First criticality for the eVinci heat-pipe microreactor
2026-08-24Westinghouse / NCERC (LANL, INL, NNSS)
Westinghouse's eVinci test article reached zero-power criticality at 10:39 a.m. PT on 24 Aug 2026 at the National Criticality Experiments Research Center in Nevada, with Los Alamos and Idaho National Laboratory. Zero-power criticality confirms the core's nuclear design — the reaction is self-sustaining — without generating usable heat or power, so it validates physics rather than demonstrating a working reactor. eVinci is a heat-pipe-cooled design with no pumps or coolant loops, sized at 5 MWe for remote sites and data centers; it was separately selected for the US Army's Janus Program at Fort Drum.
