Deep Fission, an emerging player in the nuclear energy sector, has unveiled an ambitious plan to enhance nuclear reactor safety by placing them deep underground. The company aims to install their proposed Deep Fission Borehole Reactor 1 (DFBR-1) design in boreholes reaching depths of approximately 1 mile (1.6 kilometers). This innovative approach is currently under pre-application review by the Nuclear Regulatory Commission (NRC).
The DFBR-1 microreactor, which generates 45 megawatts thermal (MWt), is designed for installation in 30-inch (76.2 cm) boreholes. The primary loop of the reactor is largely contained within the reactor module itself. Deep Fission asserts that by operating at such depths, the pressure will match that of conventional pressurized water reactors (PWRs), while a column of water above the reactor enhances safety. This configuration eliminates the need for traditional concrete containment structures, often seen in standard PWR designs.
The steam generator of the DFBR-1 is positioned at the bottom of the borehole, necessitating the transport of steam to the surface to generate an estimated 15 megawatts electrical (MWe) through a steam turbine. Additionally, the design incorporates sampling tubes that extend to the primary loop, alongside ropes for retrieving the reactor for fuel rod replacements. The company anticipates having its first reactor operational by 2026.
Evaluating the Innovation
The rationale behind Deep Fission’s underground reactor proposal lies in its potential safety advantages. By situating the reactor at significant depth, the company aims to enhance containment and reduce environmental risks, as evidenced by the minimal release of radioactive isotopes during the TMI-2 accident, which has been characterized as a negligible event by the NRC.
Despite these optimistic assertions, the unconventional nature of this approach has raised questions. Critics are divided on whether this innovative design represents groundbreaking advancements in nuclear technology or if it is overly ambitious. The company’s project is currently making strides within the Department of Energy’s advanced reactor program, where it is vying for attention against established competitors.
Among its rivals is TerraPower, which is currently constructing its Natrium project. Natrium is designed to produce significantly more power per reactor and features integrated grid-level energy storage. As the landscape of commercial nuclear power evolves, the emergence of Deep Fission’s DFBR-1 could signify a shift towards more creative solutions in energy generation.
While the commercial power sector in the United States has long been seen as stagnant, Deep Fission’s pursuit of underground reactors brings new energy and excitement. As developments continue to unfold, the industry watches closely to see how this innovative concept will impact the future of nuclear energy.
