Document: NRC Regulatory Guide
Document ID: a2b67b51-f5fe-4c86-a879-f0e439601f7f
Document Type: regulatory_guide
Title: Format and Content of Report for Thermal Annealing of Reactor Pressure Vessels
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740052.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.162
CFR Part: 
CFR Title: 

Content:
report should provide an evalu ation of the effects of mechanical and thermal stresses and temperatures on the vessel, containment, biologi cal shield, attached piping and appurtenances, and ad jacent equipment, components, and structures that demonstrates that the annealing operation will not be detrimental to reactor operation. This evaluation should include detailed thermal and structural analyses that establish appropriate time and temperature pro files, including the heatup and cooldown rates of the annealing operation, so that dimensional stability of the system will be maintained. The analyses should demonstrate that localized temperatures, thermal stress gradients, and subsequent residual stresses will not result in unacceptable dimensional changes or dis tortions in the vessel, attached piping, and appurte nances and that the thermal annealing cycle will not result in unacceptable degradation of the fatigue life of these components. The parameters to be evaluated in the thermal and stress analyses should include the annealing tempera ture, hold time at the annealing temperature, heating and cooling rates, the effect of insulation around the vessel Including the bottom head, the active heating length of the heating device, the physical constraints on the vessel, structural characteristics of attached pip ing assemblies, and any other restraints. The thermal analysis should establish the tempera ture profiles for the inside and outside surfaces of the vessel wall during heatup, start and end of steady-state conditions, and cooldown conditions. The effects of localized high temperatures should be evaluated for degradation of the concrete adjacent to the vessel, for changes, if any, in thermal and mechanical properties of the reactor insulation and for detrimental effects, if any, on containment and the biological shield. Maxi mum concrete temperatures should be based on exist ing design limits or provisions of Section III, Division 2, of the ASME Boiler and