Apollo Atomics shrinks steam generator to slash nuclear plant costs and size

Apollo Atomics, led by CEO Assil Halimi and co-founder Drew Walker, is tackling nuclear cost challenges by reimagining the steam generator, the biggest part of a reactor’s heat-to-electricity system. Their design replaces the traditional multi-story, hand-built unit with a compact, needle-channel metal block roughly the size of a person, enabling mass production. Built on MIT research, the generator allows a reactor that is 40 times smaller than conventional models and could deliver power at roughly 3 cents per kilowatt-hour, aiming to undercut natural-gas prices.

The company has already created a 40-kilowatt test unit and plans three commercial sizes up to 300 megawatts, targeting a 2028 launch. Funding for the effort includes a $26 million seed round with $5 million in debt, featuring investors such as FCVC, Telesoft Partners, Y Combinator and several venture firms. Halimi expects the factory-assembled approach to cut construction time to less than 24 months and reduce reactor costs to a fraction of existing designs.