Uranium enrichment by the separation nozzle process

The separation nozzle process developed by the Karlsruhe Nuclear Research Centre is based on the centrifugal force in a curved jet consisting of uranium hexafluoride and a light auxiliary gas. It is applied on a technical scale in Brazil, where a cascade section consisting of 24 separation stages is being constructed which will be extended in two steps into a demonstration plant with a capacity of roughly 300,000 SWU/a. To produce separation nozzle systems with extremely small characteristic dimensions permitting plant operation at atmospheric pressure, a manufacturing process is being developed which relies on combined X-ray lithography and microgalvanic deposition (LIGA process). By applying this technology the prototype separation stages under construction at the Karlsruhe Nuclear Research Centre should lead to commercial separation nozzle plants with capacities between one and four million SWU/a. Less than 300 separation stages are required for cascades with a product assay of 3.2% and a tails assay of 0.25% 235U. A cost evaluation is given for such plants. (author)