ML20084T287
| ML20084T287 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/13/1973 |
| From: | Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084T261 | List: |
| References | |
| NUDOCS 8306230110 | |
| Download: ML20084T287 (2) | |
Text
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h cea.ral OHices: 212 West Machigan Avenue, Jackson. Michigan 49201 e Area Code 517 788-0550 A,/
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December 13, 1973
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rV Mr. John F. O' Leary Re: Docket 50-255 Directorate of Licensing License DPR-20 US Atomic Energy Commission Palisades Plant Washington, DC 20545
Dear Mr. O' Leary:
By letter dated August 24, 1973, we reported an incident at the Palisades Plant that involved exceeding radioiodine release rate limits for discharges via the plant stack. The incident occurred August 15, 1973 and was associated with purging of the primary side of the "B" steam generator so that maintenance could be performed on the steam generator.
In the August 24 letter, we described the preliminary results of environmental samples that had been obtained following the August 15 release. This letter vill update these results.
Our August 24 letter reported that a milk sample from the nearest real cow was obtained and analyzed. This sample was ob-tained August 19 and a gross count showed no detectable activity.
After chemical separation and extended counting periods in a low background counting facility, a concentration of 8 x 10-12 curies per liter was measured. Subsequent samples were obtained from the nearest real cow on September 8 and 16 and analyzed, using similar techniques.
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They showed concentrations of 1 9 x 10 and 1 7 x 10-curies per liter, respectively.
Using the actual measured concen-trations, an infant thyroid total dose of 2.4 mrem was calculated.
Theoretical calculations for the milk food chain also were performed based on the assumptions given in Regulator Guide 1.42 and using recorded meteorological data. This calculation overpredicted the actual concentrations in milk by about a factor of four.
Four milk samples were taken at various locations other than the nearest real cow and failed to show any significant levels of iodine. The results were reported as less than 3 x 10-13 curies l
per liter. The apparent discrepancy in the sensitivity of the j M
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o Mr. John F. O' Leary 2
Palisades Plant December 13, 1973 various analyses is explained by the fact that the nearest real cow samples were analyzed at a lover sensitivity which, among other things, required the samples to be shipped air freight in a refrigerated con-tainer.
In addition to the above, and before results of the envi-ronmental samples analysis were obtained, theoretical calculations were made to assess the impa:t of the release.
The release was broken down into three separate periods with the major portion of the, total, 115 mci, being released the morning of August 15 Based on recorded meteorological data, a southeast vind persisted during that period.
i Since the release would have been carried out over the lake, a site boundary dose was not calculated for this portion. Site boundary concentrations and resulting doses were calculated for the remaining portion of the release with credit being taken for the fraction of time offshore breezes existed. The calculated site boundary concen-tration was 5.7 x 10-13 C1/m3 which corresponds to a total inhalation dose of 0.35 mrem. Themeasuredsiteconcentration,acepuntingfor decay between removal and analysis, was (5 1 7) x 10-1" Ci/m (decay connected to the time of release) or roughly an order of magnitude less than the calculated concentration. The difference between the actual measured and calculated concentrations again points out the conservatism known to exist in calculational techniques.
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a Yours very truly, M-9[
RBS/mel Ralph B. Sewell Nuclear Licensing Administrator 4
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