Operational Safety and Post-Closure Safety: Investigation of their Interactions by a FEP Analysis - 18040

The consideration of operational safety for a repository for high-level waste is a challenge, since it has to integrate the dimension of long-term safety. The operator has to demonstrate on the one hand the safety of the workers in the mine and of men and environment during operation. On the other hand a proper operation of the mine has to guarantee that the state of the facility at the time of closure will be compatible with the requirements for long-term safety. To achieve this, a pre-closure safety analysis should include (a) a general description of the structures, systems, components, equipment, and process activities during the operational phase, (b) identification and a systematic analysis of naturally occurring and human-induced hazards and (c) identification and documentation of the strong relationships between operational safety and post-closure safety. In a German R and D project, a FEP catalogue for the operational phase was developed based on the national disposal concepts for clay and salt. The FEP catalogue contains analyses of the processes and events that affect the components (features) of the repository system in its entirety. The FEP catalogue was applied to identify hazards for the operational phase and to document the impacts of these FEP (including the identified hazards) on post-closure safety. (authors)