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:
rsions of the GALL Report and the SRP-LR. Additional data evaluation subsequent to the publication of these two documents resulted in a revised Fen method for new reactors that the staff documented in Revision 0 of NUREG/CR-6909. The staff published guidance for the revised Fen methodology for new reactors in 2007 in Revision 0 of RG 1.207. The staff published Revision 0 of NUREG/CR-6909 as an alternative to NUREG/CR-6583 and NUREG/CR-5704 for use by licensees pursuing license renewal in 2010 as documented in Revision 2 of the GALL Report and the SRP-LR. Because the relationships in NUREG/CR-6583 and NUREG/CR-5704 were generally considered to be conservative compared to the revised expressions in Revision 0 of NUREG/CR-6909, either set of relationships was endorsed for use by license-renewal applicants in Revision 2 of the GALL Report and the SRP-LR. As part of further NRC-funded research efforts performed since the publication of Revision 0 of RG 1.207, the NRC staff evaluated additional available fatigue data (primarily from Japan), incorporated relevant data in their previously developed database, and updated the fatigue life models. The NRC staff also evaluated and incorporated relevant feedback from interested stakeholders based on the use of the Fen methods published in NUREG/CR-6583, NUREG/CR-5704, and Revision 0 of NUREG/CR-6909. The results of the NRC staff’s most recent research efforts on this topic are documented in Revision 1 of NUREG/CR-6909 (Ref. 9). Those results identified the need to revise and consolidate the previously published guidance for incorporating the effects of LWR coolant environments in fatigue life evaluations. Revision 1 of RG 1.207 maintains the previously endorsed methods for establishing fatigue design curves and defines updated Fen factors for use in evaluating the fatigue lives of reactor components exposed to LWR coolant environments. In Revision 0 of RG 1.207, the NRC staff identified a non-conservatism in the ASME Code