Document: NUREG-0800
Document ID: 805f7e09-51a2-413b-92af-e23bb9073497
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070493.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
CFR Part: 
CFR Title: 

Content:
for Power, Instrumentation, and Control Portions of Safety Systems."16 32. BTP ICSB-18 (PSB), "Application of the Single Failure Criterion to Manually 17 Controlled Electrically Operated Valves." 13. Arkansas 1, Unit 1, Safety Evaluation Report, January 23, 1973. 4. IEEE Std 603-1980, "Criteria for Safety Systems for Nuclear Power Generating Stations."18 25. IEEE Std 279-1971 , "Criteria for Protection Systems for Nuclear Power Generating 19 Stations." DRAFT Rev. 3 - April 1996 8A-6 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 (Reference 3), as endorsed in Regulatory Guide 1.32, requires that 20 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 diesel-generator sets for peaking service leads to the conclusion that the required frequent interconnection of the preferred and standby power supplies increases the probability of their common failure. B. BRANCH TECHNICAL POSITION General Design Criterion 17 and IEEE Std 308 should be interpreted as prohibiting tThe staff's position regarding use of plantonsite emergency power diesel-generator sets for purposes other than that of supplying standby power when needed is that such use should be