilaryPlant CMP (23240.36300)

Care & Maintenance - Reactor Buildings Safestore firstrecladding - Reactor Building CM (23240.36300)

Final Decommissioning - Reactor Building Deplantingand Demolition - Reactor Vessel FSC (23240.36200)

Dismantling heat Exchanger & Primary Circuit Facility -Heat Exchanger and Primary circuits FSC (23240.360)

Remove Waste Management Facility - WasteManagement Facility FSC (23245.36600)

C&M & FSC Contam Land Remediation - ContaminatedLand Remediation & Management FS (23250.3690.Z030)

Site Close Out - FSC Land Remediation -Landscaping FSC (23250.36800.E24A0)

14

20

29

28

25

16

13

15

19

23

24

2

21

26



45

Figure 23-089: Key Milestones and Gantt chart - continued

2033-2041 2042-2050 2051-2059 2060-2068 2069-2077 2078-2086 2087-2095 2096-2104 2105-2111

5

6

30

9

8

22

10

11

Plant testing enables the demonstration ofsafety control equipment as in this case oftesting fire spray systems

The environment agency is just one of theregulators that visit Dungeness A



Lifetime Plan ValueThe summary table shows the base, escalated and discounted costs for the site overthe LTP.

This section presents a financial overview.Costs are reported in tabulated formats bytotal cost and by time phasing.

Cost data used in the compilation of thisLTP has been drawn from several differentsource documents including:

• Near Term Work Plan

• Technical Baseline Plans

• Pre Decommissioning Plans

In addition, more up to date data hasbecome available from sources such asawarded contracts, tenders andquotations.



• Cost at March 2017 BCWS £515.5M

• Cost at March 2102 BCWS £664.9M

• Cost at March 2111 BCWS £1,164.2M

Key Transition (23.10)New Construction Projects (23.11)Commercial Operations 23.12)Decommissioning & Termination(23.13)Waste and Nuclear MaterialsManagement (23.14)Site Support (23.15)Support Services (23.16)Stakeholder Support (23.17)

237,049

229,278

113,542

Figure 23-105: Lifecycle categorycost distribution (£k)

253,375

73,539

198,098

43,65215,669



Reconciliation of Costs

Figure 23-107: Reconciliation of Costs

Reduction in severance figures - Note 1

Better estimating on charge chutes and increasedconfidence due to Decom enablers - See also, Note 2

Project Management cost (PMC) added to AETP from site support - category 15 - Note 2

FED/MCI costs reduced, MWRP costs increased, PMC added to individual projects - Note 2. Also Voids Retrevial Project deferred to FSC Reactor Dismantling

PMC costs added to new offices, essential services and electrical overlay projects - Note 2

New post operation preparation project included. PMC, rail transport and production operations costs added

No further planned outages

EC&I work included and works control has increased. Plant enhancement estimating, defuelling operations and maintenance are all reduced

No costs associated with this element

New work identified and now included

Additional project staff costs have been apportioned to all the projects - see note 2

Radiological clearance (PMC)

ILW operations costs have increased although treatment and temporary storage costs have reduced - see alsoNote 2

LLW operations costs have increased although treatment and temporary storage and disposal costs have reduced- see also Note 2

HZW operations costs have increased - see Note 2

NHW operations costs have increased - see Note 2

The major variance is the site utilities cost

The major variance is the redistribution of management costs across the individual projects and categories - seeNote 2

Increased resources within Finance, Environment, Safetyand Quality plus Training and Development have accounted for the Major variances.

Corporate Support costs reduced

Regulatory Support costs reduced

PA/PR Activity costs reduced

Workforce Restructuring (23.10.01)


Decommissioning (23.11.11)

Waste & Materials Management (23.11.12)


Generation (23.12.20)

Outages/Shutdowns (23.12.21)


Initial Decommissioning (23.13.30)

Surveillance and Maintenance (23.13.31)


Care & Maintenance (23.13.33)


Contaminated Land Remediation (23.13.36)

Site Close Out (23.13.37)



HZW Operations (23.14.45)

NHW Operations (23.14.46)

Site Services (23.15.51)

Ops & Project Support (23.15.52)

Functional Support (23.16.60)

Corporate Support (23.16.61)

Regulatory Support (23.17.70)

PA/PR Activities (23.17.71)

43,652 48,887 -5,235

726 925 -199

95,812 93,915 1,896

73,963 68,499 5,464

27,578 22,157 5,420

28,154 23,682 4,472

0 1 -1

45,458 40,248 5,209

0 0 0

30 0 30

87,384 50,156 37,228

1,157 1,143 13

114,362 118,151 -3,789

121,994 117,645 4,348

533 243 289

161 303 -142

154,626 125,006 29,621

74,651 156,566 -81,914

109,830 98,033 11,797

3,712 3,818 -106

12,684 15,020 -2,335

2,985 3,067 -82

Reconciliation Notes

This is due to a new Decommissioning Structure retaining more staff during the Care and Maintenance Preparations period.

The LCBL 2005 Decommissioning structure was based on the Hunterston model of 146 staff (Full time and Agency). During the course of the year this level of staffing has been assessed as inadequate by experienced overseas decommissioning agents and as a result the LTP Decommissioning Structure has been reviewed and is now based on the Hinkley Model of 345 staff (Full Time and Agency). Additionally the original management costs have been moved from site support, category 15.

1

2

38,726 38,289 437

112,967 99,145 13,822

13,111 12,947 163



LTP StaffingTransition will result in changes to staffinglevels and work practices. Consultationswill be held with staff and the TradesUnions and proposals made for manninglevels as each major phase is completed.These proposals will be incorporated intothe Management of Change (MoC)documents prepared for the Regulators.Approval from the Regulators and theClient are external constraints on movingforward to the next stage.

Upon completion of defuelling, greater useof sub-contract staff will be made for thesite to move into C&MP.

FSC will see a large increase in staffinglevels, when it is anticipated that most ofthe workforce will be on fixed timescalecontracts.

Staffing CurveThree major workforce restructuring projects will occur after the Generation,Defuelling and C&MP phases. Increased use of subcontract staff will give greaterflexibility in the control of manpower on site.

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

FT

E

050

100150200250300350400450500550600650700750800

FT

E



LCBL Key MetricsA variety of wastes are generated duringthe various phases of the LTP. Wastearisings will be generated by projects, asthe site enters C&MP. Waste is managedwithin Waste & Nuclear MaterialsManagement Category for final transportand disposal off-site

The two phases when decommissioningand demolition work will be at a high areC&MP and FSC. The following metrics arean indication of where the waste isexpected to come from.

Fig. 23-109 - the areas of project workthat will generate ILW waste during C&MP.

Fig. 23-111 – the areas of project workthat will generate LLW waste during C&MP.

Fig. 23-113 – Asbestos is a site wideproject within its own right and this metricindicates the buildings where the waste willbe generated during C&MP.

Fig. 23-115 - FSC is the final phase fordemolition and the production of wastes.Here is an indicator of what types of wastewill be generated during this phase.

Metrics & KeyQuantity CurvesTo progress Dungeness A main activities during the life of this LTP, key quantitieshave been identified and will be reported against on a monthly basis. A selection ofmetrics illustrate this type of reporting procedure.

61

17

485

12

Ponds Decommissioning

Fuel Route and Pile Cap

Mobile Waste Retrieval

Other Minor Projects

Key

Figure 23-109: Preliminary packaged ILW stored on-site during C&MP (cu.m)

369

697

1067

950

250

281

Pile Cap Decommissioning

Ponds Decommissioning

Reactor Auxiliary Plant Decommissioning

Reactor Buildings Decommissioning

Active Waste Treatment Decommissioning


Key

Figure 23-111: Preliminary packaged LLW sent off-site during C&MP (cu.m)

81

7

80

26

32

Admin Buildings & Offices

Workshops (1)

Turbine Hall Workshops

Active Waste Treatment


Key

Figure 23-113: Hazardous waste arisings (asbestos) during C&MP (cu.m)

8,417

55,363

34,539

ILW

LLW

NHW

Key

Figure 23-115: Site waste during FSC Phase (cu.m)



NTWP Key Metrics

Fig. 23-117 Cessation of generationoccurs at the end of 2006 and the averagemonthly target figures for generation areshown to obtain 2.20TWhrs for theremaining generating period.

Fig. 23-119 The graphic shows theamount of fuel contained within thereactors during the generating anddefuelling part of the NTWP

Fig. 23-121 During the NTWP, a start willbe made on decommissioning anddemolition of some conventional plant andbuildings. The graphic shows the volume ofbuildings demolished in this period.

0

50

100

150

200

250

April May June July Aug Sept Oct Nov Dec

Figure 23-117: GWh To the End of Generation

GW

hp

erM

ont

h

0

500

1,000

1,500

2,000

2,500

GW

hC

umul

ativ

e

Key GWh/Month Cumulative

0

300

600

900

1200

1500

Figure 23-121: Buildings Demolished during NTWP

Volu

mes

(cu.

m)

2006/07 2007/08 2008/09

Significant Dates

Generation 1965 – 2006

Defuelling 2007 – 2009

Care & Maintenance Preparations 2009 – 2017

Care & Maintenance 2017 – 2102

Final Site Clearance 2102 – 2111



The MOP requires Dungeness A to generate until the end of2006. The NII has confirmed that no outage is required onreactor R1 this year and a letter allowing both reactors tooperate past March 2006 is expected. Upon receipt, allsafety cases will be in place to allow continued generationon both reactors until December 31st 2006. Target output is2.20TWhr

The MXD plant is unique in the treatment of ILW fuel lugsand dramatically reduces the storage volumes required. Aproject is underway to modify the lug vaults to allowretrieval of the lugs for dissolving in the MXD plant. Theresult being minimal waste for subsequent storage on site.

Lessons learnt from other stations are on board for having aflexible safety case allowing defuelling of fuel channels inany order. Also new chutes are being made to ensure thereactors can be defuelled cold. Defuelling will be co-ordinated with other defuelling sites, operating powerstations and Sellafield reprocessing plant, as per the MOP

During C&MP most plant and buildings, with the exceptionof the reactor buildings, will have been dismantled anddemolished. The reactor buildings will be put into a safeand secure state for a prolonged period. The majority ofwaste generated in this period will be retrieved, processedand packaged.

During C&M, the remaining buildings are maintained to alevel commensurate with the risk to the plant and potentialhazards. Monitoring will demonstrate contamination control,verify the effectiveness of containment and ensurecompliance with authorised discharge limits.

During FSC the reactors and buildings will be dismantled,the ILW store dismantled, decontaminated and demolishedand the site cleared of contaminated shingle. A radiologicalsurvey will be carried out to confirm that the site licensecan be withdrawn, the site released for return to its naturalshingle state and designated an SSSI.

ConclusionThis LTP demonstrates how effective stewardship of Dungeness A site will continue,with robust plans in place to complete Generation and Defuelling and progress to FSCin a way that maximises value to the NDA.

For the remainder of generation, the goalwill be to produce electricity safely,compliantly, efficiently and effectively totargets set by the NDA.

A safety case is expected to be formallyagreed with the NII to extend operation ofboth reactors from March 2006 toDecember 2006. A case has already beenagreed with the NII to confirm that nooutage is required on reactor one.

The lug vaults will be modified to allowretrieval of the lugs for dissolving in theMagnox dissolution plant (MXD).

The post-operational and defuelling safetycase is being developed to allow thestation to defuel.

During generation the fuel route will berefurbished to enhance equipment,improving reliability and contributing toachieving the 28-month defuelling period.

As defuelling ends, more than 99.9% of thesite nuclear inventory will have beenremoved, reducing the level of staffing andsystems required for maintaining safety.This will be a significant step towards thesafe state required for C&M.

During C&MP most plant and buildings aredecommissioned, demolished andremoved from site. The reactor buildingswill be put into a safe and secure state.Operational wastes will be retrieved,processed, packaged and housed in apurpose-built store located on DungenessA site.

During C&M the level of radioactivity withinthe reactors reduces by natural decay andthis will make final decommissioning of thereactors easier and safer. This planassumes that at the end of C&M, the sitewill be cleared of all remaining buildings(including the reactors), de-licensed,returned to its natural shingle state and thebeing designated a SSSI.



Notes

British Nuclear Group is a businessgroup of British Nuclear Fuels plc

Dungeness Power Station,British Nuclear Group, Romney Marsh, Kent TN29 9PP

T +44 (0)1797 343100F +44 (0)1797 343142www.britishnucleargroup.com

© Nuclear Decommissioning Authority and Magnox Electric Ltd. 2006All rights reserved. No part of this publication may be reproduced in any material form(including photocopying or storing in any medium by electronic means), or communicated tothe public by any form of electronic transmission, without the written permission of thecopyright holders, except as permitted under the Copyright, Designs and Patents Act 1988.

Herdus HouseWestlakes Science & Technology ParkMoor Row, Cumbria, CA24 3HU

T +44 (0)1925 80 2001F +44 (0)1925 80 2003www.nda.gov.uk

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