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:
uating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations and compliance with them is not required. This regulatory guide contains information collection requirements covered by 10 CFR Part 50 that the Office of Management and Budget (OMB) approved under OMB control number 3150-0011. The NRC may neither conduct nor sponsor, and a person is not required to respond to, an information collection request or requirement unless the requesting document displays a currently valid OMB control number. B. DISCUSSION The Working Group Subcommittee 6.3 of the IEEE Nuclear Power Engineering Society developed IEEE Std 603-1991, and the IEEE Standards Board approved it on June 27, 1991. The standard provides guidance on the minimum functional design criteria for the electrical power, instrumentation, and control portions of nuclear power plant safety systems. This standard evolved from IEEE Std 279-1971 and, through interfaces with other referenced standards, reflects advances in digital technology. Nuclear power plants are currently replacing existing instrumentation and control (I&C) equipment with digital computer- based I&C systems or advanced analog systems. However, compared to existing I&C systems, these technologies may pose a number of new vulnerabilities for the nuclear power plant. This regulatory guide provides an acceptable method for establishing the design criteria for existing I&C systems and for establishing the design criteria for digital and advanced analog systems for bypassed and inoperable status indication. Clause 5.8 of IEEE Std 603-1991 presents the requirements for safety system information displays. Clause 5.8.2 of IEEE Std 603-1991 requires that “display instrumentation shall provide accurate, complete, and timely information pertinent to safety system status.” Clause 5.8.3 of the standard provides the specific guidance on the indication of bypasses, which may be