ML19330C513
| ML19330C513 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos File:GEH Hitachi icon.png |
| Issue date: | 06/29/1980 |
| From: | Thompson G AFFILIATION NOT ASSIGNED |
| To: | Kerr W Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1262, NUDOCS 8008080449 | |
| Download: ML19330C513 (2) | |
Text
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GEORGE A. THOMPSON
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421 Adobe Place Pal) Alto, C:litrnh 94306
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June 29, 1980
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{IHIS DOCUMENT CONTAINS l
POOR QUAUTY PAGES Dr. ?ll1111am Kerr w-Chairman, Subcommittee on GETR Department of h,uclear engineering i
m University of Michigan Ann Arbor, MI 46107
Dear Dr. Eerr:
Th$ s is a summary o f my observations and conclusions from the Subecmmi ttee meeting o f June 3 6 and 17.
GETR topographic elevatien behind the I made this Faul ti nr.
That tha is produce i by fau! ting is ner widely accepted.It should also be 12, 1979.
th-point in my letter of December emphasized that the fault strands at the base of the hill nor east of the GET2 have orders of magnitude greater cumulative for the displacement than any of the strands southwect of GETE, latter have relatively nccligible topographic displacement.
This evidence against any existing f aults under the foundation. Future slips beneath reenforces evidence from the nearby trench.the foundation are h Elements of conservatism in the assignment of a 1-meter analysis.
seismic slip for decign purposes include (3 ) the neglect cf h
aseismic slip or creep (in producing of fsets observed in trenc es in the trench geology) to resc1ve multi-ple events that may have produced what we assume is a singleT and (2) cur inability earthquake o f fset.
tend to be-highly unsymmetrical. Evidence fron the geclogy and seismic foc supports a straightforward tectonic model for the Livermore It is impor-Valley, which I won' t take spacc te outline here.
unusual in basins along the San Andreas fault zone, in-The model (and direct evidence claims made in the meeting.dicates that the USGS (Brabb) is incorrect in in Putting the picture together eral slip on a Pleasanton ' fault.shows that the San Fernando comparis least in the scale of the hazard.
The tectonic setting is one of thrustfaulting, d
modifiea at the upper toe of the thrust by a topographic loa.
Land slidi nc.
is charac.
In addition, like most California hillslopes, this one Any terized by creeping soil and minor shallow landslides. at l
On the other hand, bogged down in the ' noise' of creeping soil.
the hillslope shculd be analyzed for small superficial slides in relation to the. safety of the emergency water reservoirs and piping.
,8008080 %
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Cenclusien, In my judgement the staff recommendations for design accelerations and offset are appropriate and conservative o
Sincerely,
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s Ge hysicist o
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