Document Headings

                    Document headings vary by document type but may contain                    the following:                  
                -                       the agency or agencies that issued and signed a document                    
                -                       the number of the CFR title and the number of each part                      the document amends, proposes to amend, or is directly                      related to                    
                -                       the agency docket number / agency internal file number                    
                -                       the RIN which identifies each regulatory action listed in                      the Unified Agenda of Federal Regulatory and Deregulatory                      Actions                    

                    See the                                          Document Drafting Handbook                                        for more details.                  

###### Nuclear Regulatory Commission

          - [NRC-2008-0385]

# AGENCY:

Nuclear Regulatory Commission.

# ACTION:

Notice of Issuance and Availability of Regulatory Guide 1.125, Revision 2.

# FOR FURTHER INFORMATION CONTACT:

                        Mark Orr, Regulatory Guide Development Branch, Division of Engineering, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, telephone (301) 251-7495 or e-mail to                         *Mark.Orr@nrc.gov.*

# SUPPLEMENTARY INFORMATION:

## I. Introduction

The U.S. Nuclear Regulatory Commission (NRC) is issuing a revision to 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 1.125, “Physical Models for Design, and Operation of Hydraulic Structures and Systems for Nuclear Power Plants,” was issued with a temporary identification as Draft Regulatory Guide, DG-1198. This guide describes the detail and documentation of data and studies that an applicant should include in the preliminary and/or final safety analysis report (PSAR/FSAR) to support the use of physical hydraulic model testing for predicting the performance of hydraulic structures and systems for nuclear power plants. Hydraulic structures are defined as anything that can be used to divert, restrict, stop, or otherwise manage the natural flow of water. The regulatory position of this guide is applicable only to physical models used to predict the action or interaction of surface waters with features located outside the containment. The recommendations of this guide do not apply to internal plant systems or structures.

## II. Further Information

In July 2008, DG-1198 was published with a public comment period of 60 days from the issuance of the guide. The public comment period closed on September 5, 2008. The staff's responses to the public comments are located in the NRC's Agencywide Documents Access and Management System (ADAMS), Accession Number ML082810214.

                    Electronic copies of Regulatory Guide 1.125, Revision 2 are available through the NRC's public Web site under “Regulatory Guides” at                     *http://www.nrc.gov/​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                     *pdr.resource@nrc.gov.*

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

Dated at Rockville, Maryland, this 16th 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.

[FR Doc. E9-6408 Filed 3-23-09; 8:45 am]

BILLING CODE 7590-01-P