DIRECT AND FAST URANIUM DETERMINATION IN ZIRCONIUM BY TIME-RESOLVED LASER-INDUCED FLUORESCENCE SPECTROMETRY

摘要

Fast and direct determination of uranium in zirconium is required for nuclear process control. Time-resolved laser-induced fluorescence spectrometry is a very selective and sensitive method that has been largely used for uranium(VI) analysis in the nuclear fuel cycle. Due to the very low quenching constant of zirconium, the uranyl fluorescence signal is weakly affected by this element. By using direct fluorescence signal measurement, the uranium concentration is obtained in less than a minute and the limit of detection is close to 10 ng l(-1) which corresponds to 1 ng g(-1) relative to the zirconium matrix. Moreover, the zirconium dissolution medium (nitric/hydrofluoric acid) is complexing enough to allow direct measurement with no use of other complexing reagent. Such procedure can also be used for uranium determination in hafnium. [References: 16]