China will power up an ultra-efficient, nuclear waste-burning reactor with technology that it projects will safely meet humanity’s energy needs for the next 1,000 years.
Accelerator-driven subcritical systems (ADS) are advanced nuclear reactors that can both generate energy and transmute long-lived radioactive waste into shorter-lived and less hazardous isotopes.
Designed by researchers at the Chinese Academy of Sciences (CAS) along with state nuclear enterprises, the China Initiative Accelerator Driven System will be the world’s first megawatt-level prototype of such a system once it goes online in southern China’s Guangdong province next year.
He Yuan, deputy director of the Institute of Modern Physics under CAS, said the system was an “internationally recognised ideal approach for nuclear fuel breeding and nuclear waste treatment”, Science and Technology Daily reported on Monday.
It could turn nuclear power into a “green, safe, stable energy source for 1,000 years”, according to the report.
Despite the promise of this design, there are no commercial systems operating in the world, with only experimental projects such as China’s in development, according to the institute.
He said that the institute aimed to complete the installation of the system’s superconducting particle accelerators – which were key to powering the system – this year.
While much of the used fuel from conventional nuclear reactors decays fairly rapidly, a significant portion of used nuclear fuel is long-lived actinides, which can remain hazardous for tens of thousands, or even hundreds of thousands, of years.
This has prompted research into ways to break down the long-lived radionuclides into shorter-lived ones, which can make waste disposal easier and render nuclear energy greener and safer, according to the World Nuclear Association.
An ADS system is a hybrid between a nuclear reactor and a particle accelerator, with the reactor unable to maintain a chain reaction unless powered by an external accelerator, which eliminates the risk of runaway reactions.
The supply of neutrons from the accelerator can also cause heavy radionuclides to split, including those that would usually be unusable and already waste in conventional nuclear reactors.
He said their ADS design used high-current proton beams from superconducting linear accelerators to bombard a liquid lead-bismuth alloy at 0.8 times the speed of light.
This produced a massive amount of neutrons, “which then convert uranium-238 into the new nuclear fuel plutonium-239, turning ‘waste’ into treasure”, Science and Technology Daily quoted He as saying.
CAS began researching the ADS system in 2011, and in 2021, it developed a prototype that was the first in the world to reach an operational intensity suitable for industrial application since the modern ADS concept was proposed in the 1980s, according to Science and Technology Daily.
The institute’s megawatt-scale project is under construction in Huizhou, Guangdong province, and is expected to go online in 2027.
He Yuan said the device could burn uranium 100 times more efficiently while reducing the lifespan of the nuclear waste to less than a thousandth of the current span, which could provide a stable power source for the next millennium. -- SOUTH CHINA MORNING POST
