ML13308A672
| ML13308A672 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/13/1981 |
| From: | Bernreuter D Lawrence Livermore National Lab (LLNL) |
| To: | Reiter L Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13308A673 | List: |
| References | |
| EG-81-1, NUDOCS 8101230477 | |
| Download: ML13308A672 (3) | |
Text
REGULATORY *ORMATION DISTRIBUTION SY*M (RIDS)
ACCESSION NBR:8101230477 DC.DATE: 81/01/13 NOTARIZED: NO DOCKET #
FACIL:50-206 San Onofre.Nuclear Station, Unit 1, Southern Californ 05000206 AUTHNAME AUTHOR AFFILIATION BERNREUTERFD,L.
Lawrence Livermore Laboratory RECIP.NAME RECIPIENT AFFILIATION REITERL.
Geosciences Branch
SUBJECT:
Forwards corrected copy of "Review of Repts Dealing w/.
Simulation.of Earthquake Ground Motions for San Onofre Nuclear Generators StationsUnit 1 for NRC."
DISTRIBUTION CODE: A0288 COPIES RECEIVEO:LTR
/'ENCL /
SIZE:;
TITLE: Seismic Review for SEP Plants.
NOTES:1 cy each:SEP Section Leader & J Hanchett (Region V) 05000206 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL ACTION:
CRUTCHFIELD 04 7
7 INTERNAL: EQUIP QUAL 8R07 1
1 GEN ISSUES BRO 1
0 GEOSCIENCES 09 1
1 HYD/GEO BR 10 2
2 I&E 06 2
2 NRC PDR 02 1
1 1
0 OR ASSESS BR 11 1
0 L
01 1
1 SEP BR 12 1
1 EXTERNAL: ACRS 14 16 16 LPDR 03 1
1 NSIC 05 1
1 JAU R C
S R
TOTAL NUMBER OF COPIES REQUIRED: LTTR ENCL 4'
NUCLEAR SYSTEMS SAFETY PROGRAM EG-81-1 January 13, 1981 Dr. Leon Reiter Geosciences Branch Division of Engineering U. S. Nuclear Regulatory Commission Washington, D. C. 20555
SUBJECT:
Review of TERA-DELTA Modeling for SONGS Unit 1
Dear Leon:
I have given considerable thought to the recent results presented by Jerry Frazier at the December 4, 1980 meeting in Bethesda.
TERA-DELTA made a number of interesting points, but after careful review of both the results presented by TERA-DELTA and the basis for my concerns, I still think that they have failed to address my main concern-about the adequacy of the fixed value they have chosen for the dynamic stress drop. Nor do I feel they adequately addressed the important points raised by Dr. Aki in his letter of September 16, 1980.
Thus, my views and recommendations remain unchanged from those stated in my October, 1980 letter report to you. The October report is marred by a number of typographical errors. This occurred because I was out of the country and could not proofread the report before it was sent out and still meet the time frame for the report being of use to you. For your records and possible future use I am enclosing a corrected copy of the October report.
In my view, what TERA-DELTA needs to do is remodel the earth quakes that they have considered using more complex rupture models an attempt to match the main elements of the recorded time histories. From such studies, we can begin to understand the possible ranges for dynamic stress drop, how much it might vary over the fault rupture plane, appropriate ranges for rupture velocity, and better calibrate the random parameters introduced by TERA-DELTA. This is, of course, a long and expensive research process with an unknown payoff. Thus, I cannot really recommend this course of action in the current licensing context.
AnEq O vortung kgy~ rLit)/ay of California POBox 808LivernoreCalfornia 94550 5:/IphoneM
)422-1 700 Twx910-386-8339 UCLLLLV'M8R 9
123L-17~7
EG-81-1 2 -
January 13, 1981 I think the TERA-DELTA studies have been worthwhile and such studies should be encouraged from a research point of view rather than a direct application to licensing action at such an early stage in the development of the state-of-the-art.
Modeling studies can be very valuable in helping us understand the ground motion recorded from various earthquakes and how to extrapolate to any given licensing case.
Sincerely, Don L. Bernreuter, Leader Engineering Geosciences DLB/sa Enclosures cc:
T. M. Cheng, NRC G. E. Cummings LLNL W. T. Russell, NRC P.
D. Smith, LLNL