Document: NUREG-0800
Document ID: 0a15bfe3-b20f-42c5-a9ae-f05462e14c42
Document Type: srp
Title: REACTOR TRIP SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1602/ML16020A059.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.2
CFR Part: 
CFR Title: 

Content:
a. For computer-based RTSs, guidance is provided by RG 1.152. SRP Appendices 7.1-B and 7.1-C discuss the requirements of IEEE Std 279-1971 and IEEE Std 603-1991, respectively, and how the requirements are used in the review of the RTS. SRP Appendix 7.1-D discusses the criteria of IEEE Std 7-4.3.2 and how the criteria are used in the review of the RTS. Although the primary emphasis is on the equipment comprising the RTS, the reviewer must consider the overall protective functions at the system level. The RTS design should be compatible with the accident analysis. It is not sufficient to evaluate the adequacy of the RTS only on the basis that the design meets the specific requirements of IEEE Std 279-1971 or IEEE Std 603-1991. The RTS review should address all topics identified as applicable in SRP Table 7-1. SRP Appendix 7.1-A describes review methods for each topic. Major design considerations that should be emphasized in the RTS review are identified below. 7.2-6 Revision 6 – August 2016 A. Design basis - See SRP Appendix 7.1-B, Subsection 3 or SRP Appendix 7.1-C, Subsection 4. B. Single-failure criterion - See SRP Appendix 7.1-B, Subsection 4.2 or SRP Appendix 7.1-C, Subsection 5.1. C. Quality of components and modules - See 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 responding 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