Actinide says it enriched natural uranium into HALEU, a first for a startup

Actinide, a Dallas-based advanced materials company, says it has enriched natural uranium into high-assay low-enriched uranium (HALEU) on a calutron it designed and built itself. The company describes the result, announced on August 26, as the first time a startup has produced the material. Notably, the same machine was producing its flagship commercial product, enriched ytterbium-176 for Oklo Isotopes, just weeks earlier.

What was actually produced

According to the announcement, an independent ISO/IEC 17025-accredited laboratory assayed the uranium at 15.38% uranium-235. That sits inside the band US law defines as HALEU: more than 5% but less than 20% uranium-235. The material was made only in research quantities, under the laboratory-scale exclusion in Nuclear Regulatory Commission rules that covers facilities used solely for experimental purposes, and it would still have to be fabricated into rods, pellets or particles before any reactor could use it.

Skipping a missing step in the fuel chain

The sharper claim concerns the form of the output. Citing the Department of Energy, Actinide notes that most advanced reactor designs require HALEU and that no domestic supplier currently offers any. Conventional centrifuge plants enrich uranium hexafluoride gas, which must then be converted into a solid before fuel fabrication, a step for which the United States has no commercial capacity at all. The DOE contracted six companies in 2024 to build that deconversion capability. Actinide's electromagnetic separator deposits solid material directly, which the company argues bypasses the bottleneck altogether.

Manhattan Project physics with modern hardware

A calutron sorts ionised atoms by mass inside a magnetic field. The United States built them at Oak Ridge's Y-12 site during the Manhattan Project and ran some until 1998 to supply stable isotopes for medicine, industry and research. The DOE has since rebuilt federal electromagnetic separation capacity, but it remains concentrated inside the government.

Actinide says modern magnets, vacuum systems, power electronics and controls, refined through trade-secret advances, make its first-generation machine the most productive calutron ever built at its size. Co-founder and CTO Robert Mendelsohn contrasted the approach with conventional enrichment infrastructure, which he said serves a single purpose, costs billions of dollars and takes years to stand up. Actinide's machines, he said, cost a few hundred thousand dollars, produce material within months, can be deployed anywhere and can be reconfigured for a different isotope within days.

A supply chain tilted abroad

The announcement also cites 2025 figures showing that 77% of enrichment services purchased by US civilian reactor owners came from foreign suppliers, including 26% from Russia, against 23% from American sources. Co-founder and CEO Eric Olszewski argued that the country should not have to depend on other nations for materials that determine whether a reactor runs or a cancer treatment gets made.

A young company with large plans

Actinide was founded in Dallas in September 2025, after seven years of research and prototyping by Mendelsohn. Olszewski funded the work before the company was incorporated, moved his family to Dallas in early 2024 and put more than $1 million of his own capital into it. The company closed an oversubscribed seed round in March 2026 led by Onto Ventures, with participation from Neo Ventures, Mana Ventures, Discipulus Ventures, Shor Capital and several angel investors.

It is now building Fortitude, a second-generation separator that, on Actinide's own engineering estimates, would give a single machine roughly half the isotope-separation capacity of the US government's entire electromagnetic fleet.

Why it matters

HALEU supply is the gating constraint for most advanced fission reactor programmes, and the United States currently buys the bulk of its enrichment services abroad, with Russia among the largest providers. If compact, reconfigurable calutrons can genuinely produce solid HALEU directly at machine costs in the hundreds of thousands of dollars, they point toward a decentralised alternative to multi-billion-dollar centrifuge complexes.

The caveats are real. The output so far is research-scale, far short of the tonnage a reactor fleet would need, the work relied on an experimental-use regulatory carve-out, and every claim here comes from the company's own announcement rather than independent reporting. The demonstration shows the approach is plausible at small scale; scaling it is the next, harder question.