Document: NUREG-0800
Document ID: 61ddad5b-f914-4192-b39f-6f00ffa2e3c5
Document Type: srp
Title: REACTOR INTERNAL AND CORE SUPPORT STRUCTURE MATERIALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190005.pdf
Revision Date: 2023-06
Chapter: 4
Section ID: 4.5.2
CFR Part: 
CFR Title: 

Content:
described in SRP Section 5.2.3. The reviewer verifies that environmental conditions are controlled and welding procedures are developed such that the probabilities of sensitization and microfissuring are minimized. SRP Section 4.5.1, Subsection III.2, identifies an acceptable alternate to the methods described in Regulatory Guide 1.44 for verifying the degree of sensitization that occurs during welding. In addition, the reviewer 4.5.2-7 Revision 3 - March 2007 verifies that materials are selected to assure compatibility with the compositions of the reactor coolant, and that the fabrication and cleaning controls imposed on stainless steel components are adequate to prevent contamination with chloride and fluoride ions. Where cast austenitic stainless steels are proposed for use, the reviewer verifies that, under the expected environmental conditions, the selected material will provide adequate fracture toughness over its design life (e.g., considering thermal aging due to exposure to reactor coolant operating temperatures). 5. Other Materials. The reviewer verifies that the heat treatment and welding controls provided in the material specifications and fabrication procedures are appropriate for the material. The reviewer verifies that the fabrication and cleaning controls will preclude contamination of nickel-base alloys by chloride ions, fluoride ions, or lead. Operating experience has indicated that certain nickel-chromium-iron alloys (e.g. Alloy 600 and associated weld materials, Alloy 82 and 182) are susceptible to stress corrosion cracking, as documented in NUREG-1823 and NRC Generic Letter 97-01. Alloy 690, and associated weld materials Alloy 52 and 152, have improved corrosion resistance in comparison to Alloy 600 used in PWR reactor coolant pressure boundary (RCPB) applications. Where nickel-chromium-iron alloys are proposed for use in the PWR RCPB, use of Alloy 690 materials is preferred. If Alloy 600 material is proposed, the reviewer verifies that an