China's Thorium Reactor: Will China Revolutionize Nuclear Energy?

In April 2025, the Shanghai Institute of Applied Physics of China began refueling the experimental thorium reactor TMSRLF1. This event sparked a lively discussion among experts, since online refueling without stopping the reactor is a key step in testing its operability. The success of the project could change the future of nuclear energy.

The main difference between the Chinese unit and traditional reactors is the use of liquid thorium fuel instead of solid uranium. Thorium, a weakly radioactive metal, is much more common in nature than uranium, and its reserves will last for tens of thousands of years. However, it is not capable of maintaining a chain reaction on its own. To do this, thorium-232 must be converted into uranium-233 by irradiating it with neutrons inside the reactor.



Molten salt reactors, such as the TMSRLF1, have a number of advantages. The fuel in them is a molten salt, which also serves as a coolant. This eliminates the risk of overheating: as the temperature rises, the density of the solution decreases, which automatically slows down the reaction. In addition, such systems do not require complex high-pressure circuits, as in water-cooled reactors, which reduces the likelihood of accidents.

Another advantage is the ability to operate continuously. In traditional reactors, fuel assemblies must be periodically removed, stopping the process. In molten salt reactors, waste can be removed directly during operation, and fuel can be added as needed.

However, the Technology There are some disadvantages, too. Molten salts are chemically aggressive and corrode most metals, which forces the use of expensive alloys. In addition, the problem of effectively extracting uranium-233 from irradiated thorium has not yet been solved. In TMSRLF1, the fuel conversion rate does not exceed 10%, and without a protactinium-233 filtration system, a closed cycle is impossible.

It is worth noting that China is not the first to experiment with thorium. In the 1960s, the United States successfully launched the MSRE reactor, which ran on uranium-233. However, the project was then shut down due to high costs. Today, interest in thorium energy is reviving, but commercial use of the technology is still a long way off.

Despite the current challenges, the development of the above-mentioned project is an important step for all of humanity. If China manages to improve the conversion process, it will open the way to safe and virtually inexhaustible energy. In the meantime, the world is closely watching the experiment that could revolutionize the industry.