After tens of thousands of corrosion tests, the Chinese research team finally settled on an “anti-corrosion formula” to develop a nickel-based alloy material that would extend the lifespan of the pipes to more than 10 years.
Stable and clean energy
China is not the first country to explore thorium as a nuclear fuel. During the Cold War, the US pioneered thorium molten salt reactor research but eventually abandoned it, as thorium could not be used to produce nuclear weapons, shifting instead to uranium-based reactors. The Soviet Union, India, and others also experimented with thorium reactors but were ultimately constrained by technical challenges such as molten salt corrosion and the complexity of online fuel reprocessing — the continuous separation and recycling of fuel from the reactor’s molten salt while it remains in operation.
In 2011, China incorporated thorium molten salt reactors into its national strategic pilot projects, bringing together over 20 research institutions including the Chinese Academy of Sciences’ Shanghai Institute of Applied Physics for a collaborative effort. This has recently resulted in a significant breakthrough.
The most challenging issue was molten salt corrosion. High-temperature fluoride salts can dissolve most metals, which previously caused the piping of an experimental reactor in the US to fail within three months. After tens of thousands of corrosion tests, the Chinese research team finally settled on an “anti-corrosion formula” to develop a nickel-based alloy material that would extend the lifespan of the pipes to more than 10 years.
Thorium molten salt reactors do not require large amounts of water, so unlike traditional nuclear power stations, they do not need to be built near the sea or major rivers. Instead, they can be constructed in remote deserts. Once the technology matures, they can be extensively built in China’s arid inland regions, providing a supply of stable and clean energy.
