A lost radioactive capsule found after a search along a 1,400 km stretch of the arid Western Australian outback is due to arrive in Perth on Thursday as investigators work on piecing together just how it fell from a truck.
The capsule – 6mm in diameter and 8 mm long or about the size of a tic-tac sweet – was found in the state’s remote northwest on Wednesday. The week-long search retracing the truck’s journey involved 100 people from at least five government agencies using specialised radiation detection equipment.
Verified by members of Australia’s Defence Force and sealed in a lead container, the capsule will be securely stored at an unidentified facility.
Prime Minister Anthony Albanese lauded its recovery.
“Little radioactive, tiny little thing that they were looking for like a needle in a haystack. But they found it to their great credit, though,” he told a Perth radio station.
The Caesium-137 capsule lost more than two weeks ago was found when Australian-invented CORIS360 radiation equipment mounted to a car driving the Great Northern Highway detected gamma rays 74 km south of the town Newman in the state’s Kimberley region.
Using portable detection equipment, officials said the team found the capsule at 11:13 am local time (0313 GMT) on Wednesday, about 2 metres from the side of the road in an area far from any community.
No one is thought to have been exposed to radiation and the site was not permanently contaminated, officials said.
The capsule was part of a gauge used at Rio Tinto’s (RIO.AX) Gudai-Darri iron ore mine. Authorities believe the gauge broke apart on the journey, dislodging the capsule which then fell out of its crate and from the truck, a road train with multiple trailers.
Western Australia’s Chief Health Officer Andrew Robertson launched an investigation on Wednesday and said prosecutions would be considered under state radiation safety laws dating to 1975. A report for Western Australia’s Health Minister is due in several weeks.
The maximum penalty for failing to safely handle radioactive substances is A$1,000 and A$50 per day the offence continues, though the state government on Wednesday flagged new rules to upgrade penalties.
Officials said any changes would not be retrospective.
Rio Tinto has launched its own investigation and has offered to reimburse the cost of the search. It has also said it will cooperate fully with the official investigation.
Subcontractors SGS Australia, responsible for the packageing of the gauge, and Centurion, responsible for its transportation have also said they will cooperate.