Science

Nuclear fusion and how it could make COP26 redundant

University of York leads next generation into the second nuclear age

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Image Credit: Glowing plasma in the Mega Ampere Spherical Tokamak (MAST) in Culham, Oxfordshire, UK. Credit: Eye Steel Film.

World leaders have spent a week debating how much of their governments’ budget and effort should be spent on ensuring their children’s children don’t die of starvation and natural disasters. Their answer is quickly crystallising into the most cynical and yet entirely expected one: not enough. The reason is obvious: they have been put in their positions of power on the strength of their promises to limit immigration, keep the roads full of commuters, or even just maintain the status quo. Preserving the health and productivity of the ground on which we rely for our very existence is priority, hmm, maybe 26.

There is no one true path to averting ecological catastrophe. There is however, a common requirement amongst all strategies: the need for clean energy generation. Without a bedrock of green, affordable, sustainable and economically viable electricity, no plans for electric vehicles, carbon capture and storage, educational investment or green tech will be possible or even matter; it all comes down to energy.

So while there is no one true path, there is one dependency. And our best hope for fulfilling that dependency is with a technology now emerging from the science fiction phase and moving rapidly into the research facilities that traditionally precede commercialization.

The full name certainly grabs headlines: controlled thermonuclear fusion. Terms that inspire thoughts of weapons and destruction and hair blown-back by an expanding mushroom cloud as crowds of bespectacled onlookers begin to softly glow. These trinity-test vignettes couldn’t be farther from the truth, thanks to the first term in the above moniker. We know how to produce uncontrolled explosions, but we need to generate electricity without demolishing the reactor, the power station and half the surrounding city. This is where fusion plays its trump card: the total impossibility of a runaway reaction and therefore, meltdown.

Fusion is not fission, which runs the traditional nuclear reactors that supply 20% of Britain’s power. Indeed, the two operate via opposite mechanisms; while fission looks to harness the energy released from splitting up large, heavy uranium atoms, fusion attempts to bond light, fast isotopes of hydrogen into helium atoms. The inspiration for this process also supplies the evidence that it works: the sun. Almost all stars fuse hydrogen in this way which releases the incredible amounts of heat and light we English enjoy for a week or so every August.

The opposing reaction pathways create a number of critical distinctions between fusion and the decades-old technology that is fission power generation. Fusion reactors are impossible to melt down because the fuel is inert enough that when things go wrong, the reaction will simply fizzle out, without enough energy to sustain it. The reaction itself produces no nuclear waste, greenhouse gases or other toxins. The hydrogen fuel and its production doesn’t have a vulnerable or unethical supply chain and carries no risk of being co-opted for terrorist purposes -- on the contrary, some components of the fuel can even be produced as a reaction by-product, further increasing the energy efficiency. Most critically, fusion produces vastly more energy per unit than fission, making it cheaper as well as cleaner.

So, the scientific theory behind fusion is well-established. However, hurdles of practicality remain standing between researchers and solving the energy crisis. While breakeven between the amounts of energy delivered to the fuel core and that captured from the reaction was achieved eight years ago, the National Ignition Facility in California is busy continuing to break records for power generation efficiency. This is still below the critical factor of 100% energy gain due to the power lost in the laser arrays used to heat the fuel, but progress is ongoing. Additionally, there are still cost and supply considerations with the precious metals used in some reactor designs. Materials in reactor walls must be protected from neutron radiation to prevent degradation and the creation of radioactive species. And engineering challenges exist in the delivery of fuel to reactors at a high enough rate and in the exact alignments needed, and in the diversion of atomic energy into a system that can drive a turbine to generate electricity.

The good news is that the type of fusion experimented with at NIF is only one of many configurations under active research. Within the community there exists an unspoken competition to prove the best system; the most powerful lasers in the world competing with cutting-edge superconductors that couldn’t have existed even a year ago. The other good news is that as an area of science with such a clear path to solving the biggest crisis of our generation and lying so precariously on the verge of viability, investment momentum is growing. Solutions will need to come from disciplines across plasma, nuclear and high energy physics; mathematics, electro-chemistry, engineering, materials science, computing and enough business and interpersonal acumen to sell the fusion dream to financiers and the public. It’s a good thing fusion has a hell of an elevator pitch.

The University of York is an undisputed world-leader in Nuclear Fusion research, it’s name littering prestigious academic journals with fusion breakthroughs. Professor Howard Wilson was the first director of the Spherical Tokamak for Energy Production programme which aims to bring a power-plant-scale reactor to East Yorkshire within a decade. York provides the only nuclear fusion-specific masters programme in the country and heads up the centre for doctoral training, in collaboration with Oxford, Durham, Liverpool and Manchester. This guarantees the future of fusion in the UK will be significantly guided by York alumni.

Panaceas exist, all they need is money, time and the right people. It’s up to us to make the political and personal choices that lay the foundations of the next nuclear age.

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