PSA methodology study for RPV pressurized thermal shock

During transient, the inner surface of pressurized reactor pressure vessel (RPV) is cooled quickly, which is termed as pressurized thermal shock (PTS). So, a flaw may be caused and propagate through the RPV wall, that makes the RPV failure. Probabilistic safety assessment (PSA) is used to analysis the frequency of RPV flaw due to PTS. PSA model finds out the PTS event sequences, combining with the thermal hydraulic analysis, which supports the probabilistic fracture mechanics analysis for PTS. (authors)