A Possible Estimation of In-Process Inventory in Enrichment Cascades

An attempt is made to describe the in-process inventory of enrichment cascades with a close separation process as a product of gas in-flow and the average holdup time of gas molecules. The holdup time is calculated on the basis of a simple random-walk model of the transients and the output response to input perturbation. Calculations are carried out for a gaseous diffusion plant producing slightly enriched uranium. Experimental determination is proposed for safeguards purposes.