抄録
This paper provides a method for statistical degradation mode analysis of field experiences in nuclear power plants. Typical degradation modes and their causes were defined based on several risk informed databases. The statistical degradation mode analysis of NUCIA indicates that all cases can be classified into proposed degradation modes. The detail analysis was performed to investigate all cases due to inconformity of weld. Many cases of inconformity of weld was involved with high cycle fatigue due to vibration of pumps at socket welded connections. Statistical analysis was also done based on several components such as steam generator, valves, pumps and fuel assemblies.
