Document: NUREG-0800
Document ID: 644c1fee-247e-4265-9466-5876937a7120
Document Type: srp
Title: INFORMATION SYSTEMS IMPORTANT TO SAFETY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550086.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.5
CFR Part: 
CFR Title: 

Content:
or severe accident protection. They need not be subject to additional 10 CFR 50.49 environmental qualification requirements. However, they should be designed so there is reasonable assurance that they will operate in the severe accident environment for which they are intended and over the time span for which they are needed. E. Performance assessment - For systems developed in accordance with the guidance of Regulatory Guide 1.97, Revision 4, the review should confirm that the performance assessment fulfils the goals outlined in Clause 5.6, “Performance Assessment Documentation,” of IEEE Std. 497-2002. Recommended review emphasis for BISI F. Scope of BISI indications - As a minimum, BISI should be provided for the following systems: 7.5-9 Revision 5 - March 2007 - Reactor trip system (RTS) and engineered safety features actuation system (ESFAS) - See SRP Appendix 7.1-B subsection 4.13, “Indication of Bypasses,” and SRP Appendix 7.1-C subsection 5.8.3, “Indication of Bypasses.” - Interlocks for isolation of low-pressure systems from the reactor coolant system - See SRP BTP 7-1. - ECCS accumulator isolation valves - See SRP BTP 7-2. - Controls for changeover of residual heat removal from injection to recirculation mode - See SRP BTP 7-6. G. Conformance with Regulatory Guide 1.47, “Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems.” H. Independence - See SRP Appendix 7.1-B subsection 4.7, “Control and Protection System Interaction,” and SRP Appendix 7.1-C subsections 5.6, “Independence,” and 6.3, “Interaction Between the Sense and Command Features and Other Systems.” The indication system should be designed and installed in a manner that precludes the possibility of adverse effects on plant safety systems. Failure or bypass of a protective function should not be a credible consequence of failures occurring in the indication equipment, and the bypass indication should not reduce the required independence between