Worker Overexposure

The Licensee reported a potential overexposure based on a ring dosimetry report that indicated a dose between 119 and 40 mSv (11.9 and 4 rem). Licensee investigations indicated that a research technician is believed to have received between 0.5 to 4 Sv (50 to 400 rem) to his fingertips due to improper handling of bromine-76. The range of the 0.5 to 4 Sv dose estimate was based on interviews with the technician and the results of a Varskin computer calculation. There were no observable effects to the fingertips. The technician handled vials containing 1.18 GBq (32 mCi) of bromine-76 without the use of tongs, which was the approved method. The technician has approximately 6 years of experience handling this material and there was no apparent reason for the lapse in safety technique. Update: Due to perceived operational pressures that the technician deemed took precedence over principles to keep doses as low as reasonably achievable, the technician directly handled the vials on several occasions. The dose has been determined to be 260 mSv (26 rem) to the fingertips, which is below the regulatory reporting limit of 500 mSv (50 rem) to the extremities. The licensee retracted the event.

Location: Washington University St. Louis
Event date: Fri, 02-04-2010
Nuclear event report
Legenda & explanation