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:
rmal annealing require ments in § 50.66, as an option for reducing embrittle ment when the toughness requirements of those rules cannot otherwise be met. The thermal annealing rule, 10 CFR 50.66, per mits the thermal annealing of reactor vessels to restore fracture toughness of the reactor vessel material that was reduced by neutron radiation. Section 50.66(a) requires that, prior to initiation of thermal annealing, a Thermal Annealing Report be submitted to describe the licensee's plan for conducting the thermal anneal. The report must be submitted at least 3 years prior to the date at which the limiting fracture toughness crite ria in 10 CFR 50.61 or Appendix G to Part 50 would be exceeded. This 3-year period is specified to provide the NRC staff with sufficient time to review the thermal annealing program. Within 3 years of submittal of a licensee's Thermal Annealing Report and at least 30 days prior to the start of the thermal annealing, 10 CFR 50.66(a) requires the NRC staff to review the Thermal Annealing Report and place the results of its evaluation in its Public Document Room. In order to provide for public participation in the regulatory proc ess, 10 CFR 50.66(0 requires that the NRC hold a public meeting a minimum of 30 days before the li censee starts to thermal anneal the reactor vessel. The licensee may. begin thermal annealing after the NRC has placed the results of its evaluation of the Thermal Annealing Report in the Public Document Room and after the public meeting is held. The Thermal Annealing Report is required by 10 CFR 50.66(b) to include (1) a Thermal Annealing Operating Plan, (2) a Requalification Inspection and Test Program, (3) a Fracture Toughness Recovery and "Reembrittlement Trend Assurance Program, and (4) the Identification of Unreviewed Safety Questions and Technical Specification Changes. The rule also provides three methods for deter mining the percent recovery. When surveillance speci-. mens are available from a credible