Database application for multi-level area-specific FEP catalogues in the German site selection process for high-level radioactive waste disposal

Abstract. The safety case for a nuclear waste repository requires the consideration of future evolutions. Methodology and technical implementation for the systematic derivation of a limited number of expected and deviating future evolutions of potential repository siting areas are presented. Evolutions are derived from the analysis of FEP (features, events, and processes) catalogues, which are comprehensive, structured descriptions of a repository system and the interactions and dependencies of processes and components within the repository. In order to apply this work-intensive method to the ninety sub-areas which are currently under consideration in the Site Selection Procedure for the final disposal of high-level radioactive waste in Germany, a generic FEP catalogue is compiled in a first step, from which host rock-specific and area-specific FEP catalogues are created. An analysis of component and process interactions is completed at host-rock level and then transferred and adapted to individual areas, taking site-specific information into account. To facilitate the documentation and analysis of the disposal system and ensure consistency, a sophisticated in-house database solution has been developed.