Probabilistic Fracture Mechanics Analyses for Structural Integrity Assessment of Nuclear Components

The probabilistic component integrity analyses project (PROBAB) aimed at investigating the use of probabilistic fracture mechanics (PFM) for structural integrity assessment of nuclear components. This paper presents the final stage of the work performed within the project. It includes the study of an embrittled reference reactor pressure vessel (RPV) subjected to pressurized thermal shocks (PTS) and the probabilistic leak before break analyses of a dissimilar metal weld join subjected to stress corrosion cracking. The system transients are studied with the TRACE code and the probabilistic analyses performed with the Monte Carlo based FAVOR and PRO-LOCA codes. For comparison, the deterministic analysis of the RPV under a selected PTS case is also performed with the ABAQUS code. The results of the analyses confirm the benefits of the PFM approach to assess the safe and long-term operation of aged nuclear components.