THE BEHAVIOR OF THE MINOR URANIUM ISOTOPES IN SEPARATION CASCADES PART IV: SPECIAL TOPICS: A. THE EFFECT OF THE MAGNITUDE OF THE SEPARATION FACTOR B. THE EFFECT OF PROCESS GAS LOSSES C. THE EFFECT OF CASCADE NON-IDEALITY

摘要

This is the fourth part of a study directed at assessing the usefulness of determinations of the concentrations of the minor uranium isotopes (U-234 and U-236) in cascade feed and withdrawal streams as a complementary safeguards technique for U-235 enrichment plants. Three relevant o special topics are discussed in this part.nThe first topic deals with the effect of the magnitude of the U-235/U-238 separation factor on the minor isotope concentrations relative to that of U-235 in enrichment cascade withdrawal streams. It is demonstrated that the ratio of the concentrations of two components in the product and tails streams of an ideal cascade is independent of the magnitude of the separation factor of either component if the ratio of the logarithms of the separation factors for the two components is a constant. The ratios of the logarithms of the separation factors of the minor isotopes to that of U-235 is determined to be practically constant and identical for both gaseous diffusion and gas centrifugation. This signifies that the background information developed on the assumption of a small separation factor (gaseous diffusion) for the minor isotope concentrations relative to that of U-235 in cascade withdrawal streams is valid for gas centrifugation which is characterized by a considerably larger separation factor.