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:
ical and Electrical Equipment” (Ref. 6), identifies staff guidance for determining that all items of equipment that are important to safety (mechanical, electrical, and I&C equipment) are capable of performing their design safety functions under all normal environmental conditions, anticipated operational occurrences, and accident and post-accident environmental conditions. It includes all environmental conditions that may result from any normal mode of plant operation, anticipated operational occurrences, design-basis events (as defined in 10 CFR 50.49(b)(1)(ii)), post-design- basis events, and containment tests. • Prior to the issuance of the EQ rule (10 CFR 50.49), the Commission (in Memorandum and Order CLI-80-21 dated May 23, 1980) directed the staff to use NUREG-0588, “Interim Staff Position on Environmental Qualification of Safety-Related Electrical Equipment,” Revision 1 (Ref. 7), and the Division of Operating Reactors (DOR) Guidelines, “Guidelines for Evaluating Qualification of Class 1E Electrical Equipment in Operating Reactors,” November 3, 1979 (Ref. 8), as requirements that licensees and applicants must meet in order to satisfy the equipment qualification requirements of 10 CFR Part 50. At that time, NUREG-0588 consisted of what is now Part I of NUREG-0588 (i.e., only the “for comment version” of NUREG-0588). • Upon its issuance, 10 CFR 50.49, which is based on Part I of NUREG-0588 (hereinafter “NUREG-0588”) and the DOR Guidelines, did not require requalification of electric equipment by applicants for and holders of operating licenses for nuclear power plants previously required by NRC to qualify equipment in accordance with the DOR Guidelines or NUREG-0588 (Category I or II). According to NUREG-0588, all nuclear reactors with Operating Licenses as of May 23, 1980, will be evaluated by the staff against the DOR guidelines. In accordance with the statement of considerations for 10 CFR 50.49, Category I requirements of NUREG-0588,