Document: NUREG-0800
Document ID: d9e9d0a9-6390-4154-94dc-7d5e6d8145cd
Document Type: srp
Title: A-C POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350489.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
n Criterion 5 prohibits sharing unless it can be shown that the diesel generators are capable of performing all required safety functions in the event of an accident in one unit an an orderly shutdown and cooldown of the remaining units. In ensuring that the proposed design for sharing diesel generators between units meets the requirements of General Design Criteria 5 and 17 as supplemented by General Design Criteria 34, 35, 38, 41 and 44 and satisfies the positions of Regulatory Guide 1.9, the PSB reviewer is 8.3.1-13 Rev. 2 - July 1981 guided by Regulatory Guide 1.81. This guide sets forth two principal positions. Position 3 applies to those construction permit applications docketed after-June 1, 1973, and prohibits the sharing of onsite power systems between units. Conformance of the i design with Position 3 is verified by reviewing the descriptive information including electrical drawings to ensure that the onsite power system of each unit is electrically independent with respect to the onsite power system of other units. Position 2 of Regulatory Guide 1.81 establishes acceptable bases under which sharing of onsite power systems between units is permitted. Conformance with Position 2 with regard to the adequacy of diesel generator capacity and capability under the sharing mode of operation is verified by following the procedure discussed above for tabulating and summing all loads. In particular, the load tabulation and calculations establishing the diesel generator capacity are examined to ensure that the selected capacity is sufficient to power the minimum ESF loads in any unit and safely shut down the remaining units in the event of an accident in one unit and a single failure or spurious or false accident signal from another unit and loss of preferred power-to all the units. In addition, the physical arrangement of instrumentation and control devices on control room panels and consoles in one unit with respect to the other units is examined to ensure that the