Small Nuclear Startups Hit a Critical Milestone, but Big Hurdles Remain

Three startups in the DOE’s pilot program have turned on new reactors and reached criticality, a milestone meant to jump‑start a new wave of small modular reactors and carbon‑free power. While the speed is aided by regulatory cuts and lab support, experts caution these are test reactors, not commercial products, and licensing, fuel supply, and cost hurdles still loom before any grid deployment—despite Valar Atomics’ criticality demonstrations (even powering an Nvidia chip) and other pilots aiming to be critical soon, including Antares Nuclear and Deployable Energy; Aalo Atomics has yet to hit criticality.