|Royal Society of Chemistry, South Africa|
Most of the supplies of Mo-99 are produced using highly enriched uranium (HEU) at five approved nuclear reactors around the world. Neutrons bombard the uranium until it fissions, producing a Mo-99 atom about 6% of the time. Mo-99 is extracted from the radiation containment chamber through a chemical process. Next Mo-99 has to be turned into Tc-99m by a company specializing in Mo-99 processing. With a half-life of only 66 hours Mo-99 is a fast depleting material. However, Tc-99m is even flightier, with a half-life of just 6 hours. As a consequence processed Mo-99 must be shipped just-in-time to the medical facility and then placed in specialized ‘generators’ to extract Tc-99m immediately prior to the medical procedure. This makes for a complex supply chain configuration that is not well tolerant of outages or supply deficiencies.