Document: NUREG-0800
Document ID: 26aca061-b0de-4983-bbca-3fccb00afc2f
Document Type: srp
Title: PRESSURE-TEMPERATURE LIMITS AND PRESSURIZED THERMAL SHOCK1
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070431.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.3.2
CFR Part: 
CFR Title: 

Content:
ows: a. Pressure-Temperature Limits for Preservice Hydrostatic Tests During preservice hydrostatic tests (if fuel is not in the vessel), the K must be IRa 27 greater than the K caused by pressure. The expression used is: I K = K (pressure) < K I I IRa 28 b. Pressure-Temperature Limits for Inservice Leak and Hydrostatic Tests During performance of inservice leak and hydrostatic tests, the K must be IRa 29 greater than 1.5 times the K caused by pressure. The expression used is: I K = 1.5 K (pressure) < K I I IRa 30 DRAFT Rev. 2 - April 1996 5.3.2-6 c. Pressure-Temperature Limits for Heatup and Cooldown Operations At all times during heatup and cooldown operations, the K must be greater IRa 31 than the sum of 2 times the K caused by pressure and the K caused by thermal I I gradients. The expression used is: K = 2K (pressure) + K (thermal) < K I I I IRa 32 d. Pressure-Temperature Limits for Core 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, and in addition, the pressure-temperature relationship shall provide at least a 22 C (40 F) margin over that required for heatup and cooldown operations. 33 4. Material Reference Temperature Limits for PWR Pressurized Thermal Shock Events Values of RT projected using the methods of 10 CFR 50.61 for the time of the PTS initial application submittal and for the projected expiration date of the operating license must not exceed the screening criteria of 132 C (270 F) for plates, forgings, and axial weld materials, and 149 C (300 F) for circumferential weld materials. For RT values projected to exceed the screening criteria, safety PTS analyses must be provided that include proposed flux reduction programs or other corrective actions to prevent potential PTS related failure of the reactor vessel if continued plant operation beyond the screening criteria is planned.34 Technical Rationale:35 The technical