ML19322B586
| ML19322B586 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/22/1975 |
| From: | Parker W DUKE POWER CO. |
| To: | Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 7912040614 | |
| Download: ML19322B586 (2) | |
Text
.
Dunn Powen Gmnwxv POWEH UttILDINO 422.500TH CHuncH STHF.F.T. CHAHLoTTe, N. C. com WIL LI A M O PA R N E M, Je WCr Peggeotes?
Sita= Paoowction Ittgenomt:Anta 704 373-4083 December 22, 1975 Mr. Norman C. Moseley, Director U. S. Nuclear Regulatory Commission Suite 818 230 Peachtree Street, Northwest Atlanta, Georgia 30303 Re: Oconee Nuclear Station Docket Nos. 50-269, -270, -287
Dear Mr. Moseley:
My letter of October 28, 1975, submitted pursuant to the requirements of Oconce Technical Specification 6.6.2.6.c, described a condition in which a measured Icvel of radioactivity from an aquatic vegetation sample exceeded the control Icvel by greater than ten times.
This report stated that the buildup of activity in aquatic vegetation collected in the discharge area is to be expected due to the normal discharge of radioactive effluents.
The following supplemental information is submitted to provide an evaluation of release conditions, environmental factors, and other aspects necessary to explain this condition:
The expected buildup of activity in organisms living in station effluents is discussed on pp. 130-133 of the Final Environmental Statement Nuclear Station.
for Oconee calculate the concentrations one would expectFrom the information provided in to see in aquatic vegetation
'the specific information required is: samples collected from the vicinity of the 1.
The tailrace concentrations of the radionuclides found in the aquatic vegetation samples, discharged as radioactive waste.
These concentrations can be calculated from the liquid effluent release information provided in the Semiannual Operating Report for the period ending June 30, 1975.
The tailrace concentrations calculated in this manner compare favorably with those presented in Table III-12 of the FES for anticipated annual tailrace concentrations.
l 191so<o g p
Hr. Norman 'C. Honeley December 22, 1975 Page 2 2.
The biological accumulation factors for the radionuclides found in the aquatic vegetation samples. The biological accumulation factors used in the calculation of expected concentrations in aquatic vegetation are those found in Table V-7 of the FES.
t 3.
The conversion factor to convert from wet weight to dry weight of aquatic vegecation. The aquatic vegetation sample collected on August 8,1975 from Location 000.4 weighed 500 grams on wet weight basis and 18.63 grams on a dry weight basis.
The following tabic summarizes this data and provides a comparison of expected and actual concentrations:
Bioaccumulation Expected Actual Isotope 11 0 Conc.
Factor Vegetation Conc.
Vegetation Conc.
pCi/ml pCi/g dry wt.
pCi/g dry wt.
-11 134 7.74 x 10 25000 52 10+3 Cs 137 2.40 x 10 25000 161 2413
~
Cs
-9 58 2.15 x 10 2500 144 128110 Co
-10 60 4.23 x 10 2500 28 77110 Co Additional aquatic vegetation samples from the effluent discharge area were collected on October 24, 1975; the results, obtained from the analysis of these samples, indicate higher concentrations of the above listed radionuclides and in addition indicate the presence of manganese -54 and iodine -131.
The sampling area is the old Keowee riverbed.
This area fills with water during operation of the hydro and retains water in a backwater eddy when the hydro is not operating. This encourages the accumulation of radionuclides in aquatic vegetation and silt. The eddy-water concentrations of the radionuclides present in aquatic vegetation, are probably not average tailrace concentrations, but concentrations somewhere between 10 CFR 20 mpe discharge concentrations and the final effluent dilution concentrations resulting from operation of the hydro since radioactive ef fluent releases i
are also made when the hydro plant is not operating. This explains the higher concentrations seen in the follow-up aquatic vegetation samples.
Ver truly yours, q
Q O,
N William O. Parker, Jr.
EDB:mmb
~
I