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Availability of and Solicitation of Public Comments on Report on Seismic Considerations for the Transition Break Size

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Information about this document as published in the Federal Register.

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Nuclear Regulatory Commission.


Notice of opportunity for public comment.


On November 7, 2005, the Nuclear Regulatory Commission (NRC) published for public comment a proposed rule in the Federal Register (70 FR 67598) on Risk-Informed Changes to Loss-of-Coolant Accident Technical Requirements. Under the proposed § 50.46a rule, nuclear power plant licensees would be allowed to implement a voluntary, risk-informed alternative to the current requirements for analyzing the performance of emergency core cooling systems (ECCS) during loss-of-coolant accidents (LOCAs). In addition, the proposed rule would establish procedures and criteria for requesting changes in plant design and procedures based upon the results of the new analyses of ECCS performance during LOCAs. In the Federal Register notice associated with the publication of the proposed alternative § 50.46a rule, the Commission noted that the potential for seismically-induced pipe breaks was not considered in determining the area of the transition break sizes [1] (TBSs). The Commission stated that work was ongoing to investigate the possible effect of seismically-induced pipe breaks on the TBS selections and committed to put a report on the NRC Web site to facilitate public comment on the technical aspects of the issue. The NRC staff has completed its report and has posted it on the Rulemaking Forum Web site,


Comment period expires on February 6, 2006. Comments received after this date will be considered if it is practical to do so, but assurance of consideration cannot be given to comments received after this date.

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You may submit comments on the seismic report and the proposed rule by any one of the following methods. Please include the following number, RIN 3150-AH29, in the subject line of your comments. Comments on rulemakings submitted in writing or in electronic form will be made available for public inspection. 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.

Mail comments to: Secretary, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, ATTN: Rulemakings and Adjudications Staff.

E-mail comments to: If you do not receive a reply e-mail confirming that we have received your comments, contact us directly at (301) 415-1966. You may also submit comments via the NRC's rulemaking Web site at Address questions about our rulemaking website to Carol Gallagher (301) 415-5905; e-mail Comments can also be submitted via the Federal eRulemaking Portal

Hand deliver comments to: 11555 Rockville Pike, Rockville, Maryland 20852, between 7:30 a.m. and 4:15 p.m. Federal workdays. (Telephone (301) 415-1966).

Fax comments to: Secretary, U.S. Nuclear Regulatory Commission at (301) 415-1101.

Publicly available documents related to this rulemaking may be viewed electronically on the public computers located at the NRC's Public Document Room (PDR), O1 F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The PDR reproduction contractor will copy documents for a fee. Selected documents, including comments, may be viewed and downloaded electronically via the NRC rulemaking Web site at

Publicly available documents created or received at the NRC after November 1, 1999, are available electronically at the NRC's Electronic Reading Room at​reading-rm/​adams.html. From this site, the public can gain entry into the NRC's Agencywide Document Access and Management System (ADAMS), which provides text and image files of 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 Public Document Room (PDR) Reference staff at 1-800-397-4209, (301) 415-4737 or by e-mail to

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Richard Dudley, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington DC 20555-0001; telephone (301) 415-1116; e-mail:

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Dated at Rockville, Maryland, this 14th day of December, 2005.

For the Nuclear Regulatory Commission.

Eileen McKenna,

Chief, Financial, Policy and Rulemaking Branch, Division of Policy and Rulemaking, Office of Nuclear Reactor Regulation.

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1.  Different values for TBS were specified for PWRs and BWRs.

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[FR Doc. E5-7545 Filed 12-19-05; 8:45 am]