A radiation alert has been sparked across parts of Western Australia, following Rio Tinto losing a tiny radioactive capsule in the Australian Outback, for which the company officially apologises for.
The radioactive capsule – believed to have fallen from a truck – was part of a gauge used to measure the density of iron ore feed which had been entrusted to a specialist contractor to transport. The loss may have occurred up to two weeks ago.
Authorities are now grappling with the daunting task of searching along the truck’s 1,400 kilometre (870 mile) journey – a distance longer than the length of Great Britain – from north of Newman to a storage facility in the northeast suburbs of Perth.
Head of the Nuclear Physics and Accelerator Applications department at the Australian National University, Andrew Stuchbery, said, the task, while akin to finding the proverbial needle in a haystack, is “not impossible” as searchers are equipped with radiation detectors.
“That’s like if you dangled a magnet over a haystack, it’s going to give you more of a chance,” Mr Stuchbery said.
“If the source just happened to be lying in the middle of the road you might get lucky…It’s quite radioactive so if you get close to it, it will stick out.”
The gauge was picked up from Rio’s Gudai-Darri mine site on 12 January. When it was unpacked for inspection on 25 January, the gauge was found broken apart, with one of four mounting bolts missing and screws from the gauge also gone.
Authorities suspect vibrations from the truck caused the screws and the bolt to come loose, and the radioactive capsule from the gauge fell out of the package and then out of a gap in the truck.
Chief of Rio’s iron ore division, Simon Trott, said, “We are taking this incident very seriously. We recognise this is clearly very concerning and are sorry for the alarm it has caused in the Western Australian community.”
The silver capsule, 6mm in diameter and 8mm long, contains Caesium-137 which emits radiation equal to ten x-rays per hour.
Authorities have recommended people stay at least five metres away as exposure could cause radiation burns or radiation sickness, though they add that the risk to the general community is relatively low.
“From what I have read, if you drive past it, the risk is equivalent to an x-ray. But if you stand next to it or you handle it, it could be very dangerous,” Mr Stuchbery said.
The state’s emergency services department has established a hazard management team and has brought in specialised equipment that includes portable radiation survey meters to detect radiation levels across a 20m radius and which can be used from moving vehicles.
Mr Trott said Rio Tinto had engaged a third-party contractor, with appropriate expertise and certification, to safely package and transport the gauge.
“We have completed radiological surveys of all areas on site where the device had been, and surveyed roads within the mine site as well as the access road leading away from the Gudai-Darri mine site,” Mr Trott said, adding that Rio Tinto was also conducting its own investigation into how the loss occurred.
Analysts said that the transport of dangerous goods to and from mine sites was routine, adding that such incidents have been extremely rare and did not reflect poor safety standards on Rio Tinto’s part.
The incident is another headache for the mining giant following its 2020 destruction of two ancient and sacred rock shelters in the Pilbara region of Western Australia for an iron ore mine.
