Investigation into reliability evaluation methodology for structural components by probabilistic fracture mechanics analysis; Effect on in-service inspection frequencies to failure probabilities at PLR piping

Ito, Hiroto; Onizawa, Kunio 

New code of probabilistic fracture mechanics (PFM) analysis, which evaluates failure probabilities in piping, has been developed by JAEA. The methodology of Rules on Fitness-for-Service for Nuclear Power Plants of JSME is introduced into the code. It involves initiation and growth of Stress Corrosion Cracking (SCC) etc, then evaluates the failure probabilities in piping. In-Service Inspection frequencies to weld lines in PLR piping which is sensitive to SCC, largely influence the failure probabilities. Therefore, effect on the frequency differences to the failure probabilities was evaluated by the code.