ML19316A344
| ML19316A344 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/19/1978 |
| From: | Thompson O Office of Nuclear Reactor Regulation |
| To: | Stepp J Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7912110603 | |
| Download: ML19316A344 (2) | |
Text
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s I"00RN;DUM FOR:
J. Carl Stepp FR0'f :
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L. !! aller THR!i:
SEEPACE OF JCCASSEE DCI - SITE I.EETIZ SU3 JECT:
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FLA'iT UTE: Oconce Nucicac Station 56 arating Fcactor C
LICE!! SING STAGE:
269/870/237 DOCKET GUMPER:
P.ESPOMSICLE BRAMCH: 02-1; Cor tca fairtile, PM 1 site.
10, 1973, Lynan Heller and I visited the Jocassee th:) and Law Ente Ca July i'epresentatives frca Ruhe Pc'.ccr Cc::yny (uteTesting.Cap The presentation was :Me to the Federal E :ero'y the vest aLute nt.
Regulatory Cornission (FERC) and URC uas invited by Edo.
i In ny rer.orandun for Files dated July 3,1973, the sf.atus of m s sumaricca.
randen ucro verbally reported by Duke at the site reeting en July 10, The investication is not yet complete and a t:ritten report has The findings to date are su:: ari;:cd talou.
1973.
not yet been prepired.
There h3s lTan scepage froa the west atubnent of the dan since the Tbc founttion eni the reservoir ps first filled in about 1972.
abutnant have been grouted and this procedure has reduccd the scepage fron atout 1200 gpn to about CCO gpn.
The scepage fro:a the do:instrer.n abuteent has bcen *:enitored and no probims were observed by Duke until twa :,ir'; holes developed -- oneTh in 1977 and a sccor.J in early 1978.
Drain pipes excavating loose soil and backfilling sith filter stonc3.
were installed to carry the uater into the valley.
.j Cecause of turbidity of the uater at the recent sink hole, Law started Obscr-an investigation in order to deter:ciine the cause of the SaeN.ge. Tracer dyes vation wells were installed on the downstrean abutnent.
h cnd trere introduced into var}ous t:cIls and Lm believes that the patIt is their co volccity of serpage have bnen identifie3.a %!indew" remains I
scall mount of cdditicral ;rcuting, tha :ccpage might be reduced to as f
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. low as 200 to 300 gpm. Duke indicated that it would he certinthile to perforn additional grouting even though it could not he guaranteed that the sccpage vould Le significantly reduced.
rhe field investigation is still !aing perferr:ed so that the area to be grouted can be mde precisely deff n'd.
Date indicat.7d 1L3t they antici-
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pated starting the grouting progren in higust or "eptac' cr.1978.
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The findings of tr.1 Lo. ::d that the abut ~cnt scenage does rot co:cpro.,ise i
the safety of the crunkncat dan. The cater collected and tested froa j
the cink hole areas shmied quantitics of susp:r:!c ! roifds an order of tagnitude less than in the ecscrvoir.
This indicates tFat bactuard i
i ercsfon into the abutr cnt is not cccurring. Also, the testing program has shoun that there !s no seepage crcun:1 the end of the dan at the abutment /cr:':ankment in terface.
Law stated that the grouting progran would not cause the seepage path to oigrate toe:ard the ertaniment but that this assumption would be carefully tonitored during and aftcr grouting.
after the aceting, the dam and west abutment were inspected.
The field dcilling cnd dye testing was in progress during cur visit.
DISTRIBUTION:
DOCKET FILE 50-269/270/287 NRR RDG Grien O. Thompson GB RDG Geotechnical Engineer DSE RDG G20 sciences Dranch Division of Site Safety and Environmental Analysis 6
i Distribution:
R. Denise J. Stepp L. Ireller T. Cardone J. Dolicher
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