Thorium 90
Lightning God of All Elements
Thorium, a naturally occurring radioactive element, bears the symbol Th and holds the atomic number 90. Named after Thor, the Norse god of thunder, thorium is lauded for its unique properties and high potential to solve longstanding issues in its industrial setting.
This element is not just a scientific curiosity but a fertile material, meaning it can be converted into a fissile substance, such as uranium-233, through neutron absorption and subsequent nuclear reactions. Thorium's significance extends beyond its chemical characteristics; it symbolizes a prosperous future for sustainable and safer nuclear energy. Which is already the safest form of energy today.
Properties
Atomic Number: 90
Symbol: Th
Atomic Weight: 232.03806
Melting Point: 1750 °C (3182 °F)
Boiling Point: 4788 °C (8650 °F)
Density: 11.7 g/cm³
Occurrence
Thorium is about three to four times more abundant in the Earth's crust than uranium. It is found in small amounts in most rocks and soils, where it is about as common as lead. Major sources include minerals such as thorite (ThSiO4) and monazite [(Ce, La, Th, Nd, Y)PO4].
History
Thorium was discovered in 1828 by the Swedish chemist Jöns Jacob Berzelius. It was first isolated as a metal by the chemist Friedrich Wöhler in 1829. Thorium's potential as a nuclear fuel was recognized in the early 20th century, and it was used in various research reactors.
Thorium in Nuclear Energy
Thorium has significant potential as a nuclear fuel. Unlike uranium, which is primarily fissile (meaning it can sustain a nuclear chain reaction), thorium is fertile. When thorium-232 absorbs a neutron, it becomes thorium-233, which beta decays to protactinium-233 and then to uranium-233, a fissile material.
Advantages
Abundance: Thorium is more abundant than uranium, making it a more sustainable resource for long-term energy production.
Safety: Thorium reactors produce less long-lived radioactive waste compared to traditional uranium reactors. Additionally, thorium reactors operate at atmospheric pressure, reducing the risk of catastrophic accidents.
Proliferation Resistance: Thorium fuel cycles are less conducive to the production of weapons-grade materials.
Efficiency: Thorium reactors can potentially achieve higher fuel utilization rates than conventional uranium reactors.
Types of Thorium Reactors
Molten Salt Reactors (MSRs): In these reactors, thorium is dissolved in a molten salt, which acts as both the fuel and the coolant. MSRs operate at high temperatures and low pressures, enhancing their safety and efficiency. The most famous example is the Liquid Fluoride Thorium Reactor (LFTR).
Heavy Water Reactors (HWRs): These reactors use heavy water (deuterium oxide) as a moderator to sustain the nuclear chain reaction. Thorium can be used in these reactors to breed uranium-233.
Accelerator-Driven Systems (ADS): These systems use a particle accelerator to produce neutrons, which then convert thorium-232 into fissile uranium-233. ADS reactors are subcritical, meaning they require an external neutron source to sustain the reaction, adding an extra layer of safety.
Current and Future Prospects
Despite its advantages, the commercialization of thorium reactors faces several challenges, including technical, regulatory, and economic hurdles. Research and development are ongoing in several countries, including India, China, and Norway, which have active thorium reactor programs.
India
India has one of the largest thorium reserves in the world and has been actively pursuing thorium-based nuclear energy. The country’s three-stage nuclear power program aims to utilize thorium in its advanced reactors.
China
China is investing in research and development of thorium reactors, particularly molten salt reactors (TMSR). The goal is to create a safer, more efficient, and environmentally friendly nuclear energy source.
Norway
Norway has also been exploring thorium as a potential fuel for its reactors. The country’s focus is on developing thorium-based nuclear technology and contributing to the global knowledge base on thorium energy.
Environmental and Economic Impact
Thorium reactors have the potential to significantly reduce their already very low environmental impact of nuclear energy. (All Nuclear “Waste” ever created can fit in the space of a football field) They produce less 1/10th the radioactive waste and have a 1/100th lower risk of catastrophic accidents compared to boiling water reactors. Additionally, a properly designed reactor can “burn” existing waste stockpiles. The abundance of thorium can lead us to a more sustainable and cost-effective fission energy future.
Challenges
Technological Development: Developing and commercializing thorium reactors requires technological advancements, regulatory reform, and investment.
Regulatory Hurdles: The regulatory framework for thorium reactors is woefully underdeveloped compared to light water uranium reactors.
Economic Viability: The initial costs of developing thorium reactors are higher in the short term due to regulatory friction, and the economic benefits need to be clearly demonstrated to attract investment. (A problematic catch-22)
Conclusion
Thorium represents a shining alternative to traditional solid water-based uranium-235 nuclear energy we use today. Its abundance, safety features, and potential for reducing nuclear waste make it an inevitable option for future energy generation. However, overcoming the technical, regulatory, and economic challenges will be a challenge for thorium to overcome and become a commonplace energy source.