[Federal Register Volume 78, Number 64 (Wednesday, April 3, 2013)]
[Page 20148]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-07702]




Reporting Procedure for Mathematical Models Selected To Predict 
Heated Effluent Dispersion in Natural Water Bodies

AGENCY: Nuclear Regulatory Commission.

ACTION: Withdrawal notice.


SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is withdrawing 
Regulatory Guide (RG) 4.4, ``Reporting Procedure for Mathematical 
Models Selected to Predict Heated Effluent Dispersion in Natural Water 
Bodies.'' The guide is being withdrawn because it is obsolete and new 
guidance has been included in models developed by the Environmental 
Protection Agency (EPA) that provides updated direction.

ADDRESSES: Please refer to Docket ID NRC-2013-0062 when contacting the 
NRC about the availability of information on this document. You may 
access information related to this document, which the NRC possesses 
and is publicly-available, using any of the following methods:
     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. To begin search, select ``ADAMS Public Documents'' and 
then select ``Begin Web-based ADAMS Search.'' For problems with ADAMS, 
please contact the NRC's Public Document Room (PDR) reference staff at 
1-800-397-4209, or 301-415-4737, or by email at PDR.Resource@NRC.Gov. 
The ADAMS accession number for each document referenced in this notice 
(if that document is available in ADAMS) is provided the first time 
that a document is referenced. The review for the withdrawal of RG 4.4 
is available in ADAMS under Accession No. ML12269A378.
     NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 
Rockville Pike, Rockville, MD 20852.
    The documents are not copyrighted and NRC approval is not required 
to reproduce them.

Regulatory Research, U.S. Nuclear Regulatory Commission, Washington DC 
20555-0001; telephone: 301-251-7445; or by email at Ralph.Cady@nrc.gov.


I. Introduction

    The NRC is withdrawing RG 4.4 because its guidance has been 
superseded and is no longer needed. The guide was published in May 
1974, to provide guidance on meeting the requirements in Sec.  51.20 of 
Title 10 of the Code of Federal Regulations (10 CFR), ``Criteria for 
and Identification of Licensing and Regulatory Actions Requiring 
Environmental Impact Statements.''
    Regulatory Guide 4.4 provided guidance to licensees on a procedure 
acceptable to the NRC staff for providing summary details of 
mathematical modeling methods used in predicting the dispersion of 
heated effluent in natural water bodies. The guide included an itemized 
table of relevant modeling factors to accompany descriptive material 
for the one or more models submitted by an applicant. However, neither 
licensees nor the NRC staff are currently following the explicit 
recommendations in this guide, in part because the EPA has developed a 
mathematical model for this purpose that is often used by both NRC 
staff and licensees.
    EPA's National Pollutant Discharge Elimination System (NPDES) 
program regulates the discharge of effluents (including heated water) 
into natural water bodies and requires analyses for permitted 
discharge. EPA has supported the development of a model (CORMIX) for 
NPDES analyses that is generally used by both NRC staff and licensees. 
Industry groups, such as the American Petroleum Institute, also have 
guidance to support these analyses. A few other well-accepted models 
for heated effluent dispersion also exist and are used in license 
applications and by the NRC staff in their reviews.

II. Further Information

    The withdrawal of RG 4.4 does not alter any prior or existing 
licensing commitments based on its use. The guidance provided in this 
guide is no longer necessary. Regulatory guides may be withdrawn when 
their guidance no longer provides useful information, or is superseded 
by technological innovations, congressional actions, or other events.
    Regulatory guides are revised for a variety of reasons and the 
withdrawal of an RG should be thought of as the final revision of the 
guide. Although an RG is withdrawn, current licensees may continue to 
use it, and withdrawal does not affect any existing licenses or 
agreements. Withdrawal of a guide means that the guide should not be 
used for future NRC licensing activities. However, although a 
regulatory guide is withdrawn, changes to existing licenses can be 
accomplished using other regulatory products.
    Regulatory guides and publicly available NRC documents are 
available electronically through the NRC Library on the NRC's public 
Web site at: http://www.nrc.gov/reading-rm/doc-collections/. The 
documents can also be viewed online for free or printed for a fee in 
the NRC's Public Document Room (PDR) at 11555 Rockville Pike, 
Rockville, MD; the mailing address is USNRC PDR, Washington, DC 20555-
0001; telephone: 301-415-4737, or 1-800-397-4209; fax 301-415-3548; or 
by email to pdr.resource@nrc.gov. Regulatory guides are not 
copyrighted, and NRC approval is not required to reproduce them.

    Dated at Rockville, Maryland, this 22nd day of March, 2013.
    For the Nuclear Regulatory Commission.
Thomas H. Boyce,
Branch Chief, Regulatory Guide Development Branch, Division of 
Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2013-07702 Filed 4-2-13; 8:45 am]