Customs readies neutron cargo scanner

The scanner uses gamma-ray and neutron radiography to produce a detailed image of the cargo, which shows the material composition of items in addition to their size and shape.

"What we're trying to do is combine [x-ray] gamma-ray radiography with fast neutron radiography," said Dr Nick Cutmore, program manager at CSIRO Minerals, which developed the scanner.

"Neutrons, as they pass through the [cargo] material are sensitive to the composition of what's in that material. We try to fuse together these two lots of images to produce an image that represents both shape, density and composition in bulk cargo," said Cutmore at a conference in Sydney.

Part of government counter-terrorism measures, the scanner is more adept than existing technologies at detecting explosives and related security threats.

Imported air cargo will be loaded onto a U-shaped conveyor belt housed in a new building at the airport to pass through the scanner. If any risk reading is detected by the system operators, the cargo will be unpacked and examined. Otherwise, it will move onto the container terminal operator.

The construction phase of the project is almost complete, according to Roxanne Kelley, national manager of research and development, border compliance and enforcement for Customs.

The following pilot phase will then begin "early next year", she said, and run for up to 18 months.

"The purpose of the trial is to see how the scanner performs in a real-time environment… Hopefully by early new year we will be processing as much cargo as we can through the scanner," she said.

A scan of a container takes one to two minutes. As the pilot progresses, more containers will be scanned with the system and export cargo will be added later.

However, assessing the threat posed by air cargo is not as simple as just scanning it, according to Cutmore: "This scan and the scanner is not the solution… You can't just do a scan and have a computer run over it and say 'that air cargo's good, this air cargo is bad'; it's not that easy. Air cargo is extraordinarily complicated."

"So what we're doing is combining the scan with a whole lot of other operator tools and manifest information which is part of the way Customs operates," he said.

Two staff will operate the system, an operator and image analyst. The image analyst will make risk assessments of cargo based on image interpretation and other Customs information.

An "extensive" staff training package will be rolled out for the system, Kelley said.

"We know that the user of this technology is the most critical link in the chain. So it's how people analyse images and how good they are at detecting anomalies that is the most critical part of this," she said.

Once operational, a total of 34 Customs staff will work at the air cargo section of the airport, on a shift basis, between 5am and 11pm, seven days per week.

Kelley said the catalyst for the scanner dated back to 2001, when Customs approached CSIRO to make scanning more efficient: "We have lots of our regional staff at cargo terminal operators and depots and they're physically unpacking cargo and putting it through x-ray machines. So part of our thinking was, is there a technology solution where we can inspect air cargo, but it's just as effective for us?"

The federal government has since mandated Customs to inspect 70 percent of air cargo consignments that come into Australia.

As part of aviation security initiatives in the 2003/2004 federal budget, Customs received AU$8.4 million to trial CSIRO's neutron scanning technology.

A government steering committee is meeting monthly to discuss the progress of the project. It will decide whether to roll out the scanner around the country once the pilot is complete.