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:
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 regulatory positions in RG 1.65, “Materials and Inspections for Reactor Vessel Closure Studs.” Although RG 1.65 provides guidance for the design of reactor vessel closure studs, it is also appropriate for the selection of suitable steam generator bolting material. The integrity of bolting and threaded fasteners is also reviewed under SRP Section 3.13, “Threaded Fasteners - ASME Code Class 1, 2, and 3.” G. Uses a feedwater inlet design that prevents flow-accelerated corrosion (FAC), water hammer, and thermal stratification. The reviewer determines that the feedwater components in the steam generator are resistant to FAC because they are fabricated from chromium-containing low alloy steel or stainless steel. (SRP Section 10.3.6, “Steam and Feedwater System Materials,” provides detailed guidance on materials selection to avoid FAC.) The potential for water hammer can be minimized by following the guidance in Branch Technical Position (BTP) 10-2, “Design Guidelines for Avoiding Water Hammers in Steam Generators,” (NUREG-0800, Chapter 10). Examples of design features that prevent water hammer in feedring designs include top-discharge feedring tubes, a leak-limiting feedring seal assembly, and leak-tight feedring inspection port covers. Operating experience has shown that thermal stratification in the feedwater inlet nozzle can be prevented by using an elevated feedring design or “gooseneck” inlet design that forces incoming feedwater to fill the inlet nozzle. The above criteria, in conjunction with the acceptance criteria for interfacing reviews and appropriately performed inservice inspections, as discussed above, provide assurance that (1) the design is compatible with environmental conditions during normal operating, testing, maintenance, and