Radiant Industries

Radiant Industries is a nuclear technology company based in El Segundo, California, developing Kaleidos, a portable microreactor designed to be mass-produced in a factory, shipped by truck or aircraft, and installed on site within a day. Kaleidos is described as a high-temperature gas-cooled reactor using TRISO ceramic-coated uranium fuel, helium gas coolant and prismatic graphite blocks, with output reported at approximately 1.2 MW electric and 3 MW thermal in December 2025 coverage (an earlier profile cited 1 MWe / 1.9 MWth). The system is air-cooled and requires no on-site water, uses high-speed turbomachinery to operate between roughly 30% and 100% power, and is intended to leave no waste or infrastructure on site because the whole container is returned for refueling after five or more years of operation. Each unit can reportedly be refueled up to four times for a roughly 20-year product life, and fleets are monitored remotely from a centralized 24/7 monitoring operation.

The company positions the reactors as an alternative to diesel generators and as always-on power for critical infrastructure, remote communities, hospitals, disaster response, defense installations, off-grid industry and data centers. Radiant plans to build and mass-produce the reactors at a factory called R-50 in Oak Ridge, Tennessee — a name referencing the Manhattan Project's S-50 site and the goal of producing 50 reactors per year — with construction expected to start in early 2026 and the first mass-produced Kaleidos generator delivered in 2028.

Radiant is in pre-application discussions with the US Nuclear Regulatory Commission and was named one of 11 projects in the US Department of Energy's Nuclear Reactor Pilot Program. It has completed front-end engineering and experiment design for a Kaleidos prototype and plans to test the Kaleidos Demonstration Unit at Idaho National Laboratory's DOME (Demonstration of Microreactor Experiments) facility in mid-2026, which coverage describes as the first US-designed reactor to be tested at that facility. Radiant has also signed an agreement with the DOE for supply of high-assay low-enriched uranium fuel for the INL test.

Founding story

Radiant was founded in 2019 by Douglas Bernauer and Robert Urberger, both former SpaceX engineers; Bernauer worked on the Grasshopper project and on advanced propulsion and energy systems and serves as CEO. The broader team includes people from SpaceX, McMaster-Carr, national laboratories and the nuclear industry.

Business model

Radiant sells and deploys factory-assembled microreactor units, offered through direct sales or power purchase agreements, and plans volume manufacturing at its own factory to serve customers requiring transportable on-site generation.

Traction

Equinix committed in August 2025 to purchase 20 Kaleidos microreactors, and Radiant has signed delivery contracts with the US military. An earlier profile noted more than 10 reactors committed for delivery through 2030 across military and commercial customers. The company was selected for the DOE Nuclear Reactor Pilot Program, secured a DOE agreement for HALEU fuel supply for its INL test, and completed front-end engineering and experiment design for a Kaleidos prototype ahead of testing at INL's DOME facility in 2026.

Latest developments

In December 2025 Radiant announced a Series D of more than $300 million led by Draper Associates and Boost VC at a valuation above $1.8 billion, to fund commercialization, factory construction beginning in early 2026 and its DOME test schedule. It targets lab testing of a Kaleidos prototype as early as mid-2026, first mass-produced unit delivery in 2028, and production scaling to 50 reactors per year.