ML20209D706
| ML20209D706 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Diablo Canyon |
| Issue date: | 12/07/1984 |
| From: | Schierling H Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20150F500 | List:
|
| References | |
| FOIA-86-391 NUDOCS 8501040220 | |
| Download: ML20209D706 (6) | |
Text
,
E UNITED STATES
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NUCLEAR REGULATORY COMMISSION U
s WASHINGTON, D. C. 20556 k*...
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(, Y Docket Nos.: 50-275 and 50-323 1
DEC 71984 LICENSEE:
Pacific Gas and Electric Company FACILITY:
Diablo Canyon Nuclear Power Plant
SUBJECT:
NRC MEETING WITH PACIFIC GAS AND ELECTRIC COMPANY -
SEISMIC REEVALUATION PROGRAM FOR DIABLO CANYON A meeting was held on Novaber 15 and 16,1984 in Bgthesda, Maryland regarding j
the reevaluation program of the seismic design basis for the Diablo Canyon Nu-clear Power Plant. The program is included as a license condition in the full power license for Unit 1 (issued on November 2,1984) and'is discussed in SSER-27. Sections I.5 and IV.S. The program is to include the following four specific elements: geology and tectonics, earthquake magnitude, ground motion, and probabilistic/ deterministic analyses.
Pacific Gas and Electric Company (PG&E) is to submit a program plan by the end of January 1985.
The purpose of the meeting was to address Elements 2 and 3 of the program (earth-quake magnitude and ground motion).
Participants at the meeting were NRC staff, B. Slenenons and technical staff from Brookhaven National Laboratory, Lawrence livemore National Laboratory and the U. S. Geological Survey as advisors to the staff, and PG&E staff with consultants. Lists of attendees for both days -
are enclosed as Enclosure 1.
November 15, 1984 L. Wight, TERA Corporation, described for PG&E the proposed investigation pro-gram to be performed in the earthquake magnitude estimation task. The methods to evaluate the proposed maximum earthquake magnitude include fault length and area, rupture length, slip rate, single event displacement, and historical seis-micity. Details of each of these methods were presented in PG&E viewgraphs (Enclosure 2).
L. Wight described the proposed program for the estimation of ground motion based on empirical data. This study will include the compilation of existing empirical data, model development, regression analysis and the determination of site specific response spectra. Details of this study were presented in PG&E viewgraphs (Enclosure 3).
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J. Frazier and T. Bache, Science Applications International Corporation, de-scribed for PG&E the proposed numerical modelling of the ground motion program.
This program will include the formulation and development of computational methods, the modeling of earthquake recordings, estimation of prediction un-certainty and the computation of motions at the Diablo Canyon site. Details are presented in PG&E viewgraphs (Enclosure 4).
After these presentations and a caucus by the NRC staff and its advisors the following coments were provided to PG&E as the opinion of the NRC staff and its advisors based on the PG&E presentations.
Earthquake Magnitude Estimate 1.
The use of a multiple method approach is good.
2.
PG&E should determine if there is any new inforigation available regarding the 1927 Lompoc earthquake.
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3.
The. magnitude scale used in this part of the program should be consistent with that to be used in the ground motion study, i
4.
The geology studies under Element 1 and the magnitude estimate effort under Element 2 should be coordinated. Quantitative l
geologic expertise should be available at the working level.
5.
On-shore geologic investigations and remote sensing studies should not be ignored.
6.
Dependency of the conclusions on a model should be avoided 1.e.,
the study should not be based on a particular model which may be i
controversial.
7.
The result of the program should be a deterministic estimate of the magnitude.
i Empirical Ground Motion Studies 1.
The overall approach appears to be good. However, more details of the j
program are required.
1 l
2.
A free-field estimate of ground motion is needed for the program.
j The data used in the study should be free-field data and not include data recorded in large structures.
3.
The study should consider estimates of site specific spectral values and site specific estimates of peak ground acceleration and velocity (PGA, PGV) and spectral shape.
4.
A uniform set of units and scale should be used consistently throughout the entire study.
Numerical Modelling of Ground Motion 1.
The presentation included a high level of detail.
2.
Perfonning the numerical modelling study is important for providing insight into the sensitivity of the ground motion to the parameters.
3.
Bench-marking of results with actual earthquakes, flexibility of parameter estimation, and consideration of uncertainty estimates are all important in validating the results.
4.
It is important to ensure that the parameters used in the modelling study match those which result from the tectonic and geology studies and the magnitude estimates.
November 16, 1984 W. S. Tseng, Bechtel, described for PG8E the proposed soil-structure interac-tion program. Three dimensional soil-structure interaction analysis methods will be employed. All components of near-field strong ground motion will be included in the analysis simultaneously. The analysis will consider seismic wave incidence characteristics including inclined body waves and surface waves.
1 The. analysis will consider the effect of inelastic response, if significant.
of the plant structures under the strong earthquake ground motion. Available recorded earthquake data at the Diablo Canyon Plant site will be utilized to assist in calibrating the low amplit.ude dynamic characteristics of the soil-structure dynamic model. Details of the soil-structure interaction program were presented in PG&E viewgraphs (Enclosure 5).
After this presentation and a caucus by the NRC staff and its advisors the following con 1ments were made to PG8E as the opinion of the NRC staff and its advisors based on the PG&E presentation.
1.
The soil-structure interaction program as presented is impressive.
There is a question, however, of whether it can be completed in three years.
2.
Both of the proposed computer codes, SASSI and CLASSI, have limitations in their methodology and these must be considered.
3.
There should be some way of addressing the simulation of the uplift pro-blem, if it exists.
4 There is a question as to how well the local site properties are known.
l The adequacy should be addressed and demonstrated in the program plan.
5.
The site instruments and data should be reviewed to assure that the instruments are located and installed properly and that the data processing is error free.
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It is important that the ground. motion study and the soil-structure interaction study be well coordinated at the working level so that there are no mismatches.
7.
The empirical data base of free-field versus nearby in-structure recordings should be considered for applicability.
8.
The program plan to be submitted in January 1985 should contain enough detail to provide for an adequate review.
At the conclusion of the meeting it was agreed that the third meeting should be held on December 11, 1984 to address license condition Element 4 on prob-abilistic risk assessment. A final meeting was tentatively agreed on for mid January 1985 at which time PG&E will address the staff comments made at the earlier meetings and provide further information on staffing and schedules for the program.
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Hans Schierling, Pkject Manager Licensing Branch No. 3 Division of Licensing T
Enclosures:
As stated cc: See next page I
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Diablo Canyon Mr. J. D. Shiffer, Vice President Nuclear Power Generation c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Francisco, California 94106 Philip A. Crane, Jr., Esq.
Resident Inspector /Diablo Canyon NPS Pacific Gas & Electric Company c/o US Nuclear Regulatory Comission Post Office Box 7442 P. O. Box 369 San Francisco, California 94120 Avila Beach, California 93424 Mr. Malcolm H. Furbush Ms. Raye Fleming Vice President - General Counsel 1920 Mattie Road Pacific Gas & Electric Comoany Shell Beach, California 93440 Post Office Box 7442 San Francisco, California 94120 Joel Reynolds, Esq.
John R. Phillips, Esq.
Janice E. Kerr, Esq.
Center for Law in the Public Interest California Public Utilities Comission 10951 West Pico Boulevard 350 McAllister Street Third Floor San Francisco, California 94102 Los Angeles, California 90064 Mr. Frederick Eissler, President Mr. Dick Blankenburg Scenic Shoreline Preservation Editor & Co-Publisher Conference, Inc.
South County Publishing Company
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4623 More Mesa Driv'e P. O. Box 460 Santa Barbara, California 93105 Arroyo Grande, California 93420 Ms. Elizabeth Apfelberg Bruce Norton, Esq.
1415 Cozadero Norton, Burke, Berry & French, P.C.
San Luis Obispo, California 93401 202 E. Osborn Road P. O. Box 10569 Mr. Gordon A. Silver Phoenix, Arizona 85064 Ms. Sandra A. Silver 1760 Alisal Street Mr. W. C. Gangloff San Luis Obispo, California 93401 Westinghouse Electric Corporation P. O. Box 355 Harry M. Willis, Esq.
Pittsburgh, Pennsylvania 15230 Seymour & Willis 601 California Street, Suite 2100 David F. Fleischaker, Esq.
San Francisco, California 94108 P. O. Box 1178 Oklahoma City, Oklahoma 73101 Mr. Richard Hubbard MHB Technical Associates Suite K 1725 Hamilton Avenue San Jose, California 95125 Mr. John Marrs, Managing Editor San Luis Obison County Teleoram Tribune 1321 Johnson Avenue P. O. Box 112 San Luis Obispo, California 93406
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. Arthur C. Gehr, Esq.
Mr. Thomas Devine Snell & Wilmer Government Accountability 3100 Valley Center Project Phoenix, Arizona 85073 Institute for Policy Studies
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1901 Oue Street, NW Mr. Lee M. Gustafson, Director Washington, DC 20009 Federal Agency Relations Pacific Gas & Electric Company 1050 17th Street, N.W.
Suite 1180 Washington, DC 20036 Regional Administrator - Region V US Nuclear Regulatory Comission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Michael J. Strumwasser, Esq.
Special Counsel to the Attorney General State of California 3580 Wilshire Boulevard, Suite 800 Los Angeles, California 90010 Mr. Tom Harris Sacremanto Bee 21st and 0 Streets Sacramento, California 95814 Mr. H. Daniel Nix California Energy Comission 1516 9th Street, MS 18 Sacramento, California 95814 Lewis'Sho11enberger, Esq.
US Nuclear Regulatory Comission Region V 1450 Maria Lane Suite 210 Walnut Creek, California 94596 39/
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