Document: NUREG-0800
Document ID: 7e9d3620-7a94-488e-b2d5-992282113080
Document Type: srp
Title: NUREG408OO
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350480.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
chnical specifications). C. REFERENCES 1. Arkansas 1, Unit 1, Safety Evaluation Report, January 23, 1973. 2. IEEE Std 279, "Criteria for Protection Systems for Nuclear Power Generating Stations." 7A-5 Rev. 2 - July 1981 3. BTP ICSB 18 (PSB), "Application of the Single Failure Criterion to Manually-Controlled Electrically-Operated Valves." 7A-6 Rev. 2 - July 1981 BRANCH TECHNICAL POSITION ICSB 5 SCRAM BREAKER TEST REQUIREMENTS - TECHNICAL SPECIFICATIONS [BTP has been superseded by Standard Technical Specifications] I 7A-7 Rev. 2 - July 1981 BRANCH TECHNICAL POSITION ICSB 9 DEFINITION AND USE OF "CHANNEL CALIBRATION" - TECHNICAL SPECIFICATIONS [BTP has been superseded by Standard Technical Specifications] I 7A-8 Rev. 2 - July 1981 BRANCH TECHNICAL POSITION ICSB 12 PROTECTION SYSTEM TRIP POINT CHANGES FOR OPERATION WITH REACTOR COOLANT PUMPS OUT OF SERVICE A. BACKGROUND For the past several years, including a time prior to the development of IEEE Std 279, the staff has 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 paragraph 4.15, "Multiple Set Points,' of IEEE Std 279. More recently, all applicants have stated that their protection systems were designed to meet IEEE Std 279. Paragraph 4.15 of IEEE Std 279 specified that where a mode of reactor operation requires a more restrictive set point, the means for ensuring use of the more restrictive set point. shall be positive and must meet the other requirements of IEEE Std 279. A number of designs have been proposed and accepted which reliably and simply satisfy this requirement. During the review of some applications, however, certain design