ENS 46326
ENS Event | |
|---|---|
18:45 Oct 10, 2010 | |
| Title | California Agreement State Report - Damage to Radiography Camera Guide Tube |
| Event Description | The following information was received from the state via email.
On October 10, 2010, at approximately 11:45 P.M., an IESCO radiography team was performing radiography operations at the Conoco Phillips Refinery in Wilmington, CA. The team was exposing a small pipe when a 6 inch pipe spool fell approximately 2 feet from a work bench to the ground where the source guide tube was lying while the source was extended during an exposure. The flange end struck the guide tube and it crimped the tube, preventing the source from being retracted after the exposure time had elapsed. The RSO was contacted at approximately 1150 and he responded to the scene. While waiting for the RSO to arrive, the radiographer sent the assistant away from the area and proceeded to adjust the boundary around the scene to where the dose rate at the boundary was 2 mr/hour (actual dose rate) or less and to maintain constant surveillance of the boundaries so that no one could enter the area where the incident had occurred. When the RSO arrived, he had both the radiographer and assistant stay out of the area of the incident and he proceeded to retrieve the source. He proceeded to straighten the guide tube and then placed 20 lb. lead shot bags on the source (the collimator had fallen off when the pipe spool struck the guide tube) to shield the source. The RSO then proceeded to cut open the source guide tube with tin snips. He then flattened the guide tube with lead sheets to expose the drive cable at the area where the guide tube was crimped to allow the source to be retracted back to the exposure device. While he was cutting the guide tube, the RSO placed his survey meter between himself and the source to monitor his exposure, along with two direct reading pocket dosimeters (DRPD) place at his chest (on had a 0-200 Mr range and the other had a 0-500 Mr range). He stated that his hands and chest were both approximately the same distance from the source during this phase of the recovery. While cutting the guide tube, the RSO periodically went to the crank to attempt to retrieve the source and then returned to cut more of the guide tube until the source was able to cranked without any resistance. After enough of the guide tube was removed to allow source to bypass the crimp, the RSO then went to retract the source. After the source had been retrieved, the exposure device was surveyed to ensure that the source was in the shielded position and then the exposure device was locked. The whole retrieval operation took approximately 30-45 minutes. The estimated dose to the RSO during this incident was 110 millirem on both DRPD's, which is equivalent to being exposed by a radiation field of 200 mR/hr for 33 minutes. The radiographer was discovered to have a DRPD that was off scale and thus was told to stay out of the area of the incident and his dosimeter was sent to Mirion Technology (formerly Global Dosimetry) for emergency processing. The radiographers assistant's dose was estimated at 10 millirem as read by his DRPD. An estimate of the radiographer's dose will need to be reported to determine if an over exposure has occurred. Since all reporting of the incident was timely and the procedures were followed for this incident and for the off-scale DRPD, there is no evidence that a violation has occurred and the licensee will not be cited at this time. Any future actions will be determined after a review of the 30 day report which will be provided by the licensee as required under 10 CFR 34.101(a). The radiography camera is a QSA Global A424-9 with Ir-192 35.6 Ci source. |
| Where | |
|---|---|
| Iesco, Inc. Wilmington, California (NRC Region 4) | |
| License number: | 6571-19 |
| Organization: | California Radiation Control Prgm |
| Reporting | |
| 10 CFR 30.50(b)(2), Licensed Material Protection Equipment Failure | |
| Time - Person (Reporting Time:+26.5 h1.104 days <br />0.158 weeks <br />0.0363 months <br />) | |
| Opened: | Steven E. Frysinger 21:15 Oct 11, 2010 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Oct 11, 2010 |
| 46326 - NRC Website | |
Iesco, Inc. with 10 CFR 30.50(b)(2) | |
WEEKMONTHYEARENS 463262010-10-10T18:45:00010 October 2010 18:45:00
[Table view]10 CFR 30.50(b)(2) California Agreement State Report - Damage to Radiography Camera Guide Tube 2010-10-10T18:45:00 | |