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Frederic J. Coural, Er q., Cha i rman P.O. DO:( 3951 Atomic Safety and LicenAing lloard CIIARLOTTESVILLE, VIICIrlIA 2 21 U.S. Nuclear llenula tory Commission (717J533-7694 or (804)293-607 Washington, D. C.
20355 December 4,1977 Dr. Paul W.
Purdom, Director Mr. R. II. !!riggs Environmental Sttulies Institute 110 Evans Inne Drexel University Oak Hidge, Tennessee i
Philadelphia, Pennsylvania 19106 In the Mat ter of Virginia Elect ric and Power Company (North Anna Nuclear Power Station, Units 1 and '2)
Docket Nos. 50-338 OL and 50-339 OL Gentlemen:
1 i
Micro-The purpose of this letter is-to request the Doard to study
. Earthquake a map regarding micro-earthquake activity near the North Anna Map reactors entitled REGIONAL EPICENTER MAP--Pariod:
January 21 1974 through August 1 1977.-
It is a " composite fi ure showing all 5
events".related to geologic structures, as requested from VEPCO by NRC Seismologist Reiter on September 26, 1977, and submitted on October 25, 1977 (There is no copy in the U.Va. document room.)
Fault The REGIONAL EPICENTER MAP provides undeniable evidence of Reactivation the on-going seismic influence of Lake Anna -- most particular.ly by the heavy cluster of micro-earthquake activity at the point where lake Anna Neuschel's Lineament (renamed Spotsylvania Lineament on the map) not intersects the lake.
There would. appear to be no question but related to that at that point, the lake has: reactivated the lineament, which
,. Fault age has been postulated by Drs. Neuschel and fliggins of the USGS to be a major regional fault.
Linsament NAEC has been told that work this year by the National Science-ca najor Foundation lends further support to the work of Neuschel and Ilig-Regional gins in diagnosing the lineament as a major regional fau l t.
The
' Fault suppressed work of Piedmont geologist Dr. Paul Roper urged atten-tion to the relationship (in 1973) between "1) the North Anna fault, 2) Neuschel's Lineament or the Fredericksburg fault, 3) the 38th parallel. fracture..." and their possible effects upon the stability of the reactors since "it is practically impossible to design any foundation that could not be disrupted by shear if the North Anna fault were reactivated by on earthquake."
46 Seismic The REGIONAL EPICENTER MAP shows a cluster of 46 seismic Events events NNW of the North Anna dam, making obsolete the map NAEC
(" u st er submitted to the Doard on April 20, 1977 which showed only 22 NNW of events in the cluster, and those events were of smaller magnitude.
Dam The NRC Staff is unable to c:cplain the clustered seismic events, but is able to state that the " activity does not indicate any danger to the safe operation of the plants." Does the Doard find this NHC Staff position consistent and prudent?
' Af ter studying the map, can the lloard agree wi th the Staf f that such a heavy clustering of micro-eartiujunkes is not " region-ally anomalous"?
gg June Allen (Mrs. P. M.)
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OL pa r.t i en President, NAEC NRComminsioners Sena ton a llart and Me tca l f, Hepresentatives Moss, Uday l l, Diingham 8508220525 850722 PDR FOIA BELL 85-M @
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