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Radiation safety deviations in industry and research

Radiation safety deviations in industry and research

An anonymised description of the radiation safety deviations is published on this page, describing the incident, the reasons for the incident, the resolution of the incident and the measures taken to prevent similar incidents. In this way, lessons can be learned from the incident and hopefully avoid similar incidents in the future. The Radiation and Nuclear Safety Authority has recently been notified of the following radiation safety deviations in the use of radiation in industry and research:

Case 1

The shield of a radiation source used in the process industry broke off and fell from a height of a few meters. There were no workstations next to the radiation source, and the shutter of the source was locked in closed position. The workers were not exposed to radiation. The supplier of the source has maintained the device and the factory has carried out a root cause analysis of the incident to ensure that nothing similar happens in the future.

Case 2

In the production facilities of an industrial radiography site, a locked tin shed was located next to the filming location. During radiography, noises began to be heard from the shed and the radiographers immediately stopped filming. Two outside workers were present in the shed and were exposed for a total of about two minutes. Both were exposed to an estimated dose of 12.25 µSv.

Case 3

A recycling metal company reported the discovery of a radiating object in a scrap lot. The radiation gate alarmed, even though the scrap batch was driven through the gate several times, so based on this, the entire load was measured with a hand-held meter. The piece was identified as depleted uranium (uranium-238) and was stored in the company's radiation source storage. No workers were exposed to radiation due to the deviation.

Case 4

When using open sources, the worker had inadvertently touched his goggles with contaminated work gloves, and contamination had thus entered the eyebrow area. The contamination was removed by rinsing. The estimated exposure time was approximately 5 to 60 minutes. The dose to a small area of skin was estimated to be 10 mSv.

Case 5

A radiopharmaceutical manufacturing site produced a drug labelled with fluorine-18. Three people participated in the production. The drug was dispensed with a dispenser into product bottles in a lead-shielded dispensing cabinet. After dispensing, the product bottles are dropped into a radiation shield in the take-out hatch on the side of the dispensing cabinet. During the drop, the sound of breaking glass was heard and the fixed dose rate meters in the production laboratory began to alarm. The cover of the radiation shield was in place, causing the falling bottle to break when it hit the cover.

Forgetting the cover was a human error. The workers received a small additional radiation exposure because of the error, calculated at 33 µSv each. As a result of the radiation safety deviation, workers were advised to take extra care whenever handling open sources.

Case 6

A recycled metal company reported a radiating object found among scrap metal, which set off alarms at several radiation gates. The entire load of scrap metal was unloaded, and a cylindrical object was identified as the radiating object by measurements with a radiation meter. The piece was identified by as depleted uranium (uranium-238) and was stored in the company's radiation source storage after the discovery. No workers were exposed to radiation because of the incident.

Case 7

Four radiation sources to be installed were in the same transport container. The installer had to handle the radiation source capsules longer than usual to be able to choose the right source to be installed, because the identification information of the sources was not clearly marked.
For the first radiation source, the attachment was not successful, the source fell back into the transport container and had to be reattached. The second source was installed without any problems, but the third one was again difficult to install. The last source was moved as planned, as the challenging points were known due to previous events. However, the installer was exposed to extra radiation due to poorly planned installation work. The effective dose resulting from the radiation safety deviation was 0.8 mSv and the equivalent dose to the hands was 5.45 mSv.

Case 8

During a cleaning day, a small piece with a radiation source label was found in a company. This source was separate from the actual measuring equipment to which it belonged. Those working on the premises did not know what it was or where it belonged.
The measuring device, which had the radiation source as an ionizer of gases, was stored years ago when an employee retired. In that situation, apparently no knowledge was passed on that such a device even existed. Nor was the measuring device found in the company's device register. The radiation source was transferred for proper disposal. No one is known to have been exposed to radiation.

Case 9

A holder of a radiation source asked STUK how they could properly dispose of the disused sealed source device. The device contained a krypton-85 source with an initial activity of 1850 MBq. STUK (Finnish radiation and nuclear safety authority) told the owner of the device that the device would have required a safety licence and instructed on how to dispose of the source.

In response to STUK's request for further clarification, the holder of the source replied that it had acquired the source in 1999. The device was decommissioned in 2011. The holder of the source was not aware of the obligation to apply for a safety license, as the seller of the equipment had never informed of this. The device was properly disposed of.