Deep Fission Unveils the Name of Its Deep Borehole Reactor: Gravity

-- Reflects Deep Fission’s design philosophy of simplicity and elegance --

BERKELEY, Calif.--(BUSINESS WIRE)--Deep Fission, an advanced nuclear energy company redefining the industry by placing small modular pressurized water reactors in boreholes a mile underground, today announced the official name of its proprietary underground reactor: The Gravity Nuclear Reactor (“Gravity”).

“Gravity is one of the most reliable forces in nature,” said Liz Muller, Co-Founder and CEO of Deep Fission. “That same reliability is what we’ve built into our reactor design. By placing our Gravity reactors deep underground, we’re tapping into Earth’s natural forces to make nuclear power inherently safer, dramatically more cost-efficient, and faster to deploy.”

Each Gravity reactor is installed in a borehole a mile beneath the Earth’s surface, surrounded by billions of tons of bedrock. The shaft is filled with water, creating roughly 160 atmospheres of pressure – the ideal conditions for a standard pressurized water reactor. The deep underground setting provides built-in containment and pressure, reducing the need for massive above-ground structures, significantly shrinking the surface footprint.

Deep Fission’s system combines three established technologies: a standard pressurized water reactor from the nuclear sector, deep borehole drilling from the oil and gas industries, and geothermal heat transfer techniques. This approach allows the Company to use off-the-shelf components, existing supply chains, and readily available low-enriched uranium (LEU) fuel.

As a result, the Company estimates its model could reduce project costs by up to 80% compared to traditional nuclear plants and shorten construction timelines to six months from groundbreaking to operation. Deep Fission is targeting a Levelized Cost of Electricity (LCOE) of $50–70 per MWh.

“The name Gravity is more than symbolic,” said Mike Brasel, Chief Operating Officer at Deep Fission. “It underscores Deep Fission’s design philosophy, which leverages nature’s most dependable forces to power humanity safely and sustainably.”

Deep Fission is participating in the Department of Energy’s Reactor Pilot Program, which creates a pathway to build and test an advanced reactor under an accelerated licensing framework. The Company aims to achieve first criticality by July 4, 2026.

Following a recently completed go-public transaction, Deep Fission reported an expanded customer pipeline of 12.5 GW and planned sites in Texas, Utah, and Kansas.

About Deep Fission

Deep Fission is revolutionizing the energy landscape with innovative technology that places a small modular pressurized water reactor in a borehole one mile underground. Founded and led by a team of seasoned scientists, engineers, and entrepreneurs, the Company is committed to delivering safe, reliable, and affordable low-carbon power at scale. Deep Fission was recently selected for the Department of Energy’s new Reactor Pilot Program and is targeting criticality by July 2026. Deep Fission was founded in 2023 by father-daughter team Elizabeth and Richard Muller. Learn more at deepfission.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the U.S. federal securities laws, including, among other things, statements regarding Deep Fission’s development plans, anticipated project timelines, cost objectives, partnerships, and other future matters. These statements are based on current expectations and involve risks and uncertainties that could cause actual results to differ materially from those expressed or implied. Important factors are described under “Risk Factors” and “Special Note Regarding Forward-Looking Statements” in Deep Fission’s registration statement on Form S-1 filed with the U.S. Securities and Exchange Commission (as amended from time to time), and in other filings Deep Fission makes with the SEC. Deep Fission makes no guarantee of future results, performance, or achievements and undertakes no obligation to update any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by law.