Journal of Radioanalytical and Nuclear Chemistry最新文献

This study employs a High-Purity Germanium (HPGe) detector to analyse the activity concentrations of primordial radionuclides U-238, Th-232, and K-40 in the agricultural soils of the West Jaintia Hills District, Meghalaya, India, adjacent to the Dawki fault. The measured U-238 activity varied from 36.5 ± 3.1 to 57.4 ± 4.8 Bq/kg, averaging 47.2 ± 3.5 Bq/kg. The Th-232 activity elevated from 43.4 ± 3.2 to 54.5 ± 3.2 Bq/kg, with a mean of 48.1 ± 3.3 Bq/kg, which exceeds the worldwide mean. The measured K-40 activity ranged from 114.78 ± 9.6 to 150.25 ± 9.9 Bq/kg, with an average of 132.7 ± 9.7 Bq/kg. The findings indicate that the radiation risk associated with U-238 and Th-232 concentrations is elevated, whereas K-40 concentrations are within permissible limits. The evaluation provides crucial information on the radiation dosage levels at the location and their impact on public health.

In radiological emergencies, rapid ⁹⁰Sr quantification is vital. This study developed a method for ⁹⁰Sr determination in milk and drinking water, using Sr-specific resin separation followed by ICP-MS/MS detection in MS/MS mode to eliminate ⁹⁰Zr isobaric interference. Validation demonstrated high recoveries (95–97%) and detection limits (18–22 Bq kg⁻¹) compliant with European regulation Euratom 2016/52. Inter-laboratory comparisons confirmed the method reproducibility and robustness across diverse setups. Contamination control was identified as essential for method success. The method enables rapid ⁹⁰Sr measurement in milk and water, supporting radiological emergency response.

This study investigated the relationship between ¹³⁷Cs activity concentration and water quality to clarify the factors affecting variation of ¹³⁷Cs activity concentration in the waters of Maeda and Saruta Rivers within the Difficult-to-Return Zone after the Fukushima Dai-ichi Nuclear Power Stations accident. In addition, the factors influencing the variation of apparent distribution coefficient between water and sediment were examined. The variation in dissolved ¹³⁷Cs activity concentration was caused by decomposition of dissolved organic carbon in the Maeda River and the ion exchange reactions with K⁺ and Na⁺ in the Saruta River, respectively.

In order to study the influence of U tailings pond on the downstream river, the distribution, source and speciation of nuclide U and Th from the tailings pond to Linshui river were systematically analyzed by sample collection, mathematical statistics and hydro-geochemical simulation. Through the water chemical characteristics, it is found that SO₄·Ca type is the water chemical type in the tailings pond area, which changed to HCO₃·Ca type in the Linshui river. SO₄²⁻ is the main anion in the tailings pond, but HCO₃⁻ is the main anion in the Linshui river. The concentrations of U and Th decreased significantly with the distance from the tailings pond. After entering the Linshui river, U concentration was relatively stable, while Th concentration was easily concentrated in the upper reaches of the river. The correlation and principal component analysis showed that U, Th, Ni, Zn, and Cd were greatly affected by the tailings pond, and they has the same source. The hydro-geochemical simulation results showed that the speciation of U and Th in tailings pond were mainly UO₂F⁺, UO₂F₂ and ThF₃⁺, which were related to F⁻ concentration and pH value. In the Linshui river, UO₂(OH)₂ and UO₂(CO₃)₂²⁻ increased, and Th(OH)₄ was absolutely dominant speciation. It indicated that pH value and dominant anion were the main controlling factors of U and Th speciation. The results provide the basis data and support for the transformation path of the nuclides in water and the hydro-geochemical process surround U mine.

In a radiologic emergency, a large environmental area might be contaminated by radionuclides. To locate alpha emitters remotely, the project RemoteALPHA developed an optical detection system, able to measure radioluminescence photons. In this study, we chose ²⁴¹Am-doped ivy leaves, pine needles and concrete as examples representing contaminations in natural and urban areas, respectively. Measurement data was compared to the applied activity. Particularly the concrete samples showed an unexpected behaviour, because the number of photons did not rise linearly with increasing activity. We explained these apparent inconsistencies by modelling and experimentally confirming energy loss and self-shielding effects in concrete.

This pilot study aimed to establish end-to-end stereotactic radiosurgery (SRS) sessions and evaluate the accuracy of the delivered doses using EPR/alanine and GAFChromic™ EBT3 films. Six Planning Treatment Volumes (PTVs), representing variations in tumor size, location, and proximity to Organs at Risk (OARs), were assessed using an anthropomorphic male head phantom irradiated with a TomoTherapy Hi-Art system (fraction of 10.5 Gy). Maximum deviations ranged from − 0.35 to 0.16 Gy, and − 0.35 to − 0.08 Gy, for alanine and films, respectively, even under complex spatial dose distribution (e.g., PTV6). Therefore, the findings demonstrated the reliability of both systems for precise SRS dosimetry.

This study proposes a strategy to determine the purity of Ti metal for developing primary standard solutions. The mass fractions of 78 elements in Ti metal were analyzed, and 35 elements were quantified while MDV were obtained for the others by neutron activation analysis, inert gas fusion-based analytical methods, and atomic spectrometry. Additionally, mass fractions of four noble gases and six radioactive nuclides were estimated in the Ti metal. The purity of Ti with the combined standard uncertainty was determined to be 99.939% ± 0.0055%. Measurements of O, Fe, C, N, Ni, H, and Si measurements were the main source of uncertainty in the evaluation of Ti metal purity.

The elemental profiles of rooibos leaves (green and fermented) and soil samples collected from a farm in the Cederberg Mountain range of South Africa’s Western Cape were determined using instrumental neutron activation analysis and inductively coupled plasma optical emission spectrometry. Mass fractions of As, Cd, and Pb in plant material were below the World Health Organization’s limits. Soil pollution and elemental enrichment were assessed using contamination and enrichment factors, revealing elevated mass fractions of Si, Zr, Hf, Br, and Cd. The transfer factor was used to evaluate metal translocation in the soil–plant system. Health risks were assessed based on calculated Target Hazard Quotients and the Hazard Index. Both indices were well below 1.0 for all elements, indicating that the consumption of rooibos tea containing the analyzed elements poses no significant threat to human health.

Reconstructing neutron spectra from limited measured counts is a challenging inverse problem. This paper presents a dual-domain feature-enhanced deep unfolding network (DDFEDUN), integrating the advantages of compressed sensing and deep learning. By constructing a collaborative architecture consisting of a wavelet-domain deep unfolding module (WDDUM), a convolution-domain deep unfolding module (CDDUM), and a dual-scale denoising module (DSDM), the proposed method fully leverages the structural prior information of neutron spectra across multiple transformation domains. This approach effectively enhances the model’s feature representation capability and noise robustness. Experimental results have demonstrated that DDFEDUN achieves high-precision and stable reconstruction across various typical neutron spectra.

In situ treatment of uranium-containing wastewater from uranium mining areas remains a significant challenge. Herein, microorganisms resistance to uranium (VI) were isolated. Subsequently, sand column experiments were carried out using local ore as a carrier to immobilize the isolated microorganisms. The results demonstrated that the ore can effectively support a high microbial loading and exhibited favorable biocompatibility. Compared with the ore alone, the immobilized microorganisms displayed a more rapid and stable capacity for uranium transformation and removal. While the maximum removal efficiency of the ore alone reached only 50%, while that of the immobilized microorganisms achieved up to 99%. Furthermore, the influence of various reaction parameters on uranium removal performance was systematically investigated. Under optimal conditions of pH 7, temperature of 25°C, initial uranium concentration of 20 mg/L, and inoculation ratio of 10%, the removal efficiency of the ore-immobilized microorganisms reached 99.4%, with a residual uranium concentration of 0.12 mg/L. The mechanisms revealed that in-situ cultivated microorganisms efficiently converted soluble uranium (VI) into insoluble forms and stable adsorbed uranium (VI) ions, thereby significantly enhancing the uranium immobilization capacity of the ore carrier. The immobilized microorganisms reduced soluble uranium (VI) to insoluble U(IV) precipitates via biological reduction and other resistance pathways, achieving a level of uranium removal that far exceeded the adsorption capacity of the ore alone. These findings provide a solid theoretical foundation and reliable technical support for the efficient, stable, and environmentally sustainable bioremediation of uranium-containing wastewater.