Four U.S. startups fired up their first small nuclear reactors, aiming to power AI data centers on-site

Four American startups have brought their first small nuclear reactors to life, each reaching the point where the reactor can sustain a controlled chain reaction. The companies are chasing a specific goal: generating power on-site for the electricity-hungry data centers behind the artificial intelligence boom. Reaching criticality is a significant technical milestone, though it remains a long way from a fully operational commercial power plant.