Scientists in the United States are developing a method to recycle nuclear waste into tritium, a rare hydrogen isotope vital for nuclear fusion. Fusion, the process that powers the stars, releases vast energy by fusing atomic nuclei. It is the cleanest energy sources because it can provide large amounts of electricity with minimal emissions.
Unlike fusion, existing nuclear plants rely on fission, which splits heavy atoms. Fission is effective for energy generation but produces long-lasting radioactive waste that requires costly storage. Fusion reactors need deuterium and tritium as fuel. Deuterium is plentiful, but tritium is scarce. The United States currently lacks the ability to produce enough tritium to meet future energy needs.
Tritium is highly valuable. Physicist Terrence Tarnowsky of Los Alamos National Laboratory notes that commercial tritium costs around $15 million per pound, or $33 million per kilogram. Global reserves are only about 55 pounds, or 25 kilograms, which could power more than 500,000 homes for six months. Meanwhile, the United States has
thousands of tons of radioactive waste stored from nuclear plants. Tarnowsky and his team are studying ways to use this waste to generate tritium. Computer simulations show that particle accelerators could drive reactions inside the waste. As atoms split, it eventually leads to production of tritium through nuclear transitions due to release of neutrons. Unlike chain reactions in conventional reactors, accelerator-driven systems can be switched off easily, offering greater safety.
Early findings are encouraging. A one-gigawatt reactor could produce about 4.4 pounds, or 2 kilograms, of tritium each year. This is more than ten times the amount produced by a fusion reactor of equal power. Tarnowsky is now refining efficiency models and preparing cost calculations. He is also exploring designs using molten lithium salt, which could improve yields.
The project is supported by Los Alamos National Laboratory and the National Nuclear Security Administration. Tarnowsky will present his findings at the American Chemical Society fall meeting. If successful, the approach could turn nuclear waste into a valuable resource while helping power the future of clean energy.
