ML20235D067

Rept on Site Seismicity for Wh Zimmer Nuclear Power Station

ML20235D067
Person / Time
Site:	05000000, Zimmer
Issue date:	12/27/1971
From:	COMMERCE, DEPT. OF, NATIONAL OCEANIC & ATMOSPHERIC
To:
Shared Package
ML20235B311	List: IA-87-111, Submits Rept on Plant,As Discussed in ACRS 150th Meeting on 721012-14.Listed Items Can Be Resolved During Const & Facility Can Be Constructed W/Reasonable Assurance for Operation W/O Undue Risk to Public Safety IR 05000254/1972009 IR 05000358/1972003 IR 05000358/1973001 IR 05000358/1973002 IR 05000358/1973003 IR 05000358/1973005 IR 05000358/1973006 IR 05000358/1973007 IR 05000358/1974001 IR 05000358/1974002 IR 05000358/1974003 IR 05000358/1975004 ML20235B308 ML20235B364 ML20235B401 ML20235B405 ML20235B424 ML20235B456 ML20235B461 ML20235B465 ML20235B477 ML20235B488 ML20235B507 ML20235B552 ML20235B582 ML20235B585 ML20235B588 ML20235B605 ML20235B618 ML20235B623 ML20235B649 ML20235B656 ML20235B662 ML20235B670 ML20235B679 ML20235B683 ML20235B687 ML20235B702 ML20235B708 ML20235B713 ML20235B714 ML20235B718 ML20235B720 ML20235B730 ML20235B734 ML20235B748 ML20235B754 ML20235B762 ML20235B764 ... further results
References
FOIA-87-111 NUDOCS 8709250104
Download: ML20235D067 (4)

Text

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A REIORT ON.Tl!E SITE SEISMICITY FOR Tile ,

WM. H. ZI!NER NUCLEAR POWER STATION l I

At the request of the Division of Reactor Licensing of the Atomic Energy Comission, the Seismological' Investigations Group of the Earth Sciences Laboratories, NOAA, has evaluated the seismicity of the arca around the Wm. H. Zimmer Nuclear Power Station in C1cruont County, Ohio. The Group also has reviewed the seismological evaluation presented by the Cin-cinnati Gas and Electric Company in its Preliminary Safety 4 Analysis Report and Amendments.

A review of the seismic history of the area by the appli-l cant indicates that at least 8 earthquakes of intensity II-V 1

(MH) have occurred within 50 miles of this site. Within 100 miles of this site, however, there have been three intensity VII (MM) and three intensity VI (MM) earthquakes. This re-l view appears to be complete and in genet al agreement with I

our records. The areas of scismic activity considered to have the greatest effect on the evaluation of this site in-clude the concentration of earthquakes in the vicinity of Anna, Ohio with intensities as high as VII-VIII (MM) and the more distant region of New Madrid, Missouri, which ex-perienced major earthquakes in 1811-1812.

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The eieismic ar. t iv i t y nea r Anna, Ohio , corwists of a

.) j series of at 1cas t 23 observed moderate earthquakes with p- f intensities ranging f rom III to VII-VIII. The larger earth-quakes have been felt at the site but no damage has resulted from any of t hem .

These events have occurred in a zone some 30-40 miles long and some 10 miles wide. The major axis of this zone is approximately north-south. While the larger earthquakes (intensity VII and above) have been con-centrated in this zonc, there have been several small to modcrate (intennity II to VI) events which have occurred to l

the south, north and cast of the Anna concentration.

/ The 1811-1812 earthquakes of New Madrid, Missouri, occurred more than 300 miles from the site. The applicant i

l states that "it is probable that these events provided the worst shaking that Cincinnati and the site area have ever expe rience d. "

However, our records indicate that chimneys were knocked down in Cincinnati, Ohio, and our estimate of site intensit y wobid be VI to VII instead of the applicant's V-VI. A rteurrence of such a large event is considered in the evaluation of this site.

In it s report on the geology pertaining to the Zimmer site, t he U.S. Geological Survey states that this si te is "in the cent ral st abic region of North America on the tec-tonic f cature called , variously, the Cincinnati arch or

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l the Indiana-Ohio plat f orn. This broad and regionally exten-  !

sive: arch is believed to have been produced mainly in Paleozoic time and to have remained tectonically relatively inactive since that time ." However, later in the report ,-

af ter a discussion of the Anna, Ohio, earthquakes , there is the following:- "A relationship of these earthquakes to specific geologic structures .in the Paleozoic rocks or in the under-lying Precambrian crystalline basement rocks of the arch has s.ot been cicarly established because of the paucity of infor-mation concerning the deeply buried basement rocks. Con-sequently, the possibility that earthquakes similar to the Anna events might occur at other places *on the arch cannot be precluded." Therefore , with this uncertain geologic and tec t onic se t ting , it mus t be assumed that events similar to the Anna series could occur in the vicinity of the site.

Because of the possibility of liquif action in the upper level of the flood plain terrace at this site , the applicant has indicated that for all Class I structures , the foundation materials will be excavated to a Icyc1 of 450 feet and re-

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placed with compacted fill . It is with this understanding ,

1 that the succeeding der.ign values are reconunended.

As a result of this review of the seismological and geological characterit:t ics of the arco around this proposed river t errace sit e , the So intr.ological Investigations Group I

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is in agreement wi th thr: ppplicant 's values of - accelerat i~on, as stated in Amendment 5, of 0,10 g to be' adequate for repres:enting carthquake disturbances likely to occur within the lifetime of this facility. Also, the Group agrees that an acceleration of 0.20 g, as stated in Amendment 5, is adequate to represent the ground motion from the maximum earthquake likely to affect this site.

It is believed that these values would be adequate for designing pmtcetion against the loss of function of components important to safety.  ;

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Seismological Investigations Group Earth Sciences laboratories Rockville, Maryland 20852 Decembe r 27, 1971 0

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