Deep Fission is developing a concept for nuclear reactors installed deep below the Earth’s surface. Instead of traditional nuclear plants with massive reactor buildings, the system would use boreholes about 6,000 feet deep – roughly 1.8 kilometers. The reactor would be lowered into a narrow drilled shaft and operate within a closed-loop cooling system.
The design relies on a conventional water-cooled reactor, but placed vertically inside a deep borehole. According to the company, this configuration takes advantage of the natural pressure and temperature conditions found deep underground. That environment could enhance safety while reducing the need for large-scale infrastructure at the surface. The project’s developers also say the approach could significantly cut the cost of building nuclear power plants.
Deep Fission plans to construct a demonstration facility in Parsons, Kansas. The location was chosen in part because of existing industrial infrastructure and geological conditions suitable for deep drilling.
However, the proposal has raised concerns among some local residents. At public meetings, community members have questioned the safety of the technology, its potential environmental impact and what emergency response plans would look like in the event of a malfunction. Some worry that placing a nuclear installation underground could introduce risks that are still poorly understood.
Local officials emphasize that the project is still in its early stages and must go through a number of regulatory approvals, including authorization from the US Nuclear Regulatory Commission. That process includes safety assessments, environmental impact reviews and public consultations.
Borehole-based reactors are one of several emerging approaches in the next generation of nuclear energy. Companies working on small modular reactors and alternative reactor designs are trying to bring down construction costs and shorten development timelines – which for conventional nuclear plants often stretch well beyond a decade.