Designed for Commercial Operation: DOE Approves the Nuclear Safety Design Agreement for our Deep Fission Reactor

One of the biggest challenges in advanced nuclear isn't designing reactors—it's getting them onto the grid.

As part of the U.S. Department of Energy (DOE)'s Reactor Pilot Program, DOE has approved the Nuclear Safety Design Agreement (NSDA) for Deep Fission's Gravity™ Nuclear Reactor, which is intentionally designed to convert to commercial operation.

That distinction matters.

A test reactor answers an important question: do the physics work? Our full power reactor design answers the question that actually determines whether nuclear energy can meet the moment: can this machine deliver reliable electricity to the people who need it?

The NSDA is the DOE's conclusion — after rigorous, independent technical review — that the foundational safety basis of our design warrants advancing to the next stage of development. Receiving that conclusion for a reactor intended to generate commercial power, not just to reach criticality, means the pathway we've been building toward is now formally underway: a licensed route to putting real electrons on the grid.

Commercialization and safety, advancing together

I have long believed the biggest barrier to nuclear energy isn't reactor technology. It's time.

For decades, much of our industry has followed a familiar sequence: design a new reactor, prove it on paper, and only then begin figuring out how to commercialize it. Every step adds years and cost before answering the most important question — can this technology realistically be deployed where people need reliable electricity?

We took a different path. From the beginning, Deep Fission's focus has been commercialization — not because safety is secondary, but because commercialization and safety have to advance together. If nuclear energy is going to play a meaningful role in meeting future electricity demand, we have to prove it can be built responsibly, deployed practically, and licensed with confidence.

What we questioned wasn't the reactor—it was the default assumption that it belongs on the surface.

The Gravity™ Nuclear Reactor builds on pressurized water reactor technology that has safely generated electricity for decades, integrated with proven capabilities from the oil, gas, and geothermal industries.

By deploying our reactor in a borehole approximately one mile underground, we can leverage the surrounding geology and hydrostatic pressure to make the natural environment play a role in improving safety performance.

We chose proven technology and a commercialization-first approach precisely so we could move through a rigorous safety review process—and reach this milestone with a reactor designed to deliver power at scale.

From approval to demonstration

The NSDA arrives as our work on the ground accelerates. Since breaking ground at our site in Parsons, Kansas, we've proven that we can drill to 6,000 feet, collected critical geological data, and delivered our prototype reactor canister to the site. Our next objective is demonstrating a commercial-scale borehole — another step toward validating the deployment approach we've believed in from the very beginning.

Each accomplishment builds on the last, further validates our concept, and strengthens the case that nuclear energy can be deployed in a way that is practical, repeatable, and commercially viable.

We're honored to be part of the Reactor Pilot Program and are grateful for the DOE's partnership and rigorous oversight. This approval isn't the finish line — there are more reviews ahead, more engineering steps to complete, and more milestones to reach. That's exactly how it should be.

Reaching this approval milestone with our full-power reactor design tells us something important: the fastest path to commercial nuclear deployment runs exactly where we've been building it.

We still have important work ahead, but we're moving forward on our mission to deliver safe, reliable, and affordable nuclear energy for generations to come.

Right now, when people have their "eureka" moment about what we're doing at Deep Fission, it's usually followed by the question: "Why hasn't anyone ever tried this before?"

I believe that someday, the question will be very different: "Why didn’t we question the status quo sooner?"