Session: CS-03-02 Environmental Fatigue Issues (Joint M&F)

Paper Number: 61651

Start Time: Tuesday, July 13, 2021, 08:00 PM

61651 - Comparison of International Codes for a Fatigue Crack Growth Flaw Tolerance Sample Problem 

As part of the development of American Society of Mechanical Engineers (ASME) Code Case N-809 [1], a series of sample calculations were performed to gain experience in using the Code Case methods and to determine the impact on a typical application.  Specifically, the application of N-809 in a fatigue crack growth analysis was evaluated for a large diameter austenitic pipe in a pressurized water reactor (PWR) reactor coolant system (RCS) main loop using the current analytical evaluation procedures in Appendix C of Section XI of the ASME Code [2].  The example problem was used to evaluate the reference fatigue crack growth curves during the development of N-809 and the results were compared to Japan Society of Mechanical Engineers (JSME) methods.

The previous example problem used to evaluate N-809 during its development was embellished and used to evaluate proposed ASME Code changes.  For example, the Electric Power Research Institute (EPRI) investigated possible improvements to ASME Code, Section XI, Nonmandatory Appendix L [3], and the previous N-809 example problem formed the basis for flaw tolerance calculations to evaluate those proposed improvements [4].  In addition, the ASME Code Section XI, Working Group of Flaw Evaluation Reference Curves (WGFERC) continues to evaluate additional research data and related improvements to N-809 and other fatigue crack growth rate methods.

As a part of these Code investigations, EPRI performed calculations for the Appendix L flaw tolerance sample problem using three international codes and standards to evaluate fatigue crack growth (da/dN) curves for PWR environments: (1) ASME Code Case N-809, (2) JSME Code methods [5], and (3) the French RSE-M method [6].  The results of these comparative calculations are presented and discussed in this presentation.

REFERENCES

[1] Code Case N-809, Reference Fatigue Crack Growth Rate Curves for Austenitic Stainless Steels in Pressurized Water Reactor Environments, Section XI, Division 1, ASME, New York, NY, approved June 23, 2015.

[2] PVP2015-45967, W.H. Bamford, R.C. Cipolla, A. Udyawar and N.L. Glunt, Example Analysis for Environmental Fatigue Crack Growth in Austenitic Stainless Steel Piping Using Code Case N-809, Proceedings of the ASME 2015 Pressure Vessels and Piping Conference (PVP2015), Boston, MA, July 2015.

[3] ASME Code, Section XI, Division 1, Rules for Inspection and Testing of Components of Light-Water-Cooled Plants, Nonmandatory Appendix L, “Operating Plant Fatigue Assessment,” ASME, New York, NY, 2019 Edition.

[4] PVP2020-21690, D.S. Somasundaram, D. Dedhia, D.J. Shim, G.L. Stevens and S.X. Xu, Review of Technical Basis for ASME Code Section XI Appendix L, Proceedings of the ASME 2020 Pressure Vessels and Piping Conference (PVP2020), Minneapolis, MN, July 2020.

[5] PVP2006-ICPVT-11-93224, “Fatigue Crack Growth Curve for Austenitic Stainless Steels in PWR Environment,” Proceedings of PVP2006-ICPVT-11, 2006 ASME Pressure Vessels and Piping Division Conference (PVP2006), Vancouver, BC, Canada, July 2006.

[6] RSE-M, In-Service Inspection, Installation and Maintenance Rules for Mechanical Components of PWR, Volume II, Appendices, Appendix 5.6, “Material Properties,” Section II, “Fatigue Crack Growth,” AFCEN, Courbevoie, France, 2018 Edition (English).

Presenting Author: Gary Stevens Electric Power Research Institute (EPRI)

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