By Sam Thompson
At last year’s UN General Assembly, President Xi Jinping announced to the world via video link that China wants to achieve CO2 neutrality by 2060. It was a bold statement by the world’s largest contributor to increasing carbon dioxide and was welcomed by the international community.
There is much speculation as to whether this is a plausible and serious target, but first impressions suggest that government leadership in the economy may accelerate the decarbonization of the country faster than many western decentralized states. This can be achieved, among other things, through larger investments in green science.
This opens avenues for lower emissions, while also establishing China as a major player in green technologies and helping to bridge the gap with the United States as both superpowers vie for global supremacy.
In this context, the reasons for China’s newest scientific enterprise are obvious. In July, government scientists announced that they were investing heavily in new nuclear technologies: Thorium-based molten salt nuclear power plants, with the first experimental tests on a prototype reactor starting in September. Strictly speaking, these are not a new concept.
Despite its reputation for sustainability, nuclear energy is not renewable
The Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory in the Tennessee city of the same name ran on thorium fuel instead of uranium for four years in the 1960s. More recently, private corporations have revived this space age relic. However, this announcement marks the first serious endorsement from a major government.
Thorium is an element two protons smaller than uranium and both belong to the actinides, a group on the periodic table. Interest in thorium has been sustained by a small vocal minority within the scientific community, with proponents claiming a variety of benefits over uranium.
Despite its reputation for sustainability, nuclear energy is not renewable. Uranium is a finite resource in the ground and will eventually run out. Thorium does not eliminate this problem, but it is three times more abundant in the earth’s crust. This can widen the transition window between fossil fuel-based energy and fully renewable technologies, allowing further refinement of solar cells and wind generators.
The monazite ore contains only a single useful isotope of thorium, Th-232, while uranium ores contain only about 0.7% of the fissile isotope U-235. Monazite is also easier to mine in opencast mines, where there is less risk of radiation poisoning due to the high radon concentrations in underground uranium mines.
Chinese scientists claim their thorium reactor will produce a thousand times less waste, which will return to safe levels a thousand times faster than conventional nuclear waste
Thorium is melted into a liquid fluoride salt matrix, which makes water unnecessary as a heat transfer medium, increases efficiency through higher temperatures and enables use in arid desert countries. This molten salt solidifies quickly on contact with air, effectively seals leaks itself and drastically reduces the risk of explosive core melts compared to uranium-water-based reactors.
One of the biggest concerns about nuclear power is the radioactive by-products that are generated in the reactors. The Chinese scientists claim that their thorium reactor will produce a thousand times less waste, which will return to safe levels a thousand times faster than conventional nuclear waste.
All of this begs the question: why was uranium chosen over thorium when it is clearly inferior? Thorium is cleaner, safer, and more abundant. However, it has a major “disadvantage” that it is much more difficult to turn the nuclear waste produced by thorium reactors into nuclear weapons. In the mid-20th century, at the time the MSRE in Oak Ridge closed, the US and Russia were embroiled in the Cold War that rang the death knell of thorium.
As both countries rushed to increase their nuclear arsenals, uranium research intensified and massive advances in reactor technology were made that put the world on the bad track of atomic energy. In the decades that followed, any country looking to build nuclear power plants would have no choice but to go for uranium, as thorium research requires massive investments to catch up with uranium. China is the first government ready to re-enter this area.
The AUKUS announcement this month can be seen as the prelude to the arms race with China
Questions remain about the logistics of the transition to thorium. Can existing uranium reactors, if at all, be converted to thorium in the long term? How impractical is it to make weapons from thorium by-products? Will the scale-up from prototype reactors to commercial reactors be financially viable and will they be developed in time to help China achieve its CO2 neutrality target by 2060?
But this announcement is a good first step. There is no single solution to limit man-made climate change; it requires a concerted, multi-pronged approach led by science-informed governments. Hopefully China’s actions can inspire all governments to do and do more. Market-based economies like ours are efficient at what they’re supposed to do, but they have little incentive for collective action that has no financial benefits like combating climate change.
AUKUS ‘announcement this month can be seen as the prelude to the arms race with China as the West prepares for a new Cold War.
This was in stark contrast to China’s announcement in the same month of thorium, a technology that has little military use and could allow the US to allow nuclear power in semi-developed countries like Iran without fear of nefarious side projects (as these would be made nearly impossible) . ). If China is willing to share its insights, they will not only be able to provide for themselves cleaner but, like Thorium’s Norse god namesake, will help electrify the rest of the world.
Image: jplenio, Pixabay
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