ENS 44493

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v t e ENS Event
05:00 Sep 16, 2008
Title	Radiography Camera Source Failed to Return to Safe Position
Event Description	On September 12, [the] RSO for Team Industrial Svcs. called to advise that an irregularity had occurred during a routine radiography shot [deleted]. A radiography crew had been working at the Archer Daniels Midland facility in Decatur, Illinois to perform a panoramic shot within a 5 inch thick steel vessel. Following the shot, the 100 Ci Co-60 source failed to return to the safe position within the camera. The crew called their local RSO, [deleted] and requested assistance. During [the local RSO's] travel to the site, the crew secured the Fabrication Shop where the vessel was located. [The local RSO's] first actions at the site were to confirm the area was secured and the appropriate barriers were in place such that exposures to any other individuals remained below regulatory limits for members of the public. (Prior to the work beginning, the area had been evacuated and remained that way during the duration of the event). The shot was described as a 'panoramic, horizontal shot at ground level that did not require support equipment.' The lead radiographer's pocket dosimeter at the time of the notification showed a total of 50 milliR for that day's activities. Preliminary evaluation by the crew suggested the source had become disconnected in that the expected number of 'cranks' on the drive cable exceeded the number necessary to return the source to the camera from the 14 foot length guide tube with extension and there was no evident increase in radiation exposure rate as had been expected from the camera. The manufacturer of the equipment/source, QSA Global, was contacted immediately and had been asked to be on 'standby' in the event their assistance for a source recovery is necessary. Team Industrial Services is authorized to perform source retrievals and has adequate procedures/equipment for that activity for when they choose to attempt a recovery on their own. Later, [the corporate RSO] reported that [the local RSO] confirmed the source disconnect at the scene by separating the guide tube from the camera and cranking the drive cable back to the camera. Additional lead and steel shielding was brought into the area via a remote overhead crane in the Fabrication Shop to allow for more direct observation. Dose rate at the camera location was measured as 200 milliR/h unshielded. With a leaded barrier, the dose rate was brought down to 100 milliR/h at the camera. The dose rate was further reduced by extending the crank assembly an additional 15 feet away from the camera. Based on technical instruction from QSA Global's expert, source recovery was attempted by modifying the connector on a drive cable that was then attached to the crank and threaded back through the camera. Team [Industrial Services] imposed a conservative 200 milliR total dose limit for the recovery operation and 500 milliR/h dose rate limit for area occupancy during [the local RSO's] attempts. After 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of attempts to recover [the source] were unsuccessful, the maximum exposure received at that point was 60 milliR. Over twenty attempts took place however, positive connection with the source 'pigtail' could not be confirmed. A reevaluation of the arrangement suggested that the extension guide tube should be removed and the overall guide tube length be made more straight by remotely partially withdrawing the main guide tube from the vessel. Following those changes and a break, another attempt was made which was successful. The source was secured within the camera and no immediate damage to the source was evident from a field wipe test which showed background levels of radiation. The maximum recorded exposure to recovery personnel was approximately 140 milliR as measured by DRD. All associated equipment was returned to Team Industrial's permanent storage facility in Roxana, IL that same night by 23:00. Plans are to return the source with camera, drive cable and guide tubes to the manufacturer for further analysis as to a potential cause of the event. The radiography crew reported that prior to the days events, routine checks showed the equipment was in properly operating condition. They further insist that a 'misconnect' where the drive cable was not properly connected to the source did not occur in this case. The licensee has been advised that a 30 day report to the Agency is required. This item will remain open pending receipt of that report and the analysis of the manufacturer as to the state of the returned equipment. Illinois Report Number: IL080051

ENS 44493 +/-
Where
Team Industrial Services Decatur, Illinois (NRC Region 3)
License number:	IL-01136-01
Organization:	Illinois Emergency Mgmt. Agency
Reporting

Agreement State
Time - Person (Reporting Time:+10.03 h0.418 days <br />0.0597 weeks <br />0.0137 months <br />)
Opened:	Daren Perrara 15:02 Sep 16, 2008
NRC Officer:	Dan Livermore
Last Updated:	Sep 16, 2008
44493 - NRC Website
v • d • e

v t e Emergency Notification System
Team Industrial Services with Agreement State
WEEKMONTHYEAR2016-11-03T04:00:00 [Table view]
[ENS list for Team Industrial Services]

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