ASME STP-NU-039 PDF

ASME STP-NU-039 – Creep and Creep-Fatigue Crack Growth at Structural Discontinuities and Welds

The GEN IV reactor concepts require structural components to operate at high temperatures in aregime where creep damage may occur and cracks may grow. The U.S. Nuclear RegulatoryCommission (NRC) has identified the lack of a quantitative methodology for evaluating creep andcreep crack growth as a shortcoming of the ASME Subsection NH (Class 1 Components in ElevatedTemperature Service) standard [1]. The development of elastic-plastic fracture mechanics methodsand the concepts of leak-before-break (LBB) were led by the needs of the nuclear industry. Thesecrack assessment methods are now well established and used routinely in PWR and BWR plantextension applications and new designs. Quantitative creep and creep-fatigue crack growthassessment procedures are now needed for these GEN IV developments.