China plans to commence construction of the world’s first molten salt reactor power plant next year in the Gobi Desert.
The new thorium molten salt reactor does not require water for cooling, using molten salt and carbon dioxide to transfer heat and generate electricity instead. By utilizing thorium as the primary fuel, this design alleviates concerns about potential uranium shortages, as thorium is more abundant than uranium, Interesting Engineering reported on July 26.
According to estimates from several scientists, China has enough thorium reserves to meet its energy needs for the next 20,000 years. The reactor is scheduled to be completed and operational by 2029, generating heat at a maximum capacity of 60 megawatts (MW). A portion of the thermal energy will power a 10MW generator, while the remainder will produce hydrogen by splitting water molecules at high temperatures.
China’s molten salt loop experiment. (Photo: Thorium Energy World).
The modular small-scale molten salt reactor using thorium will be built and operated by the Shanghai Institute of Applied Physics, part of the Chinese Academy of Sciences. The institute shared its construction plans in an environmental assessment report. This project will “promote the development of a series of technologies including the production of advanced materials and equipment”, according to the Shanghai Nuclear Engineering Research and Design Institute. It will help China achieve energy independence.
Currently, the only operational thorium reactor on Earth is also located in the Gobi Desert, 120 km northwest of Wuwei City in Gansu Province. This experimental reactor can only produce 2 MW of thermal energy and does not generate electricity. However, it integrates several revolutionary technologies, including superalloys capable of withstanding high temperatures, radiation, and chemical corrosion.
This small reactor was licensed to operate by the China Nuclear Safety Administration in June of last year and achieved a sustainable nuclear chain reaction in October of the same year. The success of this pilot project provides a foundation and experience for the construction of larger reactors capable of generating electricity. This is the first time China has disclosed the operational status of the experimental reactor.
The thorium molten salt nuclear reactor has several potential military applications due to its compact and safe structure, such as powering naval ships, submarines, and even aircraft. The site for the new generation reactor is located west of the small experimental reactor, occupying an area smaller than a football field. The molten salt transports thorium fuel into the reactor core through pipes, allowing it to undergo a chain reaction. As the temperature rises, it flows out the other end and transfers heat to the remaining molten salt while thorium circulates in a separate loop. The non-radioactive molten salt then flows into the power plant adjacent to the reactor, helping to drive a gas turbine powered by carbon dioxide to generate electricity.
The new project also includes various facilities such as a research center and a used fuel processing plant. According to reports, over 80% of used fuel will be recycled, while the remaining radioactive waste will be vitrified and sent to a deep geological repository in the Gobi Desert. Currently, most uranium-fueled reactors that use water for cooling pose a risk of explosion if the pumps fail. However, in thorium reactors, molten salt can flow into a containment chamber beneath the reactor, posing no threat to the surrounding environment.
The new reactor will be used for scientific research by scientists. However, a wind power facility, a solar power plant, a molten salt energy storage facility, a thermal power plant, and a chemical production facility are also being developed concurrently with the thorium power plant.
Various energy types will be integrated into a smart grid to provide sufficient low-cost, low-carbon, and stable electricity for industrial production. Starting from 2020, China plans to begin constructing commercial modular thorium reactors with a power generation capacity of 100 MW or more. Chinese shipbuilders are also introducing the world’s first design for giant container ships powered by molten salt reactors.
Some scientists remain skeptical about the feasibility of this technology. One major challenge that the reactors face is that the metal pipes become brittle and even crack under the influence of molten salt at high temperatures, high corrosion, and radiation. Discovering new uranium deposits and increasing production also seem to make the transition to thorium fuel less urgent.
Currently, China is developing 6 to 8 nuclear reactors each year, using homegrown technology. In fact, Beijing’s plan aims to have 150 advanced reactors operational by 2035, surpassing the total number of reactors in the United States and France combined.
