The following is information received from the
Washington State Department of Health via email:
On 05/07/2024, three radiographers started work around 1000 [PDT] and were in the process of completing a second shot about 12-feet off the floor when the collimator attached to the source fell to the ground. This caused a bend/crimp in the guide tube preventing the radiographers from retracting the source back into its shielded position within the exposure device. After several attempts at retracting the source, the radiographers contacted the radiation safety officer (RSO) at 1026 PDT. The boundaries were expanded and the workers guarded the area. No other workers or contractors were present at the time.
At 1130 PDT, the RSO arrived with additional shielding (lead shot bags) and tools. The RSO made a first approach to the source and observed that the collimator was facing northwest. The RSO, using a long reaching tool to manipulate the collimator, turned it to face the ground. No change in activity was recorded and it was determined that the source was not within the collimator. The RSO placed a 25-pound bag of lead shot on the guide tube just below the collimator. No change in activity was observed. The team then retreated. The technician approached the source and placed a second bag further down the guide tube. Survey meters read a substantial decline in activity. The RSO then returned to the source and placed several more bags on the source location. After the source was shielded, the RSO inspected the guide tube and located a slight pinch in the tube. The RSO then used a tool to partially remove an irregularity from the guide tube and requested the technician to crank the source back into the camera. The source was returned to the camera successfully. The RSO removed the damaged guide tube from service.
The total exposure to the lead radiographer was 10.75mR. The first assistant radiographer exposure was 3.9mR. The second assistant radiographer exposure was 3.6mR. The RSO had an exposure of 20mR on their arm and 4.3mR on their trunk.
The camera is a Sentinel model 880 with an Ir-192 source of 38.7 Ci.
Washington Incident No.: WA-24-013