Document: 10 CFR Part 50
Document ID: f3d5df11-b35b-4e81-b016-39463863b59a
Document Type: cfr
Title: Requirements for thermal annealing of the reactor pressure vessel.
Source: 10 CFR Part 50
Source URL: https://www.ecfr.gov/current/title-10/part-50/section-50.66
Revision Date: 
Chapter: 
Section ID: 50.66
CFR Part: 50
CFR Title: 10

Content:
his section have been met. ( B ) If any changes requiring a license amendment pursuant to § 50.59(c)(2) or changes to Technical Specifications are identified, the licensee may not restart its reactor until approval is obtained from the Director, Office of Nuclear Reactor Regulation and the requirements of paragraph (f)(2) of this section have been met. ( d ) Thermal Annealing Results Report. Every licensee that either completes a thermal annealing, or that terminates an annealing but elects to take full or partial credit for the annealing, shall provide the following information within three months of completing the thermal anneal, unless an extension is authorized by the Director, Office of Nuclear Reactor Regulation: ( 1 ) The time and temperature profiles of the actual thermal annealing; ( 2 ) The post-anneal RT NDT and Charpy upper-shelf energy values of the reactor vessel materials for use in subsequent reactor operation; ( 3 ) The projected post-anneal reembrittlement trends for both RT NDT and Charpy upper-shelf energy; and ( 4 ) The projected values of RT PTS and Charpy upper-shelf energy at the end of the proposed period of operation addressed in the Thermal Annealing Report. ( e ) Procedures for Determining the Recovery of Fracture Toughness. The procedures of this paragraph must be used to determine the percent recovery of ΔRT NDT , R t , and percent recovery of Charpy upper-shelf energy, R u . In all cases, R t and R u may not exceed 100. ( 1 ) For those reactors with surveillance programs which have developed credible surveillance data as defined in § 50.61 , percent recovery due to thermal annealing (R t and R u ) must be evaluated by testing surveillance specimens that have been withdrawn from the surveillance program and that have been annealed under the same time and temperature conditions as those given the beltline material. ( 2 ) Alternatively, the percent recovery due to thermal annealing (R t and R u ) may be determined from the results of a