TerraPower breaks ground on major actinium-225 production site in Philadelphia

Actinium-225, one of the scarcest isotopes in cancer care, is getting a major domestic production bet in Philadelphia. TerraPower Isotopes broke ground May 6 on Bellwether Laboratory, a 250,000-square-foot facility that the company says will lift global actinium-225 output twentyfold and give the rare radionuclide a new East Coast manufacturing base.

The project carries a $450 million price tag and a direct public-health rationale. The U.S. Department of Energy has said actinium-225 supply has long been so tight that combined global production from the main routes was enough for fewer than 100 patients annually. In 2019, the department said TerraPower and Isotek’s work could eventually provide about 100 times more cancer-treatment doses per year than the roughly 4,000 doses then available worldwide. DOE later said accelerator-produced actinium-225 was slated to enter a U.S. cancer-therapy clinical trial in summer 2025, underscoring how quickly demand has moved from research interest to real therapeutic planning.

TerraPower Isotopes is tying that medical need to a broader industrial buildout. The Bellwether Laboratory is planned as a cGMP-compliant manufacturing site, and Pennsylvania is backing the project with $10 million in support. State officials said the development will create at least 225 full-time jobs over three years, while construction is expected to generate about 500 temporary jobs. The facility is going up in the Bellwether District, a 1,300-acre redevelopment of the former Philadelphia Energy Solutions refinery site, turning a long-vacant industrial property into a radioisotope production hub.

The siting process was far from routine. TerraPower said it evaluated more than 350 potential U.S. sites and completed 49 site visits across eight metropolitan areas before settling on Philadelphia. That choice gives the company a presence on the East Coast and extends a manufacturing strategy that already includes its Everett, Washington laboratory. Together, the two sites are expected to make TerraPower a much larger player in a supply chain that has been difficult to scale for hospitals, drug developers and trial sponsors.

The company has already lined up partnerships and supply agreements with Aktis Oncology, Clarity Pharmaceuticals and Point Biopharma, the latter acquired by Eli Lilly for $1.4 billion in 2023. For TerraPower, the move connects the nuclear sector’s reactor ambitions with a fast-growing medical isotope market. With targeted alpha therapy under study for prostate cancer, bladder cancer, neuroendocrine tumors, brain tumors and leukemia, actinium-225 is becoming one of the clearest places where nuclear infrastructure directly affects patient access.