Preparation and characterization of234U for mass spectrometry and alpha-spectrometry

²³⁴U of high isotopic purity (>99 atom%) as well as of high radiochemical, purity was separated from aged²³⁸Pu prepared by neutron irradiation of²³⁷Np. Methodologies based on ion exchange and solvent extraction procedures were used to achieve high decontamination factor from²³⁸Pu owing to the very high α-specific activity of²³⁸Pu (2800 times) in comparison to that of²³⁴U. Isotopic composition of purified²³⁴U was determined by thermal ionisation mass spectrometry. Alpha spectrometry was used for checking the radiochemical purity of²³⁴U with respect to concomitant α-emitting nuclides. The separated²³⁴U will be useful for different investigations using mass spectrometry and alpha spectrometry.