Document: NUREG-0800
Document ID: 61198d64-419c-45ea-aebb-cf34c3b171fe
Document Type: srp
Title: Revision 0 – July 2015
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1505/ML15057A085.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
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Content:
l Design Criteria for Nuclear Power Plants,” to 10 CFR Part 50, “Domestic Licensing of Production and Utilization Facilities,” General Design Criterion (GDC) 17, “Electric Power Systems,” or principal design criteria specified in the updated final safety analysis report. Specifically, the NRC requested licensees to provide information by October 25, 2012, regarding (1) the protection scheme to detect and automatically respond to a single phase open circuit condition or high impedance ground fault condition on GDC 17 power circuits, and (2) the operating configuration of engineered safety features buses at power. The Electrical Engineering Branch staff has reviewed the information that NRC licensees provided and the details of this review are documented in a NRC Bulletin 2012-01, “Design Vulnerability in Electric Power System,” Summary Report dated February 26, 2013 (ADAMS Accession No. ML13052A711). The purpose of this BTP is to provide guidance to the staff in reviewing various licensing actions related to electric power system design vulnerability due to open phase conditions in offsite electric power systems in accordance with Appendix A to 10 CFR Part 50, GDC 17 or principal design criteria specified in the updated final safety analysis report, 10 CFR 50.55a(h)(2), 10 CFR 50.55a(h)(3), and 10 CFR 50.36(c)(2) and 10 CFR 50.36(c)(3). B. BRANCH TECHNICAL POSITION 1. Electric power from the transmission network to the onsite electric distribution system is supplied by two physically independent circuits. The design of the electrical system and the protective relaying system should address the following open phase conditions (OPCs): BTP 8-9-4 Revision 0 – July 2015 (i) Loss of one of the three phases of the independent circuits on the high voltage side of a transformer connecting an offsite power circuit to the transmission system. The protection scheme should consider all operating electrical system configurations and loading conditions: a. with a