US-based start-up Deep Fission, which plans to place small modular pressurised water reactors in boreholes one mile underground, has selected its first three planned sites in Texas, Utah, and Kansas, signing Letters of Intent (LOIs) with partners at each location to pursue joint development projects.
Deep Fission, founded in 2023 by father-daughter team Elizabeth and Richard Muller, is developing a project using standardised pressurised water reactor (PWR) technology for a modular nuclear microreactor that can be installed at a depth of one mile in a 30-inch borehole. The company announced its emergence from stealth mode in August 2024. Heat from the reactor is transferred to a steam generator at depth to boil water, and the non-radioactive steam rises rapidly to the surface where a standard steam turbine converts the energy to electricity. Deep Fission says its reactors are scalable from 15 MWe to 1.5 GWe.
Earlier in September, the company went public through a reverse merger transaction with Surfside Acquisition raising $30m through a private placement offering. Surfside Acquisition, a special purpose acquisition company, merged with the company to form a new entity that retains the name Deep Fission.
The US Department of Energy (DOE) recently announced that Deep Fission was one of 11 companies selected to participate in President Trump’s Nuclear Reactor Pilot Program. This provides an opportunity to streamline a pilot reactor, targeting criticality by July 2026, with expected rapid commercialisation to follow.
“We’re proud to collaborate with our partners in Texas, Utah, and Kansas,” said Liz Muller, Co-Founder and CEO of Deep Fission. “Together, we’re laying the groundwork for the next era of nuclear energy in the United States. These projects reflect the urgent demand for reliable, carbon-free baseload power, and we are excited to be part of the solution to fill that need.”
