After 40 years of major nuclear fusion milestones, the Joint European Torus facility finally shut down in December 2023—but not without one final record shattering achievement. On Thursday, representatives for the groundbreaking tokamak reactor confirmed its final experiment generated 69.26 megajoules of energy in only five seconds. That’s over 10 megajoules more than JET’s previous world record, and more than triple its very first 22 megajoule peak power level back in 1997.
While multiple facilities around the world can produce nuclear fusion reactions, it remains extremely cost prohibitive. JET’s December record, for example, pulled off its all-time energy levels in only five seconds—but that 69 megajoules was still only enough to warm a few bathtubs’ worth of water. Even the most optimistic realists estimate it could take another 20 years before affordable fusion energy is a viable option.