Australia’s Missing Radioactive Capsule Found on Highway

A tiny capsule of radioactive cesium-137 has finally been found, weeks after it fell off a truck traveling along Australia’s Great Northern Highway.

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A photo of people with radiation sensors walking alongside a fire truck on the highway.
Experts searched an 870-mile stretch of highway for the radioactive material.

Last week, the deadliest game of hide and seek in the world kicked off in Australia’s outback. The search wasn’t for one of the venomous snakes, spiders or even the enormous crocodiles that could kill you in one fell swoop. It was for a tiny radioactive capsule that fell off the back of a truck. Now, authorities in Western Australia say they’ve finally managed to track down the toxic tablet on a stretch of the Great Northern Highway.

As you might have seen, Australian mining company Rio Tinto lost a tiny radioactive capsule that it was transporting between Perth and Newman in Western Australia. The pill, which measures just 8mm (63/200 inches) long and 6mm (59/250 inches) wide, went missing between January 11th and 14th.


The capsule was part of a gauge used to measure the density of iron ore in mining applications. It is packed full of cesium-137, which emits the equivalent of someone undergoing 10 x-rays every hour.

A photo of two people looking at radiation sensing equipment in Australia.
The radioactive capsule was lost on the Great Northern Highway.

As a truck carrying the gauge was traveling along the Great Northern Highway a bolt was shaken loose by the bumps and ruts in the road. This left space for the capsule to slip out and onto the road below.

Authorities finally realized the capsule was missing on January 25th, when a mass search was launched to try and track the radioactive material down. Now, according to The Independent, the material has been found just south of the town of Newman on the Great Northern Highway. The site reports:

“Officials have found a tiny but highly-radioactive capsule which fell off the back of a lorry while it was heading along a 870-mile highway through Western Australia last month.

“The capsule – 6mm in diameter and 8mm long – was found south of the mining town of Newman on the Great Northern Highway. It was detected by a search vehicle traveling at 40 miles per hour when specialist equipment picked up radiation emitting from the capsule. It was then located about six feet from the side of the road.”


According to The Independent, it took Australia’s nuclear safety agency just a day to track down the capsule. After other search crews spent almost a week scouring the area for the capsule, the agency finally turned up with specialized car-mounted and portable detection equipment.


Authorities in Australia also sent radiation specialists from the Australian Nuclear Science and Technology Organisation into the field to aid the search. They were armed with detection and imaging equipment to help speed up the search.

Mining industry giant Rio Tinto did issue an apology following the loss of the capsule. But while it said it took the whole incident very seriously, it was quick to point out it was not, in fact, the company’s fault.