Event Notification Report for May 11, 2001

LOST CHEMICAL AGENT ALARM AT FT. IRWIN, CA.


The U.S. Army Aberdeen Proving Grounds reported the loss of a chemical agent alarm, model number GID-3. The alarm contains two nickel-63 sources each with an activity of 15mCi. The chemical agent alarm was lost at FT. Irwin, CA during training exercises on May 11, 2001. Search is in progress to locate the alarm.

MEDICAL MISADMINISTRATION

A patient was being treated with Ir-192 and after 2 minutes of treatment verification of the location of the wire could not be made and a decision to terminate the treatment was made. When they attempted to terminate the treatment a problem arose with the clutch mechanism on the device which resulted in the wire slipping. The manufacturer was called and the medical staff continued to troubleshoot the system. The delivery wires for the system were cleaned and the treatment was resumed. On 5/14/01 the University RSO investigated the situation and decided not to use this device until it was evaluated by the manufacturer. On 5/16/01 it was discovered that the cable had some lubricant that leached from the cable and caused increased friction in the treatment catheter.
Further evaluation of the film that was shot during this procedure determined that the source was between 4.5 and 5mm from where the treatment site was, therefore there was a delivery to an area that was unintended. The patient and physician were notified.

A 47.5 CURIE IR-192 SOURCE WOULD NOT RETRACT INTO THE CAMERA DUE TO RESISTANCE IN THE GUIDE TUBE.

Radiographers were performing field site radiography at a refinery and a radiograph was required at about the 80 foot level on the refinery structure. The collimator was firmly taped to a wooden pole attached to the structure. The AEA Technologies, Model 660B camera and controls were placed on the next level down. Two guide tubes were connected end to end to connect camera and collimator. The area was secured and the shot timed. At the end of the exposure the radiographer attempted to retract the AEA Tech. model 424-9 source and discovered that it would only come back part way. After several unsuccessful attempts cranking the source back and forth, the radiographer left the source in the fully extended position (in the collimator) and called the RSO for assistance. The RSO made sure the site was roped off and under observation and then called AEA Technology to send a retrieval expert. The state Division of Radiation Protection was also notified and staff sent to observe the recovery operation.

The retrieval was performed by using a crane to hook onto the camera and, once the collimator was cut free from the structure, to lay out the camera and the dangling guide tube and collimator behind a concrete barrier. The control cable was also stretched out straight using the crane. Once in place and shielded, the control cable was used to easily retract the source. The manufacturer has taken the device and guide tubes for analysis. However, the immediate supposition is either dirt in the guide tube or too tight of a turn in the guide tube may have created enough friction to prevent the source from retracting smoothly even though it cranked out without difficulty. The highest exposures received due to this event were to the two individuals involved in cutting the collimator loose from the structure. The crane operator and a radiographer each received 4 millirem while using a 10 foot pole pruner to cut the wooden stick holding the collimator. One other individual received 1 millirem exposure during this event.

What is the notification or reporting criteria involved? Equipment malfunction. Activity and Isotope(s) involved: 47.5 Ci Ir-192.

Overexposure? Two individuals received 4 millirem whole body and one individual received 1 millirem whole body exposures.