Safety Review on Welding Defect Incident of In-Service Nuclear Auxiliary System Pipings

A case of a safety review was given, which was on the incident caused by welding defects of auxiliary system pipings in a nuclear power plant. The cause of the defects, the area where exists the welds with defects, and the corrective actions were analyzed and reviewed. The problems in design, manufacture and erection of nuclear safety facilities exposed in this incident were discussed.