How do you lose a radioactive capsule? Australian investigators are wondering too
Brisbane riverside city, is the capital of Queensland, eastern Australia
The discovery of a lost small radioactive capsule beside a remote highway in the West Australia raises many questions – especially how it escapes the layers of radiation-resistant packaging piled up on a moving truck.
It’s one of many confusing aspects of the case that investigators will examine in the coming weeks as they try to piece together a timeline of the capsule’s movement from January 12, when it was packed to shipping, until February 1, when the recovery team found it. side street.
The capsule – just 8 mm x 6 mm – is used in a pipeline-mounted hydrometer at Rio Tinto’s Gudai-Darri iron ore mine to measure material flow through the feeder.
Rio Tinto said in a statement on Monday that the capsule was packed for shipment to Perth, 1,400 kilometers (870 miles) away, with its presence inside the package confirmed by a Geiger counter. before it is shipped by a third party contractor.
Normally, the trip would take more than 12 hours by road, but about two hours later, the capsule leaves the vehicle as it heads south and somehow crosses a lane, to finish two meters (6 .5 feet) from the north side of the two-lane highway.
Lauren Steen, general manager of Radiation Services WA, a consulting firm that writes radiation management plans, said industry insiders were as confused as the public when they heard the capsule was lost.
“The whole team is scratching their heads. We can’t understand what happened,” said Steen, whose company was not involved in its disappearance.
“If the source has been placed in a certified package and shipped according to all code of practice requirements, that is an extremely unlikely event – one in a million,” she said. speak.
The lorry believed to be carrying the capsule arrived in Perth on January 16, four days after leaving the Gudai-Darri iron ore mine. But it was not until January 25, when the workers of SGS Australia came to carry the meter to check, they discovered it was missing.
In a statement, SGS Australia said it had been hired by Rio Tinto to pack the capsule but had nothing to do with its transportation, which was carried out by a “shipping specialist”.
“We have performed contracted service to pack equipment at the mining site and unpack equipment after shipment by qualified personnel to our customers in accordance with all standards and regulations. determined,” it said.
“Shipping of packages, organized by our client and authorized by a professional carrier, is not within the scope of SGS service. Our staff noticed a power outage at our Perth lab upon unpacking and reported the incident immediately.”
The name of the company that contracted the shipment of the package has not been disclosed.
The lost capsule triggered a six-day search along a stretch of Great Northern Avenue. Then on Wednesday morning, a car equipped with special equipment traveling south of the small town of Newman detected higher levels of radiation. Hand-held devices are then used to detect the capsule in the dirt.
In Australia, each state has its own laws relating to the handling of radioactive materials and codes of practice that follow guidelines set forth by the Australian Radiation and Nuclear Safety Authority (ARPANSA), a closely working government agency. closely with the International Atomic Energy Agency (IAEA). ) and the World Health Organization (WHO).
In Western Australia, the rules are governed by the Radiation Safety Act 1975, which Steen says is long overdue for review. “It hasn’t been rewritten since the ’70s, so I think that genre speaks for itself,” she said.
Over the decades, technological advances have made it much safer to use radiation sources in mining equipment, Steen says — and because of the safety, the devices are used more often. As of 2021, more than 150 active projects in Western Australiathe country’s mining export hub, according to the state’s Department of Minerals and Energy.
Under the Radiation Safety Act of 1975, only specially trained and licensed operators can pack radioactive materials, but other rules apply to contractors hired to transport it, Steen said.
“Any transport company can transport radioactive material as long as they have a license to do so,” she said.
Under that act, a license can be granted by taking a one-day course and passing an exam that is certified and approved by the governing body.
The licensee must supervise the transportation plan submitted to the regulator but not directly supervise the journey. There is no rule on the type of vehicle used for transportation.
Steen says there’s clearly been an incident – and she hopes the results of the investigation will be shared with the radiation community so they can avoid such problems in the future.
Discussion has begun about the need for tougher penalties – in Western Australia, mishandling of radioactive material is fined only AU$1,000 ($714) – a figure described by Australian Prime Minister Anthony Albanese was “ridiculously low” to reporters on Wednesday.
The rules around the encapsulation of radiation sources depend on the amount of radiation they emit. In some cases, the device may be encased in three layers. In the case of the capsule, the gauge can be thought of as a layer of protection before it is placed into an “overpack,” a container that is likely to be secured with a latch.
In a statement, DFES said that when the package was opened, the gauge was damaged, missing one of the four mounting pins. Referring to the capsule, the statement added, “the source itself and all screws on the gauge are also missing.”
One theory that investigators could test is whether the gauge broke and the capsule fell out of the packaging through a hole used to secure the cap.
It is expected to take several weeks before the Radiological Council submits its report to the Western Australian health minister. Meanwhile, Rio Tinto is conducting its own investigation.
Chief executive Simon Trott said the company would be willing to reimburse the government for costs associated with the search – if required.
WA Emergency Services Secretary Stephen Dawson said the offer was appreciated but the government would await the results of the investigation to allocate responsibility.
He said he did not know how much the search would cost but that at least 100 people were involved including police, firefighters, the health department and defense force personnel.
Staff from the National Emergency Management Agency, the Australian Nuclear and Scientific Technology Organization and the Australian Radiation Protection and Nuclear Safety Authority also participated.
On Thursday, DFES officials were relieved to release new images of the capsule being taken to Perth, where it will be kept securely in a facility.
This time, it moved in a closed white convoy – with large stickers warning of the presence of radioactive material.