Thermal diffusion development design parameter calculations for a pilot thermal diffusion apparatus. Part 1

摘要

Atomic Energy Commission has expressed interest in obtaining xenon with a composite neutron absorption cross section of less than one barn. This material may be obtainable from the off-gas of the Purex dissolver. A proposed gas purification facility would process the Purex off-gas through two distillation steps for isolation of a ''rough'' cut of xenon isotopes containing principally Xe(sup 131), Xe(sup 132), Xe(sup 134), Xe(sup 136), and a small quantity of krypton. This material would become the feed stream for a thermal diffusion plant for xenon isotope separation. Thermal diffusion has been shown to be the most economical way to concentrate the two heavier xenon isotopes of low cross section and to reject the krypton along with lighter xenon isotopes of high cross section. The objective of the work herein reported was to provide the basis for (l) a scope design of pilot thermal diffusion equipment and (2) design of experiments to be made with this equipment. In the absence of experimental data, the pilot design was developed from theoretical considerations of the parameters considered important in thermal diffusion column operations. It was assumed that the pilot unit would have to provide information on the correlation of theory with practice as well as delineating the sensitivity of the separation efficiency of the column to change in dimensional and operational variables. The present study is limited to single-stage columns, that is, columns with only one continuous tube as an enriching section. Calculations and graphs are given in sufficient detail in the text to permit ready duplication of results.