Apollo Atomics bets on miniaturized steam generators to cut nuclear costs

Most nuclear startups pour resources into designing exotic new reactors, but founders Assil Halimi and Drew Walker argue the industry is chasing the wrong problem. Apollo Atomics is instead rethinking thermal energy conversion. While conventional steam generators are multi-story monoliths, Apollo’s design uses a compact metal block laced with needle-thin channels to transfer heat. This engineering shift allows for a reactor footprint 40 times smaller than current industry standards.

The startup recently secured $26 million in seed funding—including $5 million in debt—to move toward a 2028 commercial deployment. Backed by research from MIT, the company plans to move away from site-specific construction, favoring factory-based assembly. By manufacturing the reactor as a modular unit, Halimi expects to build 300-megawatt plants in under 24 months at a cost four to five times lower than traditional designs. With a target of 3 cents per kilowatt-hour, Apollo intends to challenge the dominance of fossil fuels by squeezing more utility out of uranium's high energy density.