User's manuals of probabilistic fracture mechanics analysis code for Ni-based alloy welds, PASCAL-NP

Udagawa, Makoto; Katsuyama, Jinya  ; Onizawa, Kunio 

As a part of research on the structural integrity assessment for LWR components considering aging degradation, a PFM analysis code PASCAL-NP has been developed. This code evaluates the failure probabilities on a basis of Monte Carlo method caused by PWSCC / NiSCC at dissimilar metal welds and structurally discontinuous components. This PFM analysis code has functions of crack initiation and crack growth calculations for various patterns of crack locations and orientations in a probabilistic manner such as the scatters of material strength, crack growth rate and residual stress distribution, and so on. This code can also evaluate the failure probabilities such as leakage and/or break probabilities of Ni-based alloy welds due to these types of SCC. This report summarizes the failure examples in actual plants and theoretical backgrounds. This one also represents methods to execute program and the case studies using PASCAL-NP code.