Missing radioactive capsule found in Australia

The object, only 8mm long, was lost in the outback on a 1,400km stretch of motorway

Crews searching for a capsule containing radioactive material in Western Australia. EPA

A radioactive capsule lost in Australia's vast outback has been found, an emergency services official said.

The 8mm-long silver radioactive capsule was part of a gauge used to measure the density of iron ore feed.

It was found after a search that lasted almost a week along a 1,400km stretch of motorway, Reuters reported.

The Australian military said the capsule would be taken to a secure centre in Perth on Thursday after it was verified, Emergency Services Minister Stephen Dawson said.

“When you consider the scope of the research area, locating this object was a monumental challenge,” Mr Dawson said. “The search groups have quite literally found the needle in the haystack.”

Officials from Western Australia's emergency response department, defence authorities and radiation specialists combed a stretch of motorway for the tiny capsule that was lost in transit more than two weeks ago.

The small silver capsule compared in size with an Australian 10 cent coin. AAP

The ore from mining company Rio Tinto's Gudai-Darri mine in Western Australia's remote Kimberley region was being taken to a centre in the suburbs of Perth — a distance longer than the length of Britain.

Officials said the capsule fell off a lorry and landed on the side of the road.

They said it was unlikely there would be contamination in the area.

The capsule, which is 6mm in diameter, contains Caesium-137, which emits radiation equal to 10 X-rays per hour.

People had been told to stay at least five metres away from the capsule if they spot it because exposure could cause radiation burns or radiation sickness, although driving past it was believed to be relatively low risk, akin to taking an X-ray.

Chief health officer Andy Robertson said the capsule did not appear to have moved and no injuries had been reported.

Rio Tinto chief executive Simon Trott apologised for the incident and expressed gratitude for the find.

“A pretty incredible recovery when you think of the distances involved, and also the remoteness of the terrain, and I think that really speaks to the tenacity of all those who were involved in the search,” he said.

“The simple fact is this device should never have been lost. We’re sorry that that has occurred and we’re sorry for the concern that that has caused within the Western Australian community.”

'Ridiculously low' maximum fine

Mr Robertson said the investigation of the mishap could lead to a prosecution.

“We have the ability to prosecute under the Radiation Safety Act and we will certainly look at such prosecutions, and we’ve done that in the past,” Mr Robertson said.

Prime Minister Anthony Albanese said a 1,000 Australian dollar ($708) fine was an inadequate maximum penalty for mishandling radioactive material.

“It shouldn’t have been lost, that’s the first thing. And second, yeah of course that figure is ridiculously low,” he said.

Mr Dawson said the state government was reviewing the penalties under the Radiation Safety Act.