Document: NUREG-0800
Document ID: e1169529-d2cb-4947-9efe-b23d927f4aa9
Document Type: srp
Title: NUREG40800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350520.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
CFR Part: 
CFR Title: 

Content:
pecifications), or a safety injection signal is present. Both primary coolant system pressure and safety injection signals should be provided to the valve operator. 2. Visual indication in the control room of the open or closed status of the valve. 3. An audible and visual alarm, independent of item 2., above, that is actuated by a sensor on the valve when the valve is not in the fully-open position. 4. Utilization of a safety injection signal to remove automatically (override) any bypass feature that may be provided to allow an isolation valve to be closed for short periods of time when the reactor coolant system is at pressure (in accordance with provisions of the technical specifications). C. REFERENCES 1. Arkansas 1, Unit 1, Safety Evaluation Report, January 23, 1973. 8A-4 Rev. 2 - July 1981 2. IEEE Std 279, "Criteria for Protection Systems for Nuclear Power Generating. Stations." 3. BTP ICSB 18 (PSB), "Application of the Single Failure Criterion to Manually- Controlled Electrically-Operated Valves." 8A-5 Rev. 2 - July 1981 BRANCH TECHNICAL POSITION ICSB-8 (PSB) USE OF DIESEL-GENERATOR SETS FOR PEAKING A. BACKGROUND General Design Criterion 17 requires that provisions be included to minimize the probability of losing electric power from any of the remaining supplies as a result of or coincident with, loss of the main generator, loss of power from the grid, or loss of standby power supplies. Additionally, IEEE Std 308 requires that the preferred (offsite) and standby power supplies shall not have a common failure mode. Common failure mode is defined as "a mechanism by which a single design basis event can cause redundant equipment to be inoperable." Although IEEE Std 308 does not preclude the use of emergency diesels for nonsafety purposes, the staff concludes that the potential for common failure modes should preclude interconnection of onsite and offsite power sources except for short periods for the purpose of load testing. Review of the use of emergency