Imagine pulling into a petrol station with two thirds of a tank of fuel. You drain your tank and throw away that fuel before filling up again, from scratch.

It sounds incredibly wasteful, but that is essentially what we're doing with the fuel inside the nuclear reactor. Right now, we're only using a small portion of the energy available in nuclear fuel before we discharge it.

And it's all because the materials that contain the fuel slowly degrade inside the reactor. And as nuclear engineers like to be very conservative when it comes to nuclear safety, the fuel is removed before the degradation can get to a point where the material fails.

But if we could slow down the degradation of the material, we could use the fuel in the reactor for longer, producing more energy for less money, and reducing the amount of waste produced.

I’m Patrick Burr, a materials scientist and an associate professor in nuclear engineering and I want to design materials that can better withstand the extreme environment of nuclear energy.

Doing so will not only allow us to get more from nuclear reactors, it will pave the way for other new, exciting technologies. In particular, it is key to achieving fusion energy, the process that powers the sun right here on Earth.

We all know that the world needs to clean up its act when it comes to energy generation. We urgently need to replace our carbon emitting fossil fuel with something that's better for the planet. And despite its controversies, nuclear fission has clear environmental and practical benefits.

Using uranium fuel in nuclear reactors emits no carbon, and the incredible energy density of uranium makes it hard to ignore. One kilogram of nuclear fuel produces the same amount of energy as burning a hundred tonnes of coal.

The results of this incredible energy density is that nuclear power needs comparatively few resources. That means less mining, less processing, less transport, less use of land and less waste. Far less, in fact, than any other technology.

And although it's radioactive, that radioactivity will ultimately decay away so that the waste stops being a waste, and slowly becomes a resource.

Wouldn't it be wonderful if the chemical spills and the plastic in the ocean also decayed away to nothing? If we can harness the most from this technology, we can replace a huge amount of dirty carbon emitting energy with clean nuclear energy.

But to do so, we need to design more resilient materials to use in the fuel and the fuel cladding. Materials that mean we no longer need to discard the fuel before it's been exhausted. This cladding is a tube made of metal called zirconium, which has the critical job of separating nuclear fuel from the surrounding coolant.

Inside the reactor it is exposed to an extreme environment, bombarded with lots of high energy neutrons from the nuclear fission, while also being surrounded by hot water, under high pressure that's flowing really fast. Now a quick materials 101 is useful here to understand what's going on inside the cladding.

Nearly all the materials that we encounter, from the metals in our cutlery to the ceramics in our plates, are made of millions of tiny little crystals. Inside each crystal, atoms are arranged in an ordered, three-dimensional lattice. But every now and then there are defects in the lattice, like a missing atom or an extra plane of atoms between normal planes.

It's actually these defects that define many of the material properties. Defects are what make metals ductile. They make semiconductors work in computer chips and solar cells, and they give colour to gemstones like sapphire and ruby.

Without defects, all materials will be as brittle as glass and have no interesting electrical properties. It's the job of material scientist to design the materials with just the right amount of defects to get the properties we need.

However, when you expose materials to the extreme conditions found inside a nuclear reactor, you end up with many more defects than you started with and those defects start to interact with one another. Some interactions may benefit the material overall, but more often these differing interactions are detrimental and they cause voids, bubbles and precipitates which make the material brittle.

If we are to create new and better materials and get more out of nuclear fuel, we need to properly understand the way the microscopic defects evolve and make nuclear materials degrade. This isn't a straightforward task.

The conventional approach is to take samples of candidate materials which have all the properties we're interested in and place them in the core of a nuclear reactor and expose them to high energy radiation. After a set amount of time, we remove them and examine them to see what kind of damage has occurred in the material and how the mechanical properties have changed.

But unsurprisingly, putting anything inside a nuclear reactor and especially taking anything out of a reactor is complicated, expensive and very time consuming. Each radiation experiment takes years to complete, and the samples often need to be very small and handled remotely so that the scientists aren't exposed to high levels of radiation.

So to speed up the process, much of the work in my group is first done in computer simulations. We modelled the crystal lattice atom by atom and simulate what happens when the lattice is hit by a high energy neutron.

I'm interested in discovering what defects form during irradiation and how they evolve over time, and what types of defects we can add to the material on purpose in controlled amounts to slow down the degradation process.

Understanding defect evolution will allow us to predict the lifetime of components with higher confidence. It will allow us to design new materials that will last longer in a reactor environment and it will enable us to generate more energy from our existing nuclear resources and produce less radioactive waste.

Not only is this better for the environment, but ultimately it will lead to lower electricity cost for everyone. And the benefits don't end there.

Understanding behaviour of defects in extreme environments means that we can push the boundaries of what other materials can do and apply those cutting-edge materials to applications beyond nuclear fission.

Like in space, where electronic components need to cope with high energy radiation and extremely cold temperatures for the duration of a mission. And although the types of radiation in materials are different, the methods and the fundamental understanding are the same.

We also hope to inform the development of beta voltaic energy sources. You may have heard of photovoltaic technology like that used in solar cells, which takes light energy in the form of photons and turns it into electricity. Beta voltaic devices do the same, but with beta radiation from the decay of radioactive elements like those found in nuclear waste.

In this way, they behave like batteries that you never need to charge. They don't produce much power, but last for a very long time, from 30 years to 30,000 years, depending on the type of radioactive element you choose.

Imagine having a watch battery that you'd never need to replace. This kind of tech is useful in remote, dark places where you can't get enough light energy, like the furthest reaches of the solar system, the dark sides of planets and moons or deep in the ocean.

And most exciting of all, nuclear fusion technology, the holy grail of clean energy. This is where you fuse two light elements together and release an astounding amount of energy, even more than conventional nuclear energy. This technology promises to provide humankind with abundant, carbon free, reliable energy for millennia.

The joke goes that fusion energy is 20 years away and will always be. But the great news is that we're much closer to commercial fusion than most people think.

It used to be the case that we couldn’t make fusion reactors because we didn't fully understand the physics behind it. But through decades of work and many extremely expensive experiments, we now do understand the physics and have been achieving controlled fusion in several experiments. What's holding us back are the materials.

The successful experiments that proved fusion is possible only lasted for a few milliseconds.

Now we need to sustain this fusion conditions for hours or days so that we can produce electricity. And to do that, we need materials that can cope with the extreme environments of fusion for a sustained period of time. Much like fission, fusion deals with extreme environments.

The process requires heating up atoms to above 100 million degrees, hotter than the centre of the sun, while on the outside, extremely sensitive electrical components need to be cooled down to -200 degrees. And sandwiched in between those, we have materials that are being bombarded by high energy radiation.

We need materials capable of withstanding those extreme environments, and that's the challenge we're looking to solve. If we can do that, we're a big step closer to unlocking the extraordinary potential of nuclear fusion.