A medical isotope used in over 40,000 medical procedures in the United States daily has reached sufficient supply for patients worldwide without the use of highly enriched uranium (HEU) to create it – a significant milestone in nuclear nonproliferation.

The supply of medical isotope molybdenum-99 (Mo-99) was jointly confirmed by U.S. Secretary of Energy Jennifer Granholm and U.S. Secretary of Health and Human Services Xavier Becerra to have reached a level where the exporting of HEU for foreign production is no longer necessary, a U.S. Department of Energy press release said.

“Doctors and patients across the globe can be confident that the critical medical isotope Mo-99 will be there when they need it, and we can provide that assurance without making any further exports of highly enriched uranium,” Granholm said in the release. “Today’s certification is another example of DOE’s world-leading expertise creating win-win outcomes that make the world safer while advancing jobs, improving health care and increasing the quality of life here at home.” 

The milestone triggers a congressionally mandated ban on HEU exports due to its potential use in nuclear weapon production if the shipment is stolen or diverted, the release said. 

Mo-99 supply in the U.S. was reliant on foreign producers using HEU for decades, having no way of producing the isotope domestically, the release said. The use of HEU will now be replaced with low enriched uranium, a significantly less dangerous component, with funding and technical assistance being provided to global producers for the transition.

“With more than 80% of diagnostic imaging in the U.S. relying on nuclear medicine isotopes like Mo-99, the FDA has a key role to play to ensure a sufficient supply is available for critical daily medical procedures,” Acting FDA Commissioner Janet Woodcock said in the release.