Example Analysis for Environmental Fatigue Crack Growth in Austenitic Stainless Steel Piping Using Code Case N-809

Reference fatigue crack growth (da/dN) curves for pressurized water reactor (PWR) environments have been proposed for ASME Section XI flaw evaluation applications in Code Case N-809. The reference curves are dependent on temperature, loading rate, mean stress, and cyclic stress range which are all contained in the da/dN model. This paper presents the application of N-809 in a fatigue crack growth analysis for a large diameter austenitic pipe in a PWR Reactor Coolant System main loop using the current analytical evaluation procedures in Appendix C of ASME Section XI. The example problem was used to evaluate the reference fatigue crack growth curves during the development of the code case and the results have been compared with other industry codes.