ENS 47768
ENS Event | |
|---|---|
21:00 Mar 24, 2012 | |
| Title | Agreement State Report - Overexposure to Radiographer When Camera Source Became Disconnected |
| Event Description | The following information was received by facsimile:
On March 24, 2012, the licensee notified the Agency that it one of its radiography teams had experienced a disconnect of a 65 curie iridium-192 on a QSA Delta 880 radiography camera at a temporary work site in Pasadena, Texas. The crank out drive cable had broken and the source had completely disconnected. After an authorized individual performed the source retrieval, the licensee's RSO learned that the radiographer trainer disconnected the source tube from the camera and had carried the source tube around his neck while he climbed down the ladder of the scaffold. The source was in the tube at this time, but it is uncertain at this time the source's location within the tube. When the radiographer trainer reached the platform he removed the source tube from his neck. The licensee's initial dose estimates for the radiographer trainer are a whole body dose of at least 56 rem and an extremity limit that may exceed 100 rem. The radiographer's film badge is being sent for immediate reading. The licensee is conducting an investigation. NOTE: During the licensee's initial phone call to the Agency, the Agency understood the whole body dose estimate to be 6 rem and considered the event to be a 24-hour report (the Agency did report to the NRC HOO within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />). However, when the Agency received the written initial report this morning, March 26, 2012, it was discovered that the estimate is 56 rem, which requires immediate notification. This report is being submitted to update and upgrade the event. More information will be provided as it is obtained. The State also corrected the source strength to 65 curie Ir-192 source. REAC/TS was notified on 03/26/12 and the licensee has made contact with them. Texas Incident: I-8942
The radiographer's badge was processed on March 28, 2012. The badge reading was 812 mrem whole body (deep dose equivalent). Dose reconstruction continues as the investigation continues. More information will be provided as it is obtained." Notified R4DO (Farnholtz) and FSME (McKenney).
The following update from the State of Texas was received via email: Investigation of the event provided the following information. The radiographer stated he had performed a survey of the camera and source guide tube prior to disconnecting it. He stated he observed normal readings, including approximately 20 mr/hr at the camera. He lowered the camera and drive cable assembly down to the radiographer trainee who was working with him. After climbing down the ladder and removing the source guide tube from around his neck, the radiographer walked over to assist the trainee who was having trouble disconnecting the drive cable assembly. The radiographer stated he saw that the camera was not locked and was still in the red position. The radiographer stated he again surveyed the camera and then the source guide tube and got high readings at the end of the source guide tube. Sometime between the time the radiographer began attempting to disconnect the drive cable assembly and the time he surveyed the guide tube, both of their alarming rate meters (ARM) began alarming. They both moved back and notified the licensee's Radiation Safety Officer (RSO) of the apparent disconnect. The radiographer then used a pair of 3-foot long tongs to lift the guide tube from the collimator end. As he lifted the tube, the source fell out onto the floor. He again moved back, re-established a 2 mr/hr boundary, and waited on the RSO. The RSO arrived on-site as did an individual authorized to perform source retrieval. The source was then properly retrieved and secured. The RSO checked ARMs and the survey meter and all were working properly at that time. The camera, drive cable assembly, and source guide tube were sent to the manufacturer for evaluation. The manufacturer reported that . . . 'the cable was severed directly behind the 550 connector. The male connector passed the no go gauge but is heavily worn . . . The cable is corroded/rusted and stiff at the broken area and was dry of any lubricant grease . . . the control pistol assembly components showed significant signs of rusting and the control housings were taped to allow continued use . . . there are no indications of improper manufacture or defect in the Teleflex drive cable . . . Based on this evaluation, the drive cable failed due to a combination of wear, corrosion and lack of lubrication indicative of improper maintenance.' The radiographer stated he did not check the condition of the crank out drive cable prior to using it (as required) even though he initialed the daily work sheet indicating he had completed his daily equipment check. The survey meter and ARMs were sent to the manufacturer for evaluation. All were within the calibration date and all were operating properly. The ARMs began alarming at 400 mr/hr when they were checked. The radiographer was wearing his dosimetry badge on his right chest pocket. It was sent for immediate processing following the incident. The badge reading was 812 mrem. The licensee performed dose assessment calculations for the event and assigned an estimated dose of 29.32 rem for this event. Key issues identified: 1. Failure to perform proper survey. 2. Failure of licensee to properly inspect and maintain equipment (specifically the drive cable in this instance). 3. Failure of radiographer to perform daily equipment inspections and remove from service components in need of maintenance. 4. Failure to ensure camera is in locked position after cranking source into camera and before proceeding. Notified R4DO (Lantz) and FSME via email. |
| Where | |
|---|---|
| Non-Destructive Inspection Corporation Lake Jackson, Texas (NRC Region 4) | |
| Organization: | Texas Department Of Health |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+12.33 h0.514 days <br />0.0734 weeks <br />0.0169 months <br />) | |
| Opened: | Robert Free 09:20 Mar 25, 2012 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Sep 12, 2012 |
| 47768 - NRC Website | |
Non-Destructive Inspection Corporation with Agreement State | |
WEEKMONTHYEARENS 490412013-05-15T05:00:00015 May 2013 05:00:00
[Table view]Agreement State Texas Agreement State Report - Broken Radiography Camera Drive Cable ENS 477682012-03-24T21:00:00024 March 2012 21:00:00 Agreement State Agreement State Report - Overexposure to Radiographer When Camera Source Became Disconnected 2013-05-15T05:00:00 | |