Life prediction and monitoring of nuclear power plant components for service-related degradation

This paper describes industry programs to manage structural degradation and to justify continued operation of nuclear components,when unexpected degra dation has been encountered due to design materials and/or operational prob lems. Other issues have been related to operation of components beyond thei r original design life in cases where there is no evidence of fatigue crack initiation or other forms,ls of structural degradation. Data from plant op erating experience have been applied in combination with inservice inspecti ons and degradation management programs to ensure that the degradation mech anisms do not adversely impact plant safety. Probabilistic fracture I,mecha nics calculations are presented to demonstrate how component failure probab ilities carl be managed through augmented inservice inspection programs.