Document: NUREG-0800
Document ID: 08442d7c-2bb3-486e-96a7-559fcd1fdf90
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550091.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
. 279-1971 or IEEE Std. 603-1991. BTP 7-3-2 Revision 5 - March 2007 Before the development of IEEE Std. 279-1971 the staff required automatic adjustment to more restrictive settings of trips affecting reactor safety by means of circuits satisfying the single-failure criterion. The basis for this requirement is that the function can be accomplished more reliably by automatic circuitry than by a human operator. This design practice, which has also been adopted independently by the national laboratories and by much of industry, served as the basis for Clause 4.15 of IEEE Std. 279-1971 and Clause 6.8.2 of IEEE Std. 603-1991. More recently, applicants stated that their protection systems were designed to meet IEEE Std. 279-1971 or IEEE Std. 603-1991. A number of designs were proposed and accepted which reliably and simply satisfy this requirement. During the review of some applications, however, certain design deficiencies were found. The purpose of this position is to provide additional guidance on the application of Clause 4.15 of IEEE Std. 279-1971 and Clause 6.8.2 of IEEE Std. 603-1991. B. BRANCH TECHNICAL POSITION 1. If more restrictive safety trip points are required for operation with a reactor coolant pump out of service, and if operation with a reactor coolant pump out of service is of sufficient likelihood to be a planned mode of operation, the change to the more restrictive trip points should be accomplished automatically. 2. Plants with designs not in accordance with the above should have included in the plant technical specifications a requirement that the reactor be shut down prior to changing the set points manually. C. REFERENCES 1. IEEE Std. 279-1971, "Criteria for Protection Systems for Nuclear Power Generating Stations." 2. IEEE Std. 603-1991, "IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations." PAPERWORK REDUCTION ACT STATEMENT The information collections contained in the Standard Review Plan are covered by the