US data center giant Equinix has expanded its commitment to nuclear energy, announcing three major agreements with advanced nuclear developers that together could provide up to 774MWe of power.

The first deal was with Radiant, a microreactor company based in El Segundo, California. As part of the agreement, Equinix will purchase 20 Kaleidos microreactors, each designed to produce 1.2MWe and 3MWth.

The Kaleidos is a high-temperature gas-cooled reactor (HTGR) that uses TRISO fuel, a helium gas coolant, and prismatic graphite blocks. Radiant says its modular containerized system can be deployed to deliver on-site power within days.

Radiant is currently in pre-application talks with the US Nuclear Regulatory Commission and was recently named one of 11 projects in the US Department of Energy’s Nuclear Reactor Pilot Program. The company has completed front-end engineering and experiment design for a Kaleidos prototype, aiming for lab testing as early as mid-2026. It has not yet been disclosed where the microreactors will be deployed.

The second agreement saw Equinix sign a Letter of Intent with ULC-Energy for a Power Purchase Agreement of up to 250MWe to power its data centers in the Netherlands. ULC-Energy, based in Amsterdam, is the exclusive Dutch development partner for Rolls-Royce SMR and selected the company’s 470MWe light water small modular reactor as its preferred technology in 2022.

According to ULC-Energy CEO Dirk Rabelink, the SMR-powered data center model “leverages the SMR’s capability to address data center energy requirements whilst also providing a realistic and affordable solution to support the increasing regional grid and energy challenges… [It] will enable a clean digital solution and will be a strategic regional energy asset benefitting many local stakeholders.”

The Rolls-Royce SMR is currently undergoing the Generic Design Assessment process with UK regulators and is targeting grid connection around 2030. In June, Rolls-Royce was named the preferred partner for Great British Energy in developing SMRs, with CEO Tufan Erginbilgic recently telling the BBC the company could become the UK’s most valuable business thanks to AI-driven growth.

Equinix’s third deal was a pre-order power agreement with Stellaria, a French nuclear company, for 500MWe to supply data centers across Europe. Founded in June 2023 by the French Alternative Energies and Atomic Energy Commission (CEA) and Schneider Electric, Stellaria is developing the world’s first molten salt Breed & Burn reactor.

The 200MWe design breeds all of its liquid fissile fuel internally, recycles spent fuel, and burns long-life waste without refuelling. The first fission reaction is targeted for 2029, with commercial operations planned for 2035.

In June, Stellaria raised €23 million ($26.8m) to accelerate R&D, double its workforce, and finalize development of its liquid-core fast-neutron reactor demonstrator. The funding round was co-led by At One Ventures and Supernova Invest, alongside CEA Investissements, Schneider Electric, Exergon, and Technip Energies.

These agreements represent a huge bet on the SMR and microreactor sector, but are not Equinix’s first foray into nuclear. Last April, Equinix signed a pre-agreement with Oklo to procure up to 500MW of power from future fast fission plants. With the latest announcements, Equinix now has agreements covering more than 1GW of nuclear capacity.

Reflecting on the expansion, Ali Ruckteschler, SVP and chief procurement officer at Equinix, said: “Equinix has always been at the forefront of energy innovation, signing the data center industry’s first agreement with a SMR provider and pioneering the use of fuel cells a decade ago. Powering AI infrastructure responsibly is a global priority. With Equinix’s operational expertise, trusted supply chain, and close partnerships with the U.S. and global governments and utilities, we are poised to deliver safe, secure, and reliable AI solutions for our customers and the communities we serve.”

Equinix is not alone in exploring SMRs. Over the past year,Amazon, Google, Data4, Oracle, Switch, and Endeavour have all signed agreements with SMR developers.