Document: NUREG-0800
Document ID: e2737d9a-8e56-46cb-a97d-aaf62a442c6c
Document Type: srp
Title: PRESSURE-TEMPERATURE LIMITS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340637.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.3.2
CFR Part: 
CFR Title: 

Content:
sed regions. If primary stresses are calculated to be over 1.25 Sm in any region during the test, the RTNDT of the vessel must be assumed to be at least 501F higher than that of 5.3.2-15 Rev. 1 - July 1981 any region where the calculated primary stresses are over 1.25 S. (3) Alternatively, a fracture mechanics analysis, with technical justification for all assumptions and bases, may be made to determine the minimum test temperature. In no event shall the minimum temperature be lower than that resulting from calculations for the beltline region in accordance with Appendix G of the Code. 2.2.2 Heatup and Cooldown Limit Curves Heatup and cooldown pressure-temperature limit curves may be determined using single P! stress calculations, using the method given in t Appendix G of the Code. The effect of thermal gradients may be conservatively approximated by the procedures in Appendix G of the Code or from Figure 4-5 in WRC Bulletin 175. Calculations need only be performed for the beltline region, if the RTNDT of the beltline is demonstrated to be adequately higher than the RTNDT for all higher stressed regions. Alternatively, more rigorous analytical procedures may be used, provided that the intent of the Code is met, and adequate technical justification for all assumptions and bases is provided. 2.2.3 Core Operation Limits To provide added margins during actual core operation, Appendix G, 10 CFR Part 50 requires a minimum temperature during core operation, and a 400F margin in temperature over the pressure-temperature limits as determined for heatup and cooldown in 2.2.2 above. The minimum temperature, regardless of pressure, is the temperature calculated for the inservice hydrostatic test according to 2.2.1 above. 2.2.4 Upset Conditions The pressure-temperature limits described in 2.2.2 and 2.2.3 above are applicable to upset conditions. Normal operating procedures must permit variations from intended operation, including all upset conditions, without exceeding the limit