Document: NUREG-0800
Document ID: 4a96f7f8-16d2-41a4-a436-12b528d783d7
Document Type: srp
Title: REACTOR VESSEL INTEGRITY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190008.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.3.3
CFR Part: 
CFR Title: 

Content:
nnealing treatment to recover the fracture toughness of the material, subject to the requirements of 10 CFR 50.66, “Requirements for thermal annealing of the reactor pressure vessel.” Annealing of the reactor vessel provides assurance that fracture toughness properties can be restored to satisfy the fracture toughness requirements of GDC 31. 2. Materials of Construction. The basic acceptance criteria for the materials used in the construction of the reactor vessel, and the regulations that they satisfy, are detailed in SRP Sections 5.2.3 and 5.3.1. These criteria are the requirements of Appendix G, 10 CFR Part 50, as augmented by Sections III and IX of the Code. The materials must be compatible with the design requirements in the GDC. Acceptability is based on standard practice and engineering judgement, with consideration being given to such factors as material form, size-related variations in properties, and nonisotropic characteristics. Although many materials are acceptable for reactor vessels according to Section III of the Code, the special considerations relating to fracture toughness and radiation effects effectively limit the basic materials that are currently acceptable for most parts of reactor vessels to SA 533 Gr B C1 1, SA 508 C1 2, and SA 508 C1 3. Acceptability criteria for other grades will have to be developed before they can be used. Revision 2 - March 2007 5.3.3-5 Material compositions and expected neutron fluence must be compatible with the requirements for the material surveillance program. The reviewer uses published data to ensure that the predicted shift in toughness properties (RTNDT and upper shelf energy) is conservative, based on actual material composition and predicted fluence. The predicted shift in toughness properties should be at least as conservative as that obtained by use of the most recent revision of Regulatory Guide (RG) 1.99. Acceptability of the material surveillance program, as specified in Appendix H, “Reactor