Nuclear startups raise $1.1 billion to rethink reactor manufacturing

In the last several weeks of 2025, nuclear startups raised $1.1 billion. This surge in funding is driven by investor optimism that smaller, modular reactors can succeed where traditional, large-scale nuclear infrastructure has struggled. Traditional nuclear projects in the United States have historically faced severe delays and financial strain. For example, Vogtle 3 and 4—nuclear power plant units in Georgia, U.S.—rely on massive infrastructure, including tens of thousands of tons of concrete and fuel assemblies that are 14 feet tall to generate 1 gigawatt of electricity per reactor. However, the project was completed eight years late and ran $20 billion over budget. These massive overruns have prompted the industry to look for alternative manufacturing methods.

To avoid these pitfalls, the new wave of startups is betting on smaller, modular designs. However, building these reactors presents significant manufacturing challenges. Milo Werner, an investor and manufacturing expert who serves as a general partner at the venture capital firm DCVC, warns that the U.S. lacks people experienced with both factory construction and operations. Werner, who previously led new product introduction at Tesla and Fitbit—where she launched four factories in China—and co-founded the NextGen Industry Group, a nonprofit focused on manufacturing technology, noted that the U.S. has a 40-year gap in building industrial facilities. “We haven’t really built any industrial facilities in 40 years in the United States. 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,” Werner said.

This lack of domestic manufacturing experience extends to the supply chain. According to Werner, there are five to 10 materials critical for nuclear supply chains that are simply no longer made in the United States, forcing companies to buy them overseas. While startups argue that smaller reactors can be built using mass-production techniques, and that companies should get better at making reactor parts—which should drive down costs—experts caution that these benefits will not appear immediately. Achieving cost reductions through manufacturing learning curves typically takes years to materialize.

Why it matters

Nuclear startups are attracting significant investment based on the premise that smaller, modular reactors can avoid the massive cost overruns and delays associated with traditional large-scale nuclear infrastructure.