A drive cable designed for 25' controls was installed in a 35' control assembly. This resulted in 15' of usable drive cable to travel through the guide tube. The radiographers were using a guide tube and extension with a total length of 17' and were unaware that there was not enough drive cable to reach the source stop. The cable was run out past the stop, and could not be retracted.
The exposure being taken at the time of the incident was a 6:00 shot on a 12" oil line. The line was 15' off the ground near an elevated platform. There was a 42" pipe running between the platform and the pipe being inspected. The exposure device was placed on the platform and an extension was added to the guide tube to route the source around the 42" pipe. The total length of the guide tube and extension was 16'11". The control cables were rerouted to take advantage of nearby shielding. The conduits were disconnected from the Pistol Grip Assembly exposing the drive cable. The source was then retracted into the fully shielded position by pulling the drive cable by hand.
The entire inventory of control assemblies were inspected to ensure the proper drive cables are installed, as will new assemblies when they are initially received. Additionally, personnel qualified to repair control assemblies will be retrained with emphasis placed on ensuring proper length of drive cable is in place. Training will be documented and filed in personnel records.
Qualifications of personnel involved in incident:
1. Radiographer, Texas Industrial Radiographer Certification holder, Dose Received, 3mR (dosimeter)
2. Radiographer, IRRSP card holder, Dose Received, 5mR (dosimeter)
3. Radiographer, Illinois Industrial Radiography Certification holder, Dose Received, 7mR (dosimeter)
4. Assistant Radiographer, Dose Received, 2mR (dosimeter)
Source retrieval personnel: Site Radiation Safety Officer, IRRSP card holder, Source Retrieval trained by LAMCO & Associate February 25, 2011, Dose Received, 2mR (Dosimeter)
Equipment Involved:
7' flexible Guide Tube, serial # GT 1211 22
10' flexible Guide Tube Extension, serial # EXT 12 11
Crank Assembly serial # 11652
Exposure Device Model #: Sentinel Delta 880
Exposure Device serial #: D3534
Isotope: Iridium 192
Source serial #: 84462B