Andrew Yang, like many of the 2020 Democratic presidential hopefuls, has an ambitious plan to wean America off of fossil fuels. Unlike many of the other candidates, however, a key piece of his plan to address climate change involves harnessing nuclear power—in particular thorium. According to Yang, thorium is “superior to uranium on many levels.” But Yang isn’t alone; thorium boosters have been extolling its supposed virtues for years. Claim: Thorium reactors would be more economical than traditional uranium reactors, particularly because thorium is more abundant than uranium, has more energy potential than uranium, and doesn’t have to be enriched. False. Although thorium is more abundant than uranium, the cost of uranium is a small fraction of the overall cost of nuclear energy. Nuclear energy economics are driven by the capital cost of the plant, and building a power plant with a thorium reactor is no cheaper than building a power plant with a uranium reactor. Further, using thorium in existing reactors is technically possible, but it would not provide any clear commercial benefit and would require other new infrastructure. Claim: Next generation thorium reactors would be safer than current reactors. True but misleading. Nuclear energy is already very safe, and Yang is correct about that. Claim: The waste from thorium reactors would be easier to deal with than waste from today’s uranium reactors. False. A comprehensive study from the US Energy Department in 2014 found that waste from thorium-uranium fuel cycles has similar radioactivity at 100 years to uranium-plutonium fuel cycles, and actually has higher waste radioactivity at 100,000 years. Claim: Thorium would be more proliferation-resistant than current reactors—you can’t make nuclear weapons out of it. False. A 2012 study funded by the National Nuclear Security Administration found that the byproducts of a thorium fuel cycle, in particular uranium 233, can potentially be attractive material for making nuclear weapons. A 2012 study published in Nature from the University of Cambridge also concluded that thorium fuel cycles pose significant proliferation risks.
Bulletin of Atomic Scientists 18th Dec 2019 read more »