An 8mm by 6mm silver capsule, no larger than a coin, is said to be lost along a section of huge desert roadway in Australia’s largest state. Finding it is like looking for a needle in a haystack.
Rio Tinto, a mining corporation, apologized and said it was helping the state government’s search for the capsule, which contains Caesium-137, a highly radioactive material used in mining machinery.
The device was discovered in the isolated Gudai-Darri mine site in northern Western Australia, where it remained until it was picked up by a contractor to be transported south to the state capital, Perth. Rio Tinto said it had inspected all routes leading to and leaving the area.
The capsule, which emits both beta and gamma rays, is thought to have fallen off the back of a truck traveling over a 1,400 km (870 mi) stretch of the Great Northern Highway, a distance longer than the California shoreline.
Authorities caution that the chances of discovering the capsule are minimal because of its small size and the great distances involved.
Furthermore, there are worries that it may have already strayed outside the search area, posing a risk to the health of everyone who comes into contact with it for up to 300 years.
ADVERTISEMENT
Ad Suggestions
The size of the capsule in relation to a coin is depicted in this illustration by the Department of Health in Western Australia.
The size of the capsule in relation to a coin is depicted in this illustration by the Department of Health in Western Australia.
the Health Department of Western Australia
How did it disappear?
On Friday, state officials issued an alert, warning citizens that there was a radioactive spill in a southern portion of the state, including in Perth, the state’s capital and home to about 2 million people.
The capsule, according to the authorities, was placed inside a parcel on January 10 and picked up by a contractor from Rio Tinto’s Gudai-Darri mine site on January 12.
The car traveled for four days and arrived in Perth on January 16; however, it wasn’t until January 25 when it was being unloaded for examination that its whereabouts were found.
According to the Department of Fire and Emergency Services, “the gauge was torn apart upon opening the shipment with one of the four mounting bolts missing, the source itself, and all screws on the gauge also gone” (DFES).
They think that the package was harmed by strong vibrations from the rough roads, which may have caused a mounting bolt to hold it in place to fall out.
OpenStreetMap and Mapbox Enhance this map
Newman \sPerth
Just how risky is it?
Caesium-137 can cause major health issues for people who come into touch with it, including skin burns from near exposure, radiation illness, and potentially fatal cancer risks, particularly for those exposed inadvertently for extended periods of time.
Standing one meter away from the capsule for an hour would expose you to about 1.6 millisieverts (mSv), which is about the same amount of radiation as 17 regular chest X-rays, according to Radiation Services WA, a business that offers radiation protection advice.
The company stated in a statement that picking up the capsule would result in “severe harm” to your fingers and surrounding tissue.
The worst-case scenario, according to Ivan Kempson, an associate professor of biophysics at the University of Southern Australia, is that a curious toddler picks up the capsule and puts it in their pocket.
This is unusual, but it has happened previously, according to Kempson. “There have been cases in the past where people have discovered similar things and contracted radiation poisoning, but those cases included far stronger capsules than the one that is currently missing.”
“We are all constantly exposed to radiation via the environment and the foods we consume, but for now the main worry is the possible health effects on the individual who finds the capsule.”
Authorities from the state of Western Australia are looking for the capsule along a section of the Great Northern Highway.
Authorities from the state of Western Australia are looking for the capsule along a section of the Great Northern Highway.
Fire and Emergency Services Department/AP
How infrequently does one lose a radioactive object?
The incident surprised specialists because there are tight regulations for the transit, storage, and disposal of radioactive materials like Caesium-137, which are heavily regulated.
Rio Tinto said that as part of its operations, it frequently transports and warehouses hazardous goods and engages specialized subcontractors to manage radioactive materials. According to a statement, the tiny capsule was a component of a density gauge used at the Gudai-Darri mining site to monitor the density of iron ore feed utilized in the crushing circuit.
According to Radiation Services WA, radioactive materials are routinely moved throughout Western Australia without any problems. It said that the loss of the capsule had nothing to do with the apparent failure of the standard control methods that were used in this situation.
The loss of the capsule was “quite exceptional,” according to Pradip Deb, a lecturer and radiation safety officer at RMIT University in Melbourne, because Australian safety regulations call for them to be transported in extremely protective cases.
According to Rio Tinto, the name of the logistics provider who transported the device has not been disclosed.
On June 21, 2022, a conveyor belt moves iron ore at the Rio Tinto-operated Gudai-Darri mine in Western Australia’s Pilbara.
On June 21, 2022, a conveyor belt moves iron ore at the Rio Tinto-operated Gudai-Darri mine in Western Australia’s Pilbara.
Getty Images/Carla Gottgens/Bloomberg
What is the status of the search?
Vehicles traveling slowly up and down the highway in both directions at 50 kilometers per hour are being searched by authorities using specialist radiation detecting equipment (31 miles per hour).
The original route can be traveled in about five days, according to a statement released by the DFES on Monday.
The sluggish speed was necessary, according to Dale Bailey, a professor of medical imaging science at the University of Sydney, to give the machinery time to detect the radiation.
“Radiation detectors on moving vehicles can be used to detect radiation above the natural levels, but they would have to’sweep’ the area pretty slowly due to the relatively low amount of radiation in the source,” he stated.
While conceding that it would be challenging to notice from a distance, authorities have advised the public to stay five meters away from the gadget.
We are not attempting to locate a minute, obscure device with our eyes alone. The gamma rays are being located using radiation detectors, according to DFES authorities.
However, there are concerns that it may no longer be in the search area. According to police, the capsule may have become stuck in another vehicle’s tire, which would have carried it further away, or it may have even been scattered by wild animals like birds.
According to Dave Sweeney, nuclear policy analyst and environmental advocate at the Australian Conservation Foundation, “imagine if it was a bird of prey for example that picks up the capsule and carries it away from the (original) search area – there are so many uncertainties and it will pose more problems.”
Although it is clear that this source needs to be retrieved and protected, there are a lot of potential outcomes.
What occurs if it is not discovered?
The radioactivity of the capsule will halve after three decades and then again after 60 years because caesium-137 has a half-life of around 30 years.
According to Deb from RMIT University, at that rate, the capsule might remain radioactive for the next 300 years.
“Caesium-137 is typically a sealed source, so if it isn’t broken, it won’t pollute the environment or the soil… If the capsule is never discovered, it won’t pollute the soil or spread radiation, Deb continued.
If remains are lost in a remote place, according to Kempson from the University of Southern Australia, “it will be very unlikely to have much impact.”
One of the largest mining conglomerates in the world, Rio Tinto, runs 17 iron ore operations in the Pilbara region of Western Australia. In the past, the business’s mining operations have drawn criticism. For example, in 2020, the company destroyed two historic rock shelters at Juukan Gorge, which led to an apology and the resignation of the CEO at the time, Jean-Sébastien Jacques.