Search ends for lost radioactive capsule

A tiny radioactive capsule that went missing from a secure device on a truck — sparking safety fears — has now been found near Newman, WA.

The truck was travelling from a Rio Tinto mine site in the Pilbara region, to Perth, and there was concern that the missing capsule presented a threat to both humans and the environment. The incident has also posed questions about whether the correct safety procedures were followed ahead of the transportation process.

An investigation into the incident has been launched by Western Australia's Chief Health Officer, Andy Robertson. If the Radiation Safety Regulations Act is found to have been breached, prosecutions may take place — with the maximum penalty for failing to safely store or transport radioactive material being $1000.

“The loss of any radioactive material is a cause for concern. In this case, it was an industrial test source of radioactive Cesium-137. This has a moderate physical half-life (about 30 years) meaning that the source will remain radioactive and can be detected above natural background radiation levels in the environment for about 300 years. It emits beta and gamma radiation and has been used in the past for radiotherapy treatment,” said Dale Bailey, a Professor of Medical Imaging Science at the University of Sydney and Royal North Shore Hospital, Sydney.

“Events like this are uncommon because of the stringent international standards of transport container requirements and planning approvals required for moving radioactive material around.”

The recovery operation, led by the Department of Fire and Emergency Services, spanned 1400 kilometres from the outback to metropolitan Perth and yielded success in just seven days.

The tiny capsule — 8 millimetres high by 6 millimetres round — was located two metres off the northbound roadside edge of Great Northern Highway.

It was discovered by a vehicle search crew which was using specialised radiation equipment.

The capsule has been safely recovered and was securely transported in a lead container to Newman for secure storage, before being taken to a WA Health facility in Perth.

Fire and Emergency Services Commissioner Darren Klemm AFSM commended the efforts of all agencies and personnel involved in the operation.

“We have essentially found the needle in the haystack,” he said.

“When you consider the challenge of finding an object smaller than a 10 cent coin along a 1400-kilometre stretch of Great Northern Highway, it is a tremendous result.

“I want to thank everyone involved in the search — we called on a large number of agencies to assist and this was a great example of working together to achieve an outstanding result.”

Rio Tinto has apologised over the loss of the capsule.

Image caption: The radioactive capsule that went missing in WA.