ENS 52060
ENS Event | |
|---|---|
23:30 Jun 30, 2016 | |
| Title | Whole Body Badge Exposure Reading of 31 Rem |
| Event Description | The following report is a summary of information provided via email:
We [Yale University] received notification from our dosimetry vendor (Mirion Dosimetry) of the following unusually high results on three dosimeters for individuals who all work at our PET [Positron Emission Tomography] Research Center, for the month of May: Nuclear Medicine Technologist - Whole Body Badge - 31 Rem; Contract Nurse - L Extremity Dosimeter - 35 Rem; Radiochemist - L Extremity - 37 Rem The Nuclear Medicine Technologist (NMT) was only at work for six days in May. She only handled radioactive material 4 of those 6 days. She used routine NMT amounts (milliCuries) of C-11 on those 4 days and reports nothing unusual about her work those days. She wears extremity monitors as well and although I [Yale University Radiation Safety Officer (RSO)] don't have the official report from Mirion on these rings, the raw data I have indicates 50 to 85 mRem on her rings. These readings would be considered typical for her work. She is currently on medical leave and has not been at work since May 10th. She does not believe the reading to her whole body badge can be accurate. She does not recall anything unusual for the time period in question. The Contract Nurse only worked three days in May. Her other ring badge and her whole body badge recorded no exposures. She does not recall anything unusual for the time period in question and questions the validity of the result. The Radiochemist worked his typical schedule in May and handled radioactive materials as part of his work most days. He recalls nothing unusual. His other ring badge and his whole body badge recorded no exposures. We [Yale University] immediately collected all [the] PET Research Center staff June monthly badges and have sent in these three individual's badges (and several others) for emergency reads and the remaining for quick reads. [The RSO] expects to get the emergency results today and the remainder early next week. We [Yale University] also reviewed dosimetry of others in the facility, reviewed surveys conducted in May in the facility and conducted a radiation survey at the facility yesterday and find nothing unusual or out of the ordinary. We [Yale University] are in contact with several dosimetry experts at Mirion Dosimetry and they are assisting in our investigation. [The RSO] has asked for several pieces of information in writing as related to their processing of the badges including: Verification that the results of the three high readings have been scrutinized and reanalyzed for validity and accuracy. A description of the type of radiation believed to have caused the exposure on the whole body badge and the energy range of this radiation. Can any information about the orientation of the whole body badge when exposed be determined? Was it exposed upside down or backwards, for instance? If you can make any judgments about this please indicate in report. Review and confirmation that the TLD chips from each of the dosimeters in question were tracked correctly and are indeed from the badge and rings from the individuals reported. Verification that nothing unusual happened with the badges once received by Mirion. Please include the dates the badges were received by Mirion and track them each through processing. I'd like to know when each of the TLD's were analyzed at your facility and if they were analyzed on the same readers and such. [The RSO doesn't] believe that any of the three readings reflect actual doses to people. Nonetheless, We [Yale University] are taking the situation very seriously and are expending significant time and effort to try to determine the cause in a timely manner. Our RSC [Radiation Safety Committee] is aware of the situation as is senior Yale leadership. |
| Where | |
|---|---|
| Yale University New Haven, Connecticut (NRC Region 1) | |
| License number: | 06-00183-03 |
| Organization: | Yale University |
| Reporting | |
| 10 CFR 20.2202(a)(1) | |
| Time - Person (Reporting Time:+10.1 h0.421 days <br />0.0601 weeks <br />0.0138 months <br />) | |
| Opened: | Tammy Stemem 09:36 Jul 1, 2016 |
| NRC Officer: | Jeff Herrera |
| Last Updated: | Jul 1, 2016 |
| 52060 - NRC Website | |
Yale University with 10 CFR 20.2202(a)(1) | |
WEEKMONTHYEARENS 520602016-06-30T23:30:00030 June 2016 23:30:00
[Table view]10 CFR 20.2202(a)(1) Whole Body Badge Exposure Reading of 31 Rem 2016-06-30T23:30:00 | |