ML19289C372
| ML19289C372 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/04/1979 |
| From: | Stout J BALTIMORE GAS & ELECTRIC CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 7901120101 | |
| Download: ML19289C372 (2) | |
Text
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, y
I B ALTIMORE
! GAS AND j j ELECTRIC
'y CHARLES CENTER. P.O. BOX 1475 BALTIMORE MARYLAND 21203 ELECTnic ENGINEERING oa m wENr January h, 1979 Mr. Ecyce H. Grier, Director Office of Inspection and Enforcement Region 1 USNRC 631 Park Avenue King of Prussia, PA.
19h06 Decr Mr. Grier:
Subject:
Calvert Cliffs Nuclear Power Plant Units No. 1 and C.
License Nos. DPR-53 and 69 Renroutine Radiological Enviro = ental Operating Report.
This report (tvo copies) is submitted to comply with the require-ments of Appendix F Invironnental Technical Specifications Section 5.6.2.b.
The Oyster sa=ples vere collected en December 5,1978 from the Ca=p Conoy sa=pling location and analyzed for ga=a-ecitting radionuclides as required by Section 3 2 Appendix B Environmental Technical Specifications.
The results of the analyses showed the presence of Ag-110m at 81 11% pCi/Kg (vet). The oyster sanples collected on the same date from the Kenvood Beach sa=pling location (the background location) shoved Ag-llos att 7 pCi/Kg(vet).
The measurable level of Ag-110m in oysters was first detected in sa=ples collected from the Ca=p Coney sa=pling location in June 1977 Sub-sequently, samples collected in 1977 from the same location also shoved measurable levels of Ag-110s as did the. sarples collected in January and February 1978. These findings were reported to the NRC as required.
The oyster samplet, collected from the Camp Conoy location from March
,thru September 1978 showed an apparent decrease in Ag-110m concentrations.
These concentrations ranged from 310
- 10% i,o 3 60
- 15% PCi/Kg (vet), compared to the average background value of about f.40 pCi/Kg(vet). The observed de-crease may in large part be due to depuration even though the effluent releases from the plant during the period of interest contained small quantities of Ag-110=.
7 9 0112 0% lo(
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Mr. Ecyce H. Grier
- Eeginning with the fourth quarter of 1978 oyster sa=ples are no longer sent to Radie. tion Management Corporaticn (FFC) in Philadelphia for Emma analyses. These analyses are done by the Che:ical Engineering and Test Section of cur Electric Test Department, using a 10% Ge(Li) vith a Nuclear Data System 6600. The sa=ple size and the count time e.re selected to meet the required detection capabilities for a number of radionuclides induding Zr-Nb-95. ' As a result of this exercise, the MDL value for Ag-110=
is calculated at about 97 pCi/Kg (vet), which is substantially lover than the previous average PDL value of aboute LO pCi/Eg(vet). On the assu=ption that this new MDL value of T constitutes the background value, the level of Ag-llos observed in December 1978 Carp Conoy se:ples exceeded the background value by over a factor of 10.
However it does show a continuation of the general trend of decreasing Ad-110m activity in Oysters at this location.
Based on the observed levels of Ag-110: during 1978, for an average individual consu=ing 50 gra=s of oysters per day the doses to the GI Tract and Whole Body are esticated ct< 3 x 10-2 tren/ year andekx10-5 crem respectively.
These are very small fracticas of the allevable 25 tren/ year (G.I. Tract) and 25 cren/ year (Whole Body) deses to members of the general public, (k0 CFR Part 190 Enviren= ental Radiation Protection Standards for Nuclear Fever Operations) and are considered to be of no consequence to the health and safety of the public.
Very truly yours, d
N,/y
/L.
J. W. Stout, Jr.
///
Chief Environ = ental Engineer cc: Director Office of Nuclear Reactor Regulaticn Washington, DC (17 ccpies)
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