Bottling the Sun: Nuclear Fusion on the Horizon

Anyone who has watched Christopher Nolan’s pulsating biopic of theoretical nuclear physicist J. Robert Oppenheimer has probably left the cinema in deep thought about the terrifying prospects of nuclear weapons.

Nuclear energy serves a purpose not only in military affairs and international politics, but also as a very real option in the world’s search to become net-zero and sustain itself on low-carbon fuel and energy systems. In much the same way as in nuclear weapons, there is a key distinction between nuclear fission (splitting nuclei) and nuclear fusion (combining nuclei). This article will consider where advancements in nuclear fusion are at, what the potential challenges are and its prospects for the future.


Nuclear fusion, in short, is the process by which two nuclei combine to form a single, heavier nucleus, meanwhile producing significant amounts of energy. The sun, along with stars, is powered by this very reaction. Nuclei collide with each other, at extremely high temperatures (ten million degrees Celsius) which provides enough energy to overcome their mutual electrical repulsion. Once the nuclei collide, the attractive nuclear force outweighs their electrical repulsion and allows them to fuse. However, the sun’s substantial gravitational force naturally induces fusion and on Earth, without that force, we need temperatures of more than 100 million degrees Celsius for fusion to occur.

It is no surprise, therefore, that since nuclear fusion was understood in the 1930s, scientists and engineers have since been looking to harness its energy. In theory, if nuclear fusion can be replicated, and its energy harnessed, it could provide virtually limitless, clean and affordable energy to meet the ever-growing world’s demand. Nuclear fusion does not produce greenhouse gases or emit carbon dioxide and could generate four million times more energy than burning oil or coal.

At this point in time, experiments and developments continue to occur worldwide. To review the varying approaches to producing fusion reactions and a variety of designs, the International Atomic Energy Agency published a report: World Survey of Fusion Devices 2022. Tokamaks and stellarators are the most common fusion devices and the focus of much of the current research. The report indicates that there are more than 50 tokamaks and 10 stellarators in operation worldwide.

Nuclear fusion hit the news in the USA as scientists at the Lawrence Livermore National Laboratory in California successfully replicated an experiment in December 2022 where they created more energy from fusion than was put in. However, although 3.5 megajoules (MJ) of energy were released compared to the 2MJ imparted, 300MJ were used to power up the lasers used in the process. Although this is a significant breakthrough, nuclear fusion requires very specific conditions and thus there is still a fair way to go before nuclear fusion can become the cure for our energy shortages and emission problems.


As is quite clear already, nuclear fusion is by no means a straightforward process, but demanding, expensive and not without its dangers. Reactions require temperatures six times hotter than the sun’s core and currently far more energy is being used to create this atmosphere than the reactions themselves are imparting. Moreover, the neutron-rich isotopes that are being burned in fusion reactors have incredibly harmful by-products. These reactions cause radiation damage to the fusion structures and result in huge amounts of radioactive waste.

Beyond the complexities of fusion reactions is the major challenge of sourcing hydrogen isotopes. The favoured reaction by developers is deuterium-tritium as its reactivity is 20 times higher than a deuterium-deuterium fuelled reaction and requires one-third of the temperatures required for deuterium-deuterium. While deuterium is readily available in water, tritium barely exists in nature because of its radioactivity and half-life of 12.3 years. Deuterium-tritium-based fusion would be the only source of electrical power that does not exploit a naturally occurring fuel or convert a natural energy supply.

A third cause of concern is the proliferation of nuclear weapons. Production of plutonium 239, the primary fissile isotope used for the production of nuclear weapons, is possible in a fusion reactor by placing natural or depleted uranium oxide at any point where neutrons are flying about. Slower neutrons will be soaked up by uranium 238 and these fusion neutrons will be available for any use, including the production of plutonium 239, thus adding to the threat and abundance of nuclear weapons.


Nuclear fusion has the potential to solve almost all our energy woes and therefore it is no surprise that once it was theoretically discovered in the 1930s, scientists have been working continuously to put it into practice and develop it. It has proved to be an incredibly complex, demanding and expensive process with issues ranging from how to deal with the radioactive waste to the potential dangers of increasing the abundance of plutonium 239.

As the world looks to rapidly decarbonise, nuclear fusion still remains a significant part of plans to go net-zero, and if able to put theory into effect, nuclear fusion looks to be one of the most effective sources of clean energy and would satisfy energy demand. That ‘if’, putting theory into effect, continues to be a problem for scientists, but with news of developments and breakthroughs in this field, progress continues to be made and thus reliance on clean, low-carbon fuel to power our growing demands without causing more damage to the environment looks ever more realistic.

Eager to dive deeper into the world of nuclear fusion and its potential for revolutionizing our energy landscape? If you’re intrigued by the prospects of clean and limitless energy, and want to explore how your business can play a part in this exciting journey, our knowledgeable technical and financial team is just a message away.

Article by Jeremy Page

Jeremy is currently undertaking the PGDL at BPP University. He provides paralegal and research assistance to the legal team at Prospect Law and has a special interest in commercial and international law.

Prospect Law is a multi-disciplinary practice with specialist expertise in the energy and environmental sectors with particular experience in the low carbon energy sector. The firm is made up of lawyers, engineers, surveyors and finance experts.

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