Document: NRC Regulatory Guide
Document ID: 8322a959-849d-4ec6-926e-1f30ed96d71f
Document Type: regulatory_guide
Title: Periodic Testing of Protection System Actuation Functions (Rev. 0)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0833/ML083300530.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.22
CFR Part: 
CFR Title: 

Content:
U.S. NUCLEAR REGULATORY COMMISSION February 1972 Revision 0 REGULATORY GUIDE OFFICE OF NUCLEAR REGULATORY RESEARCH REGULATORY GUIDE 1.22 (Draft was issued as Safety Guide 22) PERIODIC TESTING OF PROTECTION SYSTEM ACTUATION FUNCTIONS A. INTRODUCTION General Design Criterion 20 of Appendix A to 10 CFR Part 50, “General Design Criteria for Nuclear Power Plants,” requires that the protection system be designed to initiate the operation of systems and components important to safety. General Design Criterion 21 requires that the protection system be designed to permit periodic testing of its functioning when the reactor is in operation. In current designs the ability of the protection system to initiate the operation of safety systems depends on the proper performance of actuation devices; therefore, these devices are to be tested. This safety guide describes acceptable methods of including the actuation devices in the periodic tests of the protection system during reactor operation. It does not address the frequency of such testing. B. DEFINITIONS protection system—The protection system, as defined in IEEE Std 279-1971,1 encompasses all electric and mechanical devices and circuitry (from sensors to actuation device input terminals) involved in generating those signals associated with the protective function. 1 Copies of IEEE Std 279-1971, “Criteria for Protection Systems for Nuclear Power Generating Stations,” may be obtained from the Institute of Electrical and Electronics Engineers, United Engineering Center, 345 East 47th Street, New York, New York 10017. The NRC issues regulatory guides to describe and make available to the public methods that the NRC staff considers acceptable for use in implementing specific parts of the agency’s regulations, techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the staff needs in reviewing applications for permits and licenses. Regulatory guides are not substitutes for