Probabilistic Fracture Mechanics Evaluation of Selected Passive Components – Technical Letter Report

Simonen, Fredric A. ; Doctor, Steven R. ; Gosselin, Stephen R. ; Rudland, David L. ; Xu, H. ; Wilkowski, Gery M. ; Lydell, Bengt O.

关键词: PROBABILISTIC ESTIMATION;    FRACTURE MECHANICS;    SENSITIVITY;    COMPUTERIZED SIMULATION;    STRESS CORROSION;    P CODES;    INTERGRANULAR CORROSION;    CRACK PROPAGATION;    FATIG;   

DOI  :  10.2172/909250
RP-ID  :  PNNL-16625
PID  :  OSTI ID: 909250
Others  :  Other: 401001060
Others  :  TRN: US200722%%1054

美国|英语

来源: SciTech Connect

【 摘 要 】

This report addresses the potential application of probabilistic fracture mechanics computer codes to support the Proactive Materials Degradation Assessment (PMDA) program as a method to predict component failure probabilities. The present report describes probabilistic fracture mechanics calculations that were performed for selected components using the PRO-LOCA and PRAISE computer codes. The calculations address the failure mechanisms of stress corrosion cracking, intergranular stress corrosion cracking, and fatigue for components and operating conditions that are known to make particular components susceptible to cracking. It was demonstrated that the two codes can predict essentially the same failure probabilities if both codes start with the same fracture mechanics model and the same inputs to the model. Comparisons with field experience showed that both codes predict relatively high failure probabilities for components under operating conditions that have resulted in field failures. It was found that modeling assumptions and inputs tended to give higher calculated failure probabilities than those derived from data on field failures. Sensitivity calculations were performed to show that uncertainties in the probabilistic calculations were sufficiently large to explain the differences between predicted failure probabilities and field experience.