FormerSpaceX

Radiant

Portable nuclear microreactors that ship in a container.

Founded
2019
Headquarters
El Segundo, CA
Disclosed funding
$505M
Status
Operating
Sector
Energy
Latest round
Series D, $300M
Reported valuation
—
Website
radiantnuclear.com

Overview

Radiant builds Kaleidos, a transportable high-temperature gas-cooled microreactor designed to replace diesel generators at bases, data centers and remote sites. Founder Doug Bernauer was a SpaceX engineer.

Funding

At least: $40M Series B, $165M Series C (2025), $300M+ Series D (Dec 2025).

Disclosed funding is the sum of publicly reported rounds found in the sources below. It is a floor, not a complete total.

Founders

Doug Bernauer, Founder & CEO
At SpaceX: Engineer
Bob Urberger, Co-founder
Not a SpaceX alum
nuclearmicroreactors

Sources

  1. SiliconANGLE: Radiant raises $300M
  2. Radiant: Series B
  3. Jeff Burke: The SpaceX Effect

Last verified September 30, 2026.