US Deep Fission Completes Full-Scale Reactor Vessel Deployment and Retrieval Demonstration Using Commercial Drilling Equipment

en.Wedoany.com Reported - On September 3, 2026, advanced nuclear energy development company Deep Fission, Inc. announced that it had completed a deployment and retrieval demonstration of a full-scale non-nuclear prototype reactor vessel using standard commercial drilling and hoisting equipment. The company is developing a technology pathway that deploys small modular pressurized water reactors in boreholes approximately 1 mile deep underground.

During the demonstration, a commercial drilling and hoisting team lowered a 20-foot-long prototype reactor vessel into a 34-inch-diameter, 100-foot-deep borehole, completed alignment, and then retrieved it to the surface. Deep Fission stated that all equipment used in the demonstration was standard equipment already in commercial use in the drilling industry, with no specially invented, custom-built, or modified nuclear equipment.

Liz Muller, CEO and co-founder of Deep Fission, said the key point of the demonstration is that no entirely new specialized equipment needs to be developed. She said the company is using commercially available equipment already on the market, while the reactor technology basis comes from pressurized water reactor technology that the nuclear industry has operated for decades. Deep Fission's innovation is mainly reflected in how mature components are combined, rather than reinventing systems that have never been built.

Deep Fission's technology pathway is built on two mature industrial foundations: commercial drilling and pressurized water reactors. According to the company's vision, the drilling industry has the capability to drill boreholes of the required diameter and depth and to place and retrieve loads within them; its Gravity™ nuclear reactor uses pressurized water reactor technology and standard low-enriched uranium fuel. The company states that what it changes is the reactor's installation location, not the reactor's basic physics or fuel cycle.

Under the Deep Fission approach, the reactor would be deployed in a water-filled borehole approximately 1 mile deep underground, using the water column and surrounding rock formations to provide a safety barrier, operating pressure, heat transfer, and emergency cooling conditions. The company believes this approach can help simplify plant structures, reduce some of the surface infrastructure required by traditional nuclear facilities, and potentially improve safety margins, shorten construction timelines, and lower construction costs.

The prototype vessel used in this demonstration is a full-scale non-nuclear replica intended to house the Gravity™ reactor core and contains no nuclear fuel. Deep Fission stated that the demonstration is part of its commercial validation program, with follow-on work including drilling, system integration, regulatory approval, and preparation for commercial operation.

Deep Fission has recently received approval from the U.S. Department of Energy (DOE) for its Nuclear Safety Design Agreement (NSDA) for the Gravity™ nuclear reactor. The company is currently advancing deployment arrangements under the DOE's reactor pilot program and developing its first reactor project in Parsons, Kansas.