Standard Nuclear to supply Antares up to eight tons of TRISO fuel

Standard Nuclear will supply Antares Nuclear with a minimum of one metric ton of uranium (MTU) and up to eight MTU of TRISO fuel through 2035, under a binding fuel supply agreement announced August 27, 2026 in an SEC filing. The release calls Standard Nuclear, of Oak Ridge, Tennessee, the only US company with industrial-scale TRISO fuel fabrication facilities; Antares is developing compact microreactors for defense and space applications.

The company's Form 10-Q, filed the same day, gives the split for the agreement, which was entered on August 26: one MTU (1,000 kgU) of TRISO fuel made with high-assay low-enriched uranium (HALEU) is a firm commitment Antares must take delivery of by December 31, 2030, while the other seven MTU are options, exercisable in one-MTU increments by written notice no later than December 31, 2027, with deliveries of exercised quantities beginning as early as 2028. Per the second-quarter results released August 26, the firm ton grew funded backlog approximately 93 percent, to $119.3 million, and the options grew purchase options under executed contracts to $443.5 million, a category the release says is exercised at the customer's sole discretion and not reflected in the company's financial statements until exercised.

It is the second definitive TRISO fuel supply agreement Standard Nuclear has announced in August 2026. Per the same 10-Q, the company and Radiant Industries signed a definitive agreement on August 20 for multiple metric tons of HALEU TRISO fuel to be delivered through 2031, converting a binding term sheet executed in May 2026, as amended. Antares' Mark-0 reached initial criticality at Idaho National Laboratory on June 4, 2026, and the company is one of five vendors selected for the Army's Janus microreactor program, slated for Fort Bragg; the announcement says Antares is backed by over $600 million in funding, with initial production deployments to US military installations beginning in 2028. Fuel fabrication is one link in a longer chain: the 10-Q lists feedstock availability among the factors that could delay production, and the domestic mining and enrichment base upstream of it is rebuilding from a small share of US reactor demand.