The Chinese nuclear safety body has given the go-ahead for the nation’s inaugural thorium reactor, a major step in its march towards advanced nuclear technologies.
Located in the Gobi desert city of Wuwei, in Gansu province, the Shanghai Institute of Applied Physics of the Chinese Academy of Sciences operates a 2-MW liquid-fuelled thorium molten salt reactor (MSR). On June 7, the National Nuclear Safety Administration issued a permit granting the Shanghai Institute the ability to run the reactor for a decade starting with trial operations. The Shanghai Institute is mandated to ensure the safety of the reactor in accordance with applicable laws, regulations and technical specifications laid out in the permit.
Thorium-based nuclear power plants have the potential to be more secure, produce less radioactive waste, and be more efficient with fuel than conventional uranium reactors. China is in possession of copious amounts of thorium in comparison to uranium, and their nuclear sector has seen a major milestone with the creation of the reactor. Experts from the Chinese nuclear industry have stated that the project is a representation of the nation’s advancement in the development and use of advanced nuclear technology, and it has secured a prominent position for the country in the realm of thorium reactor technology.
But, despite India’s efforts at developing thorium-based nuclear technologies, the initiative has been hindered by such issues as fuel-reprocessing, material compatibility and an overall intricate system, thus preventing its implementation at a commercial level.
Benefits of Thorium as Nuclear Fuel
Greenhouse gases trap heat, which contributes to climate change. Reducing emissions can help slow the rate of climate change and its impact. As climate change makes the world a less pleasant place to live, more people are interested in nuclear power. Solar and wind energy can help reduce greenhouse gas emissions, but nuclear power is likely to be part of any answer to climate change. But the potential risks associated with nuclear power cannot be overlooked despite the fact that it does not generate the same climate-altering gases that other electricity-generating power sources do.
Discarding radioactive wastes from nuclear power plants is a major challenge. Furthermore, if the core melts down and causes an environmental disaster—like the Chernobyl nuclear power plant meltdown and explosion in Ukraine in 1986—the repercussions can be far-reaching and potentially devastating. The generation of energy—or, in the case of nuclear bombs, a huge blast—is accomplished through nuclear fission, which is a nuclear chain reaction in which atoms are split apart.
Given the current state of India’s energy consumption, it is worth continuing to work hard to guarantee the safety of nuclear power, although there are other issues to be taken into consideration. Data collected up to the end of 2021 indicates that there are roughly 450 nuclear reactors in operation around the world and they all require fuel. Most of the reactors that use uranium-235 (U-235) as fuel are operated in numerous nations—including France, Russia and others—which recycle the fuel and add in plutonium-239 to create mixed-oxide fuel.
The byproduct of used fuel from nuclear reactors, plutonium, is employed in the recycling of nuclear fuel in France and several other countries. Yet, it is highly toxic and is the most common element utilized for nuclear weapons, leading to researchers continuing to explore other possibilities.
But, Basically, What is Thorium?
Researchers have proposed that thorium could be a viable solution to the nuclear power issues we face. This particular element is slightly radioactive and is not uncommon—it is nearly as plentiful as tin and more plentiful than uranium. Thorium is spread out over multiple locations—primarily India, Turkey, Brazil, the US and Egypt.
It is important to note that thorium is not a fuel like uranium. The difference is that uranium is ‘fissile’, meaning that it can undergo nuclear fission on its own, releasing energy in the process. The word, ‘fissile’, comes from the Latin word, ‘findere’, which means ‘to split’ or ‘to cleave’. In nuclear physics, a fissile material is one that can undergo nuclear fission. This means that it can split into two smaller nuclei, releasing a large amount of energy in the process.
Uranium-235 is the most common fissile isotope of uranium. Thorium, on the other hand, is a naturally occurring element that is more abundant than uranium. It is not fissile, meaning that it cannot undergo nuclear fission on its own. However, it can be converted into fissile uranium-233 by absorbing neutrons.
There are two main types of fissile materials:
Fissionable materials can be induced to fission by neutrons of any energy. Uranium-235 is the most common fissionable material, but it is found only in small quantities in nature
Fissile materials can only be induced to fission by neutrons of low energy. Uranium-233 and plutonium-239 are the most common fissile materials; both are created by neutron bombardment of other elements.
Indeed, a Double-Edged Sword!
Fissile materials are used in nuclear reactors and nuclear weapons. In a nuclear reactor, fissile material is used to generate heat, which is then used to produce electricity. In a nuclear weapon, fissile material is used to create a chain reaction, which releases a large amount of energy in a very short period of time.
The use of fissile materials is a double-edged sword. On one hand, they can be used to generate clean and safe energy. On the other hand, they can also be used to create destructive weapons. It is important to use fissile materials responsibly and ensure that they are not used for malicious purposes.
Thorium has some distinct advantages when it comes to energy production. Uranium-233 derived from thorium is thought to be more efficient than uranium-235 or plutonium as its reactors are much less susceptible to meltdown. This is because they can operate at higher temperatures. It also produces much less plutonium during reactor operation.
Some experts have suggested that, by using a fleet of thorium-and-uranium-233 reactors, the large amounts of hazardous plutonium that have been stockpiled since the 1950s can be destroyed. Some scientists also believe that a thorium-based system is more resistant to proliferation, as it requires more sophisticated technology to separate uranium-233 from other waste products and use it to manufacture weapons.
Thorium Reactors: Working Principle
Thorium reactors use the naturally occurring isotope thorium-232 as a fuel. When thorium-232 is irradiated in a reactor, it absorbs neutrons to form uranium-233, which is a fissile material that generates heat. The heat can then be used to generate electricity or for other purposes.
Thorium reactors’ advantages over traditional uranium reactors:
They are more proliferation-resistant as thorium cannot be used to make nuclear weapons.
They produce less waste as the thorium fuel cycle produces less long-lived radioactive isotopes.
They are potentially safer as they are less prone to meltdowns.
However, thorium reactors are still in the early stages of development and there are some challenges that need to be overcome before they can be widely deployed.