China will begin initial trials with a molten salt nuclear reactor using thorium instead of uranium

Scientists in China are about to commission an experimental reactor for the first time, which some consider to be the Holy Grail of nuclear energy – safer, cheaper, and with less weaponry.

Important points:

• In the early 1970s, the United States abandoned thorium in favor of uranium as a fuel source
• The experimental prototype reactor in the Chinese province of Gansu is said to have an output of only 2 megawatts
• The first commercial systems using the new technology are said to go online in 2030

Construction of the thorium-based molten salt reactor should be completed this month, with initial tests beginning as early as September, according to a statement from the Gansu provincial government.

Thorium is a metallic element with radioactive properties, near uranium on the periodic table, that was viewed as an alternative fuel source when the US first developed nuclear energy technology in the 1940s.

The Americans even developed an experimental thorium-based nuclear reactor at Oak Ridge National Laboratory in Tennessee, but the US closed it and abandoned thorium in favor of uranium in the early 1970s.

The new reactor, which was built in Wuwei on the edge of the Gobi desert in northern China, is an experimental prototype with an output of only 2 megawatts.

The molten salt thorium reactor at Oak Ridge National Laboratory was shut down in 1969. (

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According to a paper published in the Chinese science journal Nuclear Techniques by the Shanghai Institute of Applied Physics, the longer-term plan is to develop a series of small molten salt reactors, each with 100 megawatts of energy, enough for about 100,000 people.

Molten salt plants do not use water for cooling like traditional nuclear power plants and can therefore be built in desert areas, such as in China’s sparsely populated western regions.

The first commercial systems with the new technology are supposed to go online in 2030.

President Xi Jinping has promised to make China climate neutral by 2060.

Nigel Marks, associate professor of physics at Curtin University, said China’s advancement of thorium as a nuclear fuel is an exciting development.

“They effectively reactivated a research program that the US mothballed in the 1960s,” said Dr. Marks.

“Who knows, maybe they could make it work in a different climate with a different economy.”

Thorium is much more abundant than uranium and Australia has some of the largest reserves in the world.

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Thorium – named after Thor, the Norse god of thunder – has a number of decisive advantages over uranium.

The radioactive waste from thorium only has to be stored for about 500 years, compared to several thousand for uranium.

It is also much more difficult and time consuming to make weapons grade uranium from thorium.

Some proponents of thorium have even speculated that the US only bet on uranium, not thorium, because it was more useful for making nuclear weapons.

Dr. However, Marks said this was “all bullshit”.

“The main reason uranium has been used since the first reactor in the early 1940’s is because everything works so easily for uranium,” he said.

“There is only one element that can naturally cause a fission reaction and that is uranium.

“Thorium can in principle release the energy, but it is nowhere near as easy as with uranium.”

For example, thorium is more fertile than fissile, which means that another nuclear technology, typically a uranium reactor, is needed to kickstart the thorium chain, he said.

“Chemically, it’s a completely different element,” he said.

“Things that are just simple for uranium are just complicated for thorium.”

The new technologies could address some of the safety concerns many people have about traditional nuclear energy.

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India, which did not have access to uranium for nuclear power plants until 2008, had tried for decades to develop thorium energy but never got it working, he said.

He said the main thing holding back thorium as a potential fuel source is the cost and risk of developing a new technology that may ultimately not work or be cost effective.

Dr. Marks said the same molten salt technology could just as easily be used with uranium as it could with thorium.

Using molten salt instead of water means that a reactor cannot melt down like traditional water-cooled reactors.

Molten salt reactors are also potentially cheaper as they do not need to be pressurized to keep the cooling water from turning into steam.

Dr. Marks said China’s approach is not “keeping all your eggs in one basket”.

“They have a few different technologies and there are a lot of different reactor designs that they are pursuing across their nuclear sector,” he said.

“So try well and I’m really interested to see what happens.”