Journal of Radioanalytical and Nuclear Chemistry最新文献

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.

Since 2021, the National Nuclear Center (NNC) of the Republic of Kazakhstan has been successfully developing a project dedicated to nuclear forensics. The relevance of this project is underscored by Kazakhstan’s leading position in the global uranium mining and export market. The country operates research reactors and is involved in the production of experimental nuclear fuel. The nuclear forensics project is being implemented in several key areas: the project will develop competencies in laboratory research of samples, interpretation of results, and develop a prototype concept for the National Nuclear Forensics Library. In implementing these challenges, the NNC experts draw on the experience of colleagues from world-leading scientific and research centers. Designing a prototype National Nuclear Forensics Library (NNFL) is a challenging project. The solution to this task is based on the IAEA’s approaches, recommendations, and the experience gained from the construction of similar systems in other countries.

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.

The ²¹⁰Po isotope was used as a tracer to study the transfer of polonium from nutrient solution and soil to lettuce (Lactuca Sativa) grown in hydroponic and soil systems, respectively. The nutrient solution-to-lettuce transfer factors (TF_w) ranged from 1.23 to 5.41 L kg_{fresh weight}⁻¹, with a mean value of 3.01 L kg _{fresh weight}⁻¹. The soil-to-lettuce transfer factors (TF_s) were from 0.32 to 0.65, with a mean value of 0.51. The mean activity concentrations of ²¹⁰Po (AC_Po) in lettuce grown in hydroponic and soil systems were 4.8 Bq kg_{fresh weight}⁻¹ and 12.6 Bq kg_{fresh weight}⁻¹, respectively. The hydroponic system significantly reduces the AC_Po in lettuce with a significant value (p) of 0.05. The effective dose rate (D_e) was estimated for the normal intake rate of lettuce in Vietnam. The mean D_e values were 3.6 μSv y⁻¹ and 9.2 μSv y⁻¹ estimated for lettuce grown in hydroponic and soil systems, respectively. The dose assessment shows that the AC_Po in all lettuce samples poses no risk to humans.

The nuclear industry is continuing to grow and adopt new technologies to manufacture components. One of the technologies under consideration is additive manufacturing (AM). AM could make production of components at lower cost and could lessen lead times significantly. However, AM could be prone to proliferation risks. AM machines give off signatures during the manufacturing process, and these signatures offer an alternative means of observing the component. Correlations between these signatures and the geometry being manufactured could be developed; enabling proliferators as they could take advantage of these correlations to steal AM manufacturing instructions relating to nuclear technology. This work pertains to preliminary work exploring the feasibility of tapping into AM side channels to predict geometries being manufactured on AM machines. The feasibility of utilizing vibration to draw geometric correlations will be assessed on an Ultimaker 2 + thermoplastic 3D printer.

This study investigates uranium concentration in urine among workers in different stages of Kazakhstan’s uranium production cycle—mining, processing, and fuel fabrication. A total of 619 urine samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The highest uranium concentrations were found in workers from in-situ leaching mining facilities. Statistical analysis revealed significant variability and skewed distributions across groups, with a proportion of workers exceeding the reference value of 0.9 µgL⁻¹. The findings highlight the need for ongoing biomonitoring and further assessment of occupational exposure, particularly among residents living near uranium production sites.

In water treatment facilities, naturally occurring radionuclides of soil and rock may be accumulated in groundwater during the treatment of drinking water. The objective of this study is to assess internal radiation doses due to NORM inhalation by workers in water treatment facilities in Korea. We analyzed flow of groundwater in water treatment facilities. Airborne particle concentration and activity concentration were measured using a large-capacity, individual air sampler and HPGe detector. The annual internal radiation dose ranged from 9.52 × 10^–7 to 3.42 × 10^–5 mSv y⁻¹, which was less than the annual dose limit of the general public of 1 mSv y⁻¹.

Quartz is a common and geologically complex mineral that is most commonly used in thermoluminescence (TL) applications for dating geological events and radiation dosimetry. This review provides an overview of the TL behavior of quartz derived from igneous, metamorphic, and sedimentary environments, emphasizing how the means of formation influences defect structures, trap parameters and TL sensitivity. It summarizes experimental work on glow curve behaviors, defect centers chemistry, thermal and irradiation histories, and provides comparative perspectives across quartz types. Sedimentary quartz has the highest TL sensitivity and well-bleached trap populations, and is potentially the best for radiometric dating of geological events and retrospective environmental dosimetry. Applications as luminescence dating of geological events and retrospective dosimetry surrounding radiation exposure, are discussed as representable examples. Future research directions include recent advances in trap engineering, TL instrumentation, and Ai-analysis of glow curves, providing opportunities for standardizing methods of analysis and standardizing the methodology of quartz for luminescence-based technologies.

Natural radium isotopes (²²⁶Ra, ²²⁴Ra, ²²³Ra, and ²²⁸Ra) in groundwater reflect aquifer geochemistry, especially in uranium- and thorium-rich formations. This study compares three methodologies (M1, M2, M3) for measuring them in waters. M1 used the detection efficiency based on gamma energies from ²²⁸Ac to generate an efficiency vs. energy calibration curve. M2 utilized U and Th standards, consisting of pitchblended and monazite sand, to obtain the calibration curves. M3 accounted for matrix effects using a calibration curve based on ²²⁶Ra standards solutions of varied activity concentration. The methods were applied to groundwater samples provided from different Brazilian aquifer systems.

The treatment of radioactive graphite waste, especially due to ¹⁴C emissions, poses significant challenges. This review summarizes incineration-based volume reduction technologies and evaluates carbon isotopic separation methods. Fluidized-bed incineration offers high efficiency but requires effective control of ¹⁴C release. Among separation techniques, chemical exchange using CO₂ is identified as the most practical. A three-stage treatment strategy is proposed: incineration, off-gas purification, and ¹⁴C separation. This integrated approach enables waste minimization, emission control, and potential ¹⁴C reuse, offering a feasible and sustainable solution for managing radioactive graphite waste.