Document: NUREG-0800
Document ID: c9c204f0-a162-491c-8c25-ee0418212f29
Document Type: srp
Title: PRESSURE-TEMPERATURE LIMITS, UPPER-SHELF ENERGY, AND PRESSURIZED
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0703/ML070380185.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.3.2
CFR Part: 
CFR Title: 

Content:
alternatives to the SRP acceptance criteria provide acceptable methods of compliance with the NRC regulations. 1. Pressure-Temperature Limits A. Applicable Regulations, Codes, and Basis Documents. The regulations in 10 CFR 50.60 and associated Appendix G to 10 CFR Part 50 describe the conditions that require P-T limits and provide the general basis for these limits. Appendix G specifically requires that P-T limits must be at least as conservative as limits obtained by following Appendix G to Section XI of the ASME Code during heatup, cooldown, and test conditions. Appendix G to 10 CFR Part 50 also requires additional safety margins when the reactor core is critical. Since the regulations may not have included specific fracture toughness testing requirements for the ferritic materials in the pressure-retaining components at the time some of the reactor facilities were designed and constructed, Branch Technical Position (BTP 5-3) describes procedures for making estimates and assumptions concerning the fracture toughness properties of materials in the older plants. Although Appendix G to Section III of the ASME Code is usually referenced with regard to facility design and construction, the reviewer should instead apply the provisions of Appendix G to Section XI of the ASME Code when using this SRP. The following provide the rationale for using Appendix G to Section XI of the ASME Code instead of Appendix G to Section III of the ASME Code: i. Appendix G to 10 CFR Part 50 specifically references Appendix G to Section XI to the ASME Code, and Appendix G to Section III to the ASME Code contains similar provisions. ii. The differences between Appendix G to Section XI of the ASME Code and Appendix G to Section III of the ASME Code have resulted from a series of ASME code cases, including N-588, N-640, and N-641. Appendix G to Section III of the ASME Code has not been updated since those code cases were developed. However, the staff expects that Appendix G of Section III of