Development Of A Mobile UF₆ Processing Facility And Demonstration Of The System

ORNL has designed and fabricated a mobile highly enriched uranium hexafluoride (HEUF₆) recovery system based on the development of an ORNL alumina trapping uranium conversion process. The CONEX system will support the uranium recovery mission of the NA-232 Office of Nuclear Material Removal Mobile Uranium Facility (MUF). If a HEUF₆ cylinder of unknown certification or questionable integrity is presented to MUF, nondestructive analysis will be used to ensure safe handling and processing before the cylinder is connected to the MUF processing system. The warmed cylinder is vapor transferred to a series of γ-activated alumina traps under negative pressure at 50°C. When a trap is gravimetrically determined to be loaded, the uranium laden alumina pellets are HEPA vacuum transferred using critically safe geometry to critically safe containers for storage, packaging and subsequent shipment to the final licensed location for disposition. This presentation will begin by discussing the processing system design and assembly in a mobile CONEX box. The uranium conversion process has been validated with laboratory scale tests, but it has not been tested on the full-scale MUF alumina HEUF₆ processing system. To test the MUF processing system, a surrogate that is not radioactive, fluorinated or toxic was desired to negate the possibility of radiological contamination and unnecessary hazards. This presentation will also describe the laboratory testing used to determine a suitable surrogate, the conditions best suited for surrogate demonstrations, and the demonstration of the MUF HEUF₆ processing system. Water was identified as a surrogate from a literature search that showed it should load in large enough quantities at low temperatures to be easily measured, and it is known from our previous drying experiments that water does not readily desorb at near ambient temperatures under vacuum. The surrogate demonstration in the MUF processing system showed that the equipment is operational under the conditions required for UF­₆ processing, and the thermal loading profile was clearly visible which can be used to train the system operators to look for breakthrough indicating process completion.