X-energy Brand Guidelines: Rockville’s Pebble-Bed Reactor Developer, on Nasdaq Since 2026

A reactor and a fuel, developed together.

X-energy was founded in 2009 by Kam Ghaffarian, English Wikipedia and The Next Web (April 2026) say, and is based in Rockville, Maryland. The company describes itself as a developer of advanced nuclear reactors and fuel, and it works on two linked products: a small modular reactor called the Xe-100 and a fuel called TRISO-X. Its mission page counts “17 years of innovation,” which matches the 2009 start.

Its early growth leaned on federal programmes. English Wikipedia says the US Department of Energy gave X-energy a five-year cooperative-agreement grant in January 2016 under its Advanced Reactor Concept programme, and in October 2020 chose the Xe-100 as one of two designs for its Advanced Reactor Demonstration Program, the other being TerraPower’s. A bid to build a small military reactor under the Defense Department’s Project Pele went elsewhere: Wikipedia says the department selected BWX Technologies in 2022. In 2019 Clay Sell, a former Deputy Secretary of Energy, became chief executive, the same source says.

The route to the stock market took two tries. In December 2022 X-energy agreed to go public by merging with Ares Acquisition Corporation, a listed special-purpose acquisition company. On 31 October 2023 the two sides announced that they had mutually agreed to end the deal, citing challenging market conditions and the trading of peer companies, according to their joint release. Wikipedia notes that some staff were laid off the following month and that existing investors put in new money in December 2023. The second attempt went ahead: X-energy priced an initial public offering on 23 April 2026 and began trading on the Nasdaq under the ticker XE on 24 April 2026, The Next Web reported, calling it the largest public-market debut by an advanced nuclear company to date.

Pebbles, helium and Long Mott.

The Xe-100 is a high-temperature gas-cooled reactor of the pebble-bed type. English Wikipedia describes a core moderated by graphite and cooled by helium, with each module planned at 200 megawatts of heat or about 80 megawatts of electricity; the modules are meant to be grouped, and the US Nuclear Regulatory Commission’s project page lists the first plant as four modules with 800 megawatts thermal and 320 megawatts electric. Instead of fuel rods, the fuel sits in thousands of graphite spheres, each holding many tiny coated particles of uranium — the TRISO format, first developed for gas-cooled reactors in the 1960s, Wikipedia says. X-energy says a single Xe-100 can deliver both electricity and high-temperature steam for industry.

The first deployment is with Dow. Wikipedia says the two companies agreed in 2023 to build the plant at a Dow site on the US Gulf Coast; X-energy’s deployments page places the Long Mott Generating Station at Seadrift, Texas, where it would serve what the company calls Dow’s second-largest facility on that coast. The application for a construction permit was filed by Long Mott Energy, LLC on 31 March 2025, and the NRC’s project page lists an environmental assessment and finding of no significant impact issued in May 2026. On 30 October 2026 X-energy announced that the NRC had completed its final safety evaluation; the commission’s own schedule still listed the hearing and the construction-permit decision as to be determined, so the permit was pending at the time of writing.

The fuel side sits in Oak Ridge, Tennessee. Wikipedia says X-energy began a pilot TRISO-X line at Oak Ridge National Laboratory in 2016 and applied in 2022 for a licence for a commercial-scale plant called TX-1; the company says TX-1 is under construction there and that TX-1 and a planned second plant, TX-2, became the first Category II fuel facilities licensed by the NRC. Supplier news keeps coming: on 4 November 2026 X-energy said that Alleima would make stainless-steel tubing which Doosan Enerbility, part of the Korean Doosan group, will bend into helical coils for the Xe-100 steam generator.

How nuclear developers present themselves.

Nuclear companies sell to a small number of buyers — utilities, governments and regulators — over very long timescales, and their imagery tends to reflect that. Corporate pages and reports often return to the same few scenes: cooling towers and reactor domes photographed under clear skies, turbine halls in clean, even light, and wide views of plants set against water or open country.

Newer reactor designers, many of which have not yet built a commercial plant, lean on renders instead. Small modular plants appear as low, compact buildings in green landscapes, sometimes beside a town or a data centre, with no smoke and few people. Large-reactor vendors show construction sites, cranes and heavy components such as reactor vessels and steam generators on the move, a way of picturing scale and progress at once.

People appear mostly as engineers in hard hats and overalls, inspecting a weld, reading a control-room screen or handling fuel. Two images recur across the trade: the blue Cherenkov glow of a spent-fuel or research-reactor pool, caused by charged particles travelling through water faster than light does in it, and ceramic fuel pellets held in a gloved hand. Both are used to make an invisible process visible.

The industry also presents itself in person, at trade gatherings such as the World Nuclear Exhibition and the meetings of the American Nuclear Society, where stands, renders and scale models carry much of the message. The companies in this guide range from Framatome, founded in 1958, and Urenco, set up by treaty in the early 1970s, to much younger reactor designers, and their visual languages vary just as widely.

From the Gulf Coast to Hartlepool.

Beyond Texas, X-energy’s pipeline is a set of planned projects, none yet built. With Amazon and the Washington utility Energy Northwest it plans the Cascade Advanced Energy Facility near Richland, Washington, beside the Columbia Generating Station; Amazon describes it as one of the first small modular reactor facilities in the United States, and Wikipedia says Amazon joined in October 2024 as part of a plan for up to five gigawatts of Xe-100s, with operation expected in the 2030s. In September 2025 X-energy and the British energy group Centrica announced plans for up to 12 Xe-100s, with Hartlepool in north-east England named as the preferred first site, according to Wikipedia and the company’s deployments page. The company also lists a site evaluation in Sullivan County, Indiana, with American Electric Power and Amazon.

The identity is spare. The name is written “X-energy,” with a capital X and a lower-case e, while the listed company’s legal name is X-Energy, Inc. Its website pairs reactor renders and fuel imagery with the line “Solving for What’s Next” and a set of values that opens with “Dare to disrupt.” No official colour or typeface standard is published, so the tones in this guide are our own.

For a design guide, X-energy shows how a reactor developer presents projects that are planned and under licensing rather than built: renders, permits and supplier orders. Compare Kairos Power, another developer using pebble-type TRISO fuel with its first reactors in Tennessee, and Doosan, whose Doosan Enerbility is one of X-energy’s suppliers. For this guide we use a deep navy, a graphite grey and a cool teal with a sans, an unofficial interpretation; no product or logo is reproduced.

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