On November 1, 2025, the Shanghai Institute of Applied Physics, Chinese Academy of Sciences (SINAP), announced a pivotal success in advanced nuclear technology, confirming the completion of a crucial experiment involving their Thorium Molten Salt Reactor (TMSR). This achievement marks the first time in history that the conversion of thorium into usable uranium has been demonstrated within an operational, active facility. This breakthrough unequivocally validates the technical viability of utilizing thorium in liquid-salt systems, establishing a significant global milestone for the progression of next-generation nuclear energy.
The experimental facility responsible for this feat is the TMSR-LF1 reactor, situated in Wuwei City, Gansu Province. Currently, this installation holds the unique distinction of being the world's only operational reactor utilizing thorium fuel within a salt melt. The reactor achieved initial criticality in October 2023 and subsequently reached its full operational capacity in June 2024. The definitive proof of fissile material production came in October 2024. During a ten-day period of maximum power operation with thorium circulating in the salt loop, scientists successfully detected the presence of Protactinium-233, providing direct evidence that the necessary process for breeding fissile material was functioning as intended.
The TMSR-LF1 unit is designed as a Generation IV reactor, boasting a thermal output of 2 MW. Its core operates using a fluoride thorium melt, specifically FLiBe, and maintains working temperatures ranging from 560°C to 650°C. Structurally, the reactor infrastructure is robust, featuring an underground active core housed within a dry well that extends 14 meters deep. China initiated its ambitious Thorium Molten Salt Reactor program in January 2011, outlining a comprehensive twenty-year development plan. The successful operation of TMSR-LF1 brings China significantly closer to fully harnessing its substantial domestic thorium resources.
Thorium presents a highly attractive alternative to conventional nuclear fuels. Global reserves of thorium are estimated to be three to four times more abundant in the Earth's crust than those of traditional Uranium-235, ensuring a much longer timeframe for securing future energy supplies. Beyond mere abundance, thorium reactors possess a crucial inherent safety advantage: their design prevents the possibility of an uncontrolled chain reaction or a catastrophic nuclear explosion, addressing a key concern in public acceptance of nuclear power.
The environmental footprint is also significantly improved. The thorium fuel cycle produces substantially fewer long-lived actinides and less plutonium when contrasted with the standard uranium cycle. The efficiency metrics are remarkable: one ton of thorium holds the potential to generate the same amount of energy as 200 tons of uranium. This efficiency, combined with the extended operational life, means that fuel reloading might only be necessary every 30 to 50 years. Looking ahead, the Shanghai Institute of Applied Physics is already focused on scaling up, with plans underway to construct a 100-megawatt demonstration project intended for pilot operation by the year 2035.