Skip to Content


Draft Regulatory Guide: Granting Extension of Comment Period

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


Nuclear Regulatory Commission.


Notice of Granting of Request To Extend the Comment Period of Draft Regulatory Guide (DG)-1200, “An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities.”

Start Further Info


Mary Drouin, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, telephone: (301) 415-6675 or e-mail to

End Further Info End Preamble Start Supplemental Information


I. Introduction

The U.S. Nuclear Regulatory Commission (NRC) issued for public comment DG-1200, which was published in the Federal Register, 73 FR 35170, on June 20, 2008. DG-1200 is proposed Revision 2 of Regulatory Guide 1.200 in the agency's Regulatory Guide Series. This series has been developed to describe and make available to the public such information as methods that are acceptable to the NRC staff for implementing specific parts of the NRC'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.

II. Further Information

The NRC staff requested receipt of comments on DG-1200 by August 25, 2008, (including any implementation schedule) and its associated regulatory analysis or value/impact statement. By this action, the NRC staff is extending the comment period until September 24, 2008. Comments received after September 24, 2008, would be considered if practical to do so, but the NRC is able to ensure consideration only for comments received on or before this date. Although a time limit is given, comments and suggestions in connection with items for inclusion in guides currently being developed or improvements in all published guides are encouraged at any time.

III. Request To Extend the Comment Period

Basis for the Request

The NRC received the following extension request:

“There is currently work underway by the American Society of Mechanical Engineers (ASME) to address many fundamental issues with the Joint ASME/American Nuclear Society (ANS) PRA [probabilistic risk assessment] Standard, many of which are items likely identified in the current RG revision. These changes are identified as Addendum A to the ASME/ANS Joint PRA Standard.” “ASME is currently balloting these changes for approval, with a closure of the ballot in late August 2008. Once balloted and approved, these changes to the Joint Standard will be made available to the general public. Availability of such information will be important for the public to make an informed review of the draft RG 1.200, Revision 2. As a result of this schedule mismatch, the PWROG [pressurized water reactor owners' group] requests that the review period for the draft RG 1.200, Revision 2 be extended to allow the industry to integrate the findings and conclusions of the ASME/ANS Joint PRA Standard revisions in preparing an informed review. The Start Printed Page 49712PWROG views changes in Addendum A substantial enough to warrant an extension of the public review period. Accordingly, we request a 60-day extension to the current review period.”

Response to Request

The request for an extension to the comment period is approved for 30 days.

The staff understands that ASME/ANS is working on an initial addendum (i.e., Addendum A) to Revision 1 of the ASME/ANS PRA Standard (RA-S-2008). However, at this time, Addendum A has not been approved by ASME/ANS, and consequently is not available to the public. Since the ASME/ANS ballot period has not closed, it is not known if there will be sufficient positive ballots approving Addendum A. Consequently, it is uncertain if and when ASME/ANS will issue Addendum A, and therefore, be available to the public. A 60-day extension to the public comment period for DG 1200 will impact the December 2008 publication date of Revision 2 of RG 1.200. With the uncertainty associated with the issuance of Addendum A of the ASME/ANS PRA standard, the staff does not support an extension of the comment period to DG 1200 that would impact the schedule for publishing Revision 2 to RG 1.200. However, the staff agrees with the PWROG with regard to the importance of Addendum A. The staff understands from ASME that the ballot closes September 12, 2008, at which time the status of Addendum A will be known. A 30-day extension to the comment period of DG 1200 will enable the staff the meet the publication schedule of December 2008 for Revision 2 to RG 1.200. Therefore, the staff is approving a 30-day extension to the public comment period, with the public comment period to end on September 24, 2008. Further, at that time, the status of Addendum A of the ASME/ANS PRA Standard will be known, and dependent on the content of Addendum A and the schedule for issuance, the staff may revisit the schedule for publishing Revision 2 of RG 1.200.

Requests for technical information about DG-1200 may be directed to the NRC contact, Mary Drouin at (301) 415-6675 or e-mail to

Electronic copies of DG-1200 are available through the NRC's public Web site under Draft Regulatory Guides in the “Regulatory Guides” collection of the NRC's Electronic Reading Room at​reading-rm/​doc-collections/​. Electronic copies are also available in ADAMS (​reading-rm/​adams.html), under Accession No. ML081200566.

In addition, regulatory guides are available for inspection at the NRC's Public Document Room (PDR), which is located at 11555 Rockville Pike, Rockville, Maryland. 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) 397-4205, by fax at (301) 415-3548, and by e-mail to

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

Start Signature

Dated at Rockville, Maryland, this 19th day of August 2008.

For the Nuclear Regulatory Commission.

Stephen C. O'Connor,

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

End Signature End Supplemental Information

[FR Doc. E8-19635 Filed 8-21-08; 8:45 am]