Requirements for thermal annealing of the reactor pressure vessel.

CFR · 2024-01-01 · US · Title 10

(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, (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, (3) The requirements of paragraph (f)(1) of this section have been satisfied. (b) (1) (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 vessel, containment, biological shield, attached piping and appurtena

official document · source cfr-2024 · id 10:§ 50.66