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:
employing materials removed from the beltline region of the reactor vessel. For this method, the sam ples removed from the vessel are used to evaluate the as-irradiated or pre-anneal condition of the material and the post-anneal condition of the material. The post-anneal condition is evaluated from specimens that have been annealed at the time and temperature 1.162-9 conditions equal to or bounded by the reactor vessel annealing conditions. The number of samples to be removed from the vessel depends on many factors, including the size of the samples, the reason for the annealing (determining both RTNDT and Charpy upper-shelf energy requires more tests than determining only one of these quanti ties), the testing plans (specimen size and type), and the acceptability of removing the samples from the ves sel. The samples removed from the vessel beltdine can be used to fabricate full-size Charpy specimens, inserts for reconstitution into full-size Charpy specimens, or sub-size Charpy specimens (see subsections 3.1.4.3 and 3.1.6.4). Other test methods for irradiated vessel material may be used if appropriate justification is provided. This method is plant-specific and, as described be low, several criteria must be satisfied to demonstrate the acceptability of this method for a specific applica tion or plant. The assurance program should provide a complete description of the plans for using samples removed from the vessel beltline, including the method for re moving the samples; the number, size, and location of the samples; analyses to demonstrate acceptability of the sample removal; the experimental plans for using the samples (size and number of specimens, test plans and procedures, etc.); and the method for determin ing the percent of recovery of the vessel material from the results of the tests from the samples. 3.1.2.1 Acceptability of Removing Material from the Vessel. The acceptability of the method used for removing samples from the vessel beltline is based on