Safety assessment of a projected waste repository for HLW during its operational phase

Based on the repository concept for high level radioactive wastes (HLW) developed in Switzerland, a thorough safety assessment was performed for the repository's operational phase. The approach used is described and the results obtained are given in this paper. There were three starting points for this safety assessment, e.g.: analysis of the operations in the facility, with the aim to identify the potential for accidents which could lead to radioactivity releases; investigation of natural phenomena and other possible initiating events with repository-external origin, to determine their likely effects on the facility; study even of either hypothetical or unrealistic accident scenarios, giving an indication on the repository concept's capability to mitigate the consequences of such extreme situations