Radiant Nuclear received a $300 million funding led by Draper Associates and Boost VC, with backing from Ark Venture Fund, Chevron Technology Ventures, Friends & Family Capital, Founders Fund, and others. Earlier backers include Andreessen Horowitz, DCVC, Giant Ventures, and Union Square Ventures. The round values the company at more than $1.8 billion.
It came just a day after Last Energy secured $100 million, weeks after X-energy’s $700 million round, and months after Aalo Atomics raised another $100 million. Radiant itself had closed a $165 million round only six months rago. Together, these deals point to a sudden and concentrated rush of capital into nuclear startups.
Influx of funding in nuclear tech
As cloud providers and hyperscalers race to support ever-larger compute loads, they are searching for reliable, round-the-clock power sources that don’t depend on weather or fuel deliveries. Nuclear, once considered politically fraught and economically sluggish, has re-emerged as a serious contender.
Still, when capital pours in this quickly, questions inevitably follow. Many nuclear startups are promising first reactors within the next year. If those timelines slip, or if costs climb faster than expected, investor patience could be tested.
A microreactor built for mobility and scale
Radiant’s bet is on compact, transportable nuclear power. The company is developing a one-megawatt microreactor that can be delivered by semi-truck and deployed at remote or energy-hungry sites. The reactor will be helium-cooled and use TRISO fuel, a ceramic-coated uranium particle designed to withstand extreme temperatures and reduce meltdown risk. Each unit is expected to operate for five years without refuelling and has a planned lifespan of 20 years.
The commercial model is deliberately flexible. Customers can purchase reactors outright or opt for a power-purchase agreement. When a unit reaches the end of its service life, Radiant takes responsibility for removal, reducing long-term operational complexity for clients.
Founded by Doug Bernauer in 2020, the company is positioning these reactors as replacements for diesel generators, particularly at commercial facilities and military installations where fuel logistics are costly and unreliable.
From data centres to federal fast tracks
Data centres are central to Radiant’s early rollout. In August, the company signed an agreement with Equinix to supply 20 reactors, a signal that major infrastructure developers are willing to experiment with nuclear power at smaller scales.
Before commercial deployment, Radiant will build a demonstration reactor at Idaho National Laboratory, with testing targeted for summer 2026. The timeline aligns with a federal initiative aiming to see three new reactors reach criticality by July 4, 2026. Radiant is one of 11 companies selected for the programme, which doesn’t offer direct funding but accelerates regulatory approvals.
Whether the current wave of nuclear investment proves durable will depend less on capital raised and more on reactors delivered. For now, Radiant stands at the centre of a sector where ambition, urgency, and scrutiny are all rising at once.
Doug Bernauer, CEO and Founder of Radiant, said: “Micro-scaled nuclear, mass produced for the first time ever, can transform how the public thinks about nuclear energy. This funding enables us to build our factory and keep to our DOME schedule, where we will achieve self-sustained chain reaction on a reactor designed by, built by, fueled by, and operated by Radiant alongside our partners at the Idaho National Lab.”
Tim Draper, Founder and Managing Partner of Draper Associates, said: “Portable nuclear power is going to provide the bulk of our incremental energy in the years to come and Radiant is executing with purpose not just towards turning on their first reactor, but building them at scale in months, not years.”
