[Federal Register Volume 70, Number 30 (Tuesday, February 15, 2005)]
[Notices]
[Pages 7777-7778]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-2853]
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NUCLEAR REGULATORY COMMISSION
Draft Regulatory Guide; Issuance, Availability
The U.S. Nuclear Regulatory Commission (NRC) has issued for public
comment a draft 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.
The draft Revision 2 of Regulatory Guide 1.92, entitled ``Combining
Modal Responses and Spatial Components in Seismic Response Analysis,''
is temporarily identified by its task number, DG-1127, which should be
mentioned in all related correspondence. Like its predecessors, the
proposed revision describes methods that the NRC staff finds acceptable
for complying with the NRC's regulatory requirements in Criterion 2,
``Design Bases for Protection Against Natural Phenomena,'' as it
appears 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). Specifically, Criterion 2 requires, in part, that nuclear
power plant (NPP) structures, systems, and components (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.
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,
DG-1127 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, and incorporated the
necessary changes in DG-1127.
The NRC staff is soliciting comments on Draft Regulatory Guide DG-
1127, and specifically on the new regulatory position regarding
residual rigid response of the missing mass modes, as described in
Sections 1.4 and 1.5 of DG-1127. Comments may be accompanied by
relevant information or supporting data. Please mention DG-1127 in the
subject line of your comments. Comments on this draft regulatory guide
submitted in writing or in electronic form will be made available to
the public in their entirety in the NRC's Agencywide Documents Access
and Management System (ADAMS). Personal information will not be removed
from your comments. 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.
E-mail comments to: [email protected]. You may also submit comments
via the NRC's rulemaking Web site at http://ruleforum.llnl.gov. Address
questions about our rulemaking Web site to Carol A. Gallagher (301)
415-5905; e-mail [email protected].
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 draft regulatory guide DG-
1127 may be directed to Dr. T.Y. Chang, at (301) 415-6450 or via e-mail
to [email protected].
Comments would be most helpful if received by April 15, 2005.
Comments received after this date will be considered if it is practical
to do so, but the NRC is able to ensure consideration only for comments
received on or before
[[Page 7778]]
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.
Electronic copies of the draft regulatory guide are available
through the NRC's public Web site under Draft Regulatory Guides in the
Regulatory Guides document collection of the NRC's Electronic Reading
Room at http://www.nrc.gov/reading-rm/doc-collections/. Electronic
copies 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 ML050230006. Note, however, that the NRC has
temporarily suspended public access to ADAMS so that the agency can
complete security reviews of publicly available documents and remove
potentially sensitive information. Please check the NRC's Web site for
updates concerning the resumption of public access to ADAMS.
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. 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 3rd day of February, 2005.
For the U.S. Nuclear Regulatory Commission.
Michael E. Mayfield,
Director, Division of Engineering Technology, Office of Nuclear
Regulatory Research.
[FR Doc. 05-2853 Filed 2-14-05; 8:45 am]
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