Document: NUREG-0800
Document ID: 7a278d84-5310-4198-b914-fa3af5a0a0ef
Document Type: srp
Title: Appendix 7-A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500553.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
of any single detectable failure concurrent with all identifiable, but non-detectable failures. Consequently, self-testing and periodic testing are important elements in a design's ability to meet the single-failure criterion. 10 CFR 50 Appendix A, General Design Criterion (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. It also requires a design that permits periodic testing of its functioning when the reactor is in operation, including a capability to test channels independently to determine failures and losses of redundancy that may have occurred. 10 CFR 50 Appendix A, GDC 22, "Protection System Independence," requires in part that the protection system be designed to ensure that the effects of natural phenomena, and of normal operating, maintenance and testing do not result in loss of protection function. 10 CFR 50 Appendix B, Criterion 12, "Control of Measuring and Test Equipment," requires in part that measures be established to ensure that measuring and testing devices used in activities affecting quality are properly controlled, calibrated, and adjusted at specified periods to maintain accuracy within necessary limits. Rev. 4 — June 1997 Appendix 7-A BTP HICB-17-2 2. Relevant Guidance Reg. Guide 1.22, "Periodic Testing of Protection System Actuation Functions," describes acceptable methods of including actuation devices in the periodic tests of the protection system during reactor operations. Reg. Guide 1.47, "Bypassed and Inoperable Status Indication for Nuclear Power Plant Safety Systems," describes an acceptable method of complying with the requirements of ANSI/IEEE Std 279 with regard to indicating the inoperable status of a portion of the protection system, systems actuated or controlled by the safety system, or essential auxiliary support systems. Reg. Guide 1.53