Event Notification Report for June 03, 2003

RADIOGRAPHIC EXPOSURE DEVICE FAILURE

"Description of the equipment problem. On June 3, 2003, gamma radiography operations using an AEA Technology/QSA Model 660A exposure device in a permanent radiography facility at Shore Intermediate Maintenance Activity were being performed under the authority of Naval Radioactive Materials Permit (NRMP) No. 0465918--A1NP. On the tenth exposure of the day the radiographer attempted to retract the radiographic source into the radiographic exposure device. The radiographer placed the drive cable brake in the "off" position and rapidly cranked the source in the retract direction. The number of turns coming in matched the number of turns going out. The permanent facility gamma alarm shut off, however the radiographer did not hear the locking slide mechanism engage which is normally heard clearly when retracting the source. When attempting to re-expose the source as required by the operating procedure, the source did expose again. The Radiation Safety Officer was present and directed the radiographer to retract the source again. As with the first attempt to retract the source, the slide bar did not click in the safe position. Again and the gamma alarm shut off. The Radiation Safety Officer entered the permanent facility with, an operating survey meter. The locking slide bar indicated green (safe) but it was not locked in that position. The Radiation Safety Officer approached the device and observed a reading of approximately 8 millirem/hour on the front of the device and 10 millirem/hour on the back of the device. She exited the permanent facility and discussed the situation with the radiographer. The Radiation Safety Officer then directed the radiographer to maintain control of the crank assembly handle and she entered the permanent facility with a survey meter and pushed the slide bar to the red (expose) position. The Radiation Safety officer exited the permanent facility and instructed the radiographer to retract the source to the fully locked position. The retraction was successful and the slide bar was heard to click to the fully green (safe) position. The Radiation Safety Officer checked her self-indicating pocket dosimeters which both indicated zero exposure.

"The source was transferred to an AEA 650L source changer on June 4, 2003. A "dummy" source was installed in the exposure device and the locking slide bar was placed in various positions to experiment and recreate the scenario. Frequently during these tests, the radiographers were not able to lock the slide into place without unlocking the drive cable crank assembly and applying minimal pressure towards the expose position. This is considered a neutral position and not an exposed position. With minimal pressure the slide bar mechanism easily locked into the exposed position.

"Cause of each incident. The cause of the incident appears to be twofold. Primarily the compression springs for the posi-lock may have been excessively worn. Secondarily, the Shore Intermediate Maintenance Activity, San Diego operating procedure did not call for them to unlock the crank assembly cable lock prior to rotating the selector ring to the operate position and pushing the posi-lock slide bar from the green (retracted) position to the red (operate) position as stated in the most recent AEA exposure device manual. We believe that the faulty springs were the main factor as the posi-lock slide bar can be pushed to the red position with the crank assembly cable lock in the "on" position but that procedure may have contributed to the excessive wear on the compression springs.

"Name of the manufacturer and model number of equipment involved in the incident. The equipment involved in the incident was manufactured by AEA Technology/QSA and consisted of a Model 660A exposure device, serial number A4450 with a 13.6 curie Ir-192 source.

"Place, date and time of the incident. The incident occurred at Shore Intermediate Maintenance Activity, San Diego, California in a permanent facility on June 3, 2003.

"Actions taken to establish normal operations. The Radiation Safety Officer entered the permanent facility and manually pushed the locking slide bar to the unlocked (red) position. The Radiation Safety Officer exited the permanent facility and instructed the radiographer to attempt to retract the source. The source was successfully retracted to the fully locked position and the locking slide bar was heard to lock.

"Corrective actions taken or planned to prevent recurrence. Shore Intermediate Maintenance Facility, San Diego replaced the compression springs for the posi-lock assembly on the exposure device. Additionally, they have changed their operating procedure to unlock the crank assembly cable lock prior to rotating the selector ring to the operate position and pushing the posi-lock slide bar from the green (retracted) position to the red (operate) position."

The licensee notified R2 (Diaz).

CHEMICAL AGENT ALARM DETECTOR POTENTIALLY LOST FROM MAINTENANCE SHOP

A chemical agent alarm detector, model M22, containing a 30 millicuries Ni-63 (nickel) source was turned in to the Michigan Army National Guard owning unit maintenance shop in Lansing, Michigan for calibration in February 2003. On June 3, 2003 the owning unit reported to the Radiation Protection office of the US Army Soldier Biological Command, Aberdeen, MD, via email that the maintenance shop could not locate the detector. This incident is currently under investigation and a preliminary report will be written within 21 days followed by a final report.

TWO TROXLER MOISTURE DENSITY GAUGES DISCOVERED ABANDONED

On 6/3/03 during a special inspection for non-payment of license fees, state inspectors found the Abiotic Enterprises facility located at 2320 South Portland in Oklahoma City closed and, by all appearances, defunct. The landlord who is located in the same structure said that his tenant, i.e., Abiotic Enterprises, was five (5) months in arrears on rent and that he had not seen any activity for more than a month. The state inspectors entered the business with the assistance of the landlord and found two (2) Troxler Moisture Density Gauges, a model 3430 S/N 29405 and a model 3440 S/N 29452, inside an unlocked caged area. The cases containing the gauges and the source rods were also found unlocked. Oklahoma has revoked Abiotic Enterprises license subject to administrative appeal. On 6/4/03, both Troxlers were impounded by the state and are currently in storage within the OK rad program vault.

SOURCES IN PATIENT FOUND TO HAVE MIGRATED DURING TREATMENT

After 17 hours of irradiation with a cesium-137 source, it was discovered that the source was capable of migrating along a tube that was 16 centimeters long. While the Doctors thought the sources (left and right tubes) were at the 0 centimeter position in the tube they were probably at various locations in the tube during the patient's treatment. Spacers were not placed in the tubes to prevent the cesium-137 sources from moving. During the 17 hours the sources were in the patient the patient laid flat on his/her back but the patient was allowed to move his/her legs and move back and forth. The movements of the patient caused the sources (one cesium-137 source in each tube) to move up and down the tubes. At the end of 17 hours it was found that one of the sources was at the far end of the tube instead of being at the other end of the tube (0 centimeter position). Doctor of the patient was informed of this incident. Patient was not harmed by this error.