A dangerous radioactive capsule containing Caesium-137, measuring 8 x 6mm, has been missing since mid-January along a route approximately 1,400km long between the remote town of Newman and the suburbs north of Perth, Australia.
Mining company Rio Tinto issued an apology on December 30 and stated that they are working with state authorities to locate the radioactive capsule.
Due to the small size of the radioactive capsule and the vast search area, authorities warned that the chances of finding it are slim. There are substantial concerns that it may have been taken far beyond the search area, posing a health risk to anyone who encounters it over the next 300 years.
What Caused the Loss?
According to initial plans, the device was to be transported by truck from a mine near Newman to the suburbs north of Perth, covering a total distance of over 1,200km.
Due to the small size of the radioactive capsule, authorities warn that the chances of finding it are slim.
The truck departed from Rio Tinto’s mine on January 11 and reached a warehouse in Malaga, Perth, on January 16. However, it was not until January 25 that Australian authorities received a report from Rio Tinto indicating that the radioactive capsule was missing during an inventory check.
How Dangerous is the Radioactive Capsule?
Experts have warned that Caesium-137 can cause severe health problems for those who come into contact with it, including skin burns from close exposure, radiation sickness, and a heightened risk of fatal cancer, especially for individuals who accidentally encounter it over an extended period.
Radiation Services WA, a company that provides advice on radiation protection, stated that standing within one meter of the radioactive capsule for one hour would result in approximately 1.6 millisieverts (mSv)—equivalent to about 17 standard chest X-rays.
The company stated in a release that picking up the radioactive capsule could cause “serious harm” to fingers and surrounding tissues in the human body.
Ivan Kempson, an associate professor of physics and biology at the University of South Australia, noted that the worst-case scenario would involve a curious child picking up the capsule and putting it in their pocket.
Kempson remarked: “This is very rare but can happen and has happened before. There have been instances where people found similar items and suffered radiation poisoning, but those items were much stronger than the missing radioactive capsule.”
Why is This Incident Unusual?
The loss of the capsule has shocked experts, as they believe the handling of radioactive materials like Caesium-137 is tightly regulated with strict transport, storage, and handling protocols.
Rio Tinto stated that they frequently transport and store hazardous goods as part of their operations and hire professional contractors to handle radioactive materials. In a statement, they clarified that the radioactive capsule was part of a density gauge used at the Gudai-Darri mine to measure the density of iron ore during the crushing process.
Radiation Services WA reported that radioactive materials are transported throughout Western Australia daily without any incidents. In this case, there appears to have been a lapse in the usual control measures.
Pradip Deb, a lecturer and radiation safety officer at RMIT University in Melbourne, Australia, stated that the loss of the radioactive capsule is “very unusual” as Australia’s safety regulations require them to be transported in high-security containers.
Rio Tinto has not disclosed the name of the logistics company used to transport the equipment.
How is the Search Process Going?
Authorities are attempting to locate the radioactive capsule using specialized radiation detection equipment designed to scan vehicles moving on and off the highway at speeds of up to 50 km/h.
Authorities have warned the public not to approach the radioactive capsule if found within 5 meters, but they acknowledged that it would be difficult to see from a distance.
Authorities are attempting to locate the radioactive capsule using specialized radiation detection equipment.
However, there are concerns that the radioactive capsule may no longer be in the search area. Authorities indicated that it could have become lodged in the tire tread of a vehicle and transported far away, or even carried off by wildlife or birds.
What Happens If the Radioactive Capsule Is Not Found?
Caesium-137 has a half-life of about 30 years, meaning that after three decades, the radioactivity of the capsule will decrease by half, and it will halve again after 60 years.
“Caesium-137 is typically a sealed source, meaning that if it is not broken, it will not contaminate the soil or environment… If the radioactive capsule is never found, it will not pollute or emit radiation into the surrounding land,” Deb added.
Kempson (University of South Australia) stated that if the radioactive capsule is lost in a remote area, it is “unlikely to cause much impact.”
