Document: NRC Regulatory Guide
Document ID: 086612c4-a8a7-4f50-a166-6f1cb05bcdaf
Document Type: regulatory_guide
Title: Guidelines for Environmental Qualification of Safety-Related Computer-Based Instrumentation and Control Systems in Nuclear Power Plants
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0630/ML063040591.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.209
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Content:
draft regulatory guide. This guide applies to new plants and its use is voluntary for modifications at plants that are operating in 2006. No backfitting is intended or approved in connection with its issuance. The NRC has issued this draft guide to encourage public participation in its development. Except in those cases in which an applicant or licensee proposes or has previously established an acceptable alternative method for complying with specified portions of the NRC’s regulations, the methods to be described in the active guide will reflect public comments and will be used in evaluating (1) submittals in connection with applications for construction permits, standard plant design certifications, operating licenses, early site permits, and combined licenses; and (2) submittals from operating reactor licensees who voluntarily propose to initiate system modifications if there is a clear nexus between the proposed modifications and the subject for which guidance is provided herein. 1 As defined in 10 CFR 50.49, “design-basis events” include conditions of normal operation, including anticipated operational occurrences, design-basis accidents, external events, and natural phenomena. DG-1142, Page 9 REGULATORY ANALYSIS 1. Statement of the Problem Title 10, Part 50, of the Code of Federal Regulations (10 CFR Part 50) delineates the design and qualification-related regulations that the NRC has established for commercial nuclear power plants. In particular, 10 CFR Part 50 requires that SSCs important to safety in nuclear power plants shall be designed to accommodate the effects of environmental conditions (i.e., remain functional under postulated accident conditions) and design control measures (such as testing) shall be used to check the adequacy of design. Furthermore, 10 CFR 50.55a(h) requires that safety systems shall meet the requirements of IEEE Std. 603-1991 and the correction sheet dated January 30, 1995, or IEEE Std. 279-1971, contingent on the date that