The Potential Benefits of Thorium Nuclear Energy

by Liam Sternberg

Chernobyl Nuclear Power Plant in northern Ukraine

Historically, American citizens have feared nuclear energy. Nuclear disasters, such as the notorious Fukushima and Chernobyl reactor meltdowns, have led many to hold a deeply rooted paranoia about all things nuclear. However, technology has greatly advanced since the time of Chernobyl, and climate change is renewing interest in alternative sources of energy. Among these advances are the fact that nuclear reactors can produce energy in less time with the emission of far less greenhouse gasses than other common energy sources in the United States, such as natural gas and coal. Nevertheless, the extraordinary cost of nuclear power plants prevents their widespread use, but the use of thorium may help solve this issue and many others.

Silos for containing nuclear waste

Most nuclear power plants use a radioactive isotope of uranium: uranium-235. These power plants are known to have high operating costs and pose health hazards to workers. For instance, uranium ore releases highly toxic and radioactive radon gas during its decay. Thus, advanced ventilation machinery is required in mining to protect workers. This drives up costs significantly. In addition, uranium ore is refined into pure uranium, most of which is a different isotope: uranium-238. The filtering of the correct isotope, a process known as nuclear enrichment, requires centrifuges and other expensive machinery. The permanent storage of nuclear waste is also costly, requiring items such as cooling pools and dry casks.

However, by using earthen thorium in place of uranium-235, almost all these disadvantages can be nullified. First, consider the difference in energy density. CERN estimates that one ton of earthen thorium is equivalent in atomic energy to approx. 200 tons of enriched uranium, while producing roughly 100 times less nuclear waste. Thorium is also three times as abundant as uranium, and it is found in more concentrated ores, making it more efficient to harvest. This is especially true in the United States, where uranium is rarer and thorium is more common. The U.S. has over 800,000 tons of thorium ore in reserve.

Diagram of a molten salt nuclear reactor

Lastly, thorium is much less prone to cause reactor meltdowns when compared to uranium. Thorium is a fertile material; it needs to transmute into fissile materials before it can undergo nuclear fission. Uranium, by contrast, is already fissile and can directly undergo fission. Thorium needs a helper material, like plutonium-238, to sustain nuclear fission. While this may seem like a negative, it's an important advantage of thorium power plants. In the event of an error in a reactor, uranium will continue reacting, which may cause enormous environmental damage through the uncontrolled production of toxic nuclear waste. However, since thorium requires an intermediary to undergo fission, it can be separated from the rest of the reactants, in case of an emergency. This can easily be done via a mechanism such as a meltable cork, to cease all reactions and minimize damage to the reactor and its surroundings. Such simple safety measures work much more effectively than those used in uranium-235 plants and are less expensive.

In sum, thorium nuclear power plants have advantages that make them a powerful alternative option to uranium power plants. With their increased efficiency, lower environmental impact, and increased safety, thorium reactors are a compelling choice on the frontier for sustainable energy—one that could redefine the future of energy production!

Citations

Mecklin, John. “Why Nuclear Power Plants Cost so Much—and What Can Be Done about It.” Bulletin of the Atomic Scientists, 21 Jun 2019, thebulletin.org/2019/06/why-nuclear-power-plants-cost-so-much-and-what-can-be-done-about-it/. 

Cleveland Clinic. “Radon Gas: What Is It, Detection & Complications.” Cleveland Clinic, 21 Jun 2024, my.clevelandclinic.org/health/articles/21523-radon-gas. 

Hickman, Hannah. "What Happens to Nuclear Waste in the U.S.?", www.nei.org/news/2019/what-happens-nuclear-waste-us. Accessed 21 Jun 2024. 

Spinrad, Bernard I. and Marcum, Wade. "nuclear reactor". Encyclopedia Britannica, 27 Jan. 2025, https://www.britannica.com/technology/nuclear-reactor. Accessed 30 Jan 2025.

Thorium Reserves by Country 2024, worldpopulationreview.com/country-rankings/thorium-reserves-by-country. Accessed 30 Sept 2024.