ML19309A192
| ML19309A192 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 05/03/1971 |
| From: | Byerly P AFFILIATION NOT ASSIGNED |
| To: | |
| Shared Package | |
| ML19309A164 | List: |
| References | |
| NUDOCS 8003260899 | |
| Download: ML19309A192 (2) | |
Text
(o) s 's' ATTACHMENT 8
.p.
Perry Byerly D;
803r ontre.Costx Road-5340 Eroadway Terrace A401 c
Oakland, California 9418 6
Phone (415)89 6893 May 3, 1971 J. J. Mattimoe, Assistant Chief Engineer Sacramento Municipal Utility District Box 15830
- Sacramanto, California 95813 Re: SMUD Contract 3978 Rancho Seco Nuclear Generating Station, Unit No.1
Dear Hr. Mattimoe:
You have asked me to update my report on the Clay (Rancho Seco) site written September 22, 1966.
Earthouakes No earthquakes have been reported felt in the neighbor-hood of the site since that of September 12, 19.66--the last shock listed in Table II of my former report (copy attached).
\\~
A field study of this earthquake was made for me by James Dewey and submitted to you with the first report.
Table A attached lists earthquakes with epicenters within 100 miles of the site, since those contained in Table II, first report.
r.'he closest epicenter in this list was 46 miles (March 12,1969) ~ centering near Antioch (M = 3 3/4) and not felt in the site area.
There is therefore no reason to alter the " Conclusions" in my first report, which I quote:
"There is no reason to fear the breaking of a fault in the Clay site area.
This is supported by the earthquake history of the area as well as by the lack of epicenters in the area for the last 25 years.
"The earthquake shaking to be expected will come fromshocks centering in' other areas.
From the historical record and from knowledge of the geologic foundation, we need fear no shocks of intensity greater than intensity VI.
Hershberger (reference 9) draws a graph which sug-gests that the acceleration accompanying such ~an earth-z quake may be about 50 cm/sec or o.05 of gravity.
,,s k,
1"For any sensitive structure in an earthquake s
80032g0 y
i I
Mr. Jf. J. Mattimoe
_2-tiay 3,1971 l
region a design to resist.0.1 g without loss of function is common.
This would corre:: pond to an intensity of high VI to low VII on Hershberger's curve and should offer a lar6e margin of safety for a reactor at the Clay site."
i
.I Conclusion At the time of renderin5 the report there were no OBE and DBE apparently, for such are not mentioned in my conclusions.
I feel that an OBE of 0.1gand a DBE of 0.2 g are utterly safe.
Yours sincerely, Perry Byerly Enclosure g
a
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