Deep Fission ^{Filed Terms, Nasdaq: FISN}

Deep Fission, Inc. (“Deep Fission,” the “Company,” “we,” “our,” or “us”) is a nuclear energy technology company developing a small modular reactor (“SMR”) based on established pressurized water reactor (“PWR”) technology, with novel emplacement in deep boreholes approximately one mile below the Earth’s surface. Our reactor, which we refer to as the Gravity Reactor, will leverage subsurface conditions to support key containment and operating functions, including the use of hydrostatic pressure from a water column within the borehole to support reactor operating pressure and cooling, and the surrounding geological formation to provide structural confinement and shielding. This approach is intended to reduce reliance on large surface containment structures and other safety-related infrastructure associated with conventional nuclear power plants, support faster deployment timelines, improve security, enhance safety, and enable lower capital and operating costs relative to conventional nuclear facilities, while reducing exposure to environmental and other surface-level hazards. Individual reactors may be deployed as standalone installations or grouped in clusters of boreholes at a single site, which may enable longer refueling cycles through coordinated fuel management, staggered refueling schedules and more efficient utilization of shared infrastructure, and support larger installations.