Missing radioactive capsule found in Western Australia after massive week-long search effort

Officials have found a tiny but highly-radioactive capsule that fell off a lorry while it was on 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 when specialist equipment picked up radiation emitting from the capsule. It was then located about six feet from the side of the road.

“This is an extraordinary result ... they have quite literally found the needle in the haystack,” said the emergency services minister Stephen Dawson.

Western Australia’s state emergency services said that the capsule “no longer poses a risk to the community”.

“The radioactive substance in parts of Pilbara, Midwest Gascoyne, Goldfields-Midlands and Perth Metropolitan regions is now contained and under control as the substance has been found and secured,” the emergency services said in an alert.

The capsule contained caesium-137, which is commonly used in radiation gauges and emits dangerous amounts of radiation equivalent to receiving 10 X-rays in an hour.

It was misplaced in transit at some point on a stretch of road longer than the length of Great Britain earlier this month, prompting officials to issue a widespread radiation alert for a large part of Western Australia.

Officials said that the capsule was packaged on 10 January and dispatched to Perth for repair before leaving the site for transport by road on 12 January.

The tiny-sized capsule carried a risk of causing skin burns and prolonged exposure could cause cancer, officials said. Chief health officer Andy Robertson said the capsule did not appear to have moved and no injuries had been reported.

When the package was opened on 25 January, after it had arrived in Perth and had been kept in a secure radiation storage facility for almost 10 days, the radiation gauge was broken, with one of four mounting bolts, the capsule and all screws on the gauge missing.

The capsule was located within a day of Australia’s nuclear safety agency joining the search with specialised car-mounted and portable detection equipment. Search crews had spent six days scouring the entire length of the highway.

Authorities also dispatched radiation services specialists from the Australian Nuclear Science and Technology Organisation in the search operation on Tuesday along with detection and imaging equipment.

A government investigation has been launched into how the capsule fell off the truck and a report will be provided to the health minister.

Defence officials were verifying the identification of the capsule, which has been placed into a lead container for safety. It will be stored in a secure location in Newman before being transported to a health facility in Perth.

The mining corporation responsible for transporting the capsule, Rio Tinto, issued an apology “for the alarm” over the weekend and said it was “taking this incident very seriously”.

The chief executive of Rio Tinto Iron Ore Simon Trott 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,” Mr Trott 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.”

Prime minister Anthony Albanese said a A$1,000 (£574) 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,” Mr Albanese said.

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

Associated Press contributed to this report