Deep Fission Proposes Revolutionary Underground Nuclear Reactor

Deep Fission has unveiled an ambitious plan to enhance nuclear reactor safety by proposing the installation of pressurized water reactors (PWRs) in deep underground boreholes. Their innovative design, known as the Deep Fission Borehole Reactor 1 (DFBR-1), aims to place these reactors approximately 1 mile (1.6 km) beneath the surface, where they could operate under significant pressure and be surrounded by a protective column of water.

The company’s proposal is currently under review by the Nuclear Regulatory Commission (NRC). In their regulatory whitepaper, Deep Fission outlines a vision that could revolutionize the commercial power sector by drastically improving the safety of nuclear energy production. The DFBR-1 microreactors, each with a thermal output of 45 MWt, will be installed in 30-inch (76.2 cm) boreholes, with much of their primary systems housed within the reactor module itself.

Innovative Design and Safety Features

Deep Fission argues that locating the reactors at such depths provides safety advantages, as the pressures at that depth would equal those found within conventional PWRs. This design negates the requirement for extensive concrete containment structures, traditionally associated with nuclear reactors. The steam generator is situated at the bottom of the borehole, allowing for the generation of approximately 15 MWe via a steam turbine, although it requires transporting steam to the surface.

Additionally, the design includes sampling tubes that extend to the primary loop, facilitating maintenance and monitoring. Ropes will also be employed to retrieve components for the replacement of standard low-enriched uranium (LEU) fuel rods. The unique concept has sparked discussions in the energy community about whether it represents a groundbreaking innovation or an impractical idea.

Industry Context and Competition

As Deep Fission moves forward, it is targeting the operational launch of its first reactor by 2026. The company is navigating through the Department of Energy’s (DoE) advanced reactor program, where it faces competition from other projects like TerraPower’s Natrium. Notably, Natrium is already under construction and offers a higher power output per reactor, along with integrated grid-level energy storage capabilities.

The emergence of Deep Fission and other innovative reactor designs signals a shifting landscape in the nuclear energy sector. As the United States seeks to reduce its carbon footprint, the commercial power sector is becoming increasingly dynamic, moving away from traditional models to explore novel and potentially safer energy solutions.

Overall, Deep Fission’s proposal represents a significant step in reimagining how nuclear energy can be harnessed, with the potential to reshape public perceptions of safety in this critical industry.