Document: NUREG-0800
Document ID: b09bdecd-fb52-4a15-ab35-7b597cbbaa13
Document Type: srp
Title: Appendix 7-A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500546.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

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of appropriate systems to ensure that specified acceptable fuel design limits are not exceeded. 10 CFR 50 Appendix A, GDC 21, "Protection System Reliability and Testability," requires in part that the protection system be designed for high functional reliability and in-service testability commensurate with the safety functions to be performed. 10 CFR 50 Appendix A, GDC 24, "Separation of Protection and Control Systems," requires in part that the protection system be separated from the control systems to the extent that failure of any single control system component or channel, or failure or removal from service of any single protection system component or Rev. 4 — June 1997 Appendix 7-A BTP HICB-13-2 channel that is common to the protection system, leaves intact a system satisfying all reliability, redundancy, and independence requirements of the protection system. 10 CFR 50 Appendix A, GDC 29, "Protection against Anticipated Operational Occurrences," requires in part that protection and reactivity control systems be designed to ensure an extremely high probability of accomplishing their safety function in the event of an anticipated operational occurrence. 2. Relevant Guidance Reg. Guide 1.153, "Criteria for Power, Instrumentation, and Control Portions of Safety Systems," endorses IEEE Std. 603, "IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations" as an alternative to ANSI/IEEE Std. 279. IEEE Std 603 requires in part that the safety system design basis include the following: • The increment allotted for inaccuracies, calibration uncertainties, and errors. • The overall response times of the safety system used in establishing the setpoint allowable value. • The basis to demonstrate that the assumed values used for instrumentation inaccuracy, calibration uncertainties and error, and time response are acceptable and reasonable. Performance of an RTD is characterized by its accuracy and response time. Accuracy is a measure of how