05-3736. Availability of the Office of Nuclear Regulatory Research Draft Report Entitled, “Station Blackout Risk Evaluation for Nuclear Power Plants,” for Comment

AGENCY:

Nuclear Regulatory Commission.

ACTION:

Notice of availability of the Office of Nuclear Regulatory Research draft report entitled, “Station Blackout Risk Evaluation for Nuclear Power Plants,” and request for public comment.

SUMMARY:

The Nuclear Regulatory Commission (NRC) is announcing the availability of the Office of Nuclear Regulatory Research draft report entitled, “Station Blackout Risk Evaluation for Nuclear Power Plants.”

DATES:

Comments on this document should be submitted by April 15, 2005. Comments received after that date will be considered to the extent practicable. To ensure efficient and complete comment resolution, comments should include references to the section, page, and line numbers of the document to which the comment applies, if possible.

ADDRESSES:

Members of the public are invited and encouraged to submit written comments to Michael Lesar, Chief Rules and Directives Branch, Office of Administration, Mail Stop T-6D59, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. Hand-deliver comments attention to Michael Lesar, 11545 Rockville Pike, Rockville, MD, between 7:30 a.m. and 4:15 p.m. on Federal workdays. Comments may also be sent electronically to: [e-mail].

This document is available at the Agencywide Documents Access and Management System (ADAMS) Public Electronic Reading Room on the Internet at the NRC Web site at http://www.nrc.gov/​reading-rm/​adams.html under Accession No. ML050140399, and at the NRC Public Document Room, 11555 Rockville Pike, Rockville, MD. The PDR's mailing address is USNRC PDR, Washington, DC 20555; telephone [phone] or [phone]; fax [phone]; e-mail [e-mail].

FOR FURTHER INFORMATION CONTACT:

Dale M. Rasmuson, Division of Risk Analysis and Applications, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001. Telephone: [phone], e-mail: [e-mail].

SUPPLEMENTARY INFORMATION:

Draft Report Entitled, “Station Blackout Risk Evaluation for Nuclear Power Plants”

This report is an update of several previous reports analyzing the risk from loss of offsite power and subsequent station blackout events at U.S. commercial nuclear power plants. The risk measure used is core damage frequency. Standardized plant analysis risk (SPAR) models developed by the U.S. Nuclear Regulatory Commission, covering the 103 operating commercial nuclear power plants, were used to evaluate the risk. Core damage frequency results indicating contributions from station blackout scenarios and other loss of offsite power scenarios are presented for each of the 103 plants, along with plant class and industry averages. In addition, a comprehensive review of emergency diesel generator performance was performed to obtain current estimates for input to the SPAR models. Overall results indicate that core damage frequencies for loss of offsite power and station blackout are lower than previous estimates. Contributing to this risk reduction is an improvement in emergency diesel generator performance.

The NRC is seeking public comment in order to receive feedback from the widest range of parties and to ensure that all information relevant to developing this document is available to the NRC staff. This document is issued for comment only and is not intended for interim use. The NRC will review public comments received on the document, incorporate suggested changes as necessary, and issue the final report for use. The NRC will review public comments received on the document, incorporate suggested changes as necessary, and issue the final report for use.

Dated at Rockville, Maryland, this 16th day of February, 2005.

For the Nuclear Regulatory Commission.

Charles E. Ader,

Director, Division of Risk Analysis and Applications, Office of Nuclear Regulatory Research.