In a fusion power plant, isotopes of hydrogen fuse into helium at extremely high temperatures. The fuel source for our fusion power plant is D-T, a 50/50 mix of deuterium and tritium. Deuterium is a hydrogen isotope with one neutron, and tritium has two neutrons.

Deuterium is found naturally in water. Tritium doesn’t occur naturally on Earth in any significant quantity but can be created by lining the fusion chamber with pipes full of liquid lithium. When neutrons from the fusion reaction hit the wall, some lithium atoms will react to become tritium. Then, the tritium must be extracted from the liquid lithium to be packaged into a fuel target. This extraction process is still an area of active development. Inertia and others are developing the processes to extract the tritium from the lithium as it is carried away from the target chamber in the flowing lithium.

But lithium is a finite resource on Earth with many applications. Luckily, our 1.5 GW power plant – enough to power 1 million homes – would require only the amount of lithium in 20 electric vehicle batteries per year of operation. At startup, we need only a small amount of tritium to bring our pilot plant online. The initial tritium would be sourced from government-controlled supplies in the U.S., while we ramp up our own tritium breeding system. This small amount of tritium is well within the inventory of the U.S. civilian stockpile.

Because our design uses only milligrams of tritium per shot, our fusion power plant can operate with on-site tritium inventories of hundreds of grams at any point in time, simplifying regulatory processes and easing safety concerns.Other fusion designs, such as tokamaks, require more than twenty times the amount of tritium in use at any point in time. These multi-kilogram startup inventories would require more tritium than currently exists in the civilian stockpile. Additionally, with so much tritium required for continued operation, these designs create more complicated regulatory and public safety concerns.