Andrew Yang Wants a Thorium Reactor By 2027

An anonymous reader quotes a report from Wired: To transition the United States from fossil fuels to green energy, [Democratic Presidential candidate Andrew Yang] wants the government to invest $50 billion in the development of thorium molten-salt nuclear reactors — and he wants them on the grid by 2027. “Nuclear isn’t a perfect solution, but it’s a solid solution for now,” Yang’s climate policy page reads. It calls out thorium molten-salt reactors in particular as “a technology we should invest in as a stopgap for any shortfalls we have in our renewable energy sources as we move to a future powered by renewable energy.” Thorium molten-salt reactors were first invented 60 years ago, but Yang appears to be the first presidential candidate to campaign on their promise to make nuclear energy safer, cleaner, and cheaper. Like all molten-salt reactors, they eschew solid rods of uranium-235 in favor of a liquid fuel made of thorium and a small amount of uranium dissolved in a molten salt. This approach to nuclear energy reduces proliferation risk, produces minimal amounts of short-lived toxic waste, and resists nuclear meltdowns. As in a conventional nuclear reactor, splitting the nuclei of a nuclear fuel — a process known as fission — produces heat, which gets used to turn a turbine to generate electricity. But the Cold War arms race meant the US was already in the business of enriching uranium for weapons, so nuclear reactors based on solid uranium took off while liquid reactors stalled. No country has built a commercial molten-salt reactor. As a result, many practical questions remain about the best way to design a thorium liquid-fuel reactor. Foremost among them, says Lin-Wen Hu, director of research and irradiation services at MIT’s Nuclear Reactor Laboratory, is finding materials that can contain the corrosive molten salts. Furthermore, figuring out how to extract unwanted elements produced as thorium decays — such as protactinium-233 — from the fuel remains a major technical challenge. “The main advantage of thorium is that the waste has a half-life on the order of dozens, rather than thousands, of years,” the report adds. “From a power-generation perspective, the better option for Yang and other Democratic candidates may be to invest in advanced uranium-based technologies. This includes molten-salt reactors, but also solid-fuel systems like next-generation fast reactors, which are safer and more efficient than previous nuclear reactor designs. In some designs, next-generation reactors can even use preexisting nuclear waste as fuel.”