On the edge of the Gobi Desert, at a place called Wuwei (武威市), the People’s Government of Gansu Province (甘肃省), announced in May 2021 that it will soon test a reactor with nuclear power that has a high level of safety, very low CO2 emissions, is inexpensive, and will not need uranium and water to cool. It will have the particularity of using molten salts instead of water. For the development of this project, the Chinese government has invested more than 535 million euros over the past ten years. The construction of the site began on September 30, 2018.
This experimental nuclear reactor will use thorium as fuel. China could become the first country to have the opportunity to commercialise this technology.
A source that can supply humanity with energy for tens of thousands of years
Thorium is a weakly radioactive metal that occurs naturally in rocks. It is currently rarely used in industry. It is a by-product of the growing rare earth mining industry in China. It is therefore a very interesting alternative to uranium.
According to the co-winner of the 1984 Nobel Prize in Physics, Carlo Rubbia, the comparison of the energy produced by one tonne of thorium fission would be equivalent to about 200 tonnes of uranium. Given that 7 grams of uranium is equivalent to about one tonne of coal, one tonne of thorium would replace about 28 million tonnes of coal. Thinking about the potential success of this project, one can imagine the future tonnes of CO2 that will be avoided to manage the climate emergency.
One tonne of thorium is a sphere of about 55 cm in diameter. A piece of thorium the size of a tennis ball could electrify London for a week. One tonne of thorium would be enough to power a molten salt reactor that produces 1000 MW of electricity, for one year. The earth’s thorium reserves can supply the world’s energy needs for tens of thousands of years.
Thorium has a low cost, around €250,000 per tonne, or €0.029/electric MWh. Compared to uranium, at about €10/electric MWh, thorium would be around 350 times cheaper per electric MWh produced.
It also has the potential to generate a much smaller amount of very long-life radioactive waste than conventional reactors. The total volume could be about 35 times less than conventional reactors to produce the same amount of energy. The 99.99% of the waste would be stable in 300 years, instead of tens of thousands of years for current fuels.
There is another advantage: this type of reactor does not need to be built close to waterways. The molten salts themselves serve as a coolant, unlike conventional uranium power plants, which need huge amounts of water to cool their reactors.
By this principle, the reactors can be installed in isolated and arid regions, such as deserts.
Compared to water reactors in conventional nuclear power plants, molten salt reactors can operate at higher temperatures.
According to Nature.com, the Chinese reactor will use fluoride-based salts. They melt into a colourless, transparent liquid when heated to around 450°C. This salt is the equivalent of a coolant for the reactor core.
In addition, rather than solid fuel rods, molten salt reactors also use the liquid salt as a substrate for the fuel, such as thorium dissolved directly in the core.
Molten salt reactors have a very high level of operational safety. The fuel is dissolved in a liquid and these reactors operate at lower pressures than conventional nuclear reactors.
However, some critics argue that the feasibility of molten salt reactors remains questionable, as it creates other technical problems to be solved. At very high temperatures, the salt can corrode the reactor structures and must be protected accordingly.
China could be a major turning point for humanity
The experimental reactor to be operated by the Shanghai Institute of Applied Physics is designed to generate two megawatts of thermal energy. This is enough energy to electrify about 1,000 homes.
If the experiments are successful, China plans to build a reactor with a capacity of 373 megawatts by 2030. It could electrify hundreds of thousands of homes.
According to Jiang Kejun of the Energy Research Institute of the National Development and Reform Commission in Beijing, this type of reactor is one of the “perfect technologies” that should help China achieve its goal of zero carbon emissions by 2060.
When China starts up its pilot reactor, it will be the first thorium molten salt reactor to operate since 1969. At that time, US researchers shut down their reactor at Oak Ridge National Laboratory in Tennessee. This laboratory was originally planned to run the Molten-salt Reactor Experiment with a mixture of thorium-232 and uranium-233, but this test program was unfortunately cancelled. According to nature.com, the researchers who collaborated on the project say that the Chinese design copies the Oak Ridge design, but improves on it by drawing on decades of innovation in manufacturing, materials and instrumentation.
Molten salt reactors are just one of many advanced nuclear technologies in which China is currently investing.
In 2002, an intergovernmental forum identified six promising reactor technologies to be accelerated by 2030, including reactors cooled by lead or sodium liquids. China has research and development programs for each one of them.
While China has set itself a target of carbon neutrality by 2060, it could replace the boilers in its current coal and gas-fired power plants with thorium-fired nuclear reactors.
If successful, China is considering mass production, which could start as early as 2030.
The Chinese reactor will be a magnificent test and learning bench without precedent for mankind. It will undoubtedly allow us to discover new scientific data that can help us build humanistic and non-ideological solutions for the future.
Let’s get out the anti-nuclear obscurantism
As the European Union enters a major energy crisis, it would do well to raise its head from anti-nuclear obscurantism.
This major crisis undoubtedly finds its foundations in the antinuclear ideology of the past and the delay in nuclearising and electrifying as much as possible as many industrial processes and goods using fossil fuels as possible.
This obscurantism has undeniably delayed the construction of sufficient new nuclear production units. With these new constructions, the European Union would have been better protected from the financial increases of fossil fuels that will become unbearable for the citizens in 2021. If no new nuclear power plants are built, the increases will only become more pronounced as the exploitable reserves of fossil fuels will only decrease.
Let’s anticipate the future, in the same way that fossil fuels have replaced medieval energies such as wind and solar power, nuclear energy must replace fossil fuels for centuries to come. With the development of nuclear energy, fossil fuels will become medieval energy for centuries to come.
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