WA lost radioactive capsule smaller than 10c coin

A frantic search is underway for a tiny, potentially deadly radioactive capsule lost somewhere in a vast expanse of Western Australian bush.

The catch — the highly dangerous capsule is smaller than a 10c piece.

It was lost by a trader, contracted by the Rio Tinto mining company, somewhere on a 1300 kilometer road in outback WA, and has been missing for up to 21 days.

Measuring just 6mm by 8mm, the tiny capsule came loose at some point during its transport from the northern Pilbara mining town of Newman to the Perth suburb of Malaga.

Officials say it is unclear when the capsule went missing, but it could have been any time between January 10 and January 16.

As it is highly dangerous, a frantic search is underway – although authorities admit it may never be found.

How dangerous is it?

The small, round, silver capsule is used within meters in mining operations and contains a small but extremely dangerous amount of radioactive cesium-137.

It releases radiation equivalent to receiving about 10 X-rays every hour – or about the amount of natural radiation a person would normally receive in an entire year.

Close contact with the capsule is likely to cause serious illness and even death, according to WA Deputy Premier Roger Cook.

“My understanding is, if you come into close contact with the capsule, you are at risk of radiation burns, chronic illness and possibly death,” Mr Cook told reporters as he raised the alarm on Friday.

“That’s why we’re putting all these resources into trying to recover it.”

WA chief health officer Andrew Robertson, who is also the chairman of the Radiological Council, urged anyone who believes they may have come into contact with the capsule to seek medical advice.

“If you have touched the material, or been close to it for a long period of time, contact your local health practitioner or visit a hospital emergency department and tell them you think you may have been exposed to radioactive material,” said Dr Robertson.

“If you are very close to the material or touch it, the radiation risk increases tremendously and can seriously damage your health.”

Most worrying, Dr Robertson said, was that a member of the public could pick up and hold the capsule – at the risk of prolonged and extremely dangerous exposure.

With a half-life of 30 years, it could be between 100 and 300 years before the tiny device is no longer a threat.

1300km where it could have been lost

The capsule was packed onto a pallet at Rio Tinto’s Gudai-Darri mine site on 10 January, with the pallet then loaded onto the back of a semi-trailer which left the site for Perth between 11 and 14 January.

It arrived at a radiation service company in the northern suburb of Malaga on January 16, but the capsule was not noticed missing until the pallet was unpacked on Wednesday.

Public alarm was only made on Friday.

It is believed the capsule escaped its lead-lined gauge when a bolt worked itself loose somewhere along the journey – possibly shaken loose by the vibrations of the truck – and fell through a hole left by the missing bolt .

“It’s unusual for a meter to fall apart like this one did,” Dr Robertson said – but police ruled the incident an accident and said it was unlikely criminal charges would be laid.

Motorists who have covered the 1,300 kilometer route since January 10 are being urged to check their tyres, with authorities concerned that the capsule could have unknowingly stuck in them.

A Rio Tinto spokesman confirmed the missing capsule was lost by an expert handler of radioactive material, who reported it missing on Wednesday.

“We recognize this is clearly very concerning and are sorry for the alarm this has caused in the Western Australian community,” Rio Tinto’s Iron Ore chief executive Simon Trott said on Sunday.

“As well as fully supporting the relevant authorities, we have launched our own investigation to understand how the capsule was lost in transit.”

How to find a small radioactive capsule

Emergency services scoured the Tonkin Highway on the sixth day of the search, not on foot but in a convoy of five vehicles.

Darryl Ray, acting superintendent of the Department of Fire and Emergency Services, said the search party did not attempt to locate the device by sight alone.

The capsule is so radioactive and their equipment so sensitive, they hope to track it down by driving along highways and back roads at over 50 km/h.

GPS trackers were also in use to determine the capsule’s movements before it was spotted missing, Acting Superintendent Ray said.

Rio Tinto is working with the Radiological Board, the contractors and emergency services to assist the search and said it takes the capsule’s loss “very seriously”.

Dr Robertson defended the State Government’s decision to wait two days to inform the public of the capsule’s loss, saying the mine and depot should have been searched and ruled out, and the route confirmed.

Authorities also ruled out theft from the depot before the box was opened, saying it was equipped with anti-tamper tape.

Authorities have remained tight-lipped about their exact plans to recover the capsule, but admit their chances of finding it are slim – and in reality, it may never be recovered.

“There is the potential that we may not find it,” admitted Superintendent of the Department of Fire and Emergency Services, David Gill. “It is possible.”

Originally published as Lost, deadly radioactive capsule smaller than 10c coin