Nuclear technology company X-Energy announced that it has raised $500 million in a Series C-1 financing round, with proceeds aimed at supporting the commercialization of the company’s small modular nuclear (SMR) reactor technology.

The financing round was led by Amazon’s Climate Pledge Fund, and was announced alongside plans to use X-Energy’s reactor design to support a 320 MW project with regional utility Energy Northwest in central Washington, as well as a collaboration between the companies to bring more than 5 GW of projects online across the U.S. by 2039, representing the largest commercial deployment target of SMRs to date.

Amazon pledged in 2019 to match all of the electricity consumed across its global operations, including data centers, corporate buildings, stores and fulfillment centers, with 100% renewable energy by 2030. While the company announced in July 2024 that it achieved its 100% clean energy goal 7 years ahead of schedule, it also stated at the time that the increasing demand for generative AI “will require different sources of energy than we originally projected,” and that it will explore new carbon-free energy sources in addition to its continued investments in renewables.

Kevin Miller, Amazon’s Vice President of Global Data Centers, said:

“This collaboration between Amazon and X-energy is a significant step toward accelerating advanced nuclear technologies that can help us bring new sources of carbon-free energy to the grid cost-effectively and safely. We need smart solutions that can help us meet growing energy demands while also addressing climate change. X-energy’s technology will be integral in helping achieve this, and is an important step in Amazon’s work to achieve our Climate Pledge commitment to be net-zero by 2040.”

SMRs are advanced nuclear reactors that are substantially smaller than traditional nuclear power plants, providing benefits including faster build times and the ability to be deployed closer to the grid, while producing carbon-free energy.

Founded in 2009, Rockville, Maryland-based X-Energy is a developer of nuclear reactor and fuel technology. The company’s TRISO-X fuel seals uranium particles in a protective coating, which can withstand high temperatures without melting, making it highly resistant to fuel failure and release of radioactive materials, eliminating the need for massive containment facilities. The company’s SMR reactor, Xe-100 is a high-temperature gas-cooled reactor operates at temperatures higher than 750°C, and contains more than 200,000 TRISO-X-based fuel pebbles, which are gravity-fed in continuous rotation through the core, allowing the reactor to run without fuel interruption for 60 years. Helium is circulated through the core, absorbing immense heat, and is used to boil water into steam to turn a turbine for the production of carbon-free energy.

The initial agreement with Amazon will support a 4-unit 320 MW project, with the option to increase to 12 SMR units producing 960 MW.

X-energy CEO J. Clay Sell said:

“Amazon and X-energy are poised to define the future of advanced nuclear energy in the commercial marketplace. To fully realize the opportunities available through artificial intelligence, we must bring clean, safe, and reliable electrons onto the grid with proven technologies that can scale and grow with demand.”

Additional investors in the financing round included Citadel Founder and CEO Ken Griffin, affiliates of Ares Management Corporation, NGP, and the University of Michigan.

X-Energy said that the new capital will be used to fund the completion of its reactor design and licensing as well as the first phase of its TRISO-X fuel fabrication facility in Oak Ridge, Tennessee, and to support future carbon-free projects that will use X-energy’s Xe-100 advanced SMR reactors.

X-Energy Founder and Execuutive Chairman Kam Ghaffarian, Ph.D., said:

“Reaching this milestone is a testament to the dedication of the X-energy team and the essential energy solutions we’ve built. We remain focused on bringing our advanced reactor technology to market, enabling a future powered by sustainable, zero-carbon energy.”