Rio Tinto has lost a radioactive capsule that emits the equivalent radiation of 10 X-rays an hour after the product fell off a truck in Western Australia.
The mining giant has apologised for the alarm it has caused, and promised it was taking the incident “very seriously.”
Rio Tinto’s iron ore chief executive 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.
“We have offered our full and ongoing support to authorities in the search for the missing device. 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.”
The silver cylinder is just 8mm by 6mm – which is smaller than a penny – but it contains caesium-137, a highly radioactive isotope.
It is part of a density gauge, which was being used at Rio Tinto’s Gudai-Darri mine site in the Pilbara region of Western Australia to measure the density of iron ore feed in the crushing circuit of the fixed plant.
The cylinder fell off the back of a truck while being transported 870 miles from the mine to a depot in the Perth suburb of Malaga by a specialist contractor on 12 January.
Rio Tinto was told by the contractor that the capsule was missing nearly two weeks later on 25 January.
Authorities believe vibrations from the truck caused the density gauge’s screws to come loose, and caused the radioactive capsule to fall out of the package and then out of a gap in the vehicle.
The entire route is now expected to be searched until the missing unit is found, which is equivalent to the distance by road from John O’Groats in Scotland to Land’s End in Cornwall.
Specialist radiation detection equipment is being fitted to patrol vehicles that will cover the length of the route.
Over five days, they will travel in both directions along the Great Northern Highway at speeds of around 30mph.
A radiation alert across Western Australia remains in place, and authorities have told people to stay at least five metres away as exposure could cause radiation burns or sickness – even if the risk to the general community is relatively low.
Rio Tinto has been plagued with scandal in recent years, and was forced into a complete overhaul of its leadership team following the company’s destruction of a sacred Aboriginal cave system in 2021, which sat on top of around £75m worth of high-grade iron ore.
The cave system, in the Juukan Gorge near Pilbara, had signs of human occupation dating back more than 46,000 years – before it was blown up by the miner.
Rio Tinto subsequently commissioned an internal workplace review into its business culture.
This revealed 21 reports of actual or attempted rape in the past five years alongside widespread bullying and discrimination across its company.
Last year, the FTSE 100 company paid out a monster $16.8bn (£12.4bn) dividend to shareholders, the second biggest in the history of the FTSE 100, after it rebounded from the pandemic with record profits.