Document: NRC Regulatory Guide
Document ID: 9a8db182-3194-4663-aeb3-64f2e4edd6aa
Document Type: regulatory_guide
Title: Availability of Electric Power Sources (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1008/ML100840581.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.93
CFR Part: 
CFR Title: 

Content:
n sufficient time following a loss of all onsite alternating current (ac) power supplies and the other offsite electric power circuits. One of these circuits shall be designed to be available within a few seconds following a loss- of-coolant accident. DG-1244, Page 2 • The licensee shall provide redundant onsite ac power supplies. • The licensee shall provide redundant onsite direct current (dc) power supplies. For nuclear power plants (NPPs) that were not licensed in accordance with GDC 17, the updated final safety analysis report provides the applicable design criteria. The NRC issued Generic Letter (GL) 2006-02, “Grid Reliability and the Impact on Plant Risk and Operability of Offsite Power” on February 1, 2006 (Ref. 7) to obtain, in part, information on the following issues from its licensees: • the use of protocols between the nuclear power plant (NPP) and the transmission system operator (TSO), independent system operator (ISO), or reliability coordinator/authority (RC/RA) and the use of transmission load flow analysis tools (analysis tools) by TSOs to assist NPPs in monitoring grid conditions to determine the operability of offsite power systems under plant technical specifications; • the use of NPP/TSO protocols and analysis tools by TSOs to assist NPPs in monitoring grid conditions for consideration in maintenance risk assessments; The NRC issues regulatory guides to describe to the public methods that the staff considers acceptable for use in implementing specific parts of the agency’s regulations, to explain techniques that the staff uses in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations and compliance with them is not required. This regulatory guide contains information collection requirements covered by 10 CFR Part 50 that the Office of Management and Budget (OMB) approved under OMB control number 3150-0011. The NRC may neither conduct nor