Document: NRC Regulatory Guide
Document ID: 30181e34-3bc1-46b8-8de9-ef073c34bc13
Document Type: regulatory_guide
Title: Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems + HISTORY - HISTORY 10/2008 – DG-1205 , Proposed Revision 1 (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0821/ML082140114.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.47
CFR Part: 
CFR Title: 

Content:
actions can be taken to operate the nuclear power unit safely under normal operating conditions. GDC 21 requires that the protection system DG-1205, Page 2 be designed for high functional reliability and inservice testability. GDC 22 requires that the protection system be designed to ensure that the effects of normal operating, maintenance, and testing on redundant channels do not result in the loss of the protection function or be demonstrated to be acceptable on some other defined basis. GDC 24 requires that interconnection of the protection and control systems be limited to ensure that safety is not significantly impaired. In 10 CFR 50.55a(h), the NRC requires compliance with Institute of Electrical and Electronics Engineers (IEEE) Standard (Std) 603-1991, “IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations,” and the correction sheet dated January 30, 1995 (Ref. 2). For nuclear power plants with construction permits issued before January 1, 1971, the applicant/licensee may elect to comply instead with its plant-specific licensing basis. For nuclear power plants with construction permits issued between January 1, 1971, and May 13, 1999, the applicant/licensee may elect to comply instead with the requirements in IEEE Std 279-1971, “Criteria for Protection Systems for Nuclear Power Generating Stations” (Ref. 3). Both IEEE Std 603-1991 and IEEE Std 279-1971 list requirements with regard to bypassed and inoperable status indication for safety systems. In addition, Criterion XIV, “Inspection, Test, and Operating Status,” as given in Appendix B, “Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants,” to 10 CFR Part 50, requires that measures be established for indicating the operating status of structures, systems, and components of the nuclear power plant, such as by tagging valves and switches, to prevent inadvertent operation. The provisions of 10 CFR 50.34(f)(2)(v), “Additional TMI-Related