Nuclear power is the release of energy from the atomic core of radioactive elements, such as uranium, plutonium and thorium. It has military and civil use, with the latter referring to the generation of electricity for civil consumption. Civil nuclear power accounted in 2018 for about 10% of total global electricity generation (International Energy Agency 2019). 443 civilian nuclear reactors across the world currently produce this energy, and they are based on uranium and plutonium (IAEA 2019). Thorium has several times been launched as a candidate for improved nuclear energy production. The first part of the article explores thorium and the status of research and experimentation with thorium-based nuclear energy. The second part examines the extraction process of thorium.
Thorium, named after the Norse god of thunder Thor after it was discovered in 1828, was identified as a source of nuclear energy alongside uranium and plutonium (Atomic Energy Commission 1946). Yet the technology for exploiting thorium as a resource lagged behind, as nuclear reactors were developed for uranium and plutonium-based fuels. Today, several initiatives exist across the world seeking to take advantage of the material properties of thorium. These advantages include:
- Thorium is more abundant, with some estimates at three-four times the abundance of uranium (World Nuclear Association 2017).
- Thorium-based nuclear reactors are held to be safer than uranium-based ones both because of the material properties of thorium and the types of reactors and technology used (Cooper et al. 2011). For instance, thorium is not fissile, meaning that for it to begin to split apart, you need to throw neutrons at it. This is thus a controlled process.
- Weapons proliferation is seen as less of a concern. For instance, Stenger holds that thorium-based nuclear energy was not pursued because it could not be applied to nuclear weapons production (Stenger 2012).
- Thorium-based nuclear energy produces significantly less nuclear waste than uranium. In addition to less waste, the time-span of the waste is much shorter (Moir and Teller 2005).
- The energy efficiency of thorium is higher than uranium, with Nobel laureate Rubbia estimating that 200 tons of uranium are needed to produce the same amount of energy as one ton of thorium (Evans-Pritchard 2010).
China, India and Turkey have included thorium in their national energy policies and have initiatives in place to test the feasibility of thorium as fuel in nuclear reactors (Thor Energy 2018). China has been aiming for a working thorium reactor for several years, seeing it as a solution to the pollution problems caused by energy from coal. Two thorium reactors are being constructed and are expected to be in commercial use in 2030 (Shen 2019). India plans on being energy independent based on its thorium resources and produce up to 30% of its energy with thorium within 30 years (Katusa 2012). India holds the world’s largest known thorium reserves. Beyond this, there are research and experiment initiatives in Canada, Israel, Japan, Russia, Norway, France, the UK and the US. Some of the initiatives experiment with the use of thorium as fuel in existing reactors, such as Thor Energy in Norway (Thor Energy 2018). Others, such as initiatives in China and India, are developing new types of reactors. For instance, China is experimenting with so-called Molten Salt Reactors.
There is an expectation from countries, international organizations and scientists that increasingly large parts of the nuclear energy production will be thorium based. What does this have to say for extraction processes?
Thorium as extracted today is usually as a by-product of extracting other resources, such as rare earth elements. Most of this comes from monazite sand, and the extraction process is easier and with less radioactive waste and impact than uranium mining (IAEA 2015).
A large extraction site for thorium is India’s beaches. Thorium mining from monazite sand in India is done through placer mining – the use of water and excavating equipment to move and recover minerals. Shaking tables are used to wash out lighter minerals.
Several private companies were involved in thorium extraction until mid-2019, when the Indian government banned private mining on beaches, now granting operating rights only to state-owned companies. Uranium has also been mined in these areas, although the uranium reserves of India are marginal – an important reason for their large efforts to make thorium a viable fuel for nuclear energy production. Uranium mining and its extraction process has been met with social oppositions, as seen for instance in this protest by children against the nuclear waste resulting from uranium mining.
Given India’s firm plan on exploiting their vast thorium reserves, it remains to be seen what the effects of potential large-scale thorium extraction will be on ecosystems, the environment and on people. Although thorium extraction is held to be easier and less damaging, we have not yet experiences large-scale thorium mining.
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Contributor: Astrid Skjold