Document: NRC Regulatory Guide
Document ID: fc586342-92f7-4c77-ae76-79e3674cf288
Document Type: regulatory_guide
Title: Criteria for Programmable Digital Devices in Safety-Related Systems of  Nuclear Power Plants + HISTORY –HISTORY 02/2023 – DG-1374, Proposed Revision 4 Prior to issuance of DG-1374, RG 1.152 was entitled, “Criteria for Use of Computers in Safety-Systems of Nuclear Power Plants” 06/2010 – DG-1249, Proposed Revision 3 – Revise 12/2004 – DG-1130, Proposed Revision 2 – Revise 05/1995 – DG-1039, Proposed Revision 1 03/1983 – DG-1130, Proposed Revision 2 – Revise (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2301/ML23012A242.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.152
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CFR Title: 

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by reference in 10 CFR 50.55a(h). The staff’s endorsement of Revision 2016 of IEEE 7-4.3.2, with exceptions and clarifications, is discussed in Section C of this RG. The instrumentation and controls (I&C) design should ensure that the safety-related equipment or components can be qualified, procured, installed, commissioned, operated, and maintained to be capable of withstanding, with sufficient reliability and robustness, all conditions specified in the plant design basis or licensing basis. To achieve adequate defense in depth, the I&C architecture and systems design should meet certain fundamental I&C design principles to support the assessment of defense-in-depth adequacy for the overall plant. Fundamental I&C design principles consist of independence, redundancy, diversity and defense in depth, and deterministic behavior (predictability and repeatability). Incorporating these principles in the design facilitates addressing specific hazards within the design (e.g., fault propagation). While diversity is part of the fundamental I&C design principles, it is only considered one means to address CCF. Therefore, the review of diversity focuses more broadly on supporting the defense-in-depth assessment and other measures to address CCF.1 Working Group Subcommittee 6.4, “Application of Programmable Digital Devices to Safety Systems of Nuclear Power Generating Stations,” of the IEEE Nuclear Power Engineering Committee prepared IEEE Std 7-4.3.2-2016. This updated standard reflects advances in digital technology and represents a continued effort by IEEE to support the specification, design, and implementation of PDDs in safety-related systems of nuclear power plants. As defined in this standard, the term “programmable digital devices” refers to devices that rely on software instructions or programmable logic to accomplish a function. Examples include a computer, a programmable hardware device, or a device with firmware. 1 See the NRC Design Review Guide,