Inertia Enterprises cuts fusion fuel pellet manufacturing time from days to hours

Fusion startup Inertia Enterprises said it has cut the time to manufacture its deuterium-tritium fuel pellets from up to a week to roughly two to three hours. The company describes this as progress on one of 10 technical barriers it must clear to deliver the first phase of its commercial power plant ambitions.

Inertia’s fuel pellets consist of a spherical diamond shell with a thin frozen layer of deuterium and tritium inside and gaseous fuel at the core. Imperfections in the spherical shape can disrupt ignition, so precision remains critical even as the process is accelerated.

The startup worked with Lawrence Livermore National Lab’s National Ignition Facility (NIF) under a public-private partnership to adapt NIF’s prototype process for faster, scalable manufacturing. At NIF, making a handful of pellets per year can take a week or more and costs a substantial amount, according to Inertia CEO Jeff Lawson.

Lawson said the team aimed to turn NIF’s prototype approach into mass-manufacturable production, drawing on industrial engineers with backgrounds at companies like Apple to scale the process. The company now grows the crystal layer in about 30 minutes, compared with up to a week at NIF, and can produce a single pellet in roughly two to three hours.

Inertia’s commercial design uses a laser four times more powerful than NIF’s, which allows more tolerance for imperfections in the fuel pellets and further speeds manufacturing. Lawson described this as a strategy of “oversizing” the driver to create margin across the system.

Reducing manufacturing time also lowers the amount of tritium Inertia must hold at any given time. Tritium is radioactive, expensive at about $30,000 per gram, and only about 25 kilograms are stockpiled globally, according to the journal Science. Inertia plans to breed its own tritium via fusion reactions but still requires initial inventory.

The startup expects its full-scale commercial plant to consume 10 fuel pellets every second. By shortening the fuel filling step, Inertia says it can reduce facility size, improve speed, and increase overall efficiency.