Document: NUREG-0800
Document ID: 495c2b41-2832-4900-9000-040f3ae8c835
Document Type: srp
Title: STEAM GENERATOR MATERIALS AND DESIGN
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1614/ML16147A289.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.2.1
CFR Part: 
CFR Title: 

Content:
2016 tube support or mechanical damage to the tubes from the generation of loose parts). As a result, the materials selected for the steam generator must be fabricated and tested to quality standards commensurate with the importance of the safety functions to be performed, as required by GDC 1. In addition, the materials selected for the RCPB must be fabricated and tested to the highest quality standards practical, as required by GDC 30, “Quality of Reactor Coolant Pressure Boundary.” The materials selected for use in fabricating the steam generator are acceptable from a fabrication/manufacturing standpoint if they comply with 10 CFR 50.55a. In general, this regulation—specifically 10 CFR 50.55a(c), 10 CFR 50.55a(d), and 10 CFR 50.55a(e)—requires that the components satisfy the requirements of Section III of the ASME Code. Provisions in 10 CFR 50.55a(b) permit ASME Code cases, as discussed in Regulatory Guide (RG) 1.84, “Design, Fabrication, and Materials Code Case Acceptability, ASME Section III,” to be used to select, fabricate, and test materials for the steam generator. Section III of the ASME Code establishes—through articles such as NCA-1000, NB-2000 (for Class 1 components), and NC-2000 (for Class 2 components)— requirements for selecting, processing, testing, inspecting (during fabrication/manufacturing), and certifying materials. In general, Section III of the ASME Code references Parts C and D of Section II of the ASME Code for permitted material specifications (e.g., in Articles NB-2120 and NC-2120). Examples of materials that are currently used for Class 1 components in the steam generator include the following: Tubing: ASME SB-163, N06690, Thermally Treated Pressure Plates: ASME SA-533, Grade B, Class 1 Pressure Forgings ASME SA-508, Grade 3, Class 2 (including nozzles and (formerly referred to as Class 3a) tubesheet): Nozzle Safe Ends: ASME SA-182, F316LN Channel Heads: ASME SA-508, Grade 3, Class 2 (formerly referred to as Class 3a)