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:
est periodically (a) the operability and functional performance of the components of the systems, such as onsite power sources, relays, switches, and buses, and (b) the operability of the systems as a whole and, under conditions as close to design as practical, the full operation sequence that brings the systems into operation, including operation of applicable portions of the protection system and the transfer of power among the nuclear power unit, the offsite power system, and the onsite power system. This criterion requires that the dc power system provide the capability to perform integral periodic testing of Class 1E systems. This SRP section cites RGs 1.32, 1.47, 1.118, 1.129, and 1.153 and BTP 8-5 as establishing acceptable guidance for meeting the requirements of this criterion. Meeting the requirements of GDC 18 provides assurance that, when required, onsite dc power systems can be appropriately and unobtrusively accessed for required periodic inspection and testing, enabling verification of important system parameters, performance characteristics, and features, as well as detection of degradation and/or impending failure under controlled conditions. 6. GDCs 33, 34, 35, 38, 41, and 44 set requirements for the safety systems for which access to both offsite and onsite power sources must be provided. Compliance with these criteria requires provision of this capability for reactor coolant makeup during small breaks, residual heat removal, emergency core cooling, containment heat removal, containment atmosphere cleanup, and cooling water for SSCs important to safety. These systems must be available during normal and accident conditions, as required by the specific system. GDCs 33, 34, 35, 38, 41, and 44 require safety system redundancy such that, for onsite power system operation (assuming offsite power is unavailable), the system safety function can be accomplished, assuming a single failure. Redundancy must be reflected in the standby power system with regard