Document: NUREG-0800
Document ID: 98a045ec-37ef-46fc-9eaa-9e695c2d6e53
Document Type: srp
Title: OFFSITE POWER SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350488.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.2
CFR Part: 
CFR Title: 

Content:
grid itself but the unavailability of the immediate access circuit and the onsite power supplies) such that the reactor remains in a safe condition. If the circuit is required for immediate access or utilizes generator circuit breakers or generator load break switches, then the reviewer should use the guidelines contained in Appendix A to this SRP section. (e) Each of the circuits from the offsite system to the onsite distribu- tion buses should have the capacity and capability to supply the loads assigned to the bus or buses it is connected to during normal or abnormal operating conditions, accident conditions, or plant shutdown conditions. Therefore, the loads to be supplied during these conditions should be determined from information obtained in coordination with other branches. The capacity and electrical characteristics of transformers, breakers, buses, transmission lines, and the preferred power source for each path should be evaluated to assure that there is adequate capability to supply the maximum connected load during all plant conditions. The design should also be examined to assure that during transfer from one power source to another the design limits of equipment are not exceeded. (f) The results of the grid stability analysis must show that loss of the largest single supply to the grid does not result in the com- plete loss of preferred power. The analysis should consider the loss, through a single event, of the largest capacity being supplied to the grid, removal of the largest load from the grid, or loss of the most critical transmission line. This could be the total output of the station, the largest station on the grid, or possibly several large stations if these use a common transmission tower, transformer, or a breaker in a remote switchyard or substation. The station layout and the grid system layout drawings are reviewed to determine that all *the above events were included in the analysis. The applicant should include in the grid stability