ML20070M691
| ML20070M691 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/14/1983 |
| From: | Fuhrman G BALTIMORE GAS & ELECTRIC CO. |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 8301250298 | |
| Download: ML20070M691 (3) | |
Text
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BALTIMORE GAS AND Yl ELECTRIC CHARLES CENTER. P.O. BOX 1475 BALTIMORE, MARYLAND 21203 ELECTRIC ENGINEERING DEPARTMENT January 14, 1983 0
Mr. Ronald C. Haynes
{V Office of Inspection and Enforcement Region I, U.S. NRC 631 Park Avenue King of Prussia, PA 19406
Dear Mr. Haynes:
Subject:
Calvert Cliffs Nuclear Power Plant Unit Nos. 1 and 2 License Nos. DPR-53 and 69 Nonroutine Radiological Environment Operating Report Ref:
G. R. Fuhrman's Letters dated October 11 and November 23, 1982 to Mr. Ronald C. Haynes - U.S. NRC This report is being submitted to comply with the requirements of Appendix B. ETS Section 5.6.2.b. and a follow-up to my letters referenced above, with a review of the observed levels of Ag-110m in oyster samples collected during 1982.
Oyster samples were collected monthly from the designated locations during November and December 1982, and analyzed for complete gan:ma spectrum.
The results of the analyses showed the presence of Ag-110m as follows:
Location / Sample Data Ag-110m pCi/Kg (vet)
Camp Conoy - November 18, 1982 532
- 12 Kenwood Beach - November 18, 1982 24 ' 5 Camp Conoy - December Ib, 1982 458 i 12 Kenwood Beach - December 14, 1982 1h
- 4 During 1982 the radioactive releases of all radionuclides were well within the limits specified in the Environmental Technical Specifications (ETS) for the Calvert Cliffs Units 1 and 2.
I K 050 0 7
PDR t.3
Mr. Ronald C. Haynes January 14, 1983 The Calvert Cliffs Unit 1 was shut down on April 17, 1982 for a general inspection of the Unit, refueling, and retubing of the condensers.
Following completion of the planned maintenance work, this Unit was brought on-line on July 5, 1982. For similar maintenance work, Unit 2 came off-line on October 16, 1982. This Unit is expected to be back on-line on February 14, 1983 For the period of interest in 1982, the monthly per cent capacity factors for ooth Units were as follows:
Unit 1 Unit 2 July 72.0 80.1h August 75.h5 64.77 September 69 27 86.86 October 105.20 41.19 (Unit came off-line November 101.61 on Oct. 16, 1982)
December 100 59 During operation of Units 1 and 2, the circulating-water-pump data logs show that, on the average, at least five pumps (each rated at 200,000 GPM) per Unit were in operation. The processed radvaste from.the combined waste processing system for Units 1 and 2 was released into the circulating water prior to the discharge into the Bay. The radwaste may be released at a design rate that can range from 10 GPM to a maximum of 120 GPM.
In practice, the releases are made at a predetermined rate depending upon the measured concentra-tion of radionuclides in the radwaste, the ETS limits, as well as the established ALARA objectives. At the maximum release rate the radwaste concentration is decreased at least by a factor of about 8 x 103 prior to discharge into the Bay.
Based on the Plant effluent release data and other related factors, using assumptions per Reg. Guide 1.109, calculations were made to estimate the expected level of Ag-110m in oysters in the vicinity of the discharge area of the Bay.
These calculations show the expected level of Ag-110m in oysters substantially higher than the measured levels, indicating that the assumptions used in the calculations are very conservative and thus yield an overestimate of concentrations in the environmental media of interest.
l Oysters have a natural tendency to highly bioconcentrate environmental silver. As a result of the bioconcentration, oyster muscle tissue show radio-active silver at levels observed in a number of samples collected during 1982.
These levels are reportable on the basis of the Calvert Cliffs ETS exceedance criterion which is " ten times the background," where " background" is the " mini-mum detectable concentration" in the control sample.
However, it should be pointed out that, based on model calculations, these levels would potentially result in doses to the whole body and the GI-Tract t
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Mr. Ronald C. Haynes January 14, 1983 of a maximum individual which are a few per cent or less of the design ob-jective doses of 10 CFR Part 50, Appendix I.
The NRC Radiological Assess-ment Branch considers that "..
.-a reporting level is exceeded if the potential annual dose to an individual is equal to or greater than the design objective doses of 10 CFR Part 50, Appendix I _(Branch Technical Position Revision 1, November 1979). -Based on this criterion, the' observed levels of Ag-110m in oyster samples during 1982 would not be reportable.
Based on the average activity level of Ag-110m observed in oyster samples during 1982, the doses to the GI-Tract and the Whole Body of a max-imum exposed individual (with the consumption rate of 5 Kilogram / year.and the dose conversion factors as recommended in Reg. Guide 1.109) are estimated at less than 0.1 mrem /yr and less than 0.1 x 10-3 mrem /yr, respectively during 1982. These doses are small fractions of the permissible limit of 25 mrem / year to members of the general public as set forth in h0 CFR Part 190 " Environmental Radiation Protection Standards for Nuclear Power Operations," and are therefore considered to be of insignificant consequence to the health and safety of the public.
Very truly yours,
~
Gary R. Fuhrman, Director Environmental Studies & Monitoring GRF/eml cc: Director Office of Nuclear Reactor Regulation Washington, DC 20555 (17 copies)
Dr. Steven M. Long State of Maryland Mr. R. E. Architzel NRC Resident Inspector Calvert Cliffc w