Document: NUREG-0800
Document ID: b75d082b-2493-4543-981a-2ee136d737cf
Document Type: srp
Title: BTP 8-9-1
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1405/ML14057A433.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
CFR Part: 
CFR Title: 

Content:
of Unbalanced Voltages on the Performance of Polyphase Squirrel-Cage Induction Motors”, and IEEE Std. C37.96-2012 (Guide for AC Motor Protection), Section 5.7.2.6, “Unbalanced protection and phase failures” may be used for general guidance. c. Establish the limitations of existing protective devices for various operating and loading conditions with open phase conditions on each phase. d. The magnitude of expected unbalance voltage and current for different open phase or high impedance fault currents may dictate the operating characteristics of proposed protective devices. As an example, a protective device with two settings may be used for (a) alarm only when a low unbalanced voltage/current is detected, (b) trip when higher unbalanced voltage/current that is deemed unacceptable for plant equipment is detected. A time delay may be incorporated in both settings to avoid actuations during transient conditions. Any time delay provided must always meet the accident analysis assumptions. C. REFERENCES 1. RG 1.153, “Criteria for Power, Instrumentation, and Control Portions of Safety Systems.” 2. NRC Information Notice 2012-03, “Design Vulnerability in Electric Power System,” dated March 1, 2012, ADAMS Accession No. ML120480170. 3. NRC Bulletin 2012-01, “Design Vulnerability in Electric Power System,” dated July 27, 2012, ADAMS Accession No. ML12074A115. 4. IEEE Std. 279-1971, “Criteria for Protection Systems for Nuclear Power Stations.” BTP 8-9-8 Draft Revision 0 – May 2014 5. IEEE Std. 603-1991, “Criteria for Safety Systems for Nuclear Power Generating Stations.” 7. NRC Bulletin 2012-01Summary Report dated July 2, 2013, ADAMS Accession No. ML13052A711. 8. Industry Initiative on Open Phase Condition - Functioning of Important-to-Safety Structures, Systems and Components, ADAMS Accession No. ML13333A142. 9. SECY-13-0107, Status of the Accident Sequence Precursor Program and the Standardized Plant Analysis Risk Models,” dated October 4, 2013,