Deep Fission will power the Endeavor data center from underground small nuclear reactors at a depth of more than 1.5 km

Deep Fission, which develops small modular reactors (SMRs), has signed an agreement with US sustainable infrastructure developer Endeavor Energy, under which Endeavor Edged data centers will be powered by a total of 2 GW of reactors.

Deep Fission says while the cost of power from SMR is still high, the company’s technology is extremely safe and will deliver carbon-free electricity for 5-7 cents per kWh. The Deep Fission Borehole Reactor 1 (DFBR-1) is a pressurized water reactor (PWR) providing 15 MW of thermal and 5 MW of electrical power. One load of fuel should be enough for 10–20 years of continuous operation.

Image source: Deep Fission

DFBR-1 will be placed in wells approximately 0.76 m in diameter at depths of more than 1.5 km, where the pressure is high enough to dispense with the thick reactor shell. According to the company, this approach reduces the cost of the reactor and increases its safety. Even if a leak occurs, there will be no significant radioactive threat, since the fuel will remain below, without reaching the surface or aquifers.

After the old one has expired, the new reactor can be placed in a well nearby or in that old well at a slightly shallower depth, literally on top of its predecessor. The developers assure that such a solution will reduce both the construction cost and the project implementation time in comparison with ground-based options. Densities of more than 100 MW can also be achieved over an area of ​​0.1 hectares.

California-based Deep Fission was founded in 2023, and last August it announced a $4 million pre-seed funding round to accelerate its efforts to hire talent, gain regulatory approval and commercialize SMR. Edged is the data center division of Endeavor. The company was founded in 2021 and owns data centers in the United States and the Iberian Peninsula. It specializes in high-density AI data centers with waterless cooling systems.

In 2024, SMRs became popular in the data center sector. In October 2024, AWS entered into an agreement with Energy Northwest, X-Energy and Dominion Virginia to support the deployment of 600 MW reactors. Prior to this, Google signed an enterprise agreement to purchase nuclear power from Karios Power’s multiple SMRs, with implementation expected in 2030. Finally, data center builder Switch has signed a purchase agreement for up to 12 GW with Oklo’s SMR. This agreement became the latter’s fifth agreement with data center operators in 2024. Although there is not a single commercial SMR in the world yet, the company already has contracts to supply 14 GW.