The following was received from the state via fax:
On April 18, 2011, a gauge malfunction occurred at the licensee's facility during a device installation on a process vessel. When the 2 Curie Cesium-137 source was inserted into the vessel, the chain connecting the source to the nuclear gauge broke allowing the source to travel to the bottom of the insertion tube. The source being at the bottom of the insertion tube is its normal operating position. A radiation survey was conducted by the licensee indicating radiation levels were normal. The device was removed from the vessel, [and] the source [was] retrieved from inside of the vessel. The device and the 2 sources were taken by the service company to their facility for repair. There was no additional radiation exposure to any members of the general public or radiation workers due to this incident. Gauge information: TFS model 5220 containing (2) 2-Ci Cesium-137 sources. Device SN: B-36. Source SNs: MB-3946 and MB 3956.
Additional Information:
The sources had been removed from the process vessel back in January 2011 and were put into storage while the unit was down for repairs (a 'turnaround'). There are 6 of these custom devices on 3 vessels. The insertion tube is a divided tube and one source is lowered down each side; 2 sources each tube. Five of the sources lowered with no problems. As they were lowering the 6th one down the insertion tube, the chain attached to the source broke and the source fell to the bottom of the tube (which is its normal position when unit is in operation, so no exposure to any individual resulted from it being there). The insertion tube is approximately 25 feet down to the bottom. They were able to 'fish' the top of the chain and pulled the chain with the source out of the tube and put the source directly into a pig. All other individuals had been moved back a safe distance for ALARA. The service company took the device and sources to their facility for repair. The unit will remain out of operation until device is repaired and installed.
Texas Incident #: I - 8836