Journal of Radioanalytical and Nuclear Chemistry最新文献

Na induces the formation of acicular RuO₂ in the glass melt, and the effect of Cs on the precipitation of RuO₂ is not clear. In this study, sodium ruthenate (NaRu) and cesium ruthenate (CsRu) were prepared by quenching experiments, and RuO₂-containing waste glass was prepared by calcination of glass surfaces. The results showed that both CsRu and NaRu induced the formation of RuO₂ in the glass melts, with rod-like and acicular morphology, respectively. It can be inferred that alkali metals play an important role in the formation of RuO₂ with different shapes.

The present study focuses on investigating the conditions for acid leaching of Th and REEs and sequential oxalate precipitation to remove impurities from leach liquor. The effects of preheat treatment, leaching time, liquid/solid ratio, and acid concentration on Th, Sm, Pr, Nd, Ce, La, and U leaching yields were investigated. The best results were obtained at 400 °C preheated sample using 1 mol/L H₂SO₄, liquid/solid ratio of 1 mL/g, 60 min leaching time, and 30 °C leaching temperature. The leaching yields of Th, Sm, Pr, Nd, Ce, La, and U were found to be 41.7, 65.0, 68.2, 66.9, 84.3, 82.6, and 55.0% respectively. Th and REE liquors were treated with 0.5–1.5 mol/L H₂C₂O₄ solutions in the precipitation step. Purity was enhanced through three sequential precipitation cycles, resulting in a purity grade of 98.59%.

The elemental composition of 29 granite rock samples from the Gabel Elba–Wadi Eikhwan area situated in the southern sector of Egypt’s Eastern Desert were analyzed using neutron activation analysis (NAA) and X-ray fluorescence (XRF). Altogether, 45 major and trace elements were quantitatively determined. Bivariate and multivariate statistical analyses were conducted to distinguish and categorize the rock-forming elements according to their elemental content. The applied ratio indicators and discriminant diagrams show that the studied rock samples are well classified to be granite. The principal component analysis results demonstrate clustered samples of common geochemical features. The integration of NAA and XRF has demonstrated its efficacy and relevance in rock studies. The obtained results hold significant importance for the regions investigated and can serve as fundamental data for future assessments and prospects.

Instrumental neutron activation analysis (INAA) was employed to assay 32 minor and trace elements in bone of Bohemian Duke John of Görlitz (1370–1396) who suddenly died at the age 25 years for unknown reasons. Recently, histological examination of his illium bone was carried out, accompanied by histochemical staining reactions to learn about his health status. The INAA results disproved an elevated Al content indicated by the staining reaction with aluminon, but revealed elevated levels of Mn, As, Sb, and especially of Ag compared with literature values. The results are discussed in terms of toxicity of the above elements, especially whether their elevated levels could be the reason for Duke´s sudden death.

Fuel “hot” particles are the most unpredictable dose-forming components in the soils of uranium contaminated regions, such as Chernobyl Exclusion Zone. Over time in the environment, “hot” particles undergo gradual dissolution with the release of uranium as well as fission and neutron-activation products trapped inside the uranium-oxide fuel matrix. The environmental fate of fuel particles depends not only on the environmental conditions but mainly on the conditions of their formation in the reactor and during the accident. In the present work micromorphology, fuel burnup and uranium oxidation state of several fuel “hot” particles, collected on the Western trace of Chernobyl fallout, were studied using a combination of non-destructive or semi-non-destructive techniques: gamma-spectrometry, secondary-ion mass-spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, the X-ray absorption near-edge structure and the high-energy resolution fluorescence-detected X-ray absorption near-edge structure spectroscopy. An attempt has been made to assess the contribution of the conditions of particle formation and the conditions of being in the environment to the current state of particles after more than a quarter of a century of history in the environment.

Graphical Abstract

This study proposes a model for phytoremediation coupling transport in soil and dynamic model using sunflower plants and ¹³⁴Cs radionuclide. The model was validated by comparison with experimental measurements. The error value obtained, ranging from 0.00045–0.5268, is quite small, and the overall simulation data has approached the experiment. Factors influencing radionuclide concentration in different blocks include saturation point values, absorption rates of plant parts, soil dispersion coefficient, and velocity. The model is used to predict doses from ingesting sunflower seeds and estimates the soil-to-plant transfer factor. This new model is recommended for accurate assessment of environmental risks associated with radionuclides and for efficient decontamination.

The selective separation of Am(III) over Eu(III) from high-level radioactive liquid waste using four bis-succinamide ligands (THE-BisSCA, L¹; THDM-BisSCA, L²; THDPh-BisSCA, L³; THDⁱ⁻P-BisSCA, L⁴) was explored with density functional theory. Ligands with phenyl groups near the nitrogen, particularly L³, showed the highest Eu(III) affinity. The π bonds orbitals of the benzene ring may conjugate with the long pair N-2p orbital, and this special p-π conjugation effect can lead to charge transfer from benzene ring to the donor N atoms on L³ ligand, resulting a lower energy and more stable structure of the complex formed with the L³ ligand compared to other complexes. Thermodynamic analysis corroborates L³ has Eu(III) preference, offering valuable guidance for efficient Am(III) and Eu(III) separation with these ligands.