BERKELEY, CA – Deep Fission, a pioneering U.S. nuclear energy startup, is making headlines with its ambitious plan to deploy 15 MWe small modular reactors (SMRs) a mile underground, targeting initial criticality for a pilot project by July 4, 2026. This initiative is part of the Department of Energy’s (DOE) new Reactor Pilot Program, which seeks to fast-track advanced nuclear technologies. The company envisions these subterranean reactors as a scalable solution for the rapidly growing energy demands of data centers and other industrial applications.
Advancing Underground Nuclear Technology
Deep Fission’s core innovation lies in its “Borehole Reactor” design, which involves placing small modular pressurized water reactors one mile underground via 30-inch boreholes. This approach leverages natural geology for shielding, aiming to enhance safety and security while significantly reducing the surface footprint of nuclear power generation.
The 15 MWe Deep Fission Borehole Reactor-1 (DFBR-1)
The company’s primary project, the DFBR-1, is a 15-MWe pressurized water reactor that integrates established nuclear, drilling, and geothermal technologies. This design is expected to dramatically reduce construction time and expense, potentially cutting costs by up to 80% compared to traditional nuclear megastructures. Deep Fission aims for a levelized cost of electricity (LCOE) between 5-7 cents per kilowatt-hour for its initial commercial projects.
Strategic Timeline and DOE Partnership
Deep Fission was recently selected for the Department of Energy’s Reactor Pilot Program, an initiative under President Trump targeting reactor criticality by July 4, 2026. This program provides a pathway for reactor authorization outside national laboratories and aims to streamline the testing and commercialization of advanced reactor designs. While the pilot project targets 2026 for criticality, earlier reports also indicate that Deep Fission, in partnership with Endeavour Energy, a sustainable infrastructure firm, expects its first reactors to be operational by 2029 to supply 2 gigawatts of power to Endeavour’s Edged data centers.
Funding and Public Listing
Further solidifying its position, Deep Fission secured $30 million in an oversubscribed private placement offering and completed a go-public reverse merger with Surfside Acquisition Inc., which has since been renamed Deep Fission, Inc. This significant funding is expected to support the construction of the pilot reactor and accelerate rapid commercialization.
Addressing Growing Energy Demands
The push for underground nuclear reactors comes amid an explosion in demand for energy, particularly from data centers that power artificial intelligence (AI), cloud computing, and cryptocurrency mining. These facilities require vast amounts of electricity, and Deep Fission’s carbon-free power source offers a compelling solution to meet this demand sustainably. Deep Fission CEO Elizabeth Muller emphasized the unique moment for the nuclear industry, stating that the company believes it can scale its technology rapidly and profitably to address this global energy need.
Safety, Security, and Environmental Advantages
The decision to site reactors a mile underground provides several inherent advantages. The surrounding geology offers natural shielding and protection, with billions of tons of bedrock providing passive safety and containment. This design not only reduces the surface footprint but also strengthens security, aligning with Deep Fission’s commitment to delivering safe, reliable, and affordable low-carbon power. The company utilizes off-the-shelf parts and readily available, low-enriched uranium, simplifying supply chains compared to other advanced reactor designs.
The Road Ahead
While Deep Fission’s approach presents a promising future for nuclear energy, experts acknowledge that the technology still faces operational and regulatory challenges. However, the company is actively engaged with the Nuclear Regulatory Commission (NRC) in pre-application activities for the licensing of the DFBR-1. Deep Fission’s co-founders, father-daughter team Richard and Elizabeth Muller, also have ties to Deep Isolation, a company focused on deep borehole disposal of spent nuclear fuel, highlighting a comprehensive approach to the nuclear fuel cycle. The Department of Energy’s fast-track program, coupled with significant private investment, positions Deep Fission to potentially achieve its ambitious 2026 target and play a transformative role in the future of clean energy.
