Radiant
formerly Radiant NuclearA Portable Nuclear Microreactor that Replaces Diesel Generators
El Segundo, United States · Founded 2019 · $467.4M raised
- Headquarters
- El Segundo, California
- Employees
- 51–200
- Founded
- 2019
- Business Model
- B2B
- Website
- radiantnuclear.com
- Total Funding
- $467.4M
- Last Round
- $300.0M Series DDec 2025
- Rounds
- 4
Totals include recorded grants and other qualifying funding, not just equity. What counts toward funding.
About
Radiant is building Kaleidos, a portable nuclear microreactor designed to replace diesel generators. The self-contained unit delivers 1 MW of clean electricity and 1.9 MW of thermal power, can be transported by truck or aircraft, and requires no on-site water or excavation. Kaleidos uses TRISO fuel and helium cooling, enabling safe, zero-emission power for remote, military, and off-grid commercial sites.
Summary
Radiant is a Nuclear Energy company based in El Segundo, United States, founded in 2019. It has raised $467.4M in total across 4 rounds, most recently a $300.0M Series D round in Dec 2025. Investors include Draper Associates, Boost VC and Founders Fund.
Tech & App Stack
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Funding History
Dec 2025
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Funding: Grant through Series D. Amounts, valuations, and investors where available.
Investors
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