The Shanghai Institute of Applied Physics, a Chinese research institute, has successfully converted thorium into uranium in an experimental reactor, enabling nearly unlimited access to nuclear energy.
The two-megawatt molten salt reactor is the world's only functioning facility of its kind.
The experiment has, according to the Chinese Academy of Sciences, demonstrated that thorium-based technology is technically feasible in molten salt reactors and represents a significant breakthrough. It is the first time researchers have been able to collect experimental data from thorium operation in such a reactor, reported the newspaper Science and Technology Daily.
The reactor has produced heat through nuclear fission since reaching criticality on October 11, 2023, according to Li Qingnuan, party secretary and deputy director at the institute.
Superior fuel availability
Thorium exists in much larger quantities and is more readily available than uranium. A single mining waste site in Inner Mongolia is estimated to contain enough thorium to supply all of China with energy for over a thousand years.
The new technology is based on a process where naturally occurring thorium-232 is converted into uranium-233 inside the reactor core. Thorium-232 absorbs a neutron and becomes thorium-233, which then decays into protactinium-233 and finally into uranium-233 – a fissile material that can sustain nuclear reactions.
The thorium is dissolved in a fluoride salt that forms a high-temperature molten mixture which functions as both fuel and coolant. The system creates a self-sustaining cycle where the reactor "breeds" fuel while simultaneously producing energy.
Requires no water cooling
Unlike conventional reactors, the thorium reactor requires no water at all for cooling, allowing it to be located in dry inland areas. The molten fluoride salts efficiently transfer heat at atmospheric pressure and extreme temperatures.
Safety is, according to the developers, significantly higher than in traditional reactors because the system operates at atmospheric pressure, eliminating the risk of high-pressure explosions. In the event of a leak, the molten salt would flow into a passive collection tank where it would solidify.
The reactor reached full power in June 2024, and in October of the same year, the world's first experiment with adding thorium to a molten salt reactor was conducted. China is now building a 100-megawatt demonstration reactor in the Gobi Desert with the goal of proving the technology is commercially viable around 2035.
