ML20137D494

Forwards Segovia .Problems W/Groundwater & Unstable Saprolite at Site Discussed

ML20137D494
Person / Time
Site:	North Anna, 05000000
Issue date:	06/21/1977
From:	Allen J NORTH ANNA ENVIRONMENTAL COALITION
To:	Muller R Advisory Committee on Reactor Safeguards
Shared Package
ML20136A555	List: IA-85-363, Submits Topics for Discussion at Commission 830708 Meeting W/Acrs.Topics Include Seismic Design Margins ML20136A550 ML20136E176 ML20136E418 ML20136E423 ML20136E621 ML20136E929 ML20136F618 ML20137D336 ML20137D440 ML20137D455 ML20137D472 ML20137D477 ML20137D494 ML20137D511 ML20137D540 ML20137D551 ML20137D557 ML20137D562 ML20137D570 ML20137D576 ML20137D583 ML20137D588 ML20137D598 ML20137D601 ML20137D609 ML20137D616 ML20137D621 ML20137D627 ML20137D635 ML20137D641 ML20137D646 ML20137D652 ML20137D659 ML20137D665 ML20137D670 ML20137D849 ML20137D867 ML20137D881 ML20137D911 ML20137D924 ML20137D951 ML20137D978 ML20137E016 ML20137E026 ML20137E044 ML20137E056 ML20137E075 ML20137E098 ML20137E113 ... further results
References
FOIA-85-363 NUDOCS 8508220501
Download: ML20137D494 (2)

Text

NOiltTH ANNA LNVIRONMENTA. COALITION P.O. BOX 3951 DISTRIMjED10 Ets REMBERS cHAnwrresvnaz, VIMHNIA 22903 Ecgj 21,1977 (804)293-6039 ,

Mr. Ragnwald Muller -' JL"'"' b FE 3 13 Senicr Staff Assistant

• Advisory Cocraittee on Reactor SafegggLrsla P, U. S. Nuclear Regulatory Coccission, ,5txia i Washingtcn, D. C. 20555

""{d_ } f.4

Dear l'.r. Muller:

As we discussed on the telephcne, enclosed is a copy of Dr. Segovia's complete letter to the Coalition of May 22, 1977.

I hope you have since been able to find the transcript of the March-,pril,1974 Shcw Cause hearing on North Anna's faalt-ing at which Dr. Segcvia testified. You will note that he men-tions a second visit tc the site' with Professor John E. Foss in the Soils Division at the University of Maryland at which "the critical trenches were covered" and thus no adequate study could be made. ( At that time, the major interest in saprolite re-lated tc age-dating of the fault more than to compressibility and settling, although the latter was noted by Dr. Segovia. )

Dr. Robert Mueller's Show Cause testimony dealt in part i with the offect of a hot water impoundment upon the circulation of groundwater and its effect unen mincral stabilities at the site. It appears that even a few degrees change in temperature can make itself felt in foundation conditions. ( An excerpt frcm Dr. Mueller's testimory is enclosed. )

The late Dr. John Funkhouser, geologist whc identified faulting at North Anna in Unit #1 in 1970, expressed concern about grour.dwater in his prepared testimory for the 1974 Show Cause hearing, particularly abcut leakage beneath the reactor.

A copy of his testi?cny is erclosed.

The combination of groundwater and unstable saprolite have caused problems at mining activities in the vicinity of North Anna. A Iccal geologist describod to the Coalition what happened there during an effort to sink a shaft: "The saprolite became i i

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-2 mobile and flowed into the shaft." He stressed the fact that disturbed saprolite becemos " messy and mobile" and its bear-ing strength changes.

ACRS consultants might find it useful to talk with the geologists whc have worked recently in mining activities near the North Anna site and to inquire into the reasons for the recent near cessation of all activity.

USGS geologists might also have a substantive contribution to make in regard to the groundwater and unstable saprolite problems at North Anna.

They might wish to study the reasons rock anchcra are now required for North Anna Units 3 and 4, per ERC LER OUTPUT of May 20, 1976:

" DESIGN der'lCIENCY. Lack of adequate safety margins for earthquake forces and uplift forces due to water under structure. Rock anchors added to integrate foundaticn with rock."

Might there be a relationship between this problem in Units 3 and 4 and the groundwater access in Unit I? If there is prob-lem water beneath the structures for Units 3 and 4, is there not a comparable problem with Units 1 and 2? We have been trying since last November to clarify that relationship.

I do hope the trip to North Anna on June 23 will be a good and prcfitable one. I wish that Dr. Segovia were in the ccuntry and might accompany you.

If I do not hear from you to the contrary, I shall assume that you will copy the enclosed materials for the North Anna Subcommittee and for Drs. Richart and Philbrick.

Thank ycu for your professional assistance.

Sincerely,

&j e Allen ('. irs. P. M. )

President, NAEC Enc.: Segovia letter 5/22/77 Mueller testimony excerpts 3/74 Punkhcuser testimony 3/74 YEPCO grcundwater letter 3/15/76 5

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