Document: NUREG-0800
Document ID: f9d2d9cb-1d13-407e-ad7a-523fff64de06
Document Type: srp
Title: DC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1007/ML100740391.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.2
CFR Part: 
CFR Title: 

Content:
(e) the performance characteristic curves (e.g., voltage profile curves, discharge rate curves, and temperature effect curves) that illustrate the response of the batteries to the most severe loading conditions at the plant. The reviewer should ensure that the capacity of the battery charger is based on an evaluation of the largest combined demands of the various continuous steady-state loads plus charging capacity to restore the battery from the design minimum charge state to the fully charged state within the time stated in the design basis, regardless of the status of the plant when these demands occur. If the proposed design provides for the connection of nonsafety-related loads to the dc power system or for sharing of batteries and battery chargers between units at the same site, the reviewer should particularly emphasize ensuring against marginal capacity and degradation of reliability that may result from implementing such design provisions. Regulatory Position C.1 of Regulatory Guide (RG) 1.81 states that dc systems in multiunit sites should not be shared. For new applications licensed under Title 10 of the Code of Federal Regulations, Part 52 (10 CFR Part 52), the review should ensure that units do not share safety-related dc power systems (batteries, chargers, or inverters). In addition, if the proposed design relies on portions of the onsite dc power system to cope with an SBO event, the staff will review the capacity and capability of the dc power 8.3.2-3 Revision 4 - May 2010 system to withstand and recover from an SBO of specified duration to ensure conformance to 10 CFR 50.63. 4 Identification of Cables, Raceways, and Terminal Equipment. The staff will review the proposed means for identifying the plant=s dc power system components, including cables, raceways, and terminal equipment. The reviewer should also evaluate the identification scheme used to distinguish among redundant Class 1E systems, associated circuits assigned to redundant Class 1E