Protecting Australians from radiation with an engineering PhD

Australia has no nuclear power stations. Our only nuclear reactor, Sydney’s OPAL, is a ‘neutron source’ for research and industry.

Yet Australia is the world’s fourth-largest exporter of uranium. We must be able to detect dangerous radiation for the safety of many Australian workplaces – and the environment.

Lysander Miller is integrating a radiation detector with a drone to map radioactive sources in the environment. He is an engineering PhD candidate at the University of Melbourne. He receives a graduate research scholarship through the University of Melbourne and a top-up scholarship from the Defence Science and Technology Group.

“I've always known that I want to do a PhD, but I didn't want to do a PhD just for itself,” says Lysander.

“It had to be something that I would be very interested in and had an immediate real-world application.”

Lysander’s drone will detect gamma rays and neutrons. Gamma rays and neutrons are kinds of ionising radiation – radiation with enough energy to damage human DNA.

If you get a high dose of radiation, it can cause radiation sickness. Its symptoms include vomiting, confusion and fever. And even higher doses may lead to cancer.

Using a drone to detect radiation will prevent a human operator from having to get too close to radioactive sources. And it can go where other vehicles might not be able to.

In 2023, a tiny capsule of caesium-137 went missing on a 1400 kilometre stretch of highway in Western Australia. The source was eventually discovered by a radiation detector in a car.

“But what happens if the source is not on a road? What happens if it's not easily accessible by cars? If that source was lost further off the road, the car might not have found it. That's where the drone comes in,” Lysander says.

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Solving real-world problems through an engineering PhD

Lysander has two PhD supervisors at the University of Melbourne and another at Swinburne University of Technology.

“I'm in mechanical engineering at the University of Melbourne, but my supervisor at Swinburne is in nuclear physics. That enables me to network with people from physics and get a different perspective on problems that I'm trying to solve,” Lysander says.

Lysander has spent his first PhD year ensuring his detector is sensitive enough to detect radiation, but not too big for his drone.

“The good thing about my project is there's both experiment and simulation. I have the freedom to sit at the computer or go out and do something physical,” Lysander says.

Initially the drone will be controlled by an operator. But by the end of his PhD, Lysander aims to have it operating autonomously.

“I'll have this system where an operator goes to a site, turns the drone on, which flies up and autonomously maps a region. It then produces a map of the radioactive distribution, if any, and relays the information to someone on the ground and away from the source,” he says.

His work is mostly self-driven, but Lysander’s supervisors are always available if he wants to talk through his ideas.

“They've opened my eyes to how understanding the problem itself is more important than the solution,” Lysander says.