recent u.s. events regarding industrial radiographic operations
TRANSCRIPT
Acuren Temporary Jobsite InspectionJune 28, 2011
Buffalo, Wyoming
Recent U.S. Events Regarding Industrial Radiographic
Operations
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Industrial Radiography Events Reported to IAEA-Information obtained from IAEA Nucleus-
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Does the United States have more radiography overexposures than any
other country?
According to the 18th World Conference on Nondestructive Testing, Radiation Safety Practices of Industrial Radiography License Holders in South Africa, April 2012, the following was discovered:
During interviews with registered radiation workers, it was found that some had exceeded statutory dose limits without the mandated investigations, reports, and corrective actions.
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Out of the 14 events reported to IAEA that occurred in the United States from 2011-2014:
INES Rating 1 : 1 event
INES Rating 2 : 12 events
INES Rating 3 : 1 event
EVENT 1
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Radiographer trainee removed guide tube after an exposure and saw the iridium source protruding two inches out of the exposure device. He tried to push the source back into the device with his index finger, and then went to the crank assembly and fully retracted the source.
September 12, 2011: Port Lavaca, Texas
INES Rating : 3
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Seven days later he went to the hospital for painful blistering to his thumb and index finger. Estimated extremity exposure was over 38 Sv; whole body dosimeter was processed and revealed 14.1mSv.
September 12, 2011: Port Lavaca, Texas (cont’d)
INES Rating : 3
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2 Months After Overexposure
1 Month After Overexposure
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3 Months After Overexposure
Amputation Required 21 Months Later
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September 12, 2011: Port Lavaca, Texas
The cause of this event was determined to be human error
The radiographer trainer and assistant’s stories conflicted
The radiographer’s “trainer” status was revoked by the regulatory authority
All other radiographers in the company received additional training
QUESTIONS ON EVENT 1 ?
EVENT 2
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MARCH 12, 2014: LA PORTE, TEXAS
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A radiographer and two assistant radiographers (trainees) were shooting in a large tank; the two assistants were inside of the tank performing radiography while the radiographer was outside of the tank placing film. When one of the assistants tried to remove the guide tube, he realized the source was still inside of it.
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MARCH 12, 2014: LA PORTE, TEXAS The trainees had not retracted the source when they thought they did.
Trainee A was not wearing any dosimetry at all.
Trainee B was wearing dosimetry, but failed to turn on his alarming rate meter.
MARCH 12, 2014: LA PORTE, TEXAS
Trainee A received a TEDE of 120 mSv, and 150 mSv to his handTrainee B received a TEDE of 33 mSv
Causes of the event were:• Survey meter not used after each exposure• Alarming rate meters not used or inoperable• No direct supervision of trainees by the
radiographer• Improper connection of drive cable to source
assembly
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QUESTIONS ON EVENT 2 ?
EVENT 3
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MARCH 24, 2012: PASADENA, TEXAS
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Radiographers were working at a refinery, performing radiography using scaffolding. When the radiographer completed the first shot, he disconnected the guide tube from the camera, wrapped the guide tube around his neck, and climbed back down the scaffolding.
MARCH 24, 2012: PASADENA, TEXAS
When he reached the bottom, he noticed that the exposure device locking mechanism was still unlocked. He removed the guide tube from around his neck and performed a radiation survey and found that the source was still in the guide tube.
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MARCH 24, 2012: PASADENA, TEXAS
The source had become disconnected during the first exposure
The final assigned dose to the radiographer was 290 mSv
It was determined that the drive cable broke just behind the connection to the source assembly, due to corrosion
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Causes of the event included:
• Failure to perform daily equipment checks
• Failure to maintain radiography equipment in good working order (lubrication, cleaning)
• Failure to perform radiation surveys
• Failure to ensure exposure device was locked prior to disassembly
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QUESTIONS ON EVENT 3 ?
In all of these events, it is believed that a poor safety culture was partially to blame
From the IAEA’s Nuclear Safety Review 2013:
• Periodic, independent safety culture assessments are of key importance to maintain a strong defense in depth strategy
• Although this statement was used with regards to nuclear power plants, the same holds true to regulators of the industrial radiography profession
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IN SUMMARYThe United States continues to have the highest number of reported radiation overexposures for industrial radiographers
WHY? More industrial radiography is performed in the U.S.? Events are not reported to authorities in other countries? Reporting requirements are different? Training requirements in the U.S. are different?
What are your thoughts?
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