Radioactive capsule found in Pilbara after week-long search

Emergency services have found a tiny radioactive capsule near Newman in Western Australia’s Pilbara region, ending a large-scale interagency search for the missing object that had been widely described as a needle in a haystack.

The stainless steel capsule contains a small quantity of radioactive Caesium-137, and forms part of a level sensor (gauge) that is used in some fixed plant assets. The gauge was being used at Rio Tinto’s Gudai-Darri mine site to measure iron ore feed in the crushing circuit of the fixed plant, before being collected by a transport contractor from the site on 12 January. While the truck supposedly bearing the capsule arrived in Perth on 16 January, the device was only discovered missing on 25 January, when the container was unpacked for inspection.

The week-long search for the missing object, led by the WA Department of Fire and Emergency Services, spanned 1400 km from the Pilbara to metropolitan Perth. The capsule was ultimately discovered yesterday two metres off the northbound roadside edge of Great Northern Highway, a couple of hundred kilometres south of where its journey began, by a vehicle search crew which was driving past at 70 km/h with specialised radiation equipment.

Fire and Emergency Services Commissioner Darren Klemm AFSM commended the extraordinary 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 km 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.”

The capsule has now been safely recovered and was securely transported in a lead container to Newman for secure storage overnight, while a 20-metre ‘hot zone’ has been set up around the recovery location to ensure the public’s safety. The object will be taken to a WA Health facility in Perth today, where it will be examined.

“In the extremely unlikely situation that the capsule leaked, we will remediate the area,” Klemm said.

Rio Tinto said in a statement that it would like to thank the specialist search crews from the Australian Defence Force, the Australian Radiation Protection and Nuclear Safety Agency and the Australian Nuclear Science and Technology Organisation, as well as all other support agencies, for their crucial role in the search and recovery efforts.

“We are incredibly grateful for the hard work of everyone involved in finding the missing capsule,” said Rio Tinto Iron Ore Chief Executive Simon Trott.

“We are taking this incident very seriously and are undertaking a full and thorough investigation into how it happened.

“This sort of incident is extremely rare in our industry, which is why we need to investigate it thoroughly and learn what we can to ensure it doesn’t happen again. As part of our investigation, we will be assessing whether our processes and protocols, including the use of specialist contractors to package and transport radioactive materials, are appropriate.”

Western Australia’s Chief Health Officer and Chair of the Radiological Council, Dr Andrew Robertson, said the chances of anyone being contaminated by the source were extremely remote.

Image credit: iStock.com/JohnCrux