# X-energy A Rockville, MD-based developer of high-temperature gas-cooled reactors (HTGRs) and TRISO-X nuclear fuel. Founded in 2009 by Clay Sell, who served as Deputy Secretary of Energy under [[George W. Bush]]. The company's flagship design is the Xe-100, a small modular reactor that uses baseball-sized TRISO fuel pebbles encased in multiple layers of ceramic and carbon — a design that is physically incapable of melting down, since the fuel can withstand temperatures far exceeding anything the reactor produces. ## Xe-100 Design The Xe-100 is an 80 MW electric pebble-bed HTGR. Modules can be combined for larger capacity. The reactor uses helium gas as a coolant and graphite as a moderator, operating at high temperatures that enable both electricity generation and industrial process heat — making it attractive for applications beyond the grid, such as petrochemical manufacturing. X-energy's first commercial customer for industrial heat is Dow, which plans to deploy Xe-100 units at a Gulf Coast chemical facility. ## Amazon Partnership [[Amazon]] co-led a $500 million Series C-1 funding round for X-energy in October 2024 (alongside Ken Griffin) and secured options to deploy more than 5 GW of Xe-100 reactors in the United States by 2039. The first deployment will be the Cascade Advanced Energy Facility in Washington state. This is one of the largest commitments any hyperscaler has made to next-generation nuclear. ## Funding and IPO X-energy previously attempted to go public via a SPAC merger in 2023, but the deal fell through. The company then raised an oversubscribed $700 million Series D in 2025 and completed a traditional IPO on Nasdaq in April 2026, with shares surging 27% on debut and market capitalization topping $11 billion. It is part of the [[Department of Energy]]'s Advanced Reactor Demonstration Program. ## KB Relevance X-energy is a key player in [[The Quest for 90 Gigawatts]], representing [[Amazon]]'s primary bet on next-generation nuclear for AI data center power. The Clay Sell connection to the [[George W. Bush]] administration adds a Republican energy-policy lineage worth tracking — advanced nuclear has bipartisan support but its policy roots run through Bush-era DOE initiatives. The company's success or failure will be a bellwether for whether SMRs can actually scale at the speed and cost that [[Artificial Intelligence]] infrastructure demands. ## See Also - [[Amazon]] - [[The Quest for 90 Gigawatts]] - [[George W. Bush]] - [[Department of Energy]] - [[Nuclear Energy Debate]] - [[Artificial Intelligence]] - [[Energy Sector]]