In the present study, the concept of Generalized Failure Mechanism Knowledge (GFMK) has been proposed and applied practically to Rokkasho reprocessing plant. GFMK is a knowledge scheme that describes failure mechanism independent of particular subject. In this scheme, sets of conditions leading to specific failure are generalized, which allows us to apply to different equipment. Once GFMK have been constructed, it is possible to estimate the likelihood of the failure without expert judgments. Following two issues have been studied in this study. 1) Building a GFMK knowledgebase based on previous troubles cases 2) Application of GFMK to specific plant sub-systems to derive failure mechanism For issue 1), the GFMK knowledgebase has been constructed based on the previous failures cases in Rokkasho reprocessing plant with emphasis on the events related to aging. For issue 2), it has been confirmed that the possible failure mechanism can be obtained by applying GFMK to the realistic scale sub-system of Rokkasho reprocessing plant. The derived failure mechanism has been compared with the ones on the design specification and has been confirmed that most of the derived failure mechanism are feasible.
