The jet membrane is a new aerodynamic setaration concept for enriching uranium. The project described in this report had two objectives: (1) to demonstrate experimentally that uranium isotopes can be separated using the jet membrane concept, and (2) to make an assessment of the economic viability of the jet membrane in relation to competing processes. To address the first objective a laboratory suitable for handling UF/sub 6/ was outfitted, a jet membrane apparatus compatible with UF/sub 6/ was constructed, and a mass spectrometer capable of providing the necessary precision for UF/sub 6/ isotope measurements was purchased. Isotopic enrichment of both SF/sub 6/ and UF/sub 6/ was successfully demonstrated in our laboratory using the jet membrane apparatus. To aid in addressing the second objective two separate laboratory facilities were constructed. Program supporting experiments were conducted in these laboratories, using a variety of gas combinations, to investigate those system parameters that were identified in our economics analysis as major capital and energy cost drivers. In addition, a theoretical study was conducted to aid in analyzing data and to provide scaling laws. Our cost analysis, based upon the measured UF/sub 6/ results and the supporting experiments, indicates that the jet membrane is amore » viable concept for enriching uranium industrially. The velocity slip isotope separation process takes advantage of the difference in velocities of isotopic species in a molecular beam formed by expansion of the mixture with a light gas from a nozzle source.For the separation of the hexafluorides of uranium-235 and uranium-238 the technique has an estimated separative work factor about 500 times higher than the gaseous diffusion process and 100 times higher than the curved-jet method. The portion of the report on this process is a review and compendium of reports and articles dealing with the Velocity Slip Process.« less