Analytical Separation of Zirconium-95 and Niobium-95 from Uranium Irradiated by Thermal Neutrons

Abstract

The presence of zirconium and niobium in nuclear spent fuel is undesirable, both because these metals interfere seriously with later Fuel reprocessing steps, and because of the high level of penetrating gamma radiation emitted by radioactive zirconium and its daughter niobium. In this thesis, after discussing the origin of the problem, methods For the separation of Fission products have been reviewed. An investigation was conducted into the ability of silica gel, in a medium of hydrochloric acid, to separate zirconium and niobium From an irradiated uranium sample and from 4 non-radioactive sample. Different procedures were then considered for the determination of zirconium and niobium; gamma ray detection, X-ray Fluorescence and a colorimetric method using Alizarin Red-S. Alizarin Red-S was not found suitable for this research due to the interference of niobium, so the other techniques mentioned above were used. The results are summarised in tables which show the percentage of each element in aqueous solution. From these results it is clear that, for certain specific column dimensions and Flow rates, using several concentrations of hydrochloric acid, it is possible to separate zirconium and niobium both From each other and from other Fission products. This method was not, however, found suitable For separation of other Fission products e.g. ruthenium, cerium