DYNA JOURNAL ENGINEERING

A key prototype for “1,000-year energy”
China is getting ready to commission CiADS in Huizhou, in the southern province of Guangdong, an innovative reactor that combines a particle accelerator with a subcritical core cooled by a lead-bismuth alloy. Designed by the Chinese Academy of Sciences in cooperation with state-owned nuclear companies, it will be the first system of its kind in the world to reach megawatt-level power.

The project aims to tackle two long-standing weaknesses of traditional nuclear power: safety and the management of very long-lived radioactive waste. According to its developers, the system could turn depleted uranium and other materials now treated as waste into fresh fuel, while drastically shortening the period during which the remaining waste stays hazardous.

How the accelerator-driven reactor works
Unlike a conventional reactor, whose core sustains the chain reaction on its own, CiADS is “subcritical”: it needs an external neutron source generated by a proton accelerator to keep fission going. This feature lowers the risk of a runaway accident because, once the accelerator is shut down, the chain reaction quickly dies out.

The superconducting linear accelerator sends proton beams at around 80 per cent of the speed of light into a liquid lead-bismuth target, producing a shower of neutrons that feeds the reactor core. These neutrons can convert uranium-238 into plutonium-239 and other fertile actinides, effectively “turning waste into treasure”, as the researchers describe it.

Waste impact and energy horizon
Program leaders claim CiADS can burn uranium with an efficiency up to 100 times higher than current reactors. Combined with its ability to transmute very long-lived isotopes into much shorter-lived ones, the goal is to cut the volume of high-level waste by about 96 per cent and reduce its radiotoxic lifetime to roughly 500 years, instead of tens or hundreds of thousands.

If these promises are confirmed in real operation, China could gain a technology that extends nuclear fuel use for centuries while fitting into its carbon-neutrality targets and expansion of zero-emission energy. Experts note, however, that all accelerator-driven systems remain experimental and no design has yet made the leap to full commercial deployment.