Document: NRC Regulatory Guide
Document ID: fe0fff83-b171-47c6-a3a7-46faf8de3252
Document Type: regulatory_guide
Title: Criteria for The Protection of Safety-Related
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2415/ML24158A041.pdf
Revision Date: 2024-08
Chapter: 
Section ID: RG-1.238
CFR Part: 
CFR Title: 

Content:
dress the protection of Class 1E power systems and equipment at nuclear power plants. This RG endorses, with exceptions, additions and clarifications, Institute of Electrical and Electronics Engineers (IEEE) Standard (Std.) 741-2022, “IEEE Standard for Criteria for the Protection of Class 1E Power Systems and Equipment for Nuclear Power Generating Stations” (Ref. 1). Applicability This RG applies to applicants and licensees subject to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, “Domestic Licensing of Production and Utilization Facilities” (Ref. 2), or 10 CFR Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants” (Ref. 3). Under 10 CFR Part 50, this RG applies to applicants for and holders of licenses, as defined in 10 CFR 50.2, “Definitions.” Under 10 CFR Part 52, this RG applies to applicants for and holders of combined licenses, standard design approvals and manufacturing licenses, and applicants for standard design certifications for nuclear power plants. Applicable Regulations • 10 CFR Part 50 contains the following applicable regulations: o 10 CFR 50.36(c)(1)(ii)(A), in part, states that limiting safety system settings for nuclear reactors are settings for automatic protective devices related to those variables having significant safety functions. Where a limiting safety system setting is specified for a variable on which a safety limit has been placed, the setting must be so chosen that automatic protective action will correct the abnormal situation before a safety limit is exceeded. DG-1354, Page 2 o 10 CFR 50.55a, “Codes and standards,” requires, in part, that structures, systems, and components (SSCs) be designed, fabricated, erected, constructed, tested, and inspected to quality standards commensurate with the importance of the safety function to be performed. Furthermore, 10 CFR 50.55a(h) provides requirements for protection and safety systems and incorporates by reference IEEE Std. 279-1968,