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Event Report Forms (ERFs) are filed to the IAEA. Sometimes there are multiple event reports, updating the rating, the event description. Here you only see the latest event report

ERF send date: Wed, 17-10-2012
ERF description: Update 2012 October 10: Based on the manufacturer’s evaluation, it was determined that a faulty drive cable caused the inability to return the source back to the shielded position (which resulted in exposure to the radiographer). Specifically, the cable was corroded, rusted, stiff, and had no lubrication. Also, the control pistol assembly components showed significant signs of rusting, and the control housings were taped to allow continued use. The manufacturer concluded that the drive cable failed due to a combination of wear, corrosion, and lack of lubrication indicative of improper maintenance. The radiographer stated he had performed a survey of the camera and the source guide tube prior to disconnecting the source guide tube (and the reading was 20mR/hr, as expected). However, although required, he had not checked the condition of the drive cable prior to using it although he initialed the daily work sheet indicating he had completed his daily equipment check. The licensee performed dose calculations and assigned a dose of 290 mSv (29 rem) to the radiographer. Based on the revised dose of 290 mSv (29 rem), the rating of this event was reduced from Level 3 to Level 2. NRC EN47768

Preliminary Assessment :During work activities, a licensee’s radiographer [Radiographer A] appears to have been overexposed while carrying a guide tube that contained a 2.405 TBq (65 curies) Ir-192 source. Radiographer A was conducting work activities on a platform. When he had completed the series of shots, he signaled to Radiographer B, on the deck below, to crank in the source. Radiographer A surveyed the camera and then disconnected the source guide tube and laid it on the scaffold while he lowered the camera. He then picked up the source guide tube, placed it around his neck, and climbed down the ladder to the deck below. Radiographer A laid down the source guide tube and noticed that Radiographer B was having trouble disconnecting the crank-out device from the camera. Radiographer A observed that the camera was still unlocked. He surveyed the camera and then the source guide tube. Radiographer A reported that it was then that their survey meter indicated the source was in the source guide tube and both of their personal dose rate alarms sounded. Radiographer A picked-up the guide tube using long tongs and the source fell out of the guide tube onto the deck. Preliminary estimates are that the guide tube containing the source was around the radiographer’s neck for approximately 15 seconds and his hands were on the guide tube for approximately 30 seconds. However, the exact source location inside the guide tube is presently unknown. The licensee estimated that the radiographer received a 0.56 Sv (56 rem) dose to the whole body and possibly more than 1 Sv (100 rem) dose to the extremities. The licensee’s consultant conducted the source retrieval. Ongoing actions involve an investigation, reconstruction of the event to refine the dose estimate, expedited processing of the licensee’s dosimetry, and contact with the U.S. Radiation Emergency Assistance Center/Training Site (REAC/TS) to assist with the exposure evaluation.
ERF rating date: 10-10-2012
ERF contact person: Ms. Patricia A. Milligan
ERF address: Reported by Nuclear Regulatory Commission (NRC) of United States of America on 27 Mar 2012. Last update on 17 Oct 2012
ERF affiliation: Nuclear Regulatory Commission (NRC)

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