Test manufacture of a canister insert

This report describes the insert-manufacturing test of a disposal canister for spent nu-clear fuel that was made by Metso Paper Oy, Jyväskylä Foundry, in 2003 on contract for Posiva Oy.

The test manufacture was a part of the co-operation development programme of encap-sulation technology between SKB AB and Posiva Oy.

Insert casting was specified according to the current manufacturing specifications of SKB. The canister insert was of BWR-type with integral bottom. This was the first trial manufacture of this type of insert in Finland and, in total, the second test manufacture of insert by Metso Paper.

The result fulfilled all the requirements but the material mechanical properties and met-allurgical structure of the cast material. The measured tensile strength, ultimate strength and elongation at rupture were lower than specified. The reason for this was revealed in the metallurgical investigation of the cast material. The nodulizing of the graphite was not occurred during the casting process according to the requirements.