INES-event
INES 2

Potential Radiation Overexposure of Radiographers

On March 11, 2005, a California industrial radiography licensee notified the state that two of its employees may have incurred an occupational overexposure. The licensee reported that two radiographers were conducting radiographic operations at a refinery located in Carson, CA using an Industrial Nuclear Corporation Model IR 100 exposure device. The device contained an iridium-192 sealed source with an activity of approximately 3.3 terabecquerels (90 Curies).
The licensee reported that subsequent to performing several radiographic exposures (approximately 10), the radiographer approached the camera without any survey instrumentation and disconnected the guide tube. After disconnecting the guide tube, it became apparent to the radiographer and his assistant that there was a problem because their survey instruments were reading off-scale. Additionally, the radiography crew checked their pocket reading dosimeters and observed they were reading off-scale. The radiographer used pliers to successfully retract the source into the shielded position.
On March 17, 2005, the State of California provided the Nuclear Regulatory Commission (NRC) with updated dosimetry results that revealed that the radiographer and his assistant received a whole body dose of 16 millisievert (1.6 rem) and 27 millisievert (2.7 rem) respectively. Additionally, dose reconstruction results indicated that the radiographer received a shallow dose equivalent of 550 millisievert (55 rem) to the hands, a dose in excess of the NRC’s applicable limit of 500 millisievert (50 rem). There were no reported physical abnormalities related to the exposure.
The radiographic device was sent to the manufacturer for evaluation and repair.

Location: Carson
Event date: Fri, 11-03-2005
Nuclear event report
Legenda & explanation