On August 3, 2004, a licensee notified the Nuclear Regulatory Commission (NRC) an individual’s June film badge had a deep dose reading of 1.2 Sv (121 rem), potentially indicating an exposure in excess of NRC’s regulatory limit of 50 mSv (5 rem) total effective dose equivalent (whole body).
The badge was imaged to determine whether the dose was static or dynamic, but the results were inconclusive. The individual’s self-reading pocket dosimeter, which was worn in the same location as his whole-body dosimeter, only collected 90 uSv (9 mrem) during the month of June 2004. The licensee’s consultant stated that the individual did not exhibit any symptoms of overexposure. The individual is a manager and was in the field for only three days in June 2004, and was not present during any abnormal occurrences. Co-workers that were in the field with the individual did not have any abnormal results when their badges were processed. The individual was sent for blood cell analysis to assist in validating the dosimeter results. The blood cell analysis results were normal. The licensee also arranged for the individual’s blood to be drawn for cytogenetic testing. Results revealed that no aberrations were noted that would indicate an exposure to radiation greater than background. It is believed that there may have been an error in dosimetry processing.