ML19274D180

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Forwards Rept to Comply W/Requirements of App B ETS Section 5.6.2.b.Oyster Samples Collected from Sampling Location Showed Presence of gamma-emitting Radionuclides
ML19274D180
Person / Time
Site: Calvert Cliffs  Constellation icon.png
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 7901150132
Download: ML19274D180 (2)


Text

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14 N BALTIMORE GAS AND ELECTRIC

/

CHARLES CENTER . P.O. BOX 1475 BALTIMORE. MARYLAND 21203 ELECTRIC ENGINEERING oEMRTMENT January 4, 1979 Mr. Boyce H. Grier, Director Office of Inspection and Enforcement Region 1, USNRC 631 Park Avenue King of Prussia, PA. 19h06

Dear Mr. Grier:

Subject:

Calvert Cliffs Nuclear Power Plant Units No. 1 and 2.

License Nos. DPR-53 and 69 Nonroutine Radiological Environmental Operating Report.

This report (two copies) is submitted to comply with the require-ments of Appendix B Environmental Technical Specifications Section 5.6.2.b.

The Oyster samples were collected on December 5, 1978 from the Camp Conoy sa=pling location and analyzed for gn=na-emitting 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 samples collected on the same date from the Kenwood Beach sampling location (the background location) shoved Ag-110m att 7 pCi/Kg(vet).

The measurable level of Ag-110m in oysters was first detected in samples collected from the Camp Coney sa=pling location in June 19"". Sub-sequently, samples collected in 1977 from the same location also showed measurable levels of Ag-110m as did the samples collected in January and Februar,/ 1978. These findings were reported to the NRC as required.

The oyster samples collected from the, Camp Conoy location from March thru September 1978 shoved an apparent decrease in Ag-110m concentrations.

These concentrations ranged from 310 i 10% to 160

  • 15% pCi/Kg (vet), compared to the average background value of about $h0 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 contair ad s=all quantities of Ag-110m.

0%

0 7901150(3) l

  • 9 s

Mr. Boyce H. Grier Beginnin6 with the fourth quarter of 1978 oyster saeples are no longer sent to Radiation Management Corporation (RMC) in Philadelphia for gar =a analyses. These analyses are done by the Chemical Engineering and Test Section of our Electric Test Department, using a 10% Ge(Li) with a Nuclear Data System 6600. The sample size and the count time are selected to meet the required detection capabilities for a number of radionuclides including Zr-Nb-95.' As a result of this exercise, the MDL value for Ag-110m is calculated at about 97 pCi/Kg (vet), which is substantially lower than the previous average FDL value of aboute 40 pCi/Kg(vet). On the assumption that this new MDL value cf 7 constitutes the background value, the level of Ag-110m observed in December 1978 Camp Conoy samples exceeded the background value by over a factor of 10. However it does show a continuation of the general trend of decreasing Ag-110m activity in Oysters at this location.

Based on the observed levels of Ac-110m during 1978, for an average individual consu=ing 50 grams of oysters per day the doses to the GI Tract and Whole Body are esticated at< 3 x 10-2 cren/ year andehx10-5 = rem respectively.

These are very small fractions of the allovable 25 mren/ year (G.I. Tract) and 25 crem/ year (Whole Body) doses to members of the general public, (h0 CFR Pcrt 190 Environmental Radiation Protection Standards for Nuclear Power Operations) and are considered to be of no consequence to the health and safety of the public.

Very truly yours, W .

/ 'J. W. Stout, Jr. ' p' u Chief Environmental Engineer cc: Director Office of Nuclear Reactor Regulation Washington, DC (17 copies)