[Federal Register Volume 71, Number 145 (Friday, July 28, 2006)]
[Notices]
[Pages 42885-42886]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-12078]


-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION


Final Regulatory Guide; Issuance, Availability

    The U.S. Nuclear Regulatory Commission (NRC) has issued a revision 
to an existing guide 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.
    Revision 2 of Regulatory Guide 1.92, entitled ``Combining Modal 
Responses and Spatial Components in Seismic Response Analysis,'' 
provides licensees and applicants with improved guidance concerning 
methods that the NRC staff considers acceptable for combining modal 
responses and spatial components in seismic response analysis of 
nuclear power plant (NPP) structures, systems, and components (SSCs) 
that are important to safety. As defined in Appendix A, ``General 
Design Criteria for Nuclear Power Plants,'' to Title 10, part 50, of 
the Code of Federal Regulations (10 CFR part 50), Criterion 2, ``Design 
Bases for Protection Against Natural Phenomena,'' requires, in part, 
that SSCs that are important to safety must be designed to withstand 
the effects of natural phenomena (such as earthquakes) without losing 
their capability to perform their respective safety functions. Such 
SSCs must also be designed to accommodate the effects of, and be 
compatible with, the environmental conditions associated with normal 
operation and postulated accidents. Appendix S, ``Earthquake 
Engineering Criteria for Nuclear Power Plants,'' to 10 CFR part 50 
specifies, in part, requirements for implementing General Design 
Criterion 2 with respect to earthquakes.\1\
---------------------------------------------------------------------------

    \1\ Appendix S to 10 CFR part 50 applies to applicants for a 
design certification or combined license pursuant to 10 CFR part 52, 
``Early Site Permits; Standard Design Certifications; and Combined 
Licenses for Nuclear Power Plants,'' or a construction permit or 
operating license pursuant to 10 CFR part 50 after January 10, 1997. 
However, the earthquake engineering criteria in Section VI of 
Appendix A to 10 CFR part 100 continue to apply for either an 
operating license applicant or an operating license holder whose 
construction permit was issued before January 10, 1997.
---------------------------------------------------------------------------

    For several decades, the nuclear industry fulfilled Criterion 2 
using the response spectrum method and the time history method for 
seismic analysis and design of NPP SSCs. Then, in 1976, the NRC issued 
Revision 1 of Regulatory Guide 1.92, which described then up-to-date 
guidance for using the response spectrum and time history methods. 
Since that time, research in the United States has resulted in improved 
methods that yield more accurate estimates of SSC seismic response, 
while reducing unnecessary conservatism. In view of those improvements, 
Revision 2 of Regulatory Guide 1.92 describes methods that the NRC 
staff finds acceptable for combining modal responses and spatial 
components in seismic response analysis.
    The NRC staff initially published Revision 2 of Regulatory Guide 
1.92 as DG-1108, dated August 2001. The staff subsequently considered 
stakeholders' feedback on DG-1108, incorporated the necessary changes, 
and again solicited public comment on the revised guide by publishing a 
Federal Register notice (70 FR 7777) concerning Draft Regulatory Guide 
DG-1127 on February 15, 2005. Following the closure of the public 
comment period on April 15, 2005, the staff considered all stakeholder 
comments in the course of preparing Revision 2 of Regulatory Guide 
1.92. The staff's responses to all comments received are available in 
the NRC's Agencywide Documents Access and Management System (ADAMS) at 
http://www.nrc.gov/reading-rm/adams.html, under Accession 
ML061630344.
    The NRC staff encourages and welcomes comments and suggestions in 
connection with improvements to published regulatory guides, as well as 
items for inclusion in regulatory guides that are currently being 
developed. You may submit comments by any of the following methods.
    Mail comments to: Rules and Directives Branch, Office of 
Administration, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001.
    Hand-deliver comments to: Rules and Directives Branch, Office of 
Administration, U.S. Nuclear Regulatory Commission, 11555 Rockville 
Pike, Rockville, Maryland 20852, between 7:30 a.m. and 4:15 p.m. on 
Federal workdays.
    Fax comments to: Rules and Directives Branch, Office of 
Administration, U.S. Nuclear Regulatory Commission at (301) 415-5144.
    Requests for technical information about Revision 2 of Regulatory 
Guide 1.92 may be directed to Dr. T.Y. Chang, at (301) 415-6450 or via 
e-mail to [email protected].
    Regulatory guides are available for inspection or downloading 
through the NRC's public Web site in the Regulatory Guides document 
collection of the NRC's Electronic Reading Room at http://www.nrc.gov/reading-rm/doc-collections/. Electronic copies of Revision 2 of 
Regulatory Guide 1.92 are also available in the NRC's Agencywide 
Documents Access and Management System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html, under Accession ML053250475.
    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 [email protected]. Requests for single copies of draft or final 
guides (which may be reproduced) or for placement on an automatic 
distribution list for single copies of future draft guides in specific 
divisions should be made in writing to the U.S.

[[Page 42886]]

Nuclear Regulatory Commission, Washington, DC 20555-0001, Attention: 
Reproduction and Distribution Services Section; by e-mail to 
[email protected]; or by fax to (301) 415-2289. Telephone requests 
cannot be accommodated.
    Regulatory guides are not copyrighted, and Commission approval is 
not required to reproduce them.

(5 U.S.C. 552(a))

    Dated at Rockville, Maryland, this 10th day of July, 2006.

    For the U.S. Nuclear Regulatory Commission.
Brian W. Sheron,
Director, Office of Nuclear Regulatory Research.
 [FR Doc. E6-12078 Filed 7-27-06; 8:45 am]
BILLING CODE 7590-01-P