Nuclear startups are back in vogue with small reactors, and big challenges

The nuclear industry is in the mist of a renaissance. Old plants are being refurbished, and investors are showering startups with cash. In the last several weeks of 2025 alone, nuclear startups raised $1.1 billion, largely on investor optimism that smaller nuclear reactors will succeed where the broader industry has recently stumbled.

Traditional nuclear reactors are massive pieces of infrastructure. The newest reactors built in the U.S. — Vogtle 3 and 4 in Georgia — contain tens of thousands of tons of concrete, are powered by fuel assemblies 14 feet tall, and generate over 1 gigawatt of electricity each. But they were also eight years late and more than $20 billion over budget.

The fresh crop of nuclear startups hopes that by shrinking the reactor, they’ll be able to sidestep both problems. Need more power? Just add more reactors. Smaller reactors, they argue, can be built using mass production techniques, and as companies produce more parts, they should get better at making them, which should drive down costs.

The magnitude of that benefit is something experts are still researching, but today’s nuclear startups are depending on it being greater than zero.

But manufacturing isn’t easy. Just look at Tesla’s experience: The company struggled mightily to profitably produce the Model 3 in large numbers — and it had the benefit of being in the automotive industry, where the U.S. still has significant expertise. U.S. nuclear startups don’t have that advantage.

“I have a number of friends who work in supply chain for nuclear, and they can rattle off like five to ten materials that we just don’t make in the United States,” Milo Werner, general partner at DCVC, told TechCrunch. “We have to buy them overseas. We’ve forgotten how to make them.”

Werner knows a thing or two about manufacturing. Before becoming an investor, she worked at Tesla leading new product introduction, and before that, she did the same at FitBit, launching four factories in China for the wearables company. Today, in addition to investing at DCVC, Werner has co-founded the NextGen Industry Group, which works to advance the adoption of new technologies in the manufacturing sector.

When companies of any size want to manufacture something, they face two main challenges, Werner said. One is capital, which is often the biggest constraint since factories aren’t cheap. Fortunately for the nuclear industry, that shouldn’t pose much of a problem. “They’re awash in capital right now,” she said.

But the nuclear industry isn’t immune from the other challenge all manufacturers face, which is a lack of human capital. “We haven’t really built any industrial facilities in 40 years in the United States,” Werner said. As a result, we’ve lost the muscle memory. “It’s like we’ve been sitting on the couch watching TV for 10 years and then getting up and trying to run a marathon the next day. It’s not good.”