Startup Apollo Atomics Raises $26M to Build Smaller, Cheaper Nuclear Reactors

Apollo Atomics, a Y Combinator Spring 2026 company co-founded by CEO Assil Halimi and Drew Walker, raised $26M to shrink a key nuclear reactor part — the steam generator — from building-sized to human-sized. Based on MIT research, the design could make reactors 40x smaller and five times cheaper. A demo reactor is planned before a 2028 commercial target.