Document: NUREG-0800
Document ID: c008adb8-cf37-4130-8e02-c502bf6e1727
Document Type: srp
Title: 8.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1411/ML14114A430.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.2
CFR Part: 
CFR Title: 

Content:
ch of these circuits shall be designed to be available in sufficient time following a loss of all onsite alternating current power supplies and the other offsite electric power circuit, to assure that specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded. d. Each of the two required offsite power circuits shall be designed to be available in sufficient time to effect safe shutdown in the event of a loss of all onsite power and the loss of the other offsite circuit. (The staff has designated the second circuit as the “delayed access circuit.” The offsite power system (i.e., the two circuits considered together) must meet the single failure criterion, but only with respect to the delayed access circuit function.) One of these circuits shall be designed to be available within a few seconds following a loss-of-coolant accident to assure that core cooling, containment integrity, and other vital safety functions are maintained. e. One of these circuits shall be designed to be available within a few seconds following a loss-of-coolant accident. (The staff has designated this circuit as the “immediate access circuit.” Because only one such circuit is required, the offsite power system need not meet the single failure criterion with respect to its immediate access function.) Provisions shall be included to minimize the probability of losing electric power from any of the remaining supplies as a result of, or coincident with, the loss of power generated by the nuclear power unit, the loss of power from the transmission network, or the loss of power from the onsite electric power supplies. f. Analyses (performed by the utility) must verify that the grid remains stable in the event of a loss of the nuclear unit generator, the largest other unit on the grid, or the most critical transmission line. (There is no specific requirement for meeting the single failure criterion. However, overlapping requirement