Benchmarking PRAISE CANDU 1.0 With Nuclear Risk Based Inspection Methodology Project Fatigue Cases

Abstract

A probabilistic fracture mechanics (PFM) code, PRAISECANDU 1.0, has been developed under a software quality assurance (QA) program in full compliance with Canadian Standards Association (CSA) N286.799, and was initially released in June 2012 and officially approved for use in August 2013. Extensive verification and validation has been performed on PRAISECANDU 1.0 for the purpose of software QA. This paper presents the fatigue benchmarking against NURBIM (nuclear risk based inspection methodology for passive components) fatigue cases between PRAISECANDU 1.0 and six other PFM codes. This benchmarking is considered to be an important element of the validation of PRAISECANDU. Excellent agreement is observed in spite of the differences between the codes. The comparison of the predicted leak probability at the 40th year shows that PRAISECANDU not only captures the same trend but also bounds (higher predicted failure probability) the majority of the NURBIM results. In addition to the leak probability, the rupture probability, and uncertainty analysis, which were not reported in the NURBIM Project, are also calculated with PRAISECANDU and presented.