Document: NUREG-0800
Document ID: d3619a55-efe4-419a-9ccd-6a1d63928d7c
Document Type: srp
Title: REACTOR TRIP SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550083.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.2
CFR Part: 
CFR Title: 

Content:
SRP Appendix 7.1-B subsection 4.3 or SRP Appendix 7.1-C subsection 5.3. D. Independence - See SRP Appendix 7.1-B subsections 4.6 and 4.7 or SRP Appendix 7.1-C subsections 5.6 and 6.3. E. Diversity and defense-in-depth - RTSs should incorporate multiple means for responsding to each event discussed in the SAR Chapter 15, “Transient and Accident Analyses.” At least one pair of these means for each event should have the property of signal diversity, i.e., the use of different sensed parameters to initiate protective action, in which any of the parameters may independently indicate an abnormal condition, even if the other parameters are sensed incorrectly (see NUREG/CR-6303, “Method for Performing Diversity and Defense-in-Depth Analyses of Reactor Protection Systems”). The diverse means may actuate the same protective function or different protective functions, and may be automatically or manually activated, consistent with the response time requirements of the function. For digital computer-based RTSs, the applicant/licensee should have performed a defense-in-depth and diversity 7.2-6 Revision 5 - March 2007 analysis. Additionally, for advanced reactor design under 10 CFR Part 52, the design should provide for manual, system-level actuation of critical safety functions. SRP BTP 7-19 provides guidance for the review of diversity and defense-in-depth. F. System testing and inoperable surveillance - See Appendix SRP 7.1-B subsections 4.9 and 4.10 or SRP Appendix 7.1-C subsections 5.7, 5.8, and 6.5. G. Use of digital systems - See SRP Appendix 7.0-A and SRP Appendix 7.1-D. H. Setpoint determination - See Regulatory Guide 1.105, “Setpoints for Safety-Related Instrumentation,” and SRP BTP 7-12. 2. For review of a DC application, the reviewer should follow the above procedures to verify that the design, including requirements and restrictions (e.g., interface requirements and site parameters), set forth in the final safety analysis report (FSAR) meets the