Chinese scientists have created a milestone in clean energy by building a molten thorium reactor that can be refueled while it’s still running.
Thorium is considered the safest, cleanest, and most abundant alternative to uranium in nuclear power. The construction was unveiled at a closed-door meeting on April 8 at the Chinese Academy of Sciences (CAS), with project leader Xu Hongjie sharing the news with his peers.
The thorium reactor is already up and running! The experimental facility is located in China’s Gobi Desert. The reactor currently has a capacity of 2 megawatts!
The reactor uses thorium as a source of radioactive fuel, while the reactor uses molten salt to transport the fuel and manage heat.
The creation of thorium reactors has been seen for years as the next big step in energy innovation. According to experts, a single thorium-rich mine in Inner Mongolia could meet the energy needs of all of China for tens of thousands of years! At the same time, China would have much less radioactive waste than today’s uranium-based nuclear reactors.
Xu said China had taken the lead in the world. “We are now leading the world frontier,” he told the meeting. In fact, he used a classic fable to talk about the energy race, saying: “Rabbits sometimes make mistakes or get lazy. That’s when the tortoise seizes its opportunity.”
Thorium is currently considered the best nuclear fuel. It is abundant in the Earth’s crust and produces much less radioactive waste, and it doesn’t have as long a lifespan, compared to its uranium-based counterparts.
At the same time, its byproducts are not as suitable for weapons-grade use, which reduces the security risks for China. When combined with molten salt technology, the reactor design operates at atmospheric pressure and naturally limits overheating, improving overall safety.
In an era when we are increasingly looking for greener methods of generating energy, thorium reactors are currently the best implementation we have!
In the 1960s, American researchers built and tested early molten salt reactors, but the United States eventually abandoned the program in favor of uranium-based technology. “The US left its research publicly available, waiting for a suitable successor,” Xu said. “We were that successor.”
Xu and his team studied declassified US documents and recreated the experiments of the 1960s. But they succeeded where the US failed, improving the technology and making it operational and highly sustainable. Xu said, “We mastered every technique in the documents. Then we took it further.”
Construction of the current thorium reactor began in 2018, and the team grew from a few dozen scientists to more than 400. The team became so passionate about the project that many did not take a single day off, staying at the research facility for most of the year. They managed to bring the reactor to criticality in October 2023, while it was first put into operation in June 2024. Four months later, they refueled the reactor with thorium, while it was in operation, without any problems!
Now that they have achieved academic results and proven that the reactor works, the team is preparing to create the real solution that will power the China of tomorrow. Xu says, “We chose the most difficult path, but the right one.” In short, they first demonstrated its operation and, after securing the science around it, they are now moving on to building large reactors.
He also pointed to the symbolic moment, noting that “57 years ago today – June 17 – China detonated its first hydrogen bomb.” Now, China is aiming for a similar deterrent effect on the global energy market.
The country is already building a much larger molten thorium salt reactor that is scheduled to reach criticality by 2030 and produce 10 megawatts of electricity.
