by Authorities in Western Australia were searching for a small but potentially deadly radioactive capsule that went missing while being transported on a truck from a mine to a depot in the city of Perth, officials said Saturday.
Emergency services said they were hampered by a lack of equipment and have called on the Commonwealth and other states to provide assistance.
The Department of Fire and Emergency Services has deployed teams with handheld radiation detection devices and metal detectors along 36 kilometers (22 miles) of a busy freight route to look for the 8 millimeters by 6 millimeters (0.31 in by 0.24 in) device.
It is believed to have fallen off the back of a lorry on a 1,400-kilometre (870-mile) journey from the Rio Tinto mine in Newman to the Perth suburb of Malaga.
“What we’re not doing is trying to find a tiny little unit by sight,” Superintendent Darryl Ray said, adding they were concentrating on populated areas north of Perth and strategic locations along the Great Northern Highway.
“We use the radiation detectors to locate the gamma rays,” he said.
Authorities also used the truck’s GPS data to determine the exact route the driver took and where it stopped after it left the mine on or around January 10.
There are concerns that the solid capsule may already be lodged in another vehicle’s tire and potentially be hundreds of miles away from the search area.
It is believed that a screw came loose inside a large lead-lined meter and the unit fell through a hole.
Rio Tinto said it contracted an expert who processes radioactive material to package the capsule and transport it “safely” to the repository and was not told it was missing until Wednesday.
Health chief Andrew Robertson defended the Western Australia government’s decision to wait two days to inform the public on Friday, saying the mine and depot needed to be searched and excluded, and the route confirmed.
He said the capsule was packed in accordance with radiation safety transport and regulations inside a box bolted to a pallet.
“We think the vibration of the truck may have affected the integrity of the meter, that it fell apart and the source actually came out of it,” he said. “It’s unusual for a gauge to come apart like this one has.”
An investigation will look at the handling of the gauge and capsule at the mine site, the transport route used and the procedures at the Perth depot after it arrived on January 16.
The police have determined that the incident was an accident, and it is unlikely that there are any criminal charges.
The authorities ruled out theft at the depot before the box was opened on Wednesday.
The small silver cylinder is a 19-becquerel cesium 137 ceramic source commonly used in radiation meters.
Robertson has previously said that the device emits the equivalent of 10 X-rays in an hour, and that the public should stay at least 5 meters (16 feet) away. Contact can lead to skin damage, burns and radiation sickness, including effects on the immune system and the gastrointestinal system.
Prolonged exposure can also cause cancer, but experts say the capsule cannot be used as a weapon.
“Our concern is that someone will pick it up, not knowing what it is, think this is something interesting (and) keep it,” Robertson said.
