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:
low power physics tests) are that the reactor vessel must be at a temperature equal to or higher than the minimum temperature required for the inservice hydrostatic test, and at least 40 F higher than the minimum pressure-temperature curve for heatup and cooldown calculated as described in the preceding section. The minimum temperature for the inservice hydrostatic test for the vessel used in the preceding example was 273 F. A vertical line at 273 F on the pressure-temperature curve, intersecting a curve 40 F higher than the pressure-temperature limit curve as determined in the preceding section, constitutes the limit for core operation for this example. 4. Pressurized Thermal Shock in PWRs The reviewer evaluates the projected values for RT , including the calculational PTS methods and assumptions, and compares the projected values with the screening criteria in 10 CFR 50.61. For each PWR where the RT value for any material in the beltline is PTS projected to exceed the PTS screening criterion before the expiration date of the operating license, the licensee shall submit an analysis and schedule for implementation of flux reduction programs that are reasonably practical to avoid exceeding the PTS screening criterion. If the analysis indicates that no reasonably practical flux reduction program will prevent the value of RT from exceeding the PTS screening criterion PTS before the expirations date of the operating license, the licensee shall submit a safety analysis to determine what modifications are necessary to prevent potential failure of the reactor vessel as a result of postulated PTS events if continued operation beyond the screening criterion is allowed. These safety analyses are reviewed against the requirements of 10 CFR 50.61 and the guidance of Regulatory Guide 1.154.69 For standard design certification reviews under 10 CFR 52, the procedures above should be followed, as modified by the procedures in SRP Section 14.3 (proposed), to verify that the design