UF_6 Cylinder Cleaning, Inspection and Testing

摘要

Commercial quantities of UF_6 are stored and transported in special cylindrical steel containers. The cylinder size is typically 30-inch or 48-inch in diameter and the contents range from 2277 kg to 12,501 kg (5,020 lb to 27,560 lb). Cylinders must be cleaned, inspected and tested at periodic intervals to maintain the proper credentials to demonstrate integrity of the container. In order to be suitable for filling, a cylinder must have been cleaned and "recertified" within 5 years preceding the date of filling. During cleaning, a small residue of UF_6 (called a heel) is washed from the cylinder and then the cylinder is inspected and subjected to a series of physical tests, which demonstrate the integrity of the cylinder. A successful completion of the physical testing "recertifies" the cylinder for an additional five years of use. Historically, the washing and recertification of cylinders has been an ancillary effort at UF_6 conversion plants, enrichment plants and fuel fabrication plants. The process was not the core business of the facility and was often viewed to be a necessary nuisance by those performing the work. DAHER-TLI has developed what is believed to be the first of its kind stand-alone cylinder washing and recertification facility. The facility primarily processes 48-inch cylinders that previously contained natural or depleted UF_6. The process is unique in that extra steps have been provided to remove internal scale from the cylinder walls. A newly developed three-step uranium recovery process for the wash solution also recovers a high-purity uranium by-product from the wash solutions. Recertification inspection and testing follows the cylinder washing and uranium recovery. In addition to being able to wash and recertify 48-inch cylinders, the UCSC has the capability to store a finite number of full 48-inch cylinders containing natural UF_6. UCSC can receive, store and ultimately ship full 48-inch cylinders for our customers.