There is enough energy in the nuclear waste in the United States to power the entire country for 100 years with clean energy, says Jess C. Gehin at the Idaho National Laboratory. CNBC reports: There are 93 commercial nuclear reactors at 55 operating sites in the United States, according to Scott Burnell, spokesperson for the Nuclear Regulatory Commission. Twenty-six are in some stage of decommissioning process. All of the nuclear reactors that operate in the U.S. are light-water reactor designs […]. In a light-water reactor, uranium-235 fuel powers a fission reaction, where the nucleus of an atom splits into smaller nuclei and releases energy. The energy heats water, creating steam which is used to power a generator and produce electricity. The nuclear fission reaction leaves waste, which is radioactive and has to be maintained carefully. There are about 80,000 metric tons of used fuel from light-water nuclear reactors in the United States and the existing nuclear fleet produces approximately an additional 2,000 tons of used fuel each year, Gehin told CNBC. But after a light-water reactor has run its reactor powered by uranium-235, there is still tremendous amount of energy potential still available in what is left.
“Fundamentally, in light-water reactors, out of the uranium we dig out of the ground, we use a half a percent of the energy that’s in the uranium that’s dug out of the ground,” Gehin told CNBC in a phone interview. “You can get a large fraction of that energy if you were to recycle the fuel through fast reactors.” Fast reactors don’t slow down the neutrons that are released in the fission reaction, and faster neutrons beget more efficient fission reactions, Gehin told CNBC. “Fast neutron reactors can more effectively convert uranium-238, which is predominantly what’s in spent fuel, to plutonium, so you can fission it,” Gehin said.
Even as private companies are working to innovate and commercialize fast reactor designs, there are significant infrastructure hurdles. Before nuclear waste can be used to power fast reactors, it has to go through reprocessing. Right now, only Russia has the capacity to do this at scale. France, too, has the capacity to recycle used nuclear waste, Gehin said, but the country generally takes its recycled fuel and puts it back into existing light water reactors. For now, the Idaho National Lab can reprocess enough fuel for research and development, Gehin told CNBC, but not much more.
Private companies commercializing fast reactor technology are pushing for domestic fuel supply chains to be developed. TerraPower says it’s investing in supply chains and working with elected leaders to build political support, while Oklo has received three government awards and is working with the government to commercialize fast reactor fuel supply chains domestically. The other option to power fast reactors is to create HALEU fuel, which stands for high-assay low-enriched uranium, from scratch, rather than by recycling nuclear waste. (Where conventional reactors use uranium enriched up to 5%, HALEU is uranium enriched up to 20%.) It’s arguably easier to produce HALEU directly than by recycling spent waste, says Gehin, but ultimately, the cheaper option will win out. “It will be largely be driven by what makes sense economically.” Regardless, Russia is the only country that has the capacity to make HALEU at commercial scale.
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