From theory to thorium: while the West debated, China advanced nuclear technology

And once again, the rest of the world is watching from the sidelines

I recently shared a video challenging common anti-nuclear arguments. It went viral, and the comments section flooded with enthusiasm for thorium, with many viewers arguing that we should transition to using thorium reactors right now. So let’s take a closer look at whether that’s feasible or not.

It’s true that there’s a quiet revolution unfolding in the deserts of western China relating to a long-neglected and overlooked technology: thorium reactors. While much of the West has been locked in ideological debates over energy policy, and countries like Germany are finally beginning to confront the consequences of phasing out nuclear energy, China has quietly forged ahead, investing in and developing next-generation nuclear technology. Among the most promising of these efforts is the latest development of a thorium-based molten salt reactor.

Thorium is a naturally occurring radioactive element that has long been considered a promising alternative to traditional uranium fuel. It offers a potentially higher energy yield and a more abundant global supply. Unlike uranium, thorium is fertile rather than fissile, meaning it must be converted into uranium-233 in a reactor before it can sustain a nuclear chain reaction.

Some estimates suggest that thorium could unlock up to 500 times more usable energy than conventional uranium fuel. The implications are profound: thorium-based reactors have the potential to deliver an even cleaner, safer, and more publicly acceptable form of nuclear energy. They also generate less long-lived radioactive waste, making them a compelling option in the quest to convince people that nuclear energy is essential for any clean energy transition.

The United States was once at the forefront of thorium research. In the 1960s, scientists at Oak Ridge National Laboratory successfully operated the Molten Salt Reactor Experiment (MSRE), which used uranium-233 derived from thorium as fuel. It was a groundbreaking project that demonstrated the potential of molten salt reactor technology. But as Cold War priorities shifted toward uranium-based reactors that supported both civilian energy and weapons programs, thorium development was quietly shelved.

However, that research remained publicly accessible, which allowed China to eventually use it to build their own reactor based on those principles. Molten salt reactors remain an attractive option today - unlike most nuclear reactors that use water as a coolant, which requires high pressure to keep water from boiling and turning to steam, molten salt has a much higher boiling point and remains stable at reactor temperatures. This eliminates the risk of coolant evaporation and helps prevent radioactive material from leaking. Additionally, if the reactor starts to overheat, the molten salt expands, naturally slowing or stopping the nuclear reaction, providing a built-in safety mechanism.

Now, China has announced that it has built and operated a thorium reactor called the TMSR-LF1. This is a molten salt reactor that reportedly ran for 10 days at full power. China’s next step is already underway: a larger, 10-megawatt demonstration plant to be built in the Gobi Desert. It won’t use water, just molten salt and CO₂ for cooling and power generation.

As well, a comprehensive geological survey identified 233 thorium-rich sites across China. The country could be sitting on top of enough thorium to power its energy needs indefinitely. As China unveils this seemingly limitless source of energy, experts around the world are watching closely, recognising the groundbreaking implications for the future of clean and abundant energy.

However, it’s wise to be a little sceptical of China’s announcement, because they’re not handing over the blueprints. We know that the reactor exists and that it’s thorium-fuelled, but none of China’s claims have been verified by outside scientists. For example, did it actually breed uranium-233 from thorium? Did it generate electricity? How were the safety systems tested? And so on. For now at least, we have to take this discovery with a pinch of salt (pun intended).

And to be honest, that’s not super surprising. China tends to keep its advanced technology projects close to the chest. They’re racing to be first in next-generation nuclear, and they don’t want anyone copying their homework, or pointing out if something didn’t go well. So until we get peer-reviewed data, it’s all still a bit questionable.

Especially since, earlier this year, China's newest nuclear-powered submarine sank while docked at a shipyard near Wuhan. The incident likely occurred between May and June 2024, based on satellite imagery showing the submarine at the pier in March and the subsequent appearance of salvage cranes in June. The Chinese government has not officially acknowledged the sinking, and defence officials have expressed concerns about the lack of transparency and the potential implications for China's defence industry.

While we don’t know the exact details, it’s still likely that China is miles ahead of the rest of the world when it comes to thorium reactors. That said, we’re still years away from actually using thorium reactors at scale. The thorium fuel cycle requires new infrastructure, new fuel processing tech, and a supply chain that doesn’t exist yet. In addition, there are real technical challenges to overcome, like corrosion and reprocessing complexity. So while it’s promising news, it’s still early days for thorium reactors.

On the other hand, if thorium reactors have now become a reality, it could be revolutionary for multiple reasons. It could offer a fuel source that is more abundant than uranium. It could combat concerns people have about nuclear technology since it would produce less long-lived radioactive waste. It could reshape the future of power generation. Either way, alongside building the best reactor designs we have now, someone needs to also be advancing other nuclear technologies forward. And right now, that someone appears to be China.

While China is pursuing neglected nuclear technology, the excitement surrounding thorium should not overshadow the immediate and critical role of conventional uranium-fuelled fission reactors. For the foreseeable future, these proven reactors remain our most effective tool for combating climate change, enhancing energy security, and significantly reducing air pollution. Other emerging nuclear technologies, while promising, are, at this stage, largely aspirational compared to the pressing need for deployable solutions. That’s a long-winded way of saying that at this stage, thorium more hype than reality.