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:
should normally be located in seismic Category I structures that provide protection from the effects of tornadoes, tornado missiles, and floods. Equipment and components comprising the onsite ac power system should also generally be seismically designed and/or qualified to perform their functions in the event of an earthquake. Meeting this requirement will provide assurance that equipment and structures will be designed to withstand the effects associated with natural phenomena, thus decreasing the probability that seismically- and/or climatology-related natural phenomena could initiate accidents or prevent equipment from performing its safety function during an accident. 2. Compliance with GDC 4 requires that SSCs important to safety (a) be designed to accommodate the effects of, and be compatible with, the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents and (b) be appropriately protected against dynamic effects, including the effects of missiles, that may result from equipment failures. The ac power system is necessary to provide power to systems important to safety during normal, abnormal, accident, and postaccident conditions. 8.3.1-14 Revision 3 - March 2007 Meeting these requirements will provide assurance that the ac power system will supply electric power necessary for operation of systems important to safety even if/when subject to adverse environmental conditions and/or dynamic effects. 3. Compliance with GDC 5 requires that SSCs important to safety not be shared among nuclear power units, unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions, including, in the event of an accident in one unit, an orderly shutdown and cooldown of the remaining units. Accordingly, component parts of the ac power system should not be shared among units without sufficient justification, thereby ensuring that an accident in one unit of a multiple- unit