Document: NUREG-0800
Document ID: fe8ec6c2-e960-404c-854f-55c77bde1672
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML2400/ML24005A077.pdf
Revision Date: 2024-05
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
e for maintaining defense in depth. Other design features (or design techniques) can also contribute to overall defense in depth. Such features (or design techniques) include segmentation; predictable real-time (deterministic) processing; automated self-test provisions; and measures to control access to physical, electronic, and software-based elements that, if tampered with or corrupted, could cause adverse plant consequences. Over the years, the NRC staff has approved applications that use various design features to address CCF vulnerabilities in DI&C systems. Some of these use multiple design solutions within different parts of a single DI&C system. In reviewing these applications, the NRC staff has evaluated several solutions that successfully address CCF vulnerabilities. Consequently, the NRC staff recognizes that there may be no single solution that applies to all DI&C systems. 1. Regulatory Basis The regulations and standards listed below may not apply to all applicants. Their applicability depends on the plant-specific licensing basis and any proposed changes to the licensing basis associated with the DI&C system under evaluation. The Institute of Electrical and Electronics Engineers (IEEE) standards and design criteria listed are examples of plant-specific licensing-basis items.  IEEE Std 279-1968, “Proposed IEEE Criteria for Nuclear Power Plant Protection Systems;” IEEE Std 279-1971, “Criteria for Protection Systems for Nuclear Power Generating Stations;” and IEEE Std 603-1991, “IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations,” together with the correction sheet dated January 30, 1995, provide criteria applicable to protection and safety systems. BTP 7-19-5 Revision 9 — May 2024  General Design Criterion (GDC) 22, “Protection system independence,” of Appendix A to 10 CFR Part 50 states the following: The protection system shall be designed to assure that the effects of natural phenomena, and of normal