ML16340C699
| ML16340C699 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 07/01/1982 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Cooper W TELEDYNE ENGINEERING SERVICES |
| Shared Package | |
| ML16340C697 | List: |
| References | |
| NUDOCS 8207190023 | |
| Download: ML16340C699 (10) | |
Text
UNITED STATES N~EAR REGULATORY COMMISSIO WASHINGTON, O. C. 20555 JUL 1 l982 Dr. William Cooper Teledyne Engineering Services 130 Second Avenue Waltham, Massachusetts 02254
Dear Dr. Cooper:
During our meeting of June 10, 19B2 I noted that Brookhaven National Laboratory (BNL), a staff consultant, was preparing a report of studies performed to aid in our review of the seismic design of the Diablo Canyon Nuclear Power Plant.
I also indicated that I would provide that report to Teledyne Engineering Services for its use in the Diablo Canyon Nuclear Power Plant Unit 1 Independent Design Verification Program
( IDVP).
A pre-print copy of the final report entitled "Independent Seismic Evaluation of the Diablo Canyon Unit 1 Containment Annulus Structure and Selected Piping Systems" is enclosed.
All supporting technical documentation such as computer input and output is available for further information.
The Brookhaven study is a detailed analysis of certain aspects of the seismic response of the containment annulus steel structure and a sample of attached piping at Diablo Canyon Unit No. 1.
In addition to indepen-dent modelling of the annulus steel structure and piping, Brookhaven also independently developed vertical floor response spectra at all elevations of the annulus structure and performed an independent analysis of two piping systems supported by the annulus structure.
All computer codes employed were verified and results were checked with other codes available in the public domain.
Since early results indicated significant differences between the Brookhaven calculations and the original work by URS/Blume and PG&E, Brookhaven was also requested by the staff to attempt duplication of the original analyses using the models and computer inputs developed by URS/Blume and PGKE.
Our initial review of the report has lead us to conclude that, as a
minimum, the following items require further exploration and assessment as to their generic implications.
1.
The distributed masses of the steel members comprising the annulus structure apparently were not included in the mathematical model used in the original seismic analysis.
2.
The mathematical model used in the original analysis apparently considered the joints between the beams and columns to be rigid whereas the Brookhaven interpretation of the drawings indicate these joints are more appropriately considered flexible (shear carrying only).
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3.
Statements on page 11 of the URS/Blume May 1979 report "Diablo Canyon Nuclear Plant Unit 1 Containment Structure, Dynamic Seismic Analysis for 7.5 M Hosgri Earthquake",
May 1979, concerning the structural connections may not be consistent with the mathematical model used in the original analysis.
4.
The response spectrum smoothing techniques employed in the original analyses appears inconsistent with the FSAR commitments.
5.
Design dimensions were apparently used instead of the as-built dimensions in the two piping problems sampled (PGSE piping models, 6-11 and 4A-26).
6.
The 5D bends in the piping analysis were apparently modelled as long radius bends.
This has the effect of softening the model and reducing the natural frequencies.
7.
The piping support forces computed by the BNL model are much larger than those computed by the PGLE model.
As I stated at our meeting in Waltham, I recoranend that you consider the Brookhaven report in your decision making process for Phase I of the IDVP regarding the seismic design adequacy of the Diablo Canyon Unit 1.
You should inform us of your views regarding the validity of the BNL results and of their generic implications.
Should you require any clarification on the report, we request that you contact the NRC Project Manager to make the necessary arrangements.
Harold R. Denton, Director Office of Nuclear Reactor Regulation
cc:
Philip A. Crane, Jr.,
Esq.
Pacific Gas 5 Electric Company P. 0.
Box 7442 San Franci sco, California 94120 Janice E. Kerr, Esq.
California Public Utilities Commission 350 McAllister Street San Franci so, California 94102 Mr. Frederick Eissler, Preident Scenic Shoreline Preservation Conference, Inc.
4623 Hore Mesa Drive Santa Barbara, California 93105 Hs. Elizabeth Apfelberg 1415 Cozadero San Luis Obispo, California 93401 Mr. Gordon A. Silver Hs.
Sandra A. Silver 1760 Alisal Street San Luis Obispo, California 93401 Harry M. Willis, Esq.
Seymour
& Willis 601 California Street, Suite 2100 San Francisco, California 94108 Mr. Richard Hubbard HHB Technical Associates Suite K
1723 Hamilton Avenue San Jose, California 95125 Mr. John Marrs, Managing Editor San Luis Obisipo County Telegram-Tribune 1321 Johnson Avenue P. 0.
Box 112 San Luis Obispo, California 93406 Resident Inspector/Diablo Canyon NPS c/o U. S. Nuclear Regulatory Coranission P. 0.
Box 369 Avila Beach, California 93424 Ms.
Raye Fleming 1920 Hattie Road Shell Beach, California
,93440
cc:
Joel
- Reynolds, Esq.
John R. Phillips,. Esq.
Center for Law in the Public Interest 10951 West Pico Boulevard Third Floor Los Angeles, California 90064 Paul C. Valentine, Esq.
321 Lytton Avenue Palo Alto, California 94302 Hr. Byron S. Georgiov Legal Affairs Secretary Governor's Office State Capitol Sacramento, California 96814 Herbert H. Brown, Esq.
Hill, Christopher 8 Phillips, P.C.
1900 H Street, N.W.
Washington, D.C.
20036 Nr. Dick Blankenburg, Editor 8 Co-Publisher South County Publishing Company P. 0.
Box 460 Arroyo Grande, California 93420 Nr. James
- 0. Schuyler Vice President - Nuclear Generation Department Pacific Gas 5 Electric Company P. 0.
Box 7442 San Francisco, California 94120 Bruce Norton, Esq.
Suite 202 3216 North 3rd Street Phoenix, Arizona 85012 Hr.
W. C. Gangloff Westinghouse Electric Corporation P. 0.
Box 355 Pittsburg, Pennsylvania 15230 David F. Fleischa)er, Esq.
P. 0.
Box 1178 Oklahoma City, Oklahoma 73101
cc:
Arthur C. Gehr, Esq.
Snell 8 Wilmer 3100 Valley Center Phoenix, Arizona 85073 Mr. Owen H. Davis, Director Federal Agency Relations Pacific Gas 5 Electric Company 1050 17th Street, N.W.
Suite 1180 Washington, D.C.
20036 Robert L. Cloud Associates, Inc.
125 University Avenue Berkeley, Cali fornia 947102 Roger F.
- Reedy, Inc.
236 N. Santa Cruz Avenue Los Gatos, California 95030 Dr. Morris Reich Brookhaven National Laboratory
- Upton, New York 11973
I C.