Technical and safety aspects of handling, conditioning and storing severely damaged nuclear fuel: The TMI experience

Following the accident at the Three Mile Island (TMI) reactor plant, an extensive programme has been developed and implemented to defuel, transport and store the damaged reactor core. Phases of the programme included determination of core conditions, development of defuelling tooling, fuel storage canisters, a transportation system, core debris conditioning procedures, and preparation of facilities for core storage. Novel means of in situ core examination were employed, and a variety of manual defuelling tools were developed. A new double containment shipping cask was designed, licensed and fabricated. Means to address criticality, pyrophoricity and radiolytically generated gas questions were developed. Decisions concerning the final disposal of the core debris will be made subsequently in the context of the United States high level waste repository programme. Satisfactory conduct of this programme is demonstrating that severely damaged fuel can be safely handled and stored in a practical and effective manner. (author). 6 refs