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:
§ 50.66 Requirements for thermal annealing of the reactor pressure vessel. ( a ) For those light water nuclear power reactors where neutron radiation has reduced the fracture toughness of the reactor vessel materials, a thermal annealing may be applied to the reactor vessel to recover the fracture toughness of the material. The use of a thermal annealing treatment is subject to the requirements in this section. A report describing the licensee's plan for conducting the thermal annealing must be submitted in accordance with § 50.4 at least three years prior to the date at which the limiting fracture toughness criteria in § 50.61 or appendix G to part 50 would be exceeded. Within three years of the submittal of the Thermal Annealing Report and at least thirty days prior to the start of the thermal annealing, the NRC will review the Thermal Annealing Report and make available the results of its evaluation at the NRC Web site, http://www.nrc.gov . The licensee may begin the thermal anneal after: ( 1 ) Submitting the Thermal Annealing Report required by paragraph (b) of this section; ( 2 ) The NRC makes available the results of its evaluation of the Thermal Annealing Report at the NRC Web site, http://www.nrc.gov ; and ( 3 ) The requirements of paragraph (f)(1) of this section have been satisfied. ( b ) Thermal Annealing Report. The Thermal Annealing Report must include: a Thermal Annealing Operating Plan; a Requalification Inspection and Test Program; a Fracture Toughness Recovery and Reembrittlement Trend Assurance Program; and an Identification of Changes Requiring a License Amendment. ( 1 ) Thermal Annealing Operating Plan. The thermal annealing operating plan must include: ( i ) A detailed description of the pressure vessel and all structures and components that are expected to experience significant thermal or stress effects during the thermal annealing operation; ( ii ) An evaluation of the effects of mechanical and thermal stresses and temperatures on the