David Hill, Nuclear Forensics Working Group Chair of the Global Initiative to Combat Nuclear Terrorism (GICNT), and Manager of Nuclear Security Sciences at the Australian Nuclear Science and Technology Organization (ANSTO), spoke to the IAEA's Sasha Henriques during the International Conference on Advances in Nuclear Forensics: Countering the Evolving Threat of Nuclear and Other Radioactive Material out of Regulatory Control (7-10 July 2014) about the challenges his country faces in maintaining its nuclear forensics expertise as time passes:
"In this constrained fiscal environment, with many competing ANSTO priorities, the most important thing for our organization at the moment is to create a strategy that allows us to maintain nuclear forensic capabilities and expertise as older, more experienced scientists like me retire, or leave the organization.
"If we don't do this, don't ensure that knowledge isn't lost, our ability to support an investigation involving radioactive material, particularly the interpretation of nuclear forensics examination results, will be lost over time."
What does interpretation mean in the context of nuclear forensics?
"During an investigation of a criminal case in which uranium ore concentrate is an item of evidence for example, we can analyse its material characteristics using mass spectrometry and other means of analysis, thereby identifying a signature of the uranium ore concentrate.
"That's the easy part.
"But if we want to identify the origin and what process has been used to produce the uranium ore concentrate, we look at the elemental and isotopic composition and the morphology - size, shape and texture - of the material. The isotopic and elemental composition provides an indication of the geologic origin of the uranium ore concentrate and the morphology of the material can indicate the production process used.
"For instance, in-situ leaching - where sulphuric acid is pumped into the ground, dissolving the uranium and then transporting it to the surface for concentration - produces a different morphology in uranium ore concentrate than ore that has been mined, pulverized, extracted, and processed on the surface.
"It's the same for other conversion and fabrication processes - the history of uranium is stored in the shape and structure of its molecules, atoms, grains and material.
"And if you've got access to the right information and experience you can understand that story, and be able to make an inference about which facility the uranium may have come from."
"This is an issue for us in Australia, with regards to training new scientists and researchers, because Australia stopped research into the enrichment and conversion of uranium in the mid-1980s. So the only knowledge our new complement of nuclear forensics practitioners will have is theoretical, which is a less than optimal substitute for hands-on experience.
So what is Australia doing to bridge this knowledge gap?
"What we're just starting to do is look at the knowledge that we have, and try and find a way that we can make it accessible to our next generation of scientists. Although there are other countries that are engaging in conversion and enrichment of uranium, these processes are highly sensitive, often classified, and foreign nationals are not likely to be allowed to work with the materials in order to gain the necessary experience. So the only option we have for passing this information on, is with visual aids collected during the years when we were engaged in these activities.
"But it's not the same as actual experience.
"We just have to hope that that's enough."