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:
lations (if applicable) support conclusions of the following type to be included in the staff's safety evaluation report. The reviewer also states the bases for those conclusions. The dc power systems include those dc power sources and their distribution systems and auxiliary supporting systems provided to supply motive or control power to safety-related equipment and to equipment used to cope with an SBO event. Batteries and battery chargers serve as the power sources for the dc power system, and inverters convert dc from the dc distribution system to ac instrumentation and control power, as required. These three components, when combined, provide a UPS that furnishes a continuous, highly reliable source of ac supply. The review of the dc power system for the (name of plant) plant covered the single-line diagrams, station layout drawings, electrical control and schematic diagrams, and descriptive information. The basis for acceptance of the dc power system in the review was conformance of the design criteria and bases to the Commission’s regulations in 10 CFR 50.63 and the GDC of Appendix A to 10 CFR Part 50. The staff concludes that the plant design is acceptable and meets the requirements of GDCs 2, 4, 5, 17, 18, and 50 and of 10 CFR 50.63. This conclusion is based on the following: 1. The applicant has met the requirements of GDC 2 with respect to structures, systems, and components of the dc power systems that are capable of withstanding the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, and floods because the dc power system and components are located in seismic Category I structures, which provide protection from the effects of tornadoes, tornado missiles, and floods. In addition, the dc power system and components have a quality assurance designation of Class 1E. 2. The applicant has met the requirements of GDC 4 with respect to structures, systems, and components of the dc power system that are capable of withstanding the effects