Advanced Nuclear Power - AREVA

Nuclear ServicesNuclear ServicesTwo DecommissioningContracts in United KingdomNRTE VulcanPrototype Fast Reactor (PFR)The United Kingdom Atomic EnergyAuthority (UKAEA) was created in1954 to develop the civil nuclearindustry in the United Kingdom. Itsessential mission was research anddevelopment. Today its main area ofresearch is fusion. In 1995, the industrialactivities of the UKAEA were privatizedwithin AEA Technology,although the state is nevertheless thesole shareholder to date.UKAEA has 15 reactors andseven major radioactive facilities thathave either been completely dismantledor are in the process of beingdecommissioned. Dounreay, Scotland,presents UKAEA's biggest challenge.The site was dedicated to thedevelopment of the fast-neutron typereactor and the production of plutonium.It includes three experimentalreactors and all kinds of installationssuch as hot laboratories for the studyof materials, fuel reprocessing and productioninstallations, waste treatmentand storage installations. The270MWe Prototype Fast Reactor(PFR) operated from 1975-1994 andthe 15MWe Dounreay Fast Reactor(DFR) operated from 1959-1977.Other installations are still in operation,particularly those dedicated towaste treatment.Dounreay Restoration ProgramThe major components of theDounreay restoration program includethe decommissioning of the PFR andthe DFR, the management of radioactivewastes, and site clean up. The estimatedcost of this restoration programis around £6.5 billion ($9.2 billion).Site restoration work will take from 50- 60 years to complete.UKAEA has established fourmajor priorities for the decommissioningof these plants: the management ofuncertainty, safety standards, environmentalimpact and employment. Theuncertainty lies in the risk assessmentlinked to the project that integratesnearly 1,500 separate but interdependentactivities, some of whichare among the most technically challengingin the UK.Safety is a top priority, and thedecommissioning must provide along-term guarantee of public safety.The environmental restoration of theDounreay site is its long-term goal.The decommissioning process providessignificant employment in the areasituated north of Scotland.Framatome ANP, like other majorsuppliers of UKAEA, uses local subcontractorsto carry out in-situ work.Framatome ANP has the firstsignificant contractsThe Dismantling and WasteProcessing Division ofFramatome ANP has signed twocontracts with UKAEA for thedismantling of the experimental FastReactor at the Dounreay nuclear sitein northern Scotland. They follow aseries of option studies previouslyawarded to Framatome ANP forother projects at Dounreay.The first contract is for the developmentof tools for remote dismantlingof the reactor coolant system.The challenge is the high radiationwithin the reactor bioshield. Thebioshield contains the coolant systems.In addition, the presence of Sodiumand Potassium metal (NaK) – a highlyflammable mixture - requires thedevelopment of specific cutting toolsthat operate at very low temperatures.StoresAdmin AreaD1200 Lab ComplexFuel Cycle Area (FCA)The biological shield containing thecircuits will be kept at -18°C in orderto keep the NaK solid, thus minimizingthe risk of ignition.The second contract is for thedecommissioning of the spent-fuelstorage pond. This three-year projectwill encompass treatment of pondwater, sludge recovery, removal ofmetal racks, removal of the top layerof concrete, and roof replacement. Thedecontamination of the water requiresthe removal of Cesium before its dischargein the water treatment facilityat the site. For this, Framatome ANPhas developed a new water treatmentprocess using zeolites that can beembedded in concrete.FR ProcessingPlant (D1206)D2670DecontaminationFacility (D2800)Novatome (a Framatome ANPDivision) had already obtained a subcontractfor PFR sodium disposal andprovided process design and technicalassistance on site until the plant wasfully operational.Dounreay Fast Reactor (DFR)ShaftWRACSLow Level Waste PltsDescaling FacilityDounreay CementationPlant (DCP)DounreayMaterialsTest Reactor(DMTR)Dounreay Nuclear Power Plant siteTrainingAs a result of these contracts,Framatome ANP has become a majorplayer in the decommissioning andwaste management market in UK. @Cutting tool of NaK filled pipe in air with a band sawThis remote cutting tool with hydraulic shears is able to operate under low temperaturesallowing its use around highly-flammable materials.14 Advanced Nuclear Power 08/200108/2001 Advanced Nuclear Power 15