Probability of pipe failure in the reactor coolant loops of Westinghouse PWR plants. Volume 2. Pipe failure induced by crack growth. Load Combination Program

This report assesses the probability of reactor coolant loop (RCL) piping failures resulting from a crack growth mechanism. The Westinghouse pressurized water reactor (PWR) plants in the United States east of the Rocky Mountains are considered. After the introduction (Section 1), the assessment is presented in five parts (Sections 2 to 6). Section 2 describes the characteristics of RCL piping in these Westinghouse PWR plants. Section 3 describes the methodology used in the analysis. Sections 4 and 5 present the best-estimate and uncertainty analyses, respectively. Our conclusions are presented in Section 6, along with recommended items for consideration in future licensing regulations.