Actinium is commercially real in 2025, but the business is Ac-225 for targeted radiopharmaceuticals rather than elemental actinium metal. The mature legacy route is decay-product Ac-225 milked from thorium-229 inventory at Oak Ridge, sold by DOE/NIDC as solid actinium nitrate in millicuries and constrained by the size of the thorium-229 stock. That route is the main clinically used source identified by the IAEA, but DOE describes it as limited enough that it primarily supports basic science, pre-clinical work, and small-volume supply.

The scaling route is accelerator-produced Ac-225: thorium targets are irradiated at Brookhaven and Los Alamos, purified at Oak Ridge, and then sold either as Ac-225 nitrate or incorporated into Ac-225/Bi-213 generators. DOE's public record shows why the isotope sits in tier 2 rather than the atlas' bulk-material tiers: production is measured in millicuries per batch or per month, supply expansion is driven by regulatory and hot-cell capability, and demand is tied to a fast-growing pipeline of targeted alpha therapy clinical trials rather than tonnage.