Document: NUREG-0800
Document ID: 81256f55-72dd-4777-9472-f373c71c4554
Document Type: srp
Title: AC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550065.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
As endorsed by Regulatory Guide 1.153, IEEE Std 603 provides criteria used to evaluate all aspects of the electrical portions of safety-related systems and the onsite power system, including criteria addressing redundancy, and IEEE-279 provides criteria for protection systems, with applicability determined by the date of issuance of the construction permit (CP) as described in 10 CFR 50.55a(h). The descriptive information, including electrical single- line diagrams, physical arrangement drawings, and electrical control and schematics, is reviewed to verify that this redundancy is reflected in the standby power system with regard to both power sources and associated distribution systems. Also, it is verified in coordination with other branches that redundant safety loads are distributed between redundant distribution systems and that the instrumentation and control devices for the Class 1E loads and power system are supplied from the related redundant distribution systems. 2. Conformance with the Single Failure Criterion As required by GDC 17, the onsite ac power system must be capable of performing its safety function assuming a single failure. In evaluating the adequacy of this system in meeting the single failure criterion, both electrical and physical separation of redundant power sources and distribution systems, including their connected loads, are reviewed to assess the independence of redundant portions of the system. To ensure electrical independence, the design criteria, analyses, description, and implementation as depicted on functional logic diagrams, electrical single-line diagrams, and electrical control and schematics are reviewed to determine that the design meets the recommendations set forth in IEEE Std 308 and satisfies the positions of Regulatory Guide 1.6. As endorsed by Regulatory Guide 1.153, IEEE Std 603 provides criteria used to evaluate all aspects of the electrical portions of safety-related systems and the onsite power system, including