Document: NUREG-0800
Document ID: d9e9d0a9-6390-4154-94dc-7d5e6d8145cd
Document Type: srp
Title: A-C POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350489.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
s 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 General Design Criterion 17, the onsite a-c 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 between 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 schematics are reviewed to determine that the design meets the requirements set forth in IEEE Std 308 and satisfies the positions of Regulatory Guide 1.6. Additional guidance in evaluating this aspect of the design is derived from IEEE Std 379, "Guide for the Application of the Single-Failure Criterion to Nuclear Power Generating Station Protect on Systems," as augmented by Regulatory Guide 1.53, "Application of the Single-Failure Criterion to Nuclear Power Plant Protection Systems." Other aspects of the design where .special review attention is given to ascertain that the electrical indepen- dence and physical separation has not been compromised are as follows: 8.3.1-8 Rev. 2 - July 1981 a. Should the proposed design provide for sharing of the a-c onsite power system between units at the same site, the criteria of IEEE Std 308 governing the sharing of this system between units are not specific enough to