Australian nuclear agency joins hunt for lost radioactive capsule | Nuclear Energy News
People were told to stay away from the tiny capsule containing caesium-137, which emits radiation equal to 10 roentgens per hour.
The Australian Nuclear Safety Agency has joined the search for a tiny radioactive capsule that has gone missing somewhere in the outback, sending a team with specialized vehicle and portable detection equipment.
The loss of a radioactive capsule believed to have fallen from a truck driving about 1,400 km (870 miles) through Western Australia has sparked a week-long search and radiation alert across much of the state.
On Tuesday, the Australian Radiation Protection and Nuclear Safety Agency said it was working with the Western Australian government to find the capsule. The Australian Organization for Nuclear Science and Technology also sent radiation service specialists, as well as detection and imaging equipment.
The capsule, part of the sensor used to measure the density of iron ore, was entrusted by Rio Tinto Ltd to be transported to a specialized contractor. On Monday, Rio apologized for the loss, which happened somewhere in the last two weeks. The truck traveled from the north of Newman, a small town in the outlying Kimberley region, to a warehouse in the northeastern suburbs of Perth – a distance longer than the length of Britain.
Western Australia’s Chief Medical Officer Andrew Robertson said radioactive materials are routinely transported across Western Australia under strict regulations.
“It is extremely rare for a source to be lost,” he said in a statement.
On Tuesday, state emergency officials issued a new warning to motorists along Australia’s longest highway to be careful approaching capsule search teams as cars with radiation detectors travel down the highway at low speeds.
“It will take approximately five days to complete the original route, approximately 1,400 km/s, with crews traveling north and south along the Great Northern Highway,” DFES dispatcher Darryl Ray said in a statement late at night. . Monday.
The capsule was lifted from the Rio Tinto mine at Gooday Darry on 12 January. When it was unpacked for inspection on January 25, the sensor was found to be broken, with one of the four mounting bolts missing and the sensor screws missing.
Authorities suspect that vibrations from the truck caused the screws and bolts to loosen and the capsule fell out of the package and then out of a crevice in the truck.
The silver capsule, only 6 mm (0.24 inches) wide and 8 mm (0.31 inches) long, contains caesium-137, which emits radiation equal to 10 x-rays per hour. People were told to keep at least 5 meters (16.5 ft) apart, as exposure could cause radiation burns or radiation sickness, although experts said there would be a relatively low risk, akin to an X-ray, driving past the capsule.
The capsule poses no danger to bystanders who don’t linger, said Edward Obbard, senior lecturer in nuclear engineering at the University of New South Wales in Sydney.
“If you stood a meter away from him for an hour, you would receive a radiation dose of about 1 millisievert. This is about one-twentieth of the dose that people working with radiation can receive in a year,” Obbard wrote in The Conversation.
“If you were much closer to the capsule, say 10 cm or so, you would get about 100 millisieverts per hour, which could do you real damage,” he said.
According to Obbard, if the capsule does not go away, it will be a danger “for the next century or so”. The concern is that such a threat may be forgotten over time.
– Does anyone remember? obbard asked
“If you came across a tiny cylinder on the road today, you would know to keep your distance, but what if you found it five years from now or 20 years from now?”