X-Energy, Inc. (Nasdaq: XE) and SGL Carbon have signed a binding agreement to double SGL's production capacity for nuclear-grade graphite, known as NBG-18, a material used in X-energy's Xe-100 high-temperature gas-cooled reactor.

Under the agreement, X-energy will invest up to $8 million in milestone-based payments to support new facilities and equipment upgrades at SGL's site in Chedde, France. The expanded facility is intended to produce graphite billets for up to eight new Xe-100 reactors per year. SGL has also agreed to expand U.S. capacity for machining billets into graphite blocks. Full execution is expected to double European manufacturing capacity for NBG-18 by 2030.

The agreement builds on a 10-year Supplier Framework Agreement established in January 2026, which included an initial three-year award valued at over $100 million for X-energy's first commercial projects. The first NBG-18 billets produced in France under that award have since been shipped to SGL facilities in the United States for machining.

NBG-18 functions as a neutron moderator and structural component in the Xe-100's pebble-bed core. The material was originally developed for South Africa's Pebble Bed Modular Reactor program and later the U.S. Department of Energy's Next Generation Nuclear Plant project.

Initial production is intended to support X-energy's first proposed commercial Xe-100 deployment, a four-unit plant developed in partnership with Dow (NYSE: DOW) under the DOE's Advanced Reactor Demonstration Program.

"Commercializing new nuclear at scale rests first and foremost on our ability to significantly expand the nuclear supply chain, a challenge that extends beyond any one company, supplier, or nation," said J. Clay Sell, CEO of X-energy.

Andreas Klein, CEO of SGL Carbon, said the agreement "is a strategically important step that strengthens our position in the highly specialized growth market for nuclear-grade graphite."