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:
, 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 the ASME Code will be updated to be consistent with Appendix G to Section XI of the ASME Code. 5.3.2-5 Revision 2 - March 2007 B. Pressure-Temperature Requirements. Appendix G to 10 CFR Part 50 requires that the pressure-temperature (P-T) limits defined in that Appendix be at least as conservative as limits obtained by following the methods of analysis and the margins of safety of Appendix G of Section XI of the ASME Code, as stated below: i. Pressure-Temperature Limits for Preservice Hydrostatic Tests During preservice hydrostatic tests (if fuel is not in the vessel), a material’s lower bound static crack initiation fracture toughness, KIc, must be greater than the KI caused by pressure stresses acting on a defined, conservative hypothetical flaw, as shown in the following expression: Kapplied = KI(pressure) < KIc ii. Pressure-Temperature Limits for Inservice Leak and Hydrostatic Tests During performance of inservice leak and hydrostatic tests, a material’s KIc must be greater than 1.5 times the KI caused by pressure, as shown in the following expression: Kapplied = 1.5 KI(pressure) < KIc iii. Pressure-Temperature Limits for Heatup and Cooldown Operations At all times during heatup and cooldown operations, a material’s KIc must be greater than the sum of 2 times the KI caused by pressure and the KI caused by thermal gradients, as shown in the following expression: Kapplied = 2KI(pressure) + KI(thermal) < KIc iv. Pressure-Temperature Limits for Core Critical Operation At all times that the reactor core is critical (except for low-power physics tests), the temperature must be higher than that required for inservice hydrostatic testing. In addition, the P-T relationship must provide at least a 22 EC (40 EF) margin over that required for heatup and cooldown