Research on extent of examination in non-destructive inspection based on probabilistic fracture mechanics

Mano, Akihiro ; Yamaguchi, Yoshihito ; Katsuyama, Jinya  ; Li, Y. 

In the quantitative methodology of risk informed in-service inspection developed in the United States, extent of examination is determined based on the leak frequency evaluated for piping segment. One of important influential factors of the evaluation is probability of detection (POD) for crack. However, POD is assumed to be constant value regardless of crack size. Probabilistic fracture mechanics (PFM) analysis can evaluate leak probability of a weld considering POD curve depending on crack size. In this study, in order to plan the examination rationally, we proposed method of calculating leak frequency of piping segment from leak probability of welds, and the influence of the POD curve on extent of examination were investigated based on PFM analysis.