In the quest to safely generate limitless clean energy, China has just taken a giant step closer.
Scientists in Gansu province in the country’s west have achieved the milestone of reloading fuel to an operational nuclear fission reactor while it was running.
The achievement shows fission reactors can run and be refueled continuously – potentially offering a constant source of power generation.
Drawing upon declassified US research, Chinese engineers began constructing the experimental machine – a thorium molten salt reactor (MSR) – back in 2018.
Thorium MSRs are a type of advanced nuclear technology that use liquid fuels, typically molten salts, as both a fuel and a coolant – and are generally safer than existing fission reactors which use uranium.
It marks the first long-term, stable operation of the technology, reports South China Morning Post (SCMP), citing Chinese communist party newspaper Guangming Daily.
Xu Hongjie, the project’s chief scientist, said China ‘now leads the global frontier’ in the energy revolution, following decades of intensive research.
Xu said: ‘The US left its research publicly available, waiting for the right successor. We were that successor.’
Drawing upon declassified US research, Chinese engineers began constructing their experimental thorium reactor back in 2018
The reactor, a two-megawatt liquid-fuelled thorium molten salt reactor (MSR), is located in the Gobi Desert city of Wuwei in Gansu province
The world-first was announced by Mr Xu during a meeting at the Chinese Academy of Sciences in Beijing on April 8.
In a cheeky dig, Xu referred to America’s research into molten salt reactors in the 1960s and 1970s, eventually abandoned in favour of uranium-based systems.
‘In the nuclear game, there are no quick wins,’ he was quoted as saying. ‘You need to have strategic stamina, focusing on doing just one thing for 20, 30 years.’
In reference to Aesop’s famous fable, he said: ‘Rabbits sometimes make mistakes or grow lazy. That’s when the tortoise seizes its chance.’
His team at the CAS Shanghai Institute of Applied Physics spent years dissecting declassified American documents and bettering their experiments, SCMP reports.
‘We mastered every technique in the literature – then pushed further,’ Xu added.
This experimental reactor is hidden away in the Gobi Desert city of Wuwei in Gansu province and can generate two megawatts (2MW) of energy – enough to power 2,000 households.
Only reaching full-power operation in June last year, it is the only operational thorium reactor in the world.
Thorium MSRs are a type of advanced nuclear technology that use liquid fuels, typically molten salts, as both a fuel and a coolant. They offer several potential advantages over traditional uranium reactors, including increased safety, reduced waste and improved fuel efficiency, the site added
Drawing upon declassified US research, Chinese engineers began constructing the experimental machine – a thorium molten salt reactor (MSR) – back in 2018
But a much bigger thorium molten salt reactor now being built is set to achieve its first sustained nuclear chain reaction by 2030.
Estimated to be 500 times more abundant than the uranium-232 used in conventional nuclear reactors, thorium has been hailed as a potential solution to the demand for nuclear power.
Nuclear reactors already in operation around the world create energy by forcing radioactive elements to undergo a process called fission.
During this process, the element breaks down into smaller, more stable elements and releases heat which can be used to drive steam turbines, in turn producing electricity.
Thorium on its own is not fissile, meaning it cannot be used for fission, but it can provide the basis for a fission reaction.
This is because thorium is ‘fertile’, meaning it can transmute into uranium-233 (U-233) when bombarded with neutrons.
In a molten-salt reactor, thorium is mixed with a chemical called lithium fluoride and heated to about 1400°C (2550°F).
This mixture is then bombarded with neutrons until some of the thorium starts to transform into uranium-232, which then decays in a fission reaction.
China has rich reserves of thorium which could help improve the safety of existing nuclear fission. Pictured, mining machine is seen at the Bayan Obo mine containing rare earth minerals, in Inner Mongolia, China
Thorium Molten Salt Reactors (MSRs) are a type of nuclear fission reactor. They use molten salts as both the fuel (dissolved thorium) and the coolant
As it decays, this uranium then produces more neutrons which convert additional thorium into fuel. In theory, this reactor design could turn the extremely abundant element into a nearly limitless source of power.
Molten-salt reactors also produce significantly less nuclear waste and remove the risk of dangerous nuclear meltdown by keeping the levels of fissile material relatively low.
What’s more, China has a thorium source that could supply enough fuel to power the country for 60,000 years, geologists in Beijing have claimed.
The Bayan Obo mining complex in Inner Mongolia, an autonomous region of northern China, could contain enough thorium to supply China’s household energy demands ‘almost forever’, a national survey reportedly found.
It identified 233 thorium-rich zones across the country and, if accurate, suggests that thorium reserves in China significantly exceed previous estimates.
The Wuwei experimental reactor is different from the ‘Experimental Advanced Superconducting Tokamak’ (EAST), a fusion reactor located in Hefei in Anhui province.
Known as China’s artificial sun, it set the record for running for as hot and as long as possible – for 1,066 seconds at 180million°F (100million°C) – seven times hotter than the sun’s core.
EAST could be a precursor to the first ever fusion power plants that supply power directly to the grid and electricity to people’s homes.
These power plants could reduce greenhouse gas emissions from the power-generation sector by diverting away from the use of fossil fuels like coal and gas.
China’s self-designed ‘artificial sun’ – a device to harness the energy of fusion, has made an important advance by achieving a temperature of 180 million °F (100 million °C) in plasma
Nuclear fusion is still in the research and development phase – while nuclear fission is already making electricity. Pictured, nuclear power plant in Wuhan, China
Meanwhile, the SPARC nuclear fusion reactor, a US project involving MIT, is currently in development in Devens, Massachusetts and scheduled to start operations in 2026.
South Korea also has its own ‘artificial sun’, the Korea Superconducting Tokamak Advanced Research (KSTAR), which has run at 180million°F (100million°C) for 48 seconds.
And Japan’s reactor, called JT-60SA and switched on in Naka north of Tokyo late 2023, is a six-storey-high machine measuring 50 feet high and 44 feet wide.
Built and operated jointly by Europe and Japan, JT-60SA will be the world’s largest fusion reactor until the completion of the the International Thermonuclear Experimental Reactor (ITER) in France, set to begin delivering power in 2035.
