ML19274G205
| ML19274G205 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos File:GEH Hitachi icon.png |
| Issue date: | 08/16/1979 |
| From: | Jennifer Davis CALIFORNIA, STATE OF |
| To: | Rolonda Jackson Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19274G206 | List: |
| References | |
| NUDOCS 7908300421 | |
| Download: ML19274G205 (1) | |
Text
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STATE OF CAUFORNIA-THE RESOURCES AGENCY EDMUND G. BROWN JR., Governor DEPARTMENT OF CONSERVATION
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DIVISION OF MINES AND GEOLOGY DIVis:ON HEADQUARTERS 1416 NINTH STREET, RCOM 1341
$ACRAMENTO, CA 93814 (Phone 91W1823)
August 16, 1979 Mr. Robert Jackson Chief, Geosciences Branch U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Bob:
The staff of the California Division of Mines and Geology (CDMG) has reviewed all of the submitted reports regarding the General Electric Tev. Reactor (GETR) at the Vallecitos Nuclear Center near Iivemore.
Enclosed is a copy of Preprint Special Publication 56, " Geologic Evaluation of the General Electric Test Reactor Site, Vallecitos, Alameda County, C(lifornia", which reports our findings. As you know, staff have also been present in a number of technical discussions regarding the geology and seismicity of the site and have examined trenches which have been excavated by the licensee at the request of the U.S. Nuclear Regulatory Commission (NRC). We have the following observations:
1.
The thrusi. displacement along faults near the GETR fccility can be interpreted as tectonic off-set or landslide.
It is the staff's finding that while neither interpretation can be definitively confirmed, landsliding is a preferred conclu-sion.
Please note that in this letter and in the report, displacements are called faults, regardless of the interpretation of the mechanism of their origin.
2.
Repetitive displacement is evident along the faults which have been exposed in the trenches.
The cumulative effect of these displacements is significant.
Displacement is considered to have occurred before and during Holocene time.
3.
It is a staff conclusion that approximately three feet of surface displacement at the reactor site represents a conservative judgment as to the ground rupture which might be associated with either the landslide interpretation or the tectonic modals of Dr. D.G. Herd.
4.
The peak ground accaleration associated at the site has been generally considered by CDMG staff, assuming both an earthquake occurrence at the reactor along the 10 kilometer Verona fault postulated by D.G. Herd and a 7.5 magnitude event along the Calaveras fault, which is approximately two miles distant from the GETR location.
In our opinion, a 0.8g peak acceleration should be adequate for plant design.
If you have any questions regarding the content of the report or my remarks concerning it, please do not hesitate to contact me.
2031 ]l9 James F. Davis
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State Geologist
!x 7908800
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Enclosure