Selection by interaction matrix method of Features, Events and Processes (FEPs) required in developing evolution scenarios specific to low and intermediate level radioactive waste final repositories

The paper proposes a method which can be used in the safety analyses required during the licensing process of low and intermediate level radioactive waste final repository. According to the recommended methodology of International Atomic Energy Agency (the coordinated research project on Improvement of Safety Assessment Methodologies for Near Surface Disposal Facilities - ISAM), the safety analyses specific to a low and intermediate level radioactive waste final repository must contain the assessment of representative evolution scenarios for the repository. Development of these scenarios have to be achieved for whole life time of repository, taking into account both normal and alternative evolution of facility. Scenarios have to be generated in a systematic, transparent, reproducible and auditable manner. Main step of scenario generation process is the development of Features, Events and Processes List - FEPs List, specific to any repository, and the systematic selection of the FEPs important for repository evolution. Authors propose a selection method of FEPs, based on an interaction matrix; the proposed method is applicable to evolution scenarios generation (both normal and alternative scenarios), for Low Level Radioactive Waste Repository Baita Bihor and, also, for Low and Intermediate Level Radioactive Waste Final Repository in Cernavoda (DFDSMA). (authors)