Document: NUREG-0800
Document ID: b351c30f-74b4-4d36-833e-939d23abae4e
Document Type: srp
Title: D-C POWER-SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350494.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.2
CFR Part: 
CFR Title: 

Content:
ied to the nonsafety- related load, including control circuits and connections to the safety- related bus, must be designed to meet safety Class IE requirements. Should the d-c power supplies not have been sized to accommodate the added nonsafety-related loads during emergency conditions, the design must provide for the automatic disconnection of those nonsafety-related loads upon detection of the emergency condition. This action must be accomplished whether or not the load was already connected to the power supply. IV. EVALUATION FINDINGS The reviewer verifies that sufficient information has been provided and that the review supports conclusions of the following type, to be included in the staff's Safety Evaluation Report. 8.3.2-8 Rev. 2 - July 1981 The d-c power system includes power supplies, distribution systems, and load groups arranged to provide d-c electric power to safety-related d-c loads and for control and switching of the safety-related power systems. The d-c power system also provides d-c electric power to inverters. The inverter convert the d-c to a-c and are arranged to provide a dependable power supply for safety-related instrumentation and control loads. The review of the d-c power system for the plant covered the single line diagrams (CP and OL), station layoultdrawings (CP and OL), schematic diagrams (OL), and descriptive information. The basis for acceptance of thd d-c power system in our review was conformance of the design criteria and basess.to the Commission's regulations as set forth in the General Design Criteria (GDC) of Appendix A to 10 CFR Part 50. The staff concludes that the plant design is acceptable and meets the requirements of GDC 2, 4, 5, 17, 18, and 50. This conclusion is based on the following: .1. The applicant has met the requirements of GDC 2, "Design Basis for Protection Against Natural Phenomena," with respect to structures, systems, and components of the d-c power systems being capable of withstanding the effects of