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:
rds may result from lost independence because of interconnectivity or functional relationships among DI&C systems through their data communications. These hazards may be more difficult to identify and control because of system complexity, when the potential for faults and their impacts are considered. Thus, communication independence is needed between safety systems, between redundant divisions of a safety system, and between systems of different safety classes to ensure that faults from data communications do not propagate and adversely affect safety functions. Section C of this RG provides guidance on addressing data communications independence for DI&C. Consideration of International Standards The International Atomic Energy Agency (IAEA) works with member states and other partners to promote the safe, secure, and peaceful use of nuclear technologies. The IAEA develops Safety Requirements and Safety Guides for protecting people and the environment from harmful effects of ionizing radiation. This system of safety fundamentals, safety requirements, safety guides, and other relevant reports, reflects an international perspective on what constitutes a high level of safety. To inform its development of this RG, the NRC considered IAEA Safety Requirements and Safety Guides pursuant to the Commission’s International Policy Statement (Ref. 33) and Management Directive and Handbook 6.6, “Regulatory Guides” (Ref. 34). The international standards and guides listed below are generally consistent with the principles in the standards incorporated by reference in 10 CFR 50.55a(h). These international standards and guides provide useful information for implementing safety systems in nuclear power plants and utilization facilities, although they may not provide a one-to-one correlation with the standards incorporated by reference in 10 CFR 50.55a(h). However, the NRC does not endorse these standards and guides and does not recognize these standards and guides as an