The Two Faces of Uranium Fuels: The Imminent Demise of Nuclear Energy or Its Effective Immortality

Abstract

Fissile U-235, at only 0.72% of natural uranium, is precious, since this small quantity is the primary source of nuclear energy in all current thermal nuclear reactors. This reactor technology thus cannot capture and yield even 1% of the nuclear energy that is inherent in total uranium, even counting the energy from the small fraction of U-238 that is transmuted into fissile Pu-239/241. Therefore the 3 million tons of uranium mined since the beginning of commercial nuclear power have produced energy from a mere 16,500 tons of that heavy element. With this rather profligate thermal nuclear technology the World’s additional 6 million tons of economically accessible in-ground uranium reserves, used currently at a rate of 67,000 tonnes/year, will be exhausted in 90 years. Canada’s reserves of some 600,000 tonnes uranium, processed and exported today at about 15,000 tonnes/year will be gone sooner, by 2060. The COP28 call for tripling of nuclear energy generation would cut each of these time frames closer to 30 years and 15 years, respectively. That timeframe will toll the demise of nuclear energy as we know it. The only alternative is a timely transition from thermal reactors to fissile- maintaining fast-spectrum reactors that augment the U-235-fission-induced in-core transmutation of U-238 to fissile Pu-239/241. That technology effectively creates transuranic fissile fuel from Canada’s and the World’s stored used uranium, from the stored 3 million tonnes depleted uranium, and from all of the known 6 million tonnes of U-238-containing in-ground reserves. Since 16,500 tonnes of fissile uranium served as nuclear energy source over the last 40 years on average, the total of 9 million tonnes of transmuted U-238 would provide equivalent worldwide power for 22,000 years, i.e. for an effective eternity. It is possible and economical to do so.