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:
ty systems. Regulatory Guide 1.152, “Criteria for Digital Computers in Safety Systems of Nuclear Power Plants” (Ref. 12), endorses IEEE Std 7-4.3.2-2003 as an acceptable method for addressing high functional reliability and design requirements for computers used in safety systems of nuclear power plants, including safety-related digital communications, independence, and integrity. If bypass and inoperable status indication is deemed to be part of a safety system, the equipment qualification criterion of IEEE Std 603-1991, Clause 5.4, would apply to the indication system. Clause 5.4 requires that safety system equipment be environmentally qualified. Regulatory Guide 1.209, “Guidelines for Environmental Qualification of Safety-Related Computer-Based Instrumentation and Controls Systems in Nuclear Power Plants” (Ref. 13), endorses IEEE Std 323-2003, “IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations” (Ref. 14), as acceptable guidance for environmental qualification of safety-related computer-based I&C systems for service in mild environments. Regulatory Guide 1.89, “Environmental Qualification of Certain Electronic Equipment Important to Safety for Nuclear Power Plants” (Ref. 15), provides guidance for environmental qualification of equipment intended for use in harsh environments. Regulatory Guide 1.180, “Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems” (Ref. 16), presents guidance for complying with the NRC’s regulations on design, installation, and testing practices for addressing the effects of electromagnetic and radiofrequency interference (EMI/RFI) and power surges on DG-1205, Page 6 safety-related I&C systems. Clause 5.4 of IEEE Std 7-4.3.2-2003 provides requirements for equipment qualification of digital computers used in safety systems. REGULATORY POSITION Conformance with the requirements of IEEE Std 603-1991 provides a