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Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power

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Information about this document as published in the Federal Register.

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Nuclear Regulatory Commission.


Notice of Issuance.


The U.S. Nuclear Regulatory Commission (NRC) has issued Generic Letter (GL) 2006-02 to all holders of operating licenses for nuclear power reactors, except those who have permanently ceased operation and have certified that fuel has been removed from the reactor vessel. The NRC is issuing this generic letter to determine if compliance is being maintained with NRC regulatory requirements governing electric power sources and associated personnel training for your plant, the NRC is issuing this GL to obtain information from its licensees regarding:

1. 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 TSO, ISO, or RA/RC is responsible for preserving the reliability of the local transmission system. In this GL the term TSO is used to denote these entities);

2. Use of NPP/TSO protocols and analysis tools by TSOs to assist NPPs in monitoring grid conditions for consideration in maintenance risk assessments;

3. Offsite power restoration procedures in accordance with Section 2 of NRC Regulatory Guide (RG) 1.155, “Station Blackout”;

4. Losses of offsite power caused by grid failures at a frequency equal to or greater than once in 20 site-years in accordance with RG 1.155, and

5. Require addressees to provide a written response to the NRC in accordance with 10 CFR 50.54(f).

This Federal Register notice is available through the NRC's Agencywide Documents Access and Management System (ADAMS) under accession number ML060380343.


The GL was issued on February 1, 2006.


Not applicable.

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Paul Gill at 301-415-3316 or by e-mail or Matthew W. McConnell at 301-415-1597 or e-mail

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NRC GL 2006-02 may be examined, and/or copied for a fee, at the NRC's Public Document Room (PDR) at One White Flint North, 11555 Rockville Pike (first floor), Rockville, Maryland. Publicly available records will be accessible electronically from the ADAMS Public Electronic Reading Room on the Internet at the NRC Web site,​NRC/​ADAMS/​index.html. The ADAMS number for the GL is ML060180352.

If you do not have access to ADAMS or if you have problems in accessing the documents in ADAMS, contact the NRC PDR reference staff at 1-800-397-4209 or 301-415-4737 or by e-mail to

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Dated at Rockville, Maryland, this 9th day of February 2006.

For the Nuclear Regulatory Commission.

Christopher I. Grimes,

Director, Division of Policy and Rulemaking, Office of Nuclear Reactor Regulation.

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[FR Doc. E6-2167 Filed 2-14-06; 8:45 am]