Document: NUREG-0800
Document ID: 81256f55-72dd-4777-9472-f373c71c4554
Document Type: srp
Title: AC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550065.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
t limited to: - bus failures, involving the integrity of bus bar splice joints, torque relaxation, cyclical bus loading, and incipient damage resulting from a high fault current transient/arcing fault explosion, that can lead to a LOOP (Reference 8); - failures of safety-related circuit breakers due to problems with preventive maintenance programs, circuit breaker lubrication, licensee/vendor interface, control voltage criteria, and review of circuit breaker operating experience (References 5 & 6); - metal-clad switchgear circuit breaker failure involving an energetic arcing fault fire/explosion that propagated damage to adjacent circuit breaker cubicles and resulted in a LOOP (Reference 9); and - potential for degradation of switchgear control and protection wiring at the circuit breaker cubicle door hinges that could affect safety equipment function (Reference 10). The review should verify that medium and low-voltage switchgear, metal-enclosed bus preventive maintenance and performance and condition monitoring activities are evaluated periodically in accordance with the Maintenance Rule and that they incorporate, where practical, the insights of internal and industry-wide operating experience. 4. Standby Power Supplies The reviewer should ensure that the requirements of GDC 17 and the recommendations of IEEE Std 308 have been met with regard to the standby power supply (diesel generator sets) having sufficient capacity and capability to supply the distribution system loads. In addition, the reviewer should verify that the standby power supply meets the design bases and design criteria, and should have analyses to support the design. Further, the reviewer should verify that the standby power supply has been described and implemented as depicted on electrical drawings and physical arrangement drawings. The diesel generator sets are reviewed to verify that the bases for their 8.3.1-28 Revision 3 - March 2007 selection satisfy the positions of Regulatory Guide 1.9.