Document: NRC Regulatory Guide
Document ID: 7c9a00a8-375c-4641-bc1b-762a663a96d6
Document Type: regulatory_guide
Title: Guidelines for Evaluating Fatigue Analyses Incorporating the Life Reduction of Metal Components Due to the Effects of the Light-Water Reactor Environment for New Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1417/ML14171A584.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.207
CFR Part: 
CFR Title: 

Content:
at consider the effects of LWR coolant environments on carbon and low-alloy steels, wrought and cast austenitic stainless steels, Ni-Cr-Fe alloys, and their associated weld metals. Specifically, these methods include calculating the CUF in air using ASME Code, Section III analysis procedures, and then employing the environmental factor (Fen), as described in NUREG/CR-6909, Revision 1. In particular, Appendix A to that report includes detailed descriptions and additional guidance concerning the overall method and all the required calculations. These methods apply to those components exposed to reactor coolant that are required by regulation to have a fatigue CUF evaluation or have an existing CLB fatigue CUF calculation. 1. Carbon and Low-Alloy Steels and Welds Calculate the environmental CUF for carbon and low-alloy steel components and their associated weld metals exposed to LWR coolant environments using the procedures in Sections 1.1 through 1.3. 1.1. CUF in Air Calculate the CUF in air using ASME Code, Section III analysis procedures (Subarticle NB- 3200, “Design by Analysis,” or Subarticle NB-3600, “Piping Design”) and the fatigue air curves (updated ANL model curves) provided in Figures A.1 and A.2 and Table A.1 in Appendix A to NUREG/CR-6909, Revision 1. Alternatively, the fatigue design curve for carbon and low-alloy steel in Appendix I to Section III of the 2013 Edition of the ASME Code may be used. 1.2. Environmental Factor (Fen) Calculate the environmental factor Fen for carbon and low-alloy steels and associated welds using Equation A.2 in NUREG/CR-6909, Revision 1. In the same document, Equations A.3 through A.6 should be used to calculate the parameters used in Equation A.2; Equation A.7 defines the strain threshold. DG-1309, Page 7 1.3. Environmental CUF Calculate the environmental CUF using Equation A.19 in NUREG/CR-6909, Revision 1. 2. Wrought and Cast Austenitic Stainless Steels and Welds Calculate the environmental CUF for wrought and cast