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Investigation and review begins after radioactive source is found

The radioactive capsule drama that has made headline news nationally and even internationally has finally ended. More than two weeks after the 8mm by 6mm Caesium-137 (Cs-137) radioactive capsule, or source as it is known, was lost, it was finally located on Wednesday 1 February by search teams 74km south of Newman in the Pilbara and 200km from its point of origin.

While RSWA was not involved in any part of this event, radiation safety is our business and therefore the situation has been top of mind for us. It is an enormous relief to learn it has been found and, thankfully, away from densely populated areas.

Needle in a haystack

The search was a massive endeavour, bringing together police, the Department of Fire and Emergency Services, the Australian Defence Force, the Australian Radiation Protection and Nuclear Safety Agency and Commonwealth officials.

The success in finding the capsule has been hailed by Emergency Services Minister Stephen Dawson as extraordinary. “The search groups have, quite literally, found the needle in the haystack,” he said.

The pea-sized capsule, which is part of a radiation gauge that is used to measure density or level detection in the mining and oil & gas industries, was being transported from a Rio Tinto mine site to Perth, 1,400km away.

There is nothing unusual about transporting these sources – it’s done on a daily basis across different sites. It is extremely unusual, however, for the proper control measures not to be put in place to safeguard the source. Strict controls are in place with regard to training personnel, packaging as well as safe handling and emergency response.


Understanding radiation risk

As we previously noted, the Cs-137 source in question is in a ceramic form and is double encapsulated in stainless steel to prevent it from becoming a contamination risk. The source would be encapsulated to ISO certified standards, known as “Special Form” under Transport Regulations. As such, it’s main risk is external radiation only, but, as WA’s Chief Health Officer Andy Robertson warned, because it emits both beta rays and gamma rays, close contact can result in skin damage including burns.

It was found using radiation detection equipment by a team from the Australian Radiation Protection and Nuclear Safety Agency. The fact that the capsule emits gamma radiation did give search teams one advantage – it meant looking for something that was emitting a strong gamma signal.

While all’s well that ends well, the incident has resulted in a government investigation, which will be led by the Radiological Council. At the same time, Rio Tinto is reviewing how such a serious incident could have occurred, and the company’s iron ore chief executive Simon Trott has said the company will offer to reimburse the state for the cost of the source’s recovery. It may also lead to increased fines from the current $1,000 for incorrect transportation of radioactive materials, as well as potentially requiring the responsible party to pay the cost of recovery.

We hope all measures are put in place to ensure nothing like this occurs again. Safety must be the priority when dealing with any radioactive material.


Image credit: DFES – Department of Fire and Emergency Services


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