Chinese scientists have reached a major milestone in the global pursuit of clean energy by successfully refueling an operational thorium molten salt reactor while it was still running—an unprecedented achievement that cements China’s lead in next-generation nuclear technology. As reported by the South China Morning Post, the breakthrough was confirmed during a closed-door meeting at the Chinese Academy of Sciences (CAS) on April 8, with chief scientist Xu Hongjie revealing that the reactor had not only achieved stable, long-term operation but had also successfully undergone in-situ fuel reloading.
The experimental reactor, located in the Gobi Desert in western China, uses thorium—a radioactive element more abundant and potentially safer than uranium—as its core fuel source. Combined with molten salt as both the fuel carrier and coolant, the reactor is designed to sustainably generate 2 megawatts of thermal power. This marks the first time in history a thorium molten salt reactor has maintained continuous operations, fueling hopes that this technology could revolutionize global energy supply.
Xu Hongjie, whose team at the CAS Shanghai Institute of Applied Physics has spearheaded the project, described the achievement as a strategic leap. Drawing a metaphor from Aesop’s fable The Tortoise and the Hare, Xu likened China’s progress to the steady tortoise catching up to a complacent rabbit—referring to the United States’ early but ultimately abandoned efforts in molten salt technology during the 1970s.
The South China Morning Post notes that while American researchers initially pioneered the concept—operating a small-scale test reactor in the 1960s—interest waned in favor of uranium-based systems. However, the U.S. research was left publicly available, a trove of knowledge that Xu and his team meticulously studied, replicated, and ultimately improved upon.
The Chinese thorium project, which formally took shape in 2009, quickly scaled up from a small team to over 400 researchers. Construction of the Gobi Desert reactor began in 2018 and by October 2023, it had achieved criticality. By June 2024, the reactor reached full-power operation, and just four months later, completed a live fuel reload—solidifying its place as the only working thorium molten salt reactor on Earth.
Xu emphasized the significance of the date—June 17—when the reactor hit full power, as it marked exactly 57 years since China tested its first hydrogen bomb. “We chose the hardest path, but the right one,” he said, highlighting China’s drive for practical applications rather than academic milestones.
Looking ahead, China is already constructing a much larger version of the reactor, projected to produce 10 megawatts of electricity and reach criticality by 2030. The nation’s state-owned shipbuilding group has also revealed a design for thorium-powered cargo ships, which could pioneer emission-free oceanic transport.
In stark contrast, U.S. efforts to revive molten salt reactor development remain largely theoretical, despite bipartisan support and initiatives from the Department of Energy. Xu criticized this lack of long-term vision, remarking that “in the nuclear game, there are no quick wins. You need to have strategic stamina, focusing on doing just one thing for 20, 30 years.”
The South China Morning Post also highlighted China’s vast thorium reserves, particularly at the Bayan Obo mine in Inner Mongolia, which, according to a national geological survey, could theoretically power the country for tens of thousands of years.
With this latest success, China appears poised to not only lead the next generation of nuclear energy development but also to set a new global standard in clean, safe, and sustainable power.
