STABILIZATION OF DEPLETED URANIUM HEXAFLUORIDETAILS MATERIAL FOR DISPOSITION

摘要

Uranium Disposition Services, LLC (UDS) has been contracted by the U.S. Department ofrnEnergy (DOE) to stabilize approximately 700,000 metric tons (MT) of legacy tails material fromrnuranium enrichment activities. To accomplish this mission, UDS will design, construct, andrnoperate two Conversion Facilities: one in Paducah, Kentucky and one in Portsmouth, Ohio.rnThese facilities will convert the DOE inventory of depleted uranium hexafluoride (DUF6) nowrnlocated at the Paducah Gaseous Diffusion Plant, the Portsmouth Gaseous Diffusion Plant, andrnthe East Tennessee Technology Park to uranium oxide.rnLegacy tails material is considered a potential hazard as it is stored in the volatile DUF6 form,rnwhich is highly reactive when exposed to water including the moisture (or humidity) in air.rnAdditionally, it is stored outside in approximately 60,000 steel cylinders that could potentiallyrncorrode to the point where the primary containment is unreliable.rnThe patented conversion process, based on Framatome ANP proprietary technology, utilizes arnfluidized bed conversion unit to convert the DUF6 to its most benign form, uranium oxides, in arnsimple one-step operation. This simple process ensures that the Conversion Facility is costrneffective and has maximum operability, reliability, and maintainability. The uranium oxidernproduct is nonvolatile and nonreactive. Hydrofluoric acid (HF acid), a byproduct of thernconversion process, is recovered thereby eliminating a liquid process effluent stream. Thernrecovered HF acid will be sold to the chemical industry.rnOther key elements to minimizing the waste of processing this material are:rn? DUF6 heels (process residue) are typically extracted and treated in alternate equipment.rnThe UDS process will stabilize the heels in-situ, eliminating heel treatment equipmentrnand associated waste streams.rn? After processing, the uranium powder (uranium oxides) will be loaded back intornmodified DUF6 cylinders (with the heel). This innovative strategy eliminates the needrnfor special cylinder disposal equipment, recurrent operational cost for powder packaging,rndifferent types of container handling equipment, etc.rn? The offgas treatment chemicals are regenerated for reuse, eliminating this as a liquidrnwaste stream and minimizing the operating cost of treatment chemicals.