Preparation of 93Mo solution using proton irradiated Nb

Abstract

93Mo is an important long-lived radionuclide in nuclear waste, and is required to be measured during the characterization of decommissioning waste. However, no commercial 93Mo solution is available to be calibrated and used as standard in the analysis of nuclear waste. This work presents a method for separation of 93Mo from Nb metal used in cyclotron as a target holder and irradiated with protons for long time. The separation of 93Mo from Nb matrix was implemented by combination of precipitation and chromatographic separation. The Nb matrix was first removed by precipitating oxides-hydroxides of Nb (e.g. Nb2O5) and then by Fe(OH)3 co-precipitation; Mo in the solution was purified using an alumina (Al2O3) column. A decontamination factor of ca. 105 was achieved for Nb. A pure carrier-free 93Mo solution was successfully prepared, and the 93Mo purity was verified by liquid scintillation spectrometry.