Waste encapsulation for Oskarshamn

10 January 2007

Svensk Kärnbränslehantering AB (SKB), the company responsible for storing Swedish nuclear waste, has applied for permission to site an encapsulation plant at Oskarshamn.


The company has submittedan application to the Swedish Nuclear Power Inspectorate (SKI) for a permit toconstruct and operate a used fuel encapsulation plant next to the existinginterim storage facility (Clab). This facility – near the Oskarshamn nuclearpower plant – stores Sweden's used nuclear fuel in water basins in vaults blasted out of the rock. Clab beganoperating in 1985 and has a storage capacity for some 5000 tonnes of uranium (about20,000 BWR assemblies plus 2500 PWR assemblies). The new encapsulation facilityand Clab will eventually be operated together.


In the encapsulation plant, the spent nuclear fuel will be dried and placed in copper canisters. Thecanister will then be fitted with a lid that is welded on by means of a weldingmethod called friction stir welding (FSW). This entails that lid and canisterare machined together into a homogeneous material. The weld joint will beinspected by means of non-destructive testing (radiographic and ultrasonic).The canister can then be placed in a transport cask for transport to a proposedfinal repository.


SKB does not expect theregulatory authorities or the government to make a final ruling on theapplication under the Nuclear Activities Act until after 2009, when theapplication for the final repository itself is submitted. A comprehensive environmentalreview of the entire final repository system will then be commenced. The siteinvestigations that are currently being conducted in Östhammar and Oskarshamnare based on the KBS-3 system, which entails that the fuel is encapsulated incopper canisters deposited at a depth of approximately 500m in the Swedishbedrock, embedded in bentonite clay.


Further information


Svensk Kärnbränslehantering AB (SKB) 
Swedish Nuclear Power Inspectorate (SKI)


WNA's WasteManagement in the Nuclear Fuel Cycle information paper
 NuclearEnergy in Sweden information paper