ML19291B683
| ML19291B683 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/16/1976 |
| From: | Arnold R METROPOLITAN EDISON CO. |
| To: | |
| Shared Package | |
| ML19291B682 | List: |
| References | |
| NUDOCS 7911110161 | |
| Download: ML19291B683 (2) | |
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l'.qu!cicr:/ Docht r.3a ENCL 0SURE Metropolitan Edisen Ccmpany (Met-Ed)
Three Mile Island Nuclear Station Unit 1 (TMI-1) f46 7;f3' in :;e.Ef* ![r7b
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Dccket No. 50-289 Operating License No. DPR-50 Event Report 76-ofhL Report of an Ancmalous Measured Level of Radioactive Material Description of Measured Level As reported to Met-Ed on December 19, 1975 (by the censultant (RMC) lab oratory),
the concentration of Cs-137 in the semi-annual river bettes sediment samples collected on October 23, 1975 exceeded four (4) ti=es the centrol station value. The control station, (TM-AQS-1A2) located approximately 0 5 miles north of TMI-1 discharge, had concentrations of 190 1 31 pCi/Kg (DRY). The concentration of Cs-137 at TM-AQS-llA1, 0.2 miles downstream of the TWI-l discharge equaled 830 1 3 pCi/Kg (DRY).
8 Possible Cause The normal Cs-137 concentraticn associated with the river sediment near E4I-1 as determined by precperational surveys is approximately 300 pCi/
Kg (DRY). Every sediment sample (both background and indicator stations) ever collected at the river has had concentrations of Cs-137 Upstream (background) values have ranged from 110 to 770 pCi/Kg, while devnstream (indicator) samples have ranged frem 60 to 660 pCi/Kg.
Since the concentration indicated by this latest analysis is not statistically different frca normal concentrations, it is thought that this is an anomalous value and reportable under the criteria of Section 5.6.2.b.h of the Environmental Technical Specifications only because of the abnor= ally low control station value.
Analysis of W asured Level It is believed that neither the health nor safety of the public was threatened by the cccurrence represented by this sample in that:
a.
The estimated total body dose asscciated with this measured value frem the only significant dose pathway (shoreline deposition) is less than 0.083 mrem per year to the maximum hypothetical individual, b.
The level of Cs-137 activity in the river water at the nearest devnstrea= source of public drinking water was belov minimum detectable levels.
c.
Ncne of the T4I-1 Technical Specifications were exceeded.
d.
The level of ts-137 activity detected in the river sediment is a very lov level of activity and is expected to have little er no envircnmental i= pact.
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Corrective Actions It is thought that an increased sampling effort would be non-productive.
Sampling vill continue in accordance with T'4I-1 Env?.ron= ental Technical Specifications. The next sediment sampling period will be July,1976.
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