Uranium and plutonium analysis development for CANDU fuel reprocessing studies

This report describes some recent improvements in uranium and plutonium analyses at the Whiteshell Nuclear Research Establishment. A new, on-line, spectrophotometric, uranium analyzer has been developed. Individual sample stream treatment and the chromogenic agent, Bromo-PADAP, enable the analyzer to accommodate both aqueous and organic solvent streams, with an analysis range of 0.001 to 120 g.L-1. Another instrument is being developed for the in-line determination of uranium(IV) in a pulsed column with electrolytic uranyl ion reduction. The uranium(IV) absorption spectrum is being used to monitor uranium(IV) concentrations in the range 1 to 100 g.L-1. Our experience with a precise titrimetric method for determining less than 0.005 g of plutonium is described. The method has been used for the direct determination of plutonium in solutions of irradiated thorium fuel