Challenges of extracting and purifying fission-produced molybdenum-99

Sandia National Laboratories (SNL) has produced limited quantities of fissi on-produced molybdenum-99 (Mo-99) within industry purity specifications usi ng the Cintichem production process. Molybdenum-99 is produced by the irrad iation of a target which has an electrochemically deposited layer of enrich ed uranium oxide. The Cintichem processing method involves the dissolving t he uranium coating from the target, chemically extracting the Mo-99 from th e ther fission products, and purifying the product by column chromatography . The chemical extraction and purification of Mo-99 was performed using rem ote manipulators in the SNL Hot Cell Facility (HCF). To thoroughly understa nd the production process, two series of tests were designed: the first was a series of cold tests using 20 g samples of a depleted or low-irradiated uranium dioxide (UO2) powder and the second was conducted using irradiated targets coated with similar to 25 g of enriched uranium oxide. In addition, testing of radiation effects was performed at the SNL Gamma Irradiation Fa cility on chemicals and hardware used in the processing to evaluate the deg radation due to the high radiation field expected during the chemical separ ation. Unique production hardware, fixtures, and tools were developed to fa cilitate remote processing of irradiated targets at the HCF.