After days of searching, experts have recovered the tiny radioactive capsule that fell from a transport truck in western Australia. Response teams from Australia’s Radioactive Conservation and Nuclear Safety Authority (ARPANSA) and the Fire Service discovered the highly dangerous capsule south of the outback mining town of Newman. reported the broadcaster ABC on Wednesday, citing the Western Australian state government.
“I would like to stress that this is an exceptional result,” said the regional minister for emergency services, Stephen Dawson. “The search parties literally found a needle in a haystack.”
The mini-casing containing the highly radioactive cesium-137 fell from a truck while being transported 1400 kilometers between the Rio Tinto mines in the Pilbara region in the north and the metropolis of Perth. The incident occurred sometime after January 12th. It was not noticed until January 25, when the truck was unloaded, that the containment was empty and the capsule was missing.
The illustration shows a small, round, silver capsule containing radioactive caesium-137, the size of a coin.
(Photo: -/dpa)
At times it was feared it might have become lodged in the profile of a passing vehicle on the Great Northern Highway or ground under tires. The route is heavily used by Australian Road Trains – huge trucks with multiple trailers and up to 100 meters in length.
However, according to fire department spokesman Darren Klemm, the capsule was found two meters from the road. Using vehicle-mounted search devices, specialists drove the Great Northern Highway in both directions. The detectors can identify the capsule from a distance of up to 10 or 15 meters. A 200 meter security zone was established around the site. The capsule has been secured in a lead container and is scheduled to be stored overnight in a secure location in Newman. On Thursday, she will be transported to a facility run by the Ministry of Health, where she will be examined for any damage.
The 8 x 6 millimeter capsule contains radioactive cesium 137 and emits beta and gamma radiation. Such sleeves are often used for density or level measurement in systems in mining and in the oil and gas sector. According to the service provider Radiation Services SA, such radiation sources and their housings are designed in such a way that they can remain installed for 15 years without any maintenance – apart from regular checks. How long the capsule was already in use is unclear.
Cesium-137 is a radioactive metal with a half-life of 30.05 years; after about three decades, it is only emitting half of its initial activity. Based on its original radioactivity, the missing capsule emitted 1.665 millisieverts per hour at a distance of one meter.
Photo of the cesium capsule at its roadside location.
(Photo: HANDOUT/AFP)
In Germany, the Federal Office for Radiation Protection estimates the total natural radiation exposure or effective dose of an individual at an average of 2.1 millisieverts per year, which can vary between 1 and 10 millisieverts depending on where you live, your diet and lifestyle. Accordingly, a human remaining one meter from the missing capsule for an hour would be exposed to radiation levels of about 80 percent of natural annual radiation.
The health authority warned the Australian population to keep a distance of at least five meters if the capsule was found or even suspicious objects and not to pick it up under any circumstances. A spokesman for the health authority warned that touching the capsule could cause skin burns and serious damage to health.
Did the capsule fall through a hole in the shipping container?
Meanwhile, the mysterious loss of the capsule brings the lack of consequences for violating safety regulations in mining into the public debate. Under federal regulations, the maximum penalty for failure to safely store, package and transport radioactive material is AUD 1,000. Prime Minister Anthony Albanese called the current fine ridiculous. At least the disappearance of the capsule is not considered suspicious. The authorities ruled out that it could be used as a weapon.
The British-Australian mining giant Rio Tinto had apologized for the incident. The corporation operates the Gudai Darri mine, from where the capsule was transported. Rio Tinto says it hired a third party with the expertise and certification to securely package the capsule, which is smaller than a dime. “It baffles me how something like that could fall from the back of a truck,” Secretary Dawson said earlier. Investigations into the process are ongoing.
It is believed that vibrations caused a bolt in the container to loosen during travel and the mini-case fell through the bolt hole. It is considered unlikely that there will be legal proceedings. The government of Western Australia is currently trying to clarify how the expensive and time-consuming search should be paid for. For days, the authorities had repeatedly asked people to keep a distance of at least five meters if they discovered the silver housing. The radiation could have burned the skin and, with prolonged exposure, also caused cancer.
With material from dpa