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Notice of Issuance of Regulatory Guide

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Nuclear Regulatory Commission.


Notice of Issuance and Availability of Regulatory Guide 1.200, Revision 2.

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Mary Drouin, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, telephone (301) 251-7574 or e-mail to

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I. Introduction

The U.S. Nuclear Regulatory Commission (NRC) is issuing a revision Start Printed Page 11382to an existing guide in the agency's “Regulatory Guide” series. This series was developed to describe and make available to the public information such as methods that are acceptable to the NRC staff for implementing specific parts of the agency's regulations, techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the staff needs in its review of applications for permits and licenses.

Revision 2 of Regulatory Guide 1.200, “An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities,” was issued with a temporary identification as Draft Regulatory Guide, DG-1200. In 1995, the NRC issued a Policy Statement on the use of probabilistic risk analysis (PRA), encouraging its use in all regulatory matters. That Policy Statement states that “ * * * the use of PRA technology should be increased to the extent supported by the state-of-the-art in PRA methods and data and in a manner that complements the NRC's deterministic approach.” Since that time, many uses have been implemented or undertaken, including modification of the NRC's reactor safety inspection program and initiation of work to modify reactor safety regulations. Consequently, confidence in the information derived from a PRA is an important issue, in that the accuracy of the technical content must be sufficient to justify the specific results and insights that are used to support the decision under consideration.

This regulatory guide describes one acceptable approach for determining whether the technical adequacy of the PRA, in total or the parts that are used to support an application, is sufficient to provide confidence in the results, such that the PRA can be used in regulatory decision-making for light-water reactors. This guidance is intended to be consistent with the NRC's PRA Policy Statement. It is also intended to reflect and endorse guidance provided by standards-setting and nuclear industry organizations.

II. Further Information

In June 2008, DG-1200 was published for public comment. The public comment period closed on December 31, 2008. The staff's responses to the public comments that were received are located in the NRC's Agencywide Documents Access and Management System (ADAMS) under Accession Number ML090410020. Electronic copies of Regulatory Guide 1.200, Revision 2 are available through the NRC's public Web site under “Regulatory Guides” at​reading-rm/​doc-collections/​.

In addition, regulatory guides are available for inspection at the NRC's Public Document Room (PDR), which is located at Room O-1F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland 20852-2738. The PDR's mailing address is USNRC PDR, Washington, DC 20555-0001. The PDR can also be reached by telephone at (301) 415-4737 or (800) 397-4209, by fax at (301) 415-3548, and by e-mail to

Regulatory guides are not copyrighted, and NRC approval is not required to reproduce them.

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Dated at Rockville, Maryland, this 10th day of March 2009.

For the Nuclear Regulatory Commission.

Andrea D. Valentin,

Chief, Regulatory Guide Development Branch, Division of Engineering, Office of Nuclear Regulatory Research.

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[FR Doc. E9-5698 Filed 3-16-09; 8:45 am]