Journal of Radioanalytical and Nuclear Chemistry最新文献

A simple strategy is presented for the preparation of Prussian blue-modified g-C₃N₄. PB/g-C₃N₄ is synthesized as an efficient adsorbent for the adsorption of U (VI), and the effects of various conditions on the adsorption of U (VI) are investigated. Static adsorption experiments reveal that the adsorption of U (VI) by PB/g-C₃N₄ conforms to the Langmuir adsorption isotherm and pseudo-second-order adsorption model. The composition and morphology of the materials are characterized by XRD, FT-IR, XPS, SEM, and BET. This study demonstrates that PB/g-C₃N₄ is a promising material for uranium-containing wastewater treatment, with the advantages of low cost, environmental friendliness, and facile synthesis.

Determinations of radioactivity and stable element contents in outlet waters taken from dams (Çamlıdere, Kurtboğazı, Kesikköprü, Çubuk-2) and drinking waters from water treatment plants (İvedik, Pursaklar and Çubuk) of Ankara Water and Sewerage Administration (ASKİ) were performed by using MPC-9604 multi-detector alpha/beta (α/β) counting system, inductively coupled plasma–mass–mass spectrometer and graphite furnace atomic absorption spectrometer. Gross alpha and beta activity levels and element concentrations found in samples were compared with maximum permissible values given by World Health Organization, United State Environmental Protection Agency, Turkish Standards and Türkiye Regulation on Water for Human Consumption.

This study assessed radionuclide concentration in Murree’s natural spring water and the variation of soil mass-attenuation coefficient. Water samples from 20 springs and soil from 15 sites were analyzed. Radium-226, Thorium-232, and Potassium-40 activity concentrations averaged 0.43 ± 0.09, 0.52 ± 0.08, and 1.52 ± 0.19 Bq/L, respectively. Radiation hazard indices, including Radium equivalent, External and Internal hazard indices, External and internal absorbed and equivalent doses, and lifetime cancer risk, were quantified but found non-alarming. Mass-attenuation coefficients for various energies were measured experimentally and theoretically. Various radiation shielding parameters were calculated. Murree’s soil demonstrated lower attenuation properties compared to cement, tiles, concrete, and Egyptian soil.

The permeability of ore is a key factor affecting the leaching effect of uranium ore, and the addition of surfactants can significantly improve the permeability of ore, thereby strengthening uranium ore leaching. This article simulates two infiltration leaching processes, atmospheric heap leaching and pressurized in-situ leaching, and explores the effect of surfactant cetyltrimethylammonium bromide on uranium leaching rate and ore permeability coefficient in both processes. The results showed that in the atmospheric heap leaching test, adding surfactants increased the ore leaching rate by 30.31% during the same 13 day test cycle, and the leaching process was mainly controlled by surface chemical reactions. In the pressurized in-situ leaching test, based on the results of a leaching cycle of 13 days, the average permeability coefficient increased by 72.89% and 64.07% after adding surfactants to the drained and water containing uranium deposits, respectively. In addition, the peak uranium concentration in the leaching solution appeared 2 days earlier, indicating that the addition of surfactants has a significant promoting effect on in-situ leaching of uranium, improving the leaching efficiency of uranium, and can improve the leaching rate of uranium within the same leaching cycle.

A radiochemical procedure has been developed for the quantification of uranium and thorium isotopes in NORM samples from the ceramic industry, such as zirconium sands, zirconium flours, micronized zircon, pigments and personal aerosol filters. The method is based on a fusion pretreatment with borate salts, a separation with anion exchange resins and alpha-particle spectrometry measurement. This method is an alternative to gamma spectrometry when the amount of sample is extremely small (2–10 mg) as in the case of aerosol filters, or there is no secular equilibrium in the ²³⁸U and ²³²Th chains, as in the ceramic pigments. The method has been validated with different ceramic materials and the comparison of the results with gamma measurements. Its reproducibility was also checked with different sample masses.

Carbon-14 and tritium are important radionuclides to be present in gaseous effluents of some nuclear power plants types. Tritium being usually included in gaseous effluents bearing carbon-14, the influence of its presence in the analyzes to be done must carefully be taken into account. When Liquid Scintillation Counting method is used, this influence can’t be completely eliminated by selecting different channels only for measuring carbon-14. In this paper, experimental verification of the influence of tritium on the carbon-14 measurements also miscibility of samples, detection efficiency and measurement precision were studied.

Filter use in experiments is often unspecified, potentially affecting results. In this study, six different filters were investigated for technetium and iodine. Technetium was evaluated at pH 2.5, 6, and 11 for two concentrations. Three oxidation states of iodine (iodide, molecular iodine, and iodate) were evaluated at pH 7 for two concentration levels. The results obtained were analyzed using a t-test to determine if it was statistically different than an unfiltered sample. The experimental results are combined with a literature review highlighting the inconsistency of filter reporting in manuscripts, as well as not accounting for analyte loss on filters used.

N,N-diethylhydroxylamine (DEHA) is a new salt-free reducing agent applied in the separation of Pu from U in the reprocessing of irradiated fuel from nuclear power plants. The effect of monomethylhydrazine (MMH) on the γ-rays radiolysis of DEHA-HNO₃ solution is presented in this paper. MMH can effectively enhance DEHA stability against radiation, and the main radiolytic products are H₂, CH₄, CH₃CHO, CH₃COOH and HNO₂. The content of H₂, CH₄, CH₃CHO and CH₃COOH is raised with the dose. The amount of H₂, CH₄ and CH₃CHO enhances with the MMH concentration, but CH₃COOH concentration is reduced when MMH concentration is raised.

Radiolysis of transplutonium elements and rare earths (REE)-containing solutions in radiochemical processes destroys complexing reagents and precipitates target products. We investigated the effect of the radiation-absorbed dose (AD) and acidity on the behavior of simulated DTPA and NTA REE-containing solutions to eliminate precipitation. We measured the AD by bichromate dosimetry. Without nitric acid, the AD = 0.12–0.24 MGy causes abundant precipitation of REEs. In the presence of HNO₃ up to 2 mol L⁻¹, no precipitation occurred up to 1.53 MGy. At HNO₃ 1 mol L⁻¹ and AD = 1.02 MGy, DTPA is entirely decomposed. We have suggested a method to avoid precipitation.

As an energy-saving and facile technology, electrosorption technology has good potential in the process of separation of uranium from aqueous solution. In this study, sucrose and urea were used to prepare nitrogen-doped carbon by one-step carbonization, and polyacrylamide modified nitrogen doped carbon (PAM/NC) was obtained by modification. The electrosorption test results indicated that PAM/NC-2 had the best properties and the maximum electrosorption capacity was 619.5 mg g⁻¹. The performance loss was less than 20% after 5 adsorption–desorption cycles. Overall, this material had a potential application in U(VI) pollution remediation, meeting the need for sustainable development of nuclear energy.