multiple distillation and electro­ magnetic separation take advantage of Gaseous diffusion, distillation, and gas centrifuges exhibit small isotopic separation effects that are overcome through large-scale installations where many separation steps are performed in sequence. The use of membranes for the separation of isotopes is one of the first practical applications for membrane processes. Alternatively, a variety of laser-based techniques exist [6] that are capable of separating isotopes to a much higher degree, but require 20-4. This method relies on the differing diffusion speeds of gasses with different masses. Chemical exchange process Uranium isotope separation using chemical exchange processes relies on segregation of uranium compounds in separate, immiscible streams that are intimately contacted. Gaseous diffusion is an isotope separation method based on mass dependence of the rate of passage of gases through a membrane containing minute holes (Chapman & Dootson, 1917; Hutchinson, 1947; Heidenreich & Thiemens, 1983) Chapman & Dootson, 1917 Hutchinson, 1947 Heidenreich & Thiemens, 1983. E. V. Levin Atomic Energy volume 77, pages 760 – 767 (1994)Cite this article Gaseous Diffusion. The world has used just three very inefficient nuclear enrichment processes: gaseous diffusion, centrifugation, and Electro Magnetic Isotope Separation (EMIS.) The first application was based on the effects that were described in 1846 by Thomas Graham, as a phenomenon of molecular effusion, i.e., differentiated flow rate of gases through small holes. Diffusion separation methods refer collectively to processes such as gaseous diffusion and gas centrifugation, developed specifically for difficult separations such as those involving the isotopes of uranium. The unit separation factor in the gaseous diffusion method is a function of the square root of the ratio of the molecular weights of the component isotopes be-ing separated. The unit separation factor in a gas centrifuge is a function of the difference in the molecular weights.3 When analyzing cascades fed with repro- methods is gaseous diffusion. in which isotopes are distinguished by the slightly different rates at which they diffuse through a porous barrier; lighter atoms pass through the barrier somewhat fast­ er than heavier ones. wafers. @article{osti_4730380, title = {THE SEPARATION OF ISOTOPES OF ELEMENTS OTHER THAN URANIUM BY THE GASEOUS DIFFUSION PROCESS}, author = {Levin, S A}, abstractNote = {Preliminary studies were made of the feasibility of using the gaseous diffusion process for the production of enriched isotopes of certain specific elements which are of interest in various … Another method used to separate isotopes is the gaseous diffusion separation method. Instead, uranium hexafluoride, UF6, was used. Separation of multicomponent isotopic mixtures in a gas centrifuge — approximate method for solving the system of diffusion-transport equations and analysis of some separation characteristics. ** The laser method has been used successfully for the separation of isotopes of chlorine and sulphur. EMIS enrichment is an inefficient process: It would cost $81,000 to enrich a single pound of uranium. Gaseous diffusion is not all that much better. By forcing gasses of the isotope material through membranes, this technique can progressively separate the lighter isotopes from the heavier isotopes. In fact, the separation of U isotopes by gaseous diffusion did *not* use atomic uranium as the gaseous species -- uranium is not volatile enough. The separation factor is small, and in the range of 1.015–1.030, between that of gaseous diffusion and gas centrifuge processes. Potentially, laser isotope separation of uranium is 1000 times more efficient than gaseous diffusion separation. Gaseous centrifu­ gation.