Safety assessment of HLW disposal in Switzerland: lessons learned

In Switzerland, the chosen concept for disposal of high-level wastes is a mined repository in a deep-lying geological formation. The crystalline basement of Northern Switzerland has been considered as a potential host rock formation and a comprehensive safety analysis has been performed (Project Gewahr 1985). Geological investigations have recently been extended to assess the possibilities of disposal in the overlying sedimentary formations. The salient features of the repository concepts are described and the key issues in a safety assessment identified. The similarities and differences between the crystalline and sediment options are discussed and, finally, future investigation requirements presented. 4 refs., 1 fig