Development and Operation of a Unique Conversion/Solidification Process for Highly Radioactive and Fissile Uranium

A unique evaporation/thermal denitration process was developed, operated, and maintained successfully at Oak Ridge National Laboratory to permit the solidification and safe storage of ∼1000 kg of highly radioactive and fissile uranium, containing ∼75% ²³⁵U, ∼10% ²³³U, and ∼140 ppm ²³²U. The project, called the Consolidated Edison Uranium Solidification Program, was carried out to prepare a stable uranium form for long-term, safe storage. During the project, the uranium nitrate solution was divided into ∼400 batches, which were successfully processed. Details of the process development, equipment maintenance, and operating expertise are described.