ENS 49320
ENS Event | |
|---|---|
05:00 Aug 5, 2013 | |
| Title | Agreement State Report - Failure of Radiography Source to Retract |
| Event Description | The following report was received from the Kansas Bureau of Environmental Health via facsimile:
During radiography operations on the night of 5 Aug 2013, two employees, a radiographer and an assistant radiographer of Coder Welding & X-ray Service were finishing an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> shift (which is 2nd shift for Alstom), when the source and crank assembly would not operate correctly. At that time, they could only determine that the source had not fully retracted into the camera correctly. After several additional attempts, they concluded a malfunction of unknown causes prevented the source from retracting to a full and locked condition. Following Coder Operating and Emergency protocol, the first action was to secure and maintain a 2mr/hr boundary. A complete survey of the area determined that the original roped and placarded boundaries were still correct and valid. Next the RSO was contacted as well as the assistant RSO. The RSO advised the radiographer to secure and maintain the 2mr/hr boundary and asked if any personnel or workers had been exposed to radiation levels in excess of those in Kansas Radiation Protection Regulations, Part 4 and following, and they stated no. They were advised that the RSO would be on site in 90 minutes to oversee the incident and resolve the situation. While waiting for the RSO to arrive, the two Coder employees decided to extend the roped boundaries an additional 75 feet in addition to the existing roped area and inform Alstom management of the situation. Since this was the end of 2nd shift for Alstom workers, and no Alstom workers were in the area at the time, there was no disruption of production or evacuation needed. Any Alstom employees on site were advised not to enter plant area as a precaution. At no time were Coder or Alstom employees at risk or in danger of overexposure. The RSO arrived on site at approximately 12:15 p.m. and made a radiation survey of the area and boundaries. The RSO found correct actions had been taken and 2mr/hr boundaries were maintained. In fact, 1mr/hr was the highest reading. The RSO then walked up to the crank-out reel and found the radiation level to be 5mr/hr. He concluded that the source was in fact in the tungsten collimator (4.3 hvl [half value integers]) secured on the pipe weld where it was during earlier radiographic operations. Several attempts to return the source to its shielded and locked condition failed, so plans were made to allow for closer inspection of the cables and source tube. At this point, the assistant RSO was contacted and advised to bring additional drive cables and source tube in the event they could be needed. While the radiographer and assistant radiographer maintained security over the boundaries and source, the RSO and several Alstom management, who had arrived on site, went outside to look for suitable shielding that could be brought in. Two one inch plates were chosen for use. The plates were tack welded together and moved to an area where overhead cranes could be used to move into position. This was accomplished by using the remote controls of the crane system so no person would have to be in a high radiation environment. With help from Alstom personnel, the steel plates were directed into place by the RSO next to the source camera, providing additional shielding. It was then possible for the RSO to walk up to the source camera with a survey level of 32mr/hr. It was then possible to inspect the drive cables and look at the source tube for possible causes of the return failure. A small depression was noted some 6 to 7 feet from the camera and cable attachment. Using a hacksaw, pliers, and other tools, the outer cable shielding was removed and the RSO returned to the cable crank, and was able to retract the source into the camera in the full and locked position. During the entire operation the RSO received a whole body dose of 35 mr. Due to the time and distance for the RSO, late arrival of the assistant RSO arrival on site, and the caution taken to resolve the situation, some 3-1/2 hours elapsed from the start to the end. The help and materials provided by Alstom management aided in the safe and satisfactory conclusion of this incident. At this time, it is unknown what might have caused the depression in drive cables or why it suddenly caused a failure to retract situation. Kansas Report Number: KS130006 |
| Where | |
|---|---|
| Coder X-Ray Service Mcpherson, Kansas (NRC Region 4) | |
| License number: | 21-B165-01 |
| Organization: | Kansas Dept Of Health & Environment |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+730.12 h30.422 days <br />4.346 weeks <br />1 months <br />) | |
| Opened: | James Harris 15:07 Sep 4, 2013 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Sep 4, 2013 |
| 49320 - NRC Website | |
Coder X-Ray Service with Agreement State | |
WEEKMONTHYEARENS 493202013-08-05T05:00:0005 August 2013 05:00:00
[Table view]Agreement State Agreement State Report - Failure of Radiography Source to Retract ENS 461702010-02-13T05:00:00013 February 2010 05:00:00 Agreement State Agreement State Report - Break-In at Radiography Source Storage Location 2013-08-05T05:00:00 | |