MELBOURNE – Australia’s nuclear safety agency said on Tuesday it had joined the hunt for a tiny radioactive capsule missing somewhere in the outback, sending a team with specialised car-mounted and portable detection equipment.
The Australian Radiation Protection and Nuclear Safety Agency (Arpansa) is working with the Western Australian government to locate the capsule, it said in a statement.
Arpansa added that the Australian Nuclear Science and Technology Organisation has also sent radiation services specialists, as well as detection and imaging equipment.
The authorities have now been on a week-long search for the capsule, which is believed to have fallen from a lorry that had travelled about 1,400km in Western Australia. The loss triggered a radiation alert for large parts of the vast state.
The capsule was part of a gauge used to measure the density of iron ore feed which had been entrusted by Rio Tinto to a specialist contractor to transport.
The mining company apologised on Monday for the loss.
The lorry had travelled from north of Newman – a small town in the remote Kimberley region – to a storage facility in the north-east suburbs of Perth, a distance longer than the length of Great Britain.
The search is being led by the state’s Department of Fire and Emergency Services (DFES), alongside the radiation experts.
Western Australia state emergency officials issued a fresh alert to motorists along Australia’s longest highway on Tuesday to take care when approaching the search party.
“DFES and radiation specialists are searching along Great Northern Highway by driving north and south directions at slow speeds. Take care when approaching and use caution when overtaking.”
The gauge was picked up from Rio Tinto’s Gudai-Darri mine site on Jan 12.
The package containing the device made it back to Perth on Jan 16, where it was put in a radiation-proof facility.
But when it was unpacked for inspection last Wednesday, the gauge was found broken apart, with one of four mounting bolts missing and screws from the gauge also gone.
The authorities suspect vibrations from the lorry 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 lorry.
The silver capsule, 6mm in diameter and 8mm long, contains Caesium-137, which emits radiation equal to 10 X-rays per hour.
People have been told to stay at least 5m away as exposure could cause radiation burns or radiation sickness, though experts have said driving past the capsule would be relatively low risk, akin to taking an X-ray.
REUTERS
