Deep Fission wants to put small, pressurized water reactors a mile underground. Now, the advanced nuclear company is gaining attention from major energy users. Deep Fission recently signed letters of intent for up to 18.5 gigawatts of potential power from data centers, co-developers, and industrial parks looking for low-carbon electricity.

Early Interest in Deep Underground Nuclear Reactors

underground reactor
Demonstration graphic of a reactor a mile underground; Photo: Deep Fission

These initial agreements are non-binding, meaning no one has committed to buying electricity, building facilities, or funding a project just yet. Either side can walk away without a penalty. However, it shows real interest from groups that need large amounts of power.

“The growing pipeline is a testament to the urgent interest in our mile-deep deployment model,” said Liz Muller, CEO and co-founder of Deep Fission. “Data center developers and other industrial partners need a solution that can be deployed quickly and then scaled rapidly – and the Gravity Nuclear Reactor is a good fit for those requirements.”

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The Kansas Pilot Project

gravity reactor
A rendering of the Deep Fission gravity reactor; Photo: Deep Fission

Deep Fission is working on its first reactor project in Parsons, Kansas, as part of a Department of Energy pilot program. The company recently finished drilling their first test hole 6,000 feet deep.

Its next goal is to drill a wider, commercial-sized hole and safely drop a prototype reactor inside, called the Gravity Nuclear Reactor. It uses standard water reactor technology, but the deep underground setup is meant to simplify construction and improve safety.

The company still has to prove the tech works, secure financing, and navigate regulations. If tests go well, Deep Fission plans to apply for a commercial license with the U.S. Nuclear Regulatory Commission in the first half of 2027.