We led Radiant's Series D of more than $300 million, alongside Boost VC, because the company has done something the nuclear industry has talked about for decades and never delivered: it built a reactor you can ship.
What Radiant is building
Radiant builds portable nuclear microreactors small enough to fit on a truck. The first unit, called Kaleidos, produces one megawatt of clean power, enough to run a remote community, a disaster zone, a military base, or a data center, with no connection to the grid. It runs on TRISO fuel, the most rugged nuclear fuel ever made, goes five years between refuelings, and is designed to operate for twenty.
Founder and CEO Doug Bernauer started Radiant in 2020 after years at SpaceX, where he went looking for a way to power a base on Mars and realized the same problem was unsolved on Earth. The Series D, which values the company north of $1.8 billion, funds the leap from prototype to production.
Why we backed it
Most energy bets are bets on a slightly better version of what already exists. This is not that. Radiant is moving toward its first fueled demonstration at Idaho National Laboratory in 2026 and is building its R-50 production reactor in Oak Ridge, Tennessee, on the same ground where the Manhattan Project began. Commercial demand is already arriving ahead of the first unit. We were joined in the round by Founders Fund, Chevron Technology Ventures, the Ark Venture Fund, and Friends and Family Capital.
“Radiant Nuclear just raised $300M+ and we were honored to lead the financing. Radiant's team is both visionary and able to execute, a powerful combination.”
Tim Draper
Clean power that arrives by truck and switches on anywhere is exactly the kind of bet we exist to make.
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