Document: NUREG-0800
Document ID: 106978f1-fb10-4fa9-ad95-601f3c16bd36
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550072.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
at the system level when required." 10 CFR 50.62, "Requirements for Reduction of Risk from Anticipated Transients without Scram [ATWS]," requires in part various diverse methods of responding to ATWS. 10 CFR Part 50, Appendix A, General Design Criterion (GDC) 21, "Protection Systems Reliability and Testability," requires in part that "no single failure results in the loss of the protection system." GDC 22, "Protection System Independence," requires in part "that the effects of natural phenomena, and of normal operating, maintenance, testing, and postulated accident conditions … not result in loss of the protection function … Design techniques, such as functional diversity or diversity in component design and principles of operation, shall be used to the extent practical to prevent loss of the protection function." GDC 24, "Separation of Protection and Control Systems," requires in part that "[i]nterconnection of the protection and control systems shall be limited so as to assure that safety is not significantly impaired." GDC 29, "Protection Against Anticipated Operational Occurrences," requires in part defense against anticipated operational transients "to assure an extremely high probability of accomplishing … safety functions." 2. Relevant Guidance Regulatory Guide 1.53, "Application of the Single-Failure Criterion to Safety Systems," clarifies the application of the single-failure criterion (GDC 21) and endorses IEEE Std. 379-2000, "IEEE Standard Application of the Single-Failure Criterion to Nuclear Power Generating Station Safety BTP 7-19-3 Revision 5 - March 2007 Systems," providing supplements and an interpretation. IEEE Std. 379-2000, Clause 5.5, identifies D3 as a technique for addressing common-cause failure, and Clause 6.1 identifies logic failures as a type of failure to be considered when applying the single-failure criterion. NUREG/CR-6303, "Method for Performing Diversity and Defense-in-Depth Analyses of Reactor Protection Systems," summarizes