ML20081G093
| ML20081G093 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/17/1983 |
| From: | Schuyler J PACIFIC GAS & ELECTRIC CO. |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 8311040115 | |
| Download: ML20081G093 (2) | |
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BOWS N-71 BEAti STREET. SAN FRANCISCO, CAUFORNIA 94106. (415) 7814fif(fy TWX 910 372-6587 J.O.SCHUYLER vitt perset.F NwCLEA. POWLe GE%&aateg October 17, 1983 Mr. John B. Martin, Regional - Administrator U. S. Nuclear. Regulatory Commission, Region V 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368-Re: Docket No. 50-275, OL-DPR-76 Diablo Canyon Unic 1 Special Report - Recovery of Missing Radioactive Source
Dear Mr. Martin:
The radioactive source reported missing in our June 1,1983 special
~ report was found on September 16, 1983. This follow-up letter is being submitted pursuant to 10 CFR 20.402 (c).
1.
Descriptic. of Circumstances
~
On September 16, 1983, a survey was conducted in the locker room adjacent to the 85 foot elevation access control area because an unusually high number of pocket ion chambers stored in the locker
. room were failing their drift tests. During this survey, a higher than background reading was found next to an electrical outlet
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located at floor level in the wall between the locker room and access control. A hole was opened in the wall and the missing 100 uCi Cs-137 source from radiation monitor RE-22 was-found. The time and method of placement of the source in that location are unknown, as is the identity of the individual (s) involved. The source was placed in the locked storage safe in the chemical laboratory.
2.
Possible Doses to Individuals from Source The possible dose to individuals was analyzed, assuming that the source was placed at the discovery location shortly after its removal from RE-22. The analysis shows that no individual would -
-have received a whole body dose in excess of 1 millirem, with the possible exception of the individual (s) handling the source.
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Mr. J. B. Martin October _17,1983 Page Two-The dose to an individual passing the source location is conservatively estimated as less than 1 millirem. This is based on a calculated dose rate of 0.05 millirem per hour and an exposure time of 10 minutes per day for 19 weeks between May 4 and
' September 16 1983.
The area where the source was found is normally occupied by Chemistry and Radiation Protection Department personnel. The dose rate was calculated as.003 millirem per hour at the nearest desk to the source. A review of the TLD records for this group shows no measurable exposure which could be attributed to the source.
Sincerely, cc:
R. C. DeYoung, Director Office of Inspection and Enforcement Service List 3..