Document: NUREG-0800
Document ID: 9fa7092c-7628-402d-9028-6601d5f5fdfb
Document Type: srp
Title: DC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550063.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.2
CFR Part: 
CFR Title: 

Content:
ts of the batteries, as described in IEEE Std. 450 and Regulatory Guide 1.129. Regulatory Guide 1.128 and IEEE Std. 484 provide the basis for the review of design practices and procedures for storage, location, mounting, ventilation, instrumentation, preassembly, assembly, and charging of large lead storage batteries. In coordination with other branches, the reviewer becomes familiar with the purpose and operation of each safety system, including system component arrangements as depicted on functional P&IDs, expected system performance as established in the accident and/or other relevant analyses (e.g., for SBO), modes of system operation and interactions during normal and accident conditions, and interactions among systems. Subsequently, the reviewer will verify that the tabulation of all safety-related loads to be connected to each dc supply is consistent with the information obtained in coordination with other branches. The characteristics of each load (such as motor horsepower and volt-amp ratings, inrush current, starting volt-amps, and torque), the length of time each load is required, and the basis used to establish the power required for each safety-related load (such as motor name plate rating, pump runout condition, or estimated load under expected flow and pressure) are used to verify the calculations establishing the combined load demand to be connected to each dc supply during the worst operating conditions. In reviewing the design of the thermal overload protection for motors of motor-operated safety-related valves, the reviewer uses Regulatory Guide 1.106. If the proposed design provides for the sharing of dc supplies between units at the same site and for connection and disconnection of nonsafety-related loads to and from the safety-related distribution buses, the review gives particular attention to ensuring that the implementation of such design provisions does not compromise the capacity, capability, or reliability of these supplies. Regulatory