Radiant, a California-based clean energy startup, has raised $165 million in a Series C funding round. The company aims to use this funding to accelerate the development and production of its portable nuclear microreactors, which are designed to be a clean and efficient alternative to diesel generators.
Founded in 2020, Radiant is building a compact 1-megawatt nuclear reactor. The design is intended for mass production and is targeted for use in remote communities, disaster relief operations, and military bases. These reactors will produce zero emissions and offer a more sustainable power solution where traditional energy sources are limited or unreliable.
The funding announcement comes shortly after Radiant was selected by the U.S. Department of Energy as one of five American companies to receive high-assay low-enriched uranium (HALEU) fuel. Radiant plans to use this special fuel for its first full-scale reactor test, scheduled for 2026, at the Idaho National Laboratory’s DOME facility.
According to Radiant, the first customer-ready reactors could be deployed as early as 2028. The latest funding will be used to advance the company’s reactor technology and to begin construction of manufacturing facilities. These facilities are expected to eventually produce up to 50 microreactors each year.
So far, Radiant has raised a total of $225 million from venture investors.
Doug Bernauer, Radiant’s CEO and founder, said the new funding brings major expertise and credibility to the company’s efforts.
“Adding some of the smartest minds in technology investment to our team is a powerful vote of confidence in Radiant – and the belief that America must continue to lead the way in nuclear innovation – as we ramp up to test the first new reactor design in the U.S. in over 50 years,” Bernauer said in a statement.
The funding round was led by DCVC. Other investors include StepStone, Giant Ventures, Hanwha Asset Management Venture Fund, SGA, Crossbeam Venture Partners, Align Ventures, ARK Venture Fund, Gigascale Capital, HartBeat Ventures, and Pax Ventures.
Will Dufton, who oversees growth investments at Giant Ventures, said Radiant is part of a broader shift in the energy sector.
“We are seeing a new nuclear renaissance play out right now,” Dufton said. “Radiant’s success will uncork the final bottlenecks to progress for the entire nuclear industry.”
Radiant’s microreactors could mark a major step forward in the global push for cleaner, more reliable energy—particularly in hard-to-reach locations.
