Deep Fission is developing an ultra-deep borehole reactor concept — placing a small reactor 1-2 km underground, dramatically simplifying siting and eliminating conventional containment buildings. Selected for the DOE Reactor Pilot Programme in August 2025. The underground concept unlocks nuclear deployment in locations where surface siting is impossible due to land constraints, population density, or regulatory requirements. Deep Fission targets the urban and suburban energy market where land availability is the primary siting constraint.
US Department of Energy, private investors