Gravity Reactor™ | Small modular PWR a mile underground

Deep Fission Gravity™ Nuclear Reactor

Established Nuclear Technology, Deployed in a New Way.

Deep Fission’s Gravity Nuclear Reactor technology taps into one of nature’s most reliable forces intended to support safety functions, reduce surface infrastructure, and enable more repeatable deployment.

Integrating Three Established Technologies

An approach that enables the use of off-the-shelf components, existing supply chains, and readily available low-enriched uranium (LEU) fuel.

Gravity Well Drilling Oil & Gas

Developing advanced deep borehole drilling using standard infrastructure for containment one mile underground.

Heat Exchanger Geothermal

Novel deployment approach applies proven geothermal components and processes for energy transfer to the turbine generator at the surface.

Reactor Canister PWR

Hydrostatic pressure from one-mile-deep column of water provides 160 atm of reliable pressure, safely and naturally.

Existing LEU Fuel Supply

Deep Fission is designed to use readily available low-enriched uranium (LEU) fuel — the same category of fuel used in commercial nuclear power plants today.

Adaptable Energy Designed to Meet Any Demand

Our modular reactors are engineered for flexible deployment across a wide range of environments, from industrial hubs to remote locations. Each environment provides dependable and scalable power while supporting industries, communities, and critical infrastructure.

Initial 2x2 Configuration

Commercialization Role: Initial commercial deployment configuration, subject to additional development and regulatory approval

Target Development Time: Approximately 1 year

Target Output Per Reactor: Up to approximately 8 MWe

Number of Fuel Assemblies: 4 per reactor

Target Design Life: >40 years

Target Refueling Interval: Approximately 6 years

Design Objective: Initial commercial deployment

Future 3x3 Configuration

Commercialization Role: Future larger-scale configuration, subject to additional development and regulatory approval

Target Development Time: Approximately 2 years

Target Output Per Reactor: Up to approximately 15 MWe

Number of Fuel Assemblies: 9 per reactor

Target Design Life: >40 years

Target Refueling Interval: Approximately 7-10 years

Design Objective: Increased output and improved unit economics

Engineering Simplicity for an Energetic Impact

Each component that makes up our technology has been purposely engineered to build one of the most impactful solutions in nuclear power to date.

Read Our FAQ

A Simple Design for Advanced Nuclear Energy

Follow a step-by-step explanation of the Gravity Nuclear Reactor™ as Jason Pottorf, Director of Thermal Hydraulics, demonstrates fuel loading, coolant circulation, and heat transfer using a detailed scale model of the underground reactor system.

Underground Advantages for Above Ground Success

Scalable Power

Each reactor delivers up to 15 MWe of reliable power, with modular scalability that can expand with additional boreholes to meet growing energy demands.

Standard Fuel

The design of the reactors utilizes low-enriched uranium (LEU) technology using 2x2 and 3x3 pressurized water reactor (PWR) fuel assemblies for consistent performance.

Containment

Geological isolation at depth naturally provides operational pressures, enhances safety, and protects the public; no large, above-ground containment structures needed.

Spent Fuel

Encompasses safe interim storage pending identification of national, long-term storage solutions.

Rapid Growth from First Reactor to Full Operation

Reactor expected to produce up to 15MWe to power small commercial buildings, military, and remote locations

Reactors expected to produce 150MWe to power medium to large data centers, and large commercial buildings

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Reactors expected to produce 1.5GWe to power hyperscale data centers and large power plants