Deep Fission Proposes Revolutionary Underground Nuclear Reactor

Deep Fission has unveiled a groundbreaking proposal to enhance nuclear reactor safety by placing pressurized water reactors (PWRs) deep underground. Their innovative design, known as the Deep Fission Borehole Reactor 1 (DFBR-1), aims to install microreactors at depths of approximately 1 mile (1.6 km) in specially constructed boreholes. This concept is currently under review by the Nuclear Regulatory Commission (NRC) as part of their pre-application process, where the company has submitted a whitepaper and a regulatory engagement plan for 2025.

The DFBR-1 is designed to operate at a thermal output of 45 megawatts (MWt), with the reactor module containing most of the primary loop. According to Deep Fission, the high-pressure environment at this depth would mimic the conditions within a standard PWR, further enhancing safety. The proposed depth would also place a column of water above the reactor, which the company claims would eliminate the need for traditional concrete containment structures and other safety features commonly utilized in current PWR designs.

The operational mechanics of the DFBR-1 involve the installation of a steam generator at the base of the borehole. Generated steam must travel to the surface to produce an estimated 15 megawatts electrical (MWe) through a steam turbine. Additionally, the design incorporates sampling tubes reaching down to the primary loop, as well as mechanisms for retrieving and replacing low-enriched uranium (LEU) fuel rods.

As Deep Fission pushes ahead with its plans, the company has set a target to have the first DFBR-1 reactor operational by 2026. This ambitious timeline positions them as a competitor in the evolving nuclear energy landscape, which now includes advanced projects like TerraPower’s Natrium. Unlike Deep Fission’s microreactor, Natrium’s system is already under construction and is set to deliver significantly higher power output, along with integrated grid-level energy storage capabilities.

The implications of Deep Fission’s proposal extend beyond mere technical innovation. By challenging conventional nuclear reactor designs, the company aims to invigorate the commercial power sector in the United States, which has often been perceived as stagnant. The effectiveness and practicality of placing reactors underground will determine whether this outside-the-box thinking is seen as a visionary breakthrough or a misguided venture.

As the world increasingly turns its attention to sustainable energy sources, the development of nuclear technology remains a critical focus. Deep Fission’s efforts reflect a broader trend towards innovation in the energy sector, where safety and efficiency are paramount. The outcome of their proposals could reshape the future of nuclear energy, making it safer and more adaptable to modern energy demands.