Document: NUREG-0800
Document ID: 9cfc38bf-7808-446e-a43d-4ca9ff55df2a
Document Type: srp
Title: AC POWER SYSTEMS (ONSITE)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1007/ML100740289.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8.3.1
CFR Part: 
CFR Title: 

Content:
hat 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 RG 1.6. As endorsed by RG 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 basic criteria for addressing single failures, and IEEE-279 provides criteria for protection systems with applicability determined by the date of issuance of the CP as described in 10 CFR 50.55a(h). 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 Protection Systems," as augmented by RG 1.53, "Application of the Single-Failure Criterion to Nuclear Power Plant Protection 8.3.1-21 Revision 4 - May 2010 Systems." Other aspects of the design where special review attention is given to ascertain that the electrical independence and physical separation has not been compromised are as follows: A. Should the proposed design provide for sharing of