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A looming shortage of fuel for nuclear fusion may have an unexpected fix. A physicist at Los Alamos National Laboratory (LANL) suggests that tritium for fusion reactors could be generated using nuclear waste left over from fission plants.
If fusion energy becomes practical, it could revolutionize power production, delivering virtually limitless electricity on demand. Yet, the challenge isn’t the physics of fusion itself but a severe scarcity of the fuel it requires.
Why Fusion Needs More Than Ordinary Hydrogen
Unlike fission, which splits uranium or plutonium atoms to release energy, fusion works by merging hydrogen atoms into helium. The complication lies in the fact that fusion reactors cannot run on ordinary hydrogen—they require deuterium and tritium, heavier isotopes of hydrogen.
Deuterium, found in seawater, is abundant enough to supply humanity’s needs. Tritium, however, is extraordinarily scarce, with global reserves estimated at only 55 pounds ± 31 pounds (25 kg ± 14 kg). Its rarity drives costs up to roughly US$15 million per pound ($33 million per kilogram), with Canada’s fission reactors being the primary commercial source today.
To put it in perspective, powering one million U.S. homes for a year would require about 32 pounds (14.6 kg) of tritium—far beyond what current reserves can cover. If fusion plants were already widespread, excess power could be used to generate more tritium, but since that infrastructure doesn’t yet exist, an alternative must be found.
A New Approach from Los Alamos
Terence Tarnowsky of LANL has been exploring reactor simulations that turn fission waste into a tritium source. His approach builds on an old concept but leverages modern technology to make it viable. The process involves sealing radioactive waste—such as uranium and plutonium—inside molten lithium salt and bombarding it with high-energy particles from a superconducting linear accelerator. This triggers spallation, a nuclear reaction that releases neutrons. Those neutrons interact with lithium, eventually producing tritium.
A key advantage is safety: the reaction only continues while the accelerator is active, making it inherently subcritical. Tarnowsky estimates that a one-gigawatt system could generate enough tritium annually to power 800,000 homes—ten times the output of a fusion reactor of equivalent thermal capacity.
“Energy transitions are always expensive, so whenever there’s a way to ease that burden, we should pursue it,” Tarnowsky said.
He presented his findings last week at the American Chemical Society’s fall meeting.
Read th eoriginal article on: New Atlas
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