Radiant Nuclear, founded in 2020 in El Segundo, California, is developing the world's first mass-produced portable nuclear microreactors. The company was founded by former SpaceX engineers, and its team draws expertise from SpaceX, national laboratories, and the nuclear industry. It has raised over $525 million in funding.
The company's primary product, Kaleidos, is a 1MW microreactor designed to replace diesel generators. It fits within a standard shipping container, can be deployed rapidly, and is intended to provide zero-emissions power for remote villages, hospitals, data centers, and military installations. The reactor uses meltdown-proof TRISO fuel and helium gas cooling, can operate for over five years without refueling, and has a 20-year product lifetime.
Radiant Nuclear's technical work spans nuclear engineering, microreactor design, TRISO fuel technology, and helium gas cooling systems. The company plans its first reactor test in 2026 at Idaho National Laboratory's DOME facility, with delivery to U.S. military bases targeted by 2028. It has also secured an agreement to supply 20 reactors to Equinix data centers.
