Document: NUREG-0800
Document ID: 97120913-d26f-4324-ab62-22f3f5b73925
Document Type: srp
Title: and 8.3.2.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600410.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
or the passive reactor designs such as the AP1000. NUREG-1793 provides additional information on grid stability analyses for the AP1000. G. During the review of the electrical schematics, it should be determined that loss of standby power will not result in loss of preferred power, loss of one preferred power circuit will not result in loss of the other circuit, loss of the main generator will not result in loss of either preferred power circuit, and loss of any combination of these power sources will not prevent the use of AAC power. 8.2-18 Revision 4 - March 2007 H. The reviewer verifies that the preferred power system is independent of the onsite power system. The basis for acceptance is that no single event, including a single protective relay, interlock, or switchgear failure, in the event of loss of all standby power sources, will prevent the separation of the preferred power system from the onsite power distribution system or prevent the preferred power system from accomplishing its intended functions. In addition, the preferred and standby power supplies should not have common failure modes. An acceptable design must be capable of restoring the preferred power supply after the loss of either circuit in a time period such that the plant can be safely shut down, taking into account the effects of a single failure in the onsite distribution system. This item is also addressed in SRP Section 8.3.1. I. The reviewer verifies that adequate provisions are made in the design of the plant and the offsite and onsite power systems for grounding, surge protection, and lightning protection. The reviewer evaluates the plant/station grounding systems, the methods of equipment and structural grounding, ac power system neutral grounding and ground fault current limiting features, surge and lightning protection features for outdoor equipment and circuits, and the measures for isolation of instrumentation grounding systems. Regulatory Guide 1.204 and IEEE Stds 665, 666, 1050,