Deep Fission Advances Underground Nuclear Reactor Project

Deep Fission, a California-based nuclear startup, has commenced drilling the first of three data acquisition wells at the Great Plains Industrial Park in Parsons, Kansas. This initiative marks a pivotal moment in the development of the company’s “Gravity” reactor, a 15-megawatt (MWe) small modular reactor (SMR) designed to operate one mile beneath the Earth's surface. The initial well, which will reach a depth of approximately 6,000 feet, aims to gather essential geological, hydrological, and thermal data necessary for the reactor's engineering validation and regulatory planning.

Deep Fission begins drilling first data acquisition wellInteresting Engineering

The Gravity reactor's design leverages the Earth’s natural geology to eliminate the need for large surface containment structures. By situating the reactor underground, the system benefits from the natural pressure provided by the water column above, which reaches 160 atmospheres, thus removing the requirement for costly surface pressure vessels. Additionally, the surrounding bedrock offers substantial natural shielding, enhancing safety and reducing the project's surface footprint. Deep Fission estimates that this innovative approach could reduce nuclear plant construction costs by 70-80% compared to traditional methods.

Interesting EngineeringDeep Fission begins drilling first data acquisition well

Deep Fission has secured a significant agreement with Urenco USA to procure low-enriched uranium (LEU) from their facility in Eunice, New Mexico, which will fuel the testing and demonstration phases of the project. The company has also received $80 million in financing to support the scaling of production for AI-driven data centers and U.S. electricity grids. The modular nature of the Gravity reactor allows for scalability; for instance, 100 reactors could collectively generate 1.5 gigawatts (GWe), sufficient to power large industrial hubs or data centers while occupying a fraction of the land used by conventional nuclear plants.

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Liz Muller, CEO and Co-Founder of Deep Fission, emphasized the significance of the drilling campaign, stating, “Drilling our first borehole is a major step forward... It begins the process of demonstrating a fundamentally new approach to nuclear energy deployment.” The company aims to complete the three-well program to inform final engineering designs and regulatory planning as it progresses toward full commercialization.

Deep Fission begins drilling first data acquisition wellInteresting Engineering

While Deep Fission's innovative approach has garnered attention, some industry experts express caution regarding the feasibility of deploying such technology at scale. Concerns have been raised about the regulatory challenges and the long-term safety implications of placing reactors at such depths.

Deep Fission begins drilling first data acquisition well

Deep Fission is part of the U.S. Department of Energy’s Nuclear Reactor Pilot Program, which aims for at least three advanced reactor designs to achieve criticality by July 4, 2026. Following the completion of the data acquisition wells, the company plans to advance towards constructing a full-scale commercial plant at the Parsons site.

Deep Fission begins drilling first data acquisition wellInteresting Engineering

“Drilling our first borehole is a major step forward,” — Liz Muller, CEO and Co-Founder of Deep Fission

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“By leveraging established supply chains and techniques, Deep Fission estimates this approach can reduce construction costs by approximately 70–80 percent compared to traditional nuclear plants,” — Deep Fission

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