PROBABILISTIC METHODS FOR CONDITION ASSESSMENT AND LIFE PREDICTION OFCONCRETE STRUCTURES IN NUCLEAR-POWER-PLANTS

A probability-based methodology is being developed in support of the N RC Structural Aging Program to assist in evaluating the reliability of existing concrete structures in nuclear power plants under potential future operating loads and extreme environmental and accidental events . The methodology includes models to predict structural deterioration due to environmental stressors, a database to support the use of these models, and methods for analyzing time-dependent reliability of concr ete structural components subjected to stochastic loads. The methodolo gy can be used to support a plant license extension application by pro viding evidence that safety-related concrete structures in their curre nt (service) condition are able to withstand future extreme events wit h a level of reliability sufficient for public health and safety.