Inertia Enterprises cuts its fusion fuel-pellet time from days to minutes

Investors gave Inertia $450 million on the premise that it could commercialize technology developed at the National Ignition Facility (NIF), an elaborate science experiment where making a single fuel pellet can take a week or more and cost a small fortune. “When you really double-click on it, you’re like, wait a minute, they’re only making a handful of them a year,” Inertia co-founder and CEO Jeff Lawson told TechCrunch, in an exclusive first look at the process. “I put on my commercial hat and was like, wait a minute, I know the word for this: prototypes.” The company has been hiring industrial engineers from companies like Apple to turn that prototype process into something mass-manufacturable.

The NIF’s fuel pellet is a spherical diamond shell holding a thin frozen layer of deuterium and tritium — hydrogen isotopes that fuel a fusion reaction — around a gaseous mix of the same elements, each layer required to be nearly perfectly spherical. The pellets sit inside gold casings that convert laser energy into X-rays to compress them; even small imperfections can disrupt ignition. Inertia co-founder and chief scientist Annie Kritcher designed the first NIF experiment to release more energy than it consumed, giving the startup a head start on the physics.

After several rounds of development, Inertia can now grow the pellet’s crystal layer in about 30 minutes, versus up to a week at the NIF, and produce a full fuel pellet in about two to three hours — a process the company says can scale to industrial volumes. Inertia is planning to use a laser about four times more powerful than the NIF’s current one, letting it tolerate more pellet imperfections and speed up manufacturing. “We actually have a lot of margin,” Lawson said. “That’s our strategy, to oversize our driver, our laser, to give us lots of margin to go play with in every other part of the system.”

Faster fuel filling also cuts how much tritium Inertia needs to stockpile at once — a meaningful constraint, since the radioactive isotope costs about $30,000 per gram and only about 25 kilograms exist in stockpiles worldwide, according to the journal Science. Inertia, like other fusion startups, plans to eventually produce its own tritium from its reactions, but needs some inventory to start. The company expects its full-scale commercial plant to consume 10 fuel pellets every second.

Why it matters

Manufacturing speed, not just fusion physics, has become one of the harder bottlenecks between lab-scale ignition and a plant that runs continuously — and Inertia’s pellet-speed gain suggests that bottleneck is more tractable than it looked.