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Deep Fission
Deep Fission designs compact nuclear reactors for deep borehole deployment, advancing a structural alternative to large surface power plants.
Deep Fission
Deep Fission is engineering a small modular reactor designed to operate at depth, aiming to simplify siting and reduce construction costs. The approach uses standard pressurized water reactor technology in a geometry that allows natural convection cooling and passive safety without relying on large steel pressure vessels. The target is carbon-free baseload power competitive with established energy sources. The company's development work focuses on regulatory engagement and technical validation, rather than a single announced commercial project. Early-stage backing has included climate technology investors drawn to the promise of cost reduction through design simplification. The deep borehole concept avoids the visual footprint and land-use constraints of traditional nuclear plants, which the firm argues can unlock sites that are inaccessible to surface reactors. With a pre-revenue engineering team, Deep Fission's progress is marked by technical milestones rather than financial metrics. The organization is led by its founders and a small group of nuclear engineers working toward licensing submissions with the U.S. Nuclear Regulatory Commission. What distinguishes the firm is a single design bet: that putting a reactor a mile underground eliminates the cost of containment structures, making nuclear power genuinely scalable. The business does not diversify into adjacent energy technologies, focusing entirely on convincing regulators and utilities that the deep borehole concept is viable.
General information
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Unclassified
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AUM
Undisclosed
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Frequently asked questions
What reactor technology does Deep Fission use?
Deep Fission's design is based on a standard pressurized water reactor, adapted to a narrow borehole form factor. The reactor is lowered into a mile-deep shaft where it operates at high pressure, using natural convection to circulate coolant without primary pumps. The company states that this approach eliminates the need for large containment buildings by using the surrounding geology as a pressure boundary.
How does Deep Fission handle safety and waste?
The deep borehole configuration provides passive cooling through natural groundwater if required, and the depth ensures that any radiological release remains isolated from the biosphere. Spent fuel assemblies would be retrieved in the same cask used for deployment and stored accordingly. The design relies on inherent physics rather than active safety systems to maintain safe shutdown margins.
What is Deep Fission's stage of commercialization?
Deep Fission is in a pre-licensing engineering phase, engaging with the U.S. Nuclear Regulatory Commission to map a path toward a design certification application. No commercial project, demonstration reactor, or power purchase agreement has been publicly announced. The firm is primarily funded through early-stage venture support.
What makes the deep borehole design different from other small modular reactors?
Conventional small modular reactors still require above-ground containment structures and substantial site preparation. Deep Fission's borehole approach eliminates the containment dome and most civil works by placing the reactor vessel underground. The company contends that this yields a radically lower overnight capital cost per megawatt and opens up sites close to existing grid interconnections without large exclusion zones.
Who leads Deep Fission?
Deep Fission has not publicly listed a full leadership team or board on its official digital channels. Available public commentary references a founding group with nuclear engineering backgrounds, though the firm has not released detailed professional biographies or organizational structure information through verifiable primary sources.
Profile maintained by Altss using OSINT (open-source intelligence), regulatory filings, licensed data partners, and verified direct submissions. Read the methodology. Last updated: . Continuous refresh with full update cycles at least every 30 days.
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