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:
the test results. Testing to evaluate percent recovery of ARTNDT should result in an unambiguous evaluation of the tem perature at which the average Charpy energy versus temperature curve achieves an energy level of 30 ft-lb. It is preferable that the testing cover a broad range of results based on the shear percentage (from near 0 percent to greater than 95 percent) to permit a more complete assessment of the Charpy data trends for the material and to preclude false trends from data cluster ing around the 30 ft-lb level. Testing to evaluate Charpy upper-shelf energy re covery should provide an unambiguous definition of the Charpy upper-shelf energy for the material. All tests used in evaluating the Charpy upper-shelf energy should result in 100 percent shear. 3.1.6 Quantification of Post-Anneal Initial Properties Quantification of the post-anneal initial proper ties, RTNDT and Charpy upper-shelf energy, is depen dent on the method used to determine the percent re covery by annealing. 3.1.6.1 Vessel Surveillance Program Method. The assurance program should describe the surveil lance results to be used in evaluating percent recovery, along with the proposed method to relate the observed percent recovery from the surveillance results to the percent recovery of the vessel material. One method for relating the observed recovery to the vessel recovery is to compare the measured recov ery from the test (or tests) of surveillance specimens to the percent recovery from Equations 1 and 2 for the surveillance capsule. The average ratio (or the ratio from a single capsule) between the measured recovery from the surveillance capsules and that evaluated from Equations 1 and 2 for the surveillance capsule provides a material-specific adjustment for the generic equa tion. In this method, the vessel percent recovery would be calculated by multiplying the percent recovery de termined from Equations 1 and 2 for the vessel by the average ratio adjustment. Values of Rt and RUSE de