Centrus signs third HALEU supply deal in two months, this time with microreactor developer Antares

Centrus Energy (NYSE: LEU) and Antares Nuclear signed a definitive multi-year HALEU supply contract on 17 September 2026, with deliveries set to begin before the end of the decade.^[1] The deal is the third HALEU offtake agreement Centrus has signed in roughly two months, following contracts with X-energy in August and Radiant in early September.

What the contract covers

The agreement commits Centrus to supply Antares with High-Assay Low-Enriched Uranium from its American Centrifuge Plant in Piketon, Ohio - the only licensed HALEU production facility in the western world.^[1] The contract includes prepayments from Antares to support Centrus' ongoing capacity buildout.^[1] Centrus has described the production as "unobligated," meaning it can also be directed toward national security missions.

Key terms disclosed in the SEC filing:

• Deliveries commencing before the end of the decade
• Prepayments from Antares to advance domestic enrichment capacity
• Production designated as unobligated, eligible for national security use
• Fuel to support Antares' compact microreactor projects across defense and space programmes

Antares' order book and why HALEU matters

Antares is a Torrance, California-based developer of compact, factory-produced microreactors. Its near-term pipeline is heavily defence-oriented:

• Selected by the Department of the Air Force in April 2026 to build a microreactor at Joint Base San Antonio, Texas, under the Advanced Nuclear Power for Installations (ANPI) programme
• Awarded an Other Transactions Authority agreement under the U.S. Army's Janus Programme on 26 August 2026 to own, construct and operate a microreactor at Fort Bragg, North Carolina
• Awarded a $161 million Department of the Air Force contract to develop and demonstrate a nuclear reactor for spacecraft

Antares CEO Jordan Bramble framed the fuel question bluntly in the press release: "Fuel supply is one of the practical questions every advanced reactor developer has to answer."

HALEU - enriched above 5% and below 20% U-235 - enables smaller, more energy-dense reactor cores than conventional low-enriched uranium, which is why microreactor developers depend on it.

Centrus' expanding backlog

The Antares deal adds to a Centrus order book that has grown rapidly this year. By the end of Q2 2026, Centrus had grown its contingent LEU and HALEU enrichment backlog to $3.0 billion, up from $2.4 billion definitized earlier in the year. The company also holds a $900 million DOE task order, awarded in January 2026, to expand commercial-scale HALEU production at Piketon.

Centrus is simultaneously scaling its centrifuge manufacturing plant in Oak Ridge, Tennessee, with the first new centrifuges expected to come online at Piketon in 2029. The first phase of the Piketon expansion targets 12 metric tons of HALEU per year.

Centrus CEO Amir Vexler said in the announcement that "binding orders from Antares and others are supporting our expansion to commercial-scale production - an expansion that is now well underway."

What to watch

The pace of HALEU contracting is now running well ahead of production capacity. Centrus has signed three supply deals in roughly eight weeks, each including customer prepayments - a structure that de-risks the capital build but also means deliveries are contingent on the Piketon expansion proceeding on schedule. The Army's Janus programme targets an Army-regulated reactor on an Army installation by September 2028, which sits inside the "before end of decade" delivery window Centrus has committed to. Whether the enrichment ramp keeps pace with that deployment timeline is the key variable to track.