Nuclear plant would be placed one mile deep, with geology offering natural shielding and protection
Deep Fission, a US-based advanced nuclear energy company placing small modular reactors in boreholes underground, has raised $30m (€25m) in a heavily oversubscribed private placement as it begins efforts to build a pilot reactor with the goal of completion in 2026.
Deep Fission also announced it has gone public through a reverse merger transaction with Surfside Acquisition. As a result of the deal, Surfside Acquisition, a special purpose acquisition company, has merged with the operational company. The new entity will retain the name of Deep Fission.
This development comes after the US Department of Energy (DOE) recently selected California-based Deep Fission to participate in president Donald Trump’s advanced reactor pilot programme, a DOE initiative launched in 2025 following Trump’s executive order to speed up the testing and development of advanced nuclear reactor technologies.
Deep Fission said its proprietary pressurised water reactor (PWR) design combines proven methods from the nuclear, oil and gas and geothermal industries, while using off-the-shelf parts and readily available, low-enriched uranium (LEU) to simplify supply chains.
By siting the reactor one mile underground, the surrounding geology offers natural shielding and protection with billions of tonnes of bedrock providing passive safety and containment.
Deep Fission said the approach reduces the surface footprint, strengthens security and is designed to enable a faster, more affordable path to deployment.
Each Deep Fission reactor generates 15 MW. With a small footprint and dense power output, 10 reactors require just a quarter of an acre (about 0.1 hectares) to produce 150 MW, while 100 reactors delivering 1.5 GW require less than three acres (1.2 hectares) of land.
The company’s intellectual property portfolio includes 24 pending patent applications, with one US application that has been allowed, and over 40 unique innovations.
It said is targeting a levelised cost of electricity (LCOE) of 5-7 cents per kWh ($50 to $70/MWh) from its first-of-a-kind commercial implementation.
LCOE estimates for different energy sources vary, but the International Energy Agency as has said the LCOE for advanced nuclear is $63.10/MWh. The lowest LCOE is $30.43/MWh for standalone solar and the highest is $120.51/MWh for offshore wind.
LCOE captures both capital and operating costs that need to be covered. It is essentially the long-term price at which the electricity produced by a power plant will have to be sold at for the investor to cover all their costs.
Deep Fission chief executive officer and co-founder Liz Muller said: “This is a unique moment for the nuclear industry.
“We believe we can scale our technology rapidly and profitably to address the massive energy demand from AI data centres and other customers around the world.”
