ML20237A523
| ML20237A523 | |
| Person / Time | |
|---|---|
| Issue date: | 08/06/1998 |
| From: | Murphy A NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Bagchi G, Wessman R NRC (Affiliation Not Assigned) |
| References | |
| REF-GTECI-A-40, REF-GTECI-SC, RTR-NUREG-CR-5347, RTR-REGGD-01.092, RTR-REGGD-1.092, TASK-A-40, TASK-OR NUDOCS 9808140151 | |
| Download: ML20237A523 (2) | |
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NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. 20566 0001 August 6, 1998 MEMORANDUM TO: Richard H. Wessman, Chief Mechanical Engineering Branch Division of Engineering Office of Nuclear Reactor Regulation Goutam Bagchi, Chief Civil Engineering and Geosciences Branch Division of Engineering Office of Nuclear Reactor Regulation FROM:
Andrew J. Murphy, Chief
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Structural & Geological Engineering Branch Division of Engineering Technology Office of Nuclear Regulatory Research
SUBJECT:
REVIEW OF DRAFT FINAL REPORT " REEVALUATION OF REGULATORY GUIDANCE ON MODAL COMBINATION METHODS FOR SEISMIC RESPONSE SPECTRUM ANALYSIS"
Reference:
Memorandum from William T. Russell to Eric S. Beckjord,
Subject:
" User Need" Request for Research Related to Areas of Seismic, Structural, and Geotechnical Engineering, dated December 16,1994.
I am requesting your comments on the attached draft final report " Reevaluation of Regulatory Guidance on Modal Combination Methods for Seismic Response Spectrum Analysis." This report was developed in response to the referenced " user need" memorandum that requcsted j
the Office of Nuclear Regulatory Research to initiate a project that would provide the technical I
basis to revise Regulatory Guide 1.92, " Combining Modal Responses and Spatial Components in Seismic Response Analysis," Revision 1, February 1976.
The " user need" memorandum noted that a number of methods for combining the responses of closely spaced modes have been devised which are not as conservative as those specified in the current regulatory guide but are nonetheless considered to be more accurate and appropriate to use. The " user need" memorandum also noted that during the revision of Standard Review Plan Section 3.7.2 (as put of the resolution of USl A-40 the staff decided to t
incorporate the use of these alternative methods by reference (to be reviewed on a case by jg case basis) with an implicit understanding to revise the regulatory guide later in response to public comments (see NUREG/CR-5347, " Recommendations for Resolution of Public I
Comments on USI A-40").
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Several members of your staff, for example, Mark Hartzman, John Fair, Kamal Manoly, and s
David Jeng have participated in project review meetings with the contractor. Their input has been incorporated into the draft final report. ~80$
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Your comments on the attached report are requested by September 11,1998. Questions should be directed to Roger M. Kenneally (telephone: 415-6303, email: rmk).
After the report is published, Roger Kenneally will develop and distribute for your review and comment, draft technical positions that will be used in the revision of Regulatory Guide 1.92.
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You input will be elicited on all aspects of the regulatory guide revision.
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Attachment:
As Stated cc: PDR j
Distribution:
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'MMayfield i
DOCUMENT NAME: g:\\rmk\\ mod-comb.rev
' Ta receive e copr of this document. Indicate in the boa:
"C' = Copy without attachment / enclosure "E' = Copy with attachment / enclosure
- N' = No copy 0FFICE SGEB/RES
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NAME RKenneally/)..,//
AMurphy
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DATE 8/ 6 /98 76Ff 8/f,/98 0FFICIAL RECORD COPY I