In August 2021, China completed an experimental Thorium-based nuclear reactor in the Gobi Desert. If the tests underway are successful, the Chinese plan on following up with another reactor capable of powering 100,000 houses. India, which has the largest proven reserves of Thorium, plans to generate 30% of its electricity via Thorium by 2050. The US, Japan, the UK and Israel have also demonstrated enthusiasm for research into the possible deployment of Thorium reactors. So, is there a possibility we might see a shift in the nuclear sector – from Uranium towards Thorium? Thorium Reactors are a promising source of nuclear energy and could potentially transform the way we generate power. Traditional Uranium reactors rely on the fission of Uranium – 225. Thorium reactors use the fission of Thorium – 232, a more abundant and safer fuel source. When Thorium – 232 absorbs a neutron, it transitions into Thorium – 233, then decays into Protactinium – 233 and finally transforms into Uranium – 233, which is fissile and may be used to generate electricity. This process may occur in either Fast reactors or Thermal reactors. Fast reactors use a liquid metal such as Sodium or Lead to transfer heat from the fuel and generate electricity while Thermal reactors use a moderator such as water or Graphite to slow down neutrons so they are more readily absorbed by the Thorium fuel. Traditional Uranium-225 and Uranium-238-based fuel cycles require a Fast Reactor with a superior neutron economy and end up producing more fissile material than is consumed. An advantage of Thorium reactors is that they produce less waste. Thorium reactors can operate in a closed fuel cycle, implying that fuel can be reprocessed and reused. This reduces the amount of nuclear waste generated and is a more sustainable process. The waste produced by Thorium reactors has a shorter half-life than that produced by Uranium reactors, thereby reducing the risks and costs associated with long-term storage. This ameliorates the problem of storing fissile material that occurs in traditional Uranium fuel cycles. Furthermore, Thorium is more stable and less reactive than Uranium, implying that it is less likely to undergo a runaway reaction or meltdown. Since Thorium reactors are a new technology, regulatory approval may be needed before they can be deployed extensively. Thorium reactors are also more efficient than traditional Uranium reactors. A single tonne of Thorium burnt in a Molten Salt Reactor can generate 1 Gigawatt of energy. A traditional Pressurised Water Reactor would require 250 Tonnes of Uranium for the equivalent. Thorium reactors have a higher burnup rate which results in greater energy extraction from fuel, making Thorium a more cost-effective and effective source of nuclear energy. Thorium is much more abundant than Uranium, with an estimated four times more proven reserves. As a result, Thorium reactors could provide a more sustainable source of nuclear energy in the long run. Additionally, utilizing Thorium reduces the potential for nuclear proliferation. Thorium reactors do not produce Plutonium, which is a key material for nuclear reactors. This reduces the risk that nuclear tech could be diverted for military purposes. Before we conclude that Thorium reactors are a miracle answer to our energy woes, I would stress that there are some disadvantages to the technology and some technical challenges must be addressed for Thorium to become a viable source of energy. Firstly, the technology is still in the early stages of development. While there are some experimental Thorium reactors, no commercial reactors are currently in operation. This means that many technical trials must be overcome before Thorium can be widely adopted. Moreover, Thorium reactors require a higher level of technical expertise to operate. Consequently, it may be more difficult to train personnel to operate and maintain these reactors, increasing the commercial costs associated with the technology. Despite the greater abundance of reserves, Thorium is not mined on a large scale, which implies that a new supply chain would have to be established to support the operations of Thorium reactors. Moreover, there are concerns about the safety of Liquid Metal Fast Reactors. These reactors use a liquid metal such as Sodium or Lead as a coolant. While these coolants can transfer heat more efficiently than water or gas coolants, they are highly reactive and combustible. This increases the risks of accidents and safety hazards associated with Thorium reactors despite Thorium itself being safer than Uranium. For Thorium reactors to become a viable source of energy, we would require the development of commercial reactors and their deployment on a larger scale to bring down inventory costs. To support the deployment of Thorium reactors, a new supply chain must be established to support the production and distribution of Thorium fuel as well as plant equipment. Consequently, the commercial costs of developing and operating the first few Thorium reactors would be prohibitive and will only be reduced by large-scale adoption. This may be a barrier for developing countries with limited resources and capital. Since Thorium reactors are a new technology, regulatory approval may be needed before they can be deployed extensively. This requires a comprehensive review of safety standards and the environmental impact of the technology. Furthermore, public opinion in most countries tends to view nuclear power with a degree of scepticism and there are concerns about the safety of nuclear reactors. It will be imperative to engage with the public and address these concerns to garner public support and alter current perceptions about nuclear reactors. Thorium Reactors have the potential to revolutionise the way we generate nuclear energy. They are safer, more sustainable and more efficient than Uranium reactors. However, there are a plethora of issues that must be addressed before the technology can be widely adopted, mainly, but not limited to, the deployment of commercial reactors, regulatory approval, infrastructure development, initial high costs of deployment and negative public perceptions. With continued research and investment, Thorium reactors could become a major source of clean, sustainable energy in the future. The writer is a freelance columnist.