Document: NRC Regulatory Guide
Document ID: 0df18aa6-42a8-4990-aa7e-3df6d0907f3f
Document Type: regulatory_guide
Title: Criteria for Safety Systems (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2511/ML25114A021.pdf
Revision Date: 2025-11
Chapter: 
Section ID: RG-1.153
CFR Part: 
CFR Title: 

Content:
stems for nuclear power plants as specified in Section 50.55a(h), Title 10, Part 50 of the Code of Federal Regulations (10 CFR Section 50.55a(h)) (Ref. 1), which incorporates by reference, among other standards, Institute of Electrical and Electronics Engineers (IEEE) Standard (IEEE Std) 603-2018, “IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations,” (Ref. 2). This revision provides supplemental and clarifying information for implementing certain criteria in IEEE Std 603-2018. Applicability This RG applies to applicants and licensees subject to 10 CFR Part 50, “Domestic Licensing of Production and Utilization Facilities” 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 governs the licensing of nuclear power plants, and it requires, in part, that structures, systems, and components (SSCs) that are important to safety in a nuclear power plant must be designed to remain functional under postulated design-basis events. o 10 CFR 50.49 “Environmental qualification of electric equipment important to safety for nuclear power plants” establishes requirement criteria for qualifying electric equipment. DG-1251, Page 2 o 10 CFR 50.55a, “Codes and standards,” requires, in part, that 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, “Proposed IEEE