A shortage in global supplies of molybdenum-99 (Mo-99) and iodine-131 (I-131) is expected due to a mechanical failure at Belgium's BR2 reactor in Mol, according to a report by Nuclear Medicine Europe (NMEU).

Officials at the BR2 reactor informed NMEU's emergency response team on October 28 that investigators have not yet identified the cause of a mechanical failure detected during a reactor restart after scheduled maintenance. The earliest date for a possible return to function is now set for November 18, officials said.

As a result, NMEU is warning that Mo-99 supply disruptions are anticipated at the end of the first week of November, and both Mo-99 and I-131 shortages are expected through and beyond the third week of November, NMEU said.

"Investigations to date have not yet been able to resolve the mechanical failure detected during inspections and, as a result, the investigations continue," the organizations said.

There are only five nuclear reactors in the world capable of producing the Mo-99, an isotope used to produce technetium-99 (Tc-99m). Tc-99m is used in approximately 50,000 diagnostic medical procedures every day in the U.S. for advanced diagnostic imaging tests and limits in production directly impact patient care and access.