Journal of Radioanalytical and Nuclear Chemistry最新文献

In this study, the stable isotopic and hydrochemical composition of surface water is systematically investigated to reveal the potential sources, influencing factors and chemical weathering processes. Results show that the primary recharge source of surface water is local precipitation, and its isotopic composition influenced by both evaporation effects and altitude effects. Multiple factors can affect the major ion composition in surface water, including the atmospheric precipitation, anthropogenic input, and rock weathering. The average contribution rates from each endmember are 7.17%, 25.16% and 67.67%, respectively.

The cross-sections of the ⁹⁷Mo(α,x)^95,97Ru and ⁹⁷Mo(α,x)^96gTc reactions were measured by the stacked foil technique within the energy range 58.5 → 19.4 MeV on cyclotron U-150. Cross-section of ⁹⁷Ru reaches 650 mb at ~ 50 MeV. Data for energies above 46 MeV were obtained for the first time. The experimental data are in a good agreement with the simulation with TALYS software. The TTY (thick target yield) of ⁹⁷Ru at 58.5 MeV is ~ 12 MBq/(μA∙h), which is enough for practical application. The presence of radioisotopic impurities of ⁹⁵Ru is not a critical concern due to its short half-life.

The separation of actinium (²²⁸Ac) from radium (^223,228Ra) on cation exchange resin with a diethylenetriaminpentaacetic acid-lactate buffer solution is demonstrated with series of columns. High yield, high radiopurity (~ 100%) separations of Ac from Ra are feasible with small columns in biologically compatible conditions and pHs. As Ac is eluted before Ra on these columns, further studies were performed to determine if this separation system could be applied to Ra/Ac isotope generators, but these were not successful. The separations presented in this work may be relevant for radiopharmaceutical purifications of ²²⁵Ac which is typically obtained from its ²²⁵Ra parent isotope.

The continuous release of radon-222 from uranium tailings can be regarded as a tracer for dam damage assessment. In this paper, the initial dam body numerical model Model-O was constructed by COMSOL Multiphysics software based on Darcy's law and Biot porous elasticity theory, and the model was updated according to the shaking table test data, then the radon exhalation pattern under the dam body damage state was simulated by the updated model. The results show that radon can be used as a tracer to assess the dam damage, and the updated model simulates radon exhalation more accurately.

Rare earth elements have received widespread attention due to their extensive industrial applications. However, the production process of rare earth generates radioactive waste, which poses a threat to the environment. This article develops a safe, efficient, and convenient method to separate Th(IV), U(VI) from radioactive waste leachate to reduce environmental hazards. Bastnaesite is one of the rare earth minerals with the largest reserves in China. This article analyzes the main chemical components of two different types of radioactive residue leachate from bastnaesite. For the first time, TRPO (a mixture of trialkylphosphine oxides) has been used to simultaneously separate Th(IV) and U(VI) in the leachate. The optimal parameters for the separation were determined, including the leachate acidity, extractant concentration, and equilibration time between the aqueous phase and organic phase in extraction, scrubbing, and stripping processes. Based on the optimal parameters, the stage numbers and phase volumetric ratios were obtained using equations based on mass conservation and McCabe–Thiele diagrams. Furthermore, a counter-current extraction-scrubbing-stripping process was developed for the simultaneous separation of Th(IV) and U(VI) in the leachate. The results show that Th(IV) and U(VI) can be selectively and simultaneously separated in the leachate of radioactive waste residues.

This study introduces a novel strategy for uranium-contaminated soil remediation by synergizing vertical electrokinetic migration with deep-layer phosphate passivation. The system successfully concentrates uranium at a target depth of 20–25 cm and immobilizes it through the formation of stable uranyl phosphate minerals (e.g., autunite). This approach reduced surface soil (0–20 cm) uranium leaching to near-background levels and increased the stable residual fraction to over 50%, demonstrating a sustainable solution for the long-term stabilization of deep-layer radioactive contamination.

To handle radioactive iodine, two polyethyleneimine-based (PEI) adsorbents (PEI-TC and PEI-CC) were synthesized through using terephthaloyl chloride (TC) and cyanuric chloride (CC) as the linker. The adsorption capacity of PEI-TC was 7.00 g/g for gas-phase iodine and 2.00 g/g for liquid-phase iodine, while for PEI-CC were 0.20 g/g and 1.11 g/g respectively. The adsorption behavior followed the pseudo-second-order equation and the Langmuir model. Both adsorbents can resist competitive anions and can be recycled for more than 5 times. The structure of the cross-linking agent affected the adsorption performance; the mechanism involved electrostatic attraction and van der Waals forces.

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The feasibility of using commercially available polyvinylpolypyrrolidone (PVPP) as a separate actinides was investigated. Uranium, thorium, and plutonium were used as actinides in the study. Adsorption data for An(IV) and An(VI) were obtained by adsorption experiments in nitric acid. In addition, An(III)/An(IV)/An(VI) sequential separation was successfully performed by a column separation method using PVPP. Furthermore, the elution efficiency of U(VI) was improved by the introduction of carbonate ions. This method may be applicable as a sequential separation for actinide.

The growing demand for high-specific-activity ¹⁷⁷Lu necessitates efficient Yb/Lu separation. This study synthesized and characterized novel phosphorus-containing levextrel resins. HEH(EHP)-based resin achieved over 99% Lu adsorption under low acidity with a separation factor (SF_Yb/Lu) exceeding 3, while HDEHP-based resin showed faster kinetics. Using the optimized HDEHP/HEH(EHP)-XAD-7 resin, a three-cycle process yielded 94.98% Lu recovery, and a secondary separation achieved 83.37% Yb removal. These findings demonstrate the resin’s high efficacy for producing high-purity ¹⁷⁷Lu.

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Oxide materials with a cubic perovskite structure and randomly distributed oxide-ion vacancies were synthesized by partially substituting Ln (Ln: Tm, Yb, Lu) for Sr or Fe in SrFeO_3−δ. Mössbauer spectroscopy showed that the Fe chemical state depended on the substitution site rather than the Ln type. Although Sr_0.9Ln_0.1FeO_3−δ and SrFe_0.9Ln_0.1O_3−δ exhibited similar mean Fe valence, the former demonstrated greater charge carrier delocalization, higher conductivity, and lower activation energy. Notably, Sr_0.9Tm_0.1FeO_3−δ exhibited the highest conductivity without structural phase transition, indicating strong potential as an electrode material for solid oxide fuel cells.