Fusion component failure rate database, status and evolution

Nuclear fusion is expected to be available as a source of energy from the middle of the present century. One key aspect of the success of this technology will be the reliability growth implemented in the design from the early phases. Nuclear fusion plants are expected to exploit many fusion plant-specific components with a relatively low technology readiness level, or in some cases exploit components with mature technology from fission plants, but within different and poorly explored operating domain windows (e.g. in terms of loads, operation regimes, etc). An important source of uncertainty in reliability assessment then resides in the failure and repair model definition for fusion plant components. To limit such uncertainty, a fusion component failure rate database was developed to collect failure and repair screening data suitable for fusion system reliability analyses. The records of the database were validated by field expert collaborative efforts and mainly consist of two categories: (i) nuclear fission data recommended values to be used for fusion applications, and (ii) data estimated from nuclear fusion research facility operating experience. First, a review of available data and the database organization status is presented. The database evolution is then described in terms of added failure and repair data records derived from engineering selection, specific component selection datasheets and failure modelling.