ML20090D399
| ML20090D399 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/21/1973 |
| From: | Burt P NIAGARA MOHAWK POWER CORP. |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| 10CFR-020.405, 10CFR-20.405, 30515, NUDOCS 8302280109 | |
| Download: ML20090D399 (3) | |
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NIAGARA MOHAWK POWER CORPORATION NIAGARA MOHAWK Nine Mile Point Nuc1 car Station Post Office Box 32 Lycoming, New York 13093 June 21,1973 Director, Division of Compliance United States Atomic Energy Commission Washington, D. C.
20545
Dear Sir:
Re:
Provisional Operating License:
DPR-17 Docket No.:
50-220 This report along with an attachment is sent to you in compliance with 10 CFR 20.405 (Reports of overexposures and excessive levels and concentrations).
The individual named in the attachment received an exposure of 3350 mrem to the whole body during the second calendar quarter, 1973
( i.e. April 8,1973 to June 30, 1973). The individual's film and self reading dosimeter records show the following results:
Whole Body Exposures mrem Self-reading Film Period of Exposure Dosimeter Badge 4/08/73 to 4/21/73 200 260 4/22/73 to 5/05/73 690 890 5/06/73 to 5/19/73 940 1900 5/20/73 to 6/02/73 340 300 2170 3350 We received a telegram from our film badge service on May 25, 1973 informing us that the individual in question received 1900 mrem for the period May 6, 1973 to May 19, 1973; this exposure value put him over the 3 Rem /qtr. limit. We immediately prohibited this man from entering any restricted areas so that he would receive no more exposure for this calendar quarter. Between the time the badge was sent in and the time we received the telegram, however, he received an additional 300 mrem.
As can be seen from the above tabic of dosimeter readings versus film badge readings, there is a large discrepancy between the two readings for the period May 6,1973 to May 19,1973 (i.e.1900 mrem vs. 940 mrem).
The individual's self reading dosimeter was calibrated and at two different dose rates (400 mr/hr and 25 mr/hr.). The dosi eter showed a + 15% accuracy.
3 0515 8302280109 730621
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o Director, Desion of Compliance o
i June 21, 1973 United States Atomic Energy Commission An interview with the individual failed to adequately explain why there should be such a large discrepancy. The two week period in question' (5/6/73 to 5/19/73) involved only four (4) days of work in a Radiation Area or Hi Radiation Areas (drywell maintenance work during shutdown) and a review of the radiation work permits for these four days indicate that the 940 mrem as read by the dosimeter would not be an unreasonable exposure.
It should be pointed out, however, if we assume the individual in question received the maximum dose that any man on each R.W.P. received he could have received 2050 mrem for the two week period. This leads one <
to believe that the individual allowed his dosimeter to go off scale and might have been reporting inaccurate exposure results based on dose rate' estimates.
In order to prevent a recurrence, we plan to re-instruct all individuals at the Station to keep a constant watch on their dosimeters so that no off scale readings are encountered; we plan to purchase a TLD dosimeter system with in-house capability. TLD dosimeters will be issued to men involved in the higher dose rate jobs (such as drywell work during a shutdown) this should help to eliminate "off scale" occurances, provide more accurate dosimetry and allow immediate on-site read out to ensure that no limits are exceeded.
Very truly yours, P. Allister Burt General Superintendent Nuclear Generation PAB:cm Enclosure cc:
Region I, Division of Compliance
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JUNE 21, 1973 Provisional Operating License:
DPR-17 Docket No.:
50-220 ATTAOIMENT TO 10 CFR 20.405 REPORT Name of Individual Exposed:
Thomas A. Masuicca Social Security Number:
076-16-3733 Date of Birth:
March 31, 1919 Exposure - Lifetime to Date:
12.58 Rem Exposure - Year 1973.to date:
4.09 Rem Exposure - Second Quarter 1973:
3.35 Rem a