Gaseous diffusion technology was the primary technology used commercially to enrich uranium, awaiting the early 1980s, it was the only process of commercial enrichment in use worldwide. Presently, this is the only procedure being used in the United States to supplement uranium for commercial purposes. To facilitate the use of gaseous diffusion to enrich uranium, the UF6 must initially be transformed from a solid to a gas using a combination of high temperatures and pressures. Once the UF6 has been transformed to a gas, it is piped through a sequence of permeable membranes. The holes in the membranes are so small that UF6 can hardly pass through, and the lighter isotopes (U234 and U235) be likely to diffuse through the membranes quicker than the heavier isotopes surrounding U238.
It obtains many hundreds of membranes (about 1,200 diffusions) to reach the concentration of U235 necessary for commercial grade uranium since the molecular speeds of the two uranium isotopes be different by only about .4%. By placing the fences in a multistage cluster arrangement, a pressure gradient is created transversely a cluster of stages (2 to 4) so as to avoid the recompression of the non subtle fraction to be fed from each stage to the previous one. The recompression take place only once in each cluster, which subordinates the operation costs of the plant and increases the density efficiency.
At the conclusion of the process, the UF6 is reduced back into liquid form and then dispensed into containers in which the liquid UF6 will harden before transport.
Troubles with the gaseous diffusion technology include the vast amount of energy necessary and the need for large amounts of space to place an enormous physical structure which houses the cascades. As of the problems connected with gaseous diffusion, no new gaseous diffusion plants are being constructed.
Thermal diffusion:It obtains many hundreds of membranes (about 1,200 diffusions) to reach the concentration of U235 necessary for commercial grade uranium since the molecular speeds of the two uranium isotopes be different by only about .4%. By placing the fences in a multistage cluster arrangement, a pressure gradient is created transversely a cluster of stages (2 to 4) so as to avoid the recompression of the non subtle fraction to be fed from each stage to the previous one. The recompression take place only once in each cluster, which subordinates the operation costs of the plant and increases the density efficiency.
At the conclusion of the process, the UF6 is reduced back into liquid form and then dispensed into containers in which the liquid UF6 will harden before transport.
Troubles with the gaseous diffusion technology include the vast amount of energy necessary and the need for large amounts of space to place an enormous physical structure which houses the cascades. As of the problems connected with gaseous diffusion, no new gaseous diffusion plants are being constructed.
“Thermal diffusion uses the transfer of heat transversely a thin liquid or gas to achieve isotope separation. By cooling a perpendicular film on one side and heating it on the other side, the resultant convection currents will generate an uphill flow next to the burning surface and a sliding flow along the cold surface.” In these conditions, the lighter U235 gas molecules will spread toward the hot surface, and the heavier U238 molecules will spread toward the cold surface. These two diffusive motions shared with the convection currents will cause the lighter U235 molecules to focus at the top of the film and the heavier U238 molecules to think at the bottom of the film.
This technology has not at all been used commercially to enrich uranium even though it was used briefly during World War II at the S-50 plant in Oak Ridge Tennessee. The technique was discarded in good turn of gaseous diffusion because gaseous diffusion is a more competent way to separate the uranium isotopes.
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