Document: NRC Regulatory Guide
Document ID: e16da529-b6b4-4fdf-bc3f-7490180363f3
Document Type: regulatory_guide
Title: Environmental Qualification of Certain Electric Equipment Important to Safety for Nuclear Power Plants (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2018/ML20183A423.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.89
CFR Part: 
CFR Title: 

Content:
ion may be performed by motor-operated valves. These valve motor-operators should be environmentally qualified. Example 4 Harsh environments associated with high-energy line breaks (HELBs) could cause control system malfunctions resulting in consequences more severe than those for the HELBs generally analyzed in Chapter 15 of each licensee’s final safety analysis report or beyond the capability of operators or safety systems. In these cases, the control system failures could prevent satisfactory accomplishment of the safety functions required for the HELBs. The following are typical examples of control systems that could fail as a result of an HELB and whose consequential failure may not be bounded by HELBs analyzed in the final safety analysis report: DG-1361, Appendix B, Page B-2 • automatic rod control system • pressurizer power-operated relief valve control system • main feedwater control system • steam generator power-operated relief valve control system • turbine generator control system Based on the above, it may be necessary to environmentally qualify components associated with various control systems. DG-1361, Appendix C, Page C-1 APPENDIX C10 METHODS FOR CALCULATING MASS AND ENERGY RELEASE C-1. Loss-of-Coolant Accident The following documents describe acceptable methods for calculating the mass and energy release to determine the loss-of-coolant accident environment for pressurized- and boiling-water reactors: (1) Topical Report WCAP-8312A for Westinghouse plants is the non-proprietary version of WCAP- 8264-P-A, "Westinghouse Mass and Energy Release Data for Containment Design," Revision 1, August 1975 (2) Section 6.2.1 of the preliminary safety analysis report for CESSAR System 80 for Combustion Engineering plants (3) Appendix 6A to B-SAR-205 for Babcock & Wilcox plants (4) NEDO-10320 and Supplements 1 and 2 for General Electric plants; NEDO-20533, dated June 1974, and Supplement 1, dated August 1975, for General Electric Mark III C-2. Main