BWX Technologies, Inc. (NYSE:BWXT) announced today that its TRISO nuclear fuel has powered Antares Nuclear Inc.'s reactor through the first successful criticality milestone under the Administration's Executive Order 14301, Reforming Nuclear Reactor Testing at the Department of Energy. BWXT also processed the high assay low enriched uranium (HALEU) feedstock material used to manufacture the Antares TRISO fuel compacts from scrap materials provided by NNSA, underscoring the company's leadership across the full spectrum of next generation fuel production.

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BWXT prepares TRISO fuel compacts for shipment at its Lynchburg, Virginia, facility.

"This marks a historic milestone for advanced nuclear fuel fabrication in the United States," said U.S. Energy Secretary Chris Wright. "The Trump administration is proud to partner with private companies such as BWXT, as we strengthen the foundation of a reliable and secure nuclear supply chain to support both national defense and commercial energy needs."

"BWXT is delivering leading-edge nuclear products that support the energy dominance goals of our nation, and this milestone underscores that fact," said Rex D. Geveden, BWXT president and chief executive officer. "Our skilled workforce, advanced manufacturing technologies and nuclear-qualified supply chain are driving a new generation of reactor demonstrations across the country."

"BWXT's TRISO fuel supported our path to criticality," said Jordan Bramble, CEO, Antares. "Building on a proven fuel specification developed through Project Pele let our team focus on what we had to prove ourselves: our control system and reactor physics. We're grateful for a partnership that continues as we move from neutrons to electrons."

Antares modeled its reactor fuel on the TRISO (TRi-structural ISOtropic) fuel compacts BWXT delivered for Project Pele, the 1.5 megawatt transportable microreactor BWXT is building for the U.S. Army's Strategic Capabilities Office. That TRISO fuel specification, developed within DOE's Advanced Gas Reactor (AGR) program over the past several decades, paired with BWXT's decades of TRISO development at its Specialty Fuels Fabrication facility in Lynchburg, helped accelerate Antares' path to a successful criticality test, and demonstrates the value of mature, scalable U.S. fuel manufacturing infrastructure.

"BWXT is proud to work with Antares and deliver the fuel necessary for this important milestone at the Idaho National Lab and for the future," said Joe Miller, BWXT's president for Government Operations. "Antares is moving quickly to progress from concept to criticality and we are proud to supply this team with the TRISO needed to do so."

BWXT continues to support Antares with ongoing TRISO fuel manufacturing, reinforcing the company's readiness to meet customer timelines and the growing national demand for advanced reactor fuel.

Forward-Looking Statements

BWXT cautions that this release contains forward-looking statements, including, without limitation, statements relating to the performance, design, suitability and impact of advanced reactor technology and TRISO nuclear fuel compacts. These forward-looking statements involve a number of risks and uncertainties, including, among other things, the timing of technology development; our ability to obtain the necessary regulatory approvals, licenses and permits in a timely manner; the ability to commercialize this technology; competition in an environment of rapid technological changes; and the enforcement and protection of our intellectual property rights. If one or more of these or other risks materialize, actual results may vary materially from those expressed. For a more complete discussion of these and other risk factors, please see BWXT's annual report on Form 10-K for the year ended December 31, 2025, and subsequent quarterly reports on Form 10-Q filed with the Securities and Exchange Commission. BWXT cautions not to place undue reliance on these forward-looking statements, which speak only as of the date of this release and undertakes no obligation to update or revise any forward-looking statement, except to the extent required by applicable law.

About BWXT

At BWX Technologies, Inc. (NYSE:BWXT), we are People Strong, Innovation Driven. A U.S.-based company with approximately 10,000 employees, BWXT is a Fortune 1000 and Defense News Top 100 manufacturing and engineering innovator that provides safe and effective nuclear solutions for global security, clean energy, nuclear medicine, space exploration and environmental restoration. BWXT owns and operates 17 manufacturing facilities globally, and its 14 strategic partnerships support the U.S. and Canadian governments at more than two dozen additional locations.

For more information, visit www.bwxt.com. Follow us on LinkedIn, X, Facebook and Instagram.

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jcdobken@bwxt.com

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BWXT Manufactures TRISO Fuel Enabling First New Reactor Criticality Under DOE Program