Where are we at with nuclear fusion?

Control the lightning – where are we at with nuclear fusion?

Last month, Japan inaugurated the world’s largest operational experimental nuclear fusion reactor. The JT-60SA reactor aims to investigate the feasibility of fusion as a safe, large-scale, and carbon-free nett energy source.

The six-story-high machine, housed in a hangar in Naka, north of Tokyo, is a collaboration between the European Union and Japan, and it serves as a forerunner to its larger brother in France, the under-construction International Thermonuclear Experimental Reactor (ITER).

The ultimate goal of both projects is to replicate the reaction that powers the sun to release energy in the form of light and heat.

Matteo Barbarino, a Nuclear Plasma Fusion Specialist at the International Atomic Energy Agency (IAEA), says it’s a dream that has only grown more compelling in the face of escalating climate change. Harnessing thermonuclear fusion has the potential to render all of our carbon-emitting coal and gas-fired plants an old memory.

Fusion power plants could provide zero-carbon electricity that runs day and night, without care for wind or weather, and the drawbacks of today’s nuclear fission plants, says Tammy Ma, the Lead for the Inertial Fusion Energy (IFE) Initiative at Lawrence Livermore National Laboratory.

It was Australian Sir Mark Oliphant who discovered fusion in 1934. As research and investments in the field advance, fusion might be at the forefront of becoming the dominant energy source – by the end of the century.

Nuclear fusion and its potential

Fusion is the exact opposite of fission: rather than splitting heavy elements like uranium into lighter atoms, you slam deuterium and tritium, isotopes of heavy hydrogen, together at a sun-hot temperature to produce a helium nucleus and a neutron and a huge amount of energy.

Today, the fusion community is awash with ideas for more practical machines

The equation E=mc2 comes into play: if you weigh the deuterium and tritium before the reaction and then the products after fusion (the neutron and helium nucleus), these will weigh a little less. In Einstein’s equation, liberated mass (represented by “m”) is multiplied by the speed of light squared (c2), yielding a massive amount of energy.

“One pound of Fusion fuel is equivalent to the amount of energy you would have in 5000 barrels of oil, which equals 3.5 million pounds of coal,” says Ma. So, imagine if a glass of water were deuterium and tritium fuel could effectively power Melbourne for an entire day.

However, to create miniature stars on Earth, those light isotopes must be placed in a reactor and heated to hundreds of millions of degrees Celsius, transforming them into an ionised “plasma” similar to the insides of a lightning bolt but hotter and more difficult to control. It means figuring out how to control the lightning, usually with a magnetic field that grabs the plasma and holds it tight while it tries to flee.

It wasn’t until 2022 that the Joint European Torus (JET) near Oxford, UK, smashed the record for the amount of energy created through fusion. Then, a multibillion-dollar fusion experiment at the National Ignition Facility (NIF) in California finally produced a tiny isotope sample to emit more thermonuclear energy than was expended to ignite it. And that event, which lasted only about a tenth of a nanosecond, had to be triggered by the combined output of 192 of the world’s most potent lasers. Now, NIF routinely generates more energy from a fusion reaction than put in, although the NIF calculations do not include the entire energy required to run the entire facility.

Today, the fusion community is awash with ideas for more practical machines. Novel technologies, such as high-temperature superconductors, can reduce the size, complexity, cost, and efficiency of fusion reactors. Better yet, decades of slow progress have reached a tipping point, with fusion researchers now experienced enough to design plasma experiments that almost precisely match predictions.

Artificial intelligence (AI) has been critical in advancing fusion research. AI has been used to optimise designs and streamline the development of complex fusion machines, drawing on plasma physics principles that govern fusion processes. Advanced computer hardware and software have accelerated the design process, making it more efficient and responsive to the changing challenges of fusion research.

A burst of interest

Fusion energy is appealing for various reasons, the most important being its inherent safety. The fusion reaction requires a large amount of energy to begin. As a result, stopping a fusion reaction is as simple as turning off the initial energy source, eliminating the risk of runaway reactions, which is a significant difference from fission. Furthermore, fusion is sustainable because we have the know-how to produce the necessary fuel without causing environmental damage, explains Ma. Approximately one out of every 10,000 particles in seawater is deuterium oxide (D2O) rather than regular water. While tritium requires breeding, she says we have perfected its production techniques.

This surge in private sector engagement in fusion research stems from the convergence of various factors

The private sector’s interest and investments have increased significantly over the last five years, raising about US$7.7 billion. According to Barbarino, this trend marks a departure from the historical paradigm in which fusion research and development were primarily government-funded activities in national labs and research institutions with public funds.

In recent years, investment has increased dramatically, resulting in the formation of numerous fusion startups. Over 40 private fusion companies operate around the world, with the United States accounting for roughly 80% of them. The remaining companies are spread across the United Kingdom, Japan, China, several European countries, and Israel.

In Australia, research interest has grown, too. Researchers at the University of Sydney are developing an Inertial Electrostatic Confinement, rather than using a magnetic field, allowing for benchtop fusion. At the University of New South Wales, students plan to build a nuclear fusion device to produce the extreme heat necessary to initiate fusion.

Australian company HB11 Energy, which has received a $6 million government grant and $16 million in contributions from partners, is proposing an alternative reactor design that involves a modestly sized fuel pellet made up of hydrogen and boron-11, held in the centre of a largely empty metal sphere with apertures on different sides for two lasers. One laser establishes the magnetic containment field for the plasma, while the second laser triggers an avalanche fusion chain reaction. Unlike other nuclear fusion technologies, the HB11 concept will directly generate electricity with no steam turbines required.

The use of lasers in nuclear fusion is not new, but in 2022, HB11 demonstrated that its hydrogen-boron energy technology is 4 orders of magnitude away from achieving net energy gain when catalysed by a laser.

The fusion of hydrogen and boron creates a couple of helium atoms, which are naked and have no electrons. This lack of electrons means that the helium atoms have a positive charge, which HB11’s machine harnesses to create a current that can be used directly.

If HB11 succeeds, its reactors would be smaller and simpler than the high-temperature fusion reactors, and we could see very small, cheap industrial units on the outskirts of every town and city worldwide, producing unlimited, safe, clean, zero-carbon electricity.

This surge in private sector engagement in fusion research stems from the convergence of various factors, says Barbarino.

Nuclear reactor tokamak in japan jt-60sa
The completed tokamak at JT-60SA in Japan. Credit: JT-60SA.

An influential force has been the commitment of over $20 billion by an international consortium of funding agencies to construct ITER, a tokamak magnified to the proportions of a 10-story building. ITER is currently under construction in southern France since 2010 and is anticipated to initiate experiments with deuterium-tritium fuel in 2035.

However, the machine assembly has encountered setbacks primarily linked to the complexity of coordinating the efforts of multiple nations, including the EU, US, China, Japan, South Korea, Russia, and India, and the disruption of the manufacturing processes during the pandemic.

Despite the repeated delays of the project, Barbarino says this collaboration has not only spurred the growth of the fusion industry but has also nurtured supply chains and facilitated the exchange of knowledge among participating nations.

In late 2016, ITER welcomed Australia into the mix when ANSTO signed a cooperation agreement, which would allow Australia to share ideas and deliver solutions to some of the physics and engineering problems relevant to ITER.

The complexity and time-consuming nature of fusion research have prompted innovative thinking within the community. Private companies have devised novel ideas based on the wealth of knowledge accumulated in traditional government-funded fusion R&D, such as ITER. When the UK government announced the decommissioning of JET last year, 40 years after it began operations, researchers began to study in great detail the 17-year-long process to ensure future fusion power plants are financially viable.

Furthermore, a shifting global focus on addressing climate change and enhancing energy security has increased interest in investing in new technologies.

Energy justice

Only with political support can we build this idealistic energy.

Tammy Ma, Lead for the IFE Initiative

Nuclear fusion is incredibly flexible and geographically versatile, says Ma. It can be established anywhere without the need for geologic storage or the generation of high-level nuclear waste.

However, the complexity and cost of these plants raise concerns about their flexibility, especially in regions with lower incomes, such as Southeast Asia and Africa.

As policies for fusion energy are being developed, it is crucial to factor in considerations of global distribution and accessibility, says Barbarino. Environmental justice, energy justice, and the inclusion of the global south are paramount considerations. Establishing equitable policies is essential to fulfilling the promise of fusion as the energy of the future, addressing challenges, and fostering a sophisticated and prosperous civilisation.

It’s essential to recognise that while fusion fuel may free us from geopolitical conflicts, the raw materials, such as lithium or magnets, may not be equally distributed globally. Export control policies must be in place to ensure widespread access to fusion technology, balancing the need for security with global cooperation.

“Only with political support can we build this idealistic energy.”

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