Abstract: A method for assessing the mass concentration of uranium in a sample of uranium-bearing material by gamma spectrometry, includes a) acquiring (200) an energy spectrum of gamma radiation from the sample using a scintillator detector, the energy spectrum (100) comprising at least a first energy band (110) between 87 keV and 110 keV, and a second energy band (120) between 560 keV and 660 keV, the second energy band comprising at least one energy line (130) at 609 keV from 214Bi, b) calculating (210) an initial mass concentration of uranium (CmU0) using the energy spectrum, c) measuring (220) a parameter representative of the height of the sample and a parameter representative of the density of the sample, d) calculating (230) a corrective coefficient (K), and e) calculating (240) a corrected mass concentration of uranium (CmU) using the initial mass concentration of uranium (CmU0) and the corrective coefficient (K).

Abstract: A mesoporous organic material which makes it possible to extract, using the liquid-solid extraction technique, the uranium(VI) contained in an aqueous medium including phosphoric acid, with high efficiency and high selectivity for the iron that the medium can likewise contain. The material is likely to be obtained by cross-linking polymerisation of a monomer of formula (I) below, wherein: R1, R2 and R3 are, independently from one another, H, a C1 to C12 saturated or unsaturated, linear or branched hydrocarbon group, or a polymerisable group, with the condition that at least one of R1, R2 and R3 is a polymerisable group; R4 and R5 are, independently from one another, H or a C1 to C8 saturated or unsaturated, linear or branched hydrocarbon group; the cross-linking polymerisation being carried out in the presence of a cross-linking agent and one or more pore-forming agents.

Abstract: A method is for analyzing, using a detector of alpha particles, a sample comprising at least one radionuclide emitter of a plurality of alpha particles. The detector comprises a detection medium and a plurality of measurement cells suitable for measuring at least one incident signal generated by an interaction of the alpha particle with said detection medium. The detector is designed to provide an autoradiographic image of said sample. The method comprises a step for determining (E1) an initial energy of each alpha particle. The step comprises repeating three sub-steps: determining (D1) a position of a first interaction of an alpha particle with the detection medium, determining (D2) an energy deposited by the particle in the interior of the detector and determining (D3) the initial energy of the alpha particle. The method then comprises constructing an energy spectrum for one zone of the autoradiographic image.