2011-33471. Methodology for Low Power/Shutdown Fire PRA

AGENCY:

Nuclear Regulatory Commission.

ACTION:

Draft NUREG/CR; request for comment.

SUMMARY:

The U.S. Nuclear Regulatory Commission (NRC) is issuing for public comment a draft NUREG/CR, NUREG/CR-7114, Revision 0, “Methodology for Low Power/Shutdown Fire PRA—Draft Report for Comment.”

DATES:

Submit comments by March 01, 2012. Comments received after this date will be considered if it is practical to do so, but the NRC staff is able to ensure consideration only for comments received on or before this date.

ADDRESSES:

Please include Docket ID NRC-2011-0295 in the subject line of your comments. For additional instructions on submitting comments and instructions on accessing documents related to this action, see “Submitting Comments and Accessing Information” in the SUPPLEMENTARY INFORMATION section of this document. You may submit comments by any of the following methods:

• Federal Rulemaking Web site: Go to http://www.regulations.gov and search for documents filed under Docket ID NRC-2011-0295. Address questions about NRC dockets to Carol Gallagher [phone]; email [e-mail].
• Mail comments to: Mail comments to: Cindy Bladey, Chief, Rules, Announcements, and Directives Branch (RADB), Office of Administration, Mail Stop: TWB-05-B01M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by fax to RADB at [phone].
• Fax comments to: RADB at [phone].

FOR FURTHER INFORMATION CONTACT:

Felix E. Gonzalez, Division of Risk Analysis, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: [phone], email: [e-mail] or Hugh W. Woods, Division of Risk Analysis, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: [phone], email: [e-mail].

SUPPLEMENTARY INFORMATION:

Submitting Comments and Accessing Information

Comments submitted in writing or in electronic form will be posted on the NRC Web site and on the Federal rulemaking Web site, http://www.regulations.gov. Because your comments will not be edited to remove any identifying or contact information, the NRC cautions you against including any information in your submission that you do not want to be publicly disclosed.

The NRC requests that any party soliciting or aggregating comments received from other persons for submission to the NRC inform those persons that the NRC will not edit their comments to remove any identifying or contact information, and therefore, they should not include any information in their comments that they do not want publicly disclosed.

You can access publicly available documents related to this document using the following methods:

• NRC's Public Document Room (PDR): The public may examine and have copied, for a fee, publicly available documents at the NRC's PDR, O1-F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland 20852.
• NRC's Agencywide Documents Access and Management System (ADAMS): Publicly available documents created or received at the NRC are available online in the NRC Library at http://www.nrc.gov/​reading-rm/​adams.html. From this page, the public can gain entry into ADAMS, which provides text and image files of the NRC's public documents. If you do not have access to ADAMS or if there are problems in accessing the documents located in ADAMS, contact the NRC's PDR reference staff at 1-[phone], [phone], or by email to [e-mail]. The draft NUREG is available electronically under ADAMS Accession No. ML11353A377. The draft NUREG will also be accessible through the NRC's public site under draft NUREGs for comment.
• Federal Rulemaking Web Site: Public comments and supporting materials related to this notice can be found at http://www.regulations.gov by searching on Docket ID NRC-2011-0295.

Discussion

The draft NUREG presents a probabilistic risk assessment (PRA) method for quantitatively analyzing fire risk in commercial nuclear power plants during low power operation and shutdown (LPSD) conditions, including the determination of core damage frequency (CDF) and large early release frequency (LERF). Future updates are expected to be made to this document as experience is gained with LPSD quantitative risk analyses of both internal events and fires.

The NRC developed this LPSD fire quantitative risk method so analysts would be able to use a quantitative approach for estimating fire risk during LPSD conditions. While current LPSD safety analyses for fires performed under National Fire Protection Association Standard 805 (NFPA 805) focus on qualitative, defense-in-depth methods, it is envisioned that applications in the future may evolve to a more quantitative method.

Dated at Rockville, Maryland, this 21 day of December, 2011.

For the Nuclear Regulatory Commission.

Mark H. Salley,

Chief, Fire Research Branch, Division of Risk Analysis, Office of Nuclear Regulatory Research.