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:
herefore the material’s susceptibility to corrosion), the U-bend region of short-radius tubes should be stress-relieved after bending. The materials that support the tubes and other materials on the secondary side should be sufficiently resistant to degradation to ensure that the tubes will remain adequately supported and to reduce the potential for the generation of loose parts, which can result in a loss of tube integrity. The corrosion-resistant cladding on the tubesheet and on other primary side components should be weld-deposited, fabricated, and inspected according to the requirements in Part QW of Section IX of the ASME Code. 5.4.2.1-9 Revision 4 - July 2016 D. Limits the crevice and residual stresses in the tubesheet region. The extent of the tube-to-tubesheet crevice should be limited. This can be accomplished by expanding the tube throughout the tubesheet region, if practical (given other design considerations such as the desired preload in the tube for once-through steam generators). The choice of the method for expansion should consider limiting the stresses in the tube. Limiting the crevices will restrict the buildup of corrosion product and sludge that can lead to corrosion. Limiting the stresses will diminish the potential for stress-corrosion cracking. The tube-to-tubesheet weld should be designed for structural and leakage integrity under operating and design-basis accident conditions. This is generally accomplished through compliance with Section III of the ASME Code. E. Includes an appropriate allowance for deterioration (including corrosion) of the steam generator materials. This is accomplished through compliance with Section III of the ASME Code (Articles NB-2160 and NB-3121 for Class 1 components and Articles NC-2160 and NC-3121 for Class 2 components). F. Uses bolting material that will perform adequately under the expected service conditions and that is not subject to stress-corrosion cracking. This can be accomplished by following the