Document: NRC Regulatory Guide
Document ID: 2704425a-c58a-45c4-93ab-8761721c3e7a
Document Type: regulatory_guide
Title: Evaluation of Reactor Pressure Vessels with Charpy Upper-Shelf Energy Less Than 50 Ft-Lb
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740038.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.161
CFR Part: 
CFR Title: 

Content:
sees that would be incurred by plant-specific analyses is estimated as 9 plants x 6 staff-months per plant, or 54 staff-months (9360 hours). In addition to the increased burden on the licensees, it is estimated that an additional 1.5 NRC staff-month would be required to review each plant-specific submittal. Thus, the total increased burden on the NRC staff assuming that half of the affected plants can be grouped, is estimated to be 9 plants x 1.5 staff-month per plant, or 13.5 staff-months (2340 hours). This estimate assumes that there would be only minor discussions with the licensees. 4.2 Take No Action As discussed in Section 3.2 above, taking no action is judged to be a nonviable alternative. 5. DECISION RATIONALE K It is rehmnded tat the reglatory guide be issued because it would offer a comprehensive set of acceptance criteria, evaluation procedures, and material properties that can be used to perform the analyses required under Appendix 0 to 10 CFR Part 50 for those pressum vessels that have Charpy upper-shelf energy of any beltline material that falls below 50 ft-lb. Issuing the regulatory guide is recommended over the alternative of endorsing Appendix K to ASME Section XI because Appendix K does not currently include (1) analysis procedures for Service Levels C and D, (2) guidance on selecting the transients for evaluation, or (3) details on tempesture-dependent material properties. Further, it is estimated that preparing plant-specific analyses that include the procedures and data that are not addressed in Appendix K would require approximately 54 staff-months of effort for the industry and approximately 9 staff-months for the NRC to review the additional information. The NRC staff considered the possibility of worling with the ASME Code Section XI working group to modify Appendix K to include the missing procedures and data. However, given the number of plants that could need the guidance in the near term, and given the ASME codification process and the