Journal of Radioanalytical and Nuclear Chemistry最新文献

To date, radiopharmaceuticals containing micro-sized carriers of radionuclides are actively being studied, as well as their use in radioembolization instead of ⁹⁰Y-containing microspheres. For such purposes, bentonite clays widely studied as a carrier of drugs seems perspective but their research as carriers of radionuclides in nuclear medicine is almost absent. In this study, bentonite samples were tested for the first time as a platform for a wide range of therapeutic radionuclides. Optimal conditions for the sorption of di- and trivalent therapeutic isotopes by the studied samples were identified. Stability in model biological media was investigated. Adsorption isotherms for the corresponding elements were obtained using the Freundlich and Langmuir models, and ΔG of the adsorption processes were determined. As a result, the studied samples were found to be promising carriers of bismuth (^212,213Bi) and ²²⁵Ac isotopes, including an “in vivo generator” ²²⁵Ac/²¹³Bi, opening up prospects for further research in laboratory animals.

Thermodynamic and experimental approaches were used to examine the stable phases, chlorination, and evaporation of chloride products during carbonization–chlorination decontamination of Cs- and Co-contaminated ion-exchange resins. Cs₂SO₄ was the stable phase for Cs under carbonization at 800 °C. Chlorination at 1000 °C for 30 min resulted in conversion and evaporation ratios of 0.925 and 0.314, respectively. Residual CsCl was completely removed by an additional heat treatment. For Co, Co₃O₄ was the primary carbonization product. At 900 and 1000 °C, only CoO was detected. Chlorination at 1000 °C led to conversion and evaporation ratios of 0.701 and 1.00, respectively.

Sodium salt waste (SSW) mainly contains sodium salts and ⁹⁰Sr/¹³⁷Cs, with a complex composition. This review presents the advantages and disadvantages of typical immobilization materials, focuses on analyzing the advantages of geopolymers in immobilizing SSW, and addresses the problems that need to be solved in the future, such as the solidification efficiency caused by the change of SSW compositions and the decline in the durability of the geopolymer waste–forms due to salt residues. The article also proposes coping strategies, including optimizing the solidification method through a multi–phase coexisting structure and improving the material durability through sintering technology.

Fluorapatite-based glass-ceramics (GCs) have been prepared by a two-step hot-pressing (HP) sintering as novel nuclear wasteforms for incorporating fluoride-based salt waste. Other sets of GCs were also prepared by the solid-state (SS) method for comparison. The crystallization of fluorapatite (Ca(_{9})Sr(PO(_{4}))(_{6})F(_{2})) as the main host phase within the borosilicate glasses was identified by x-ray diffraction (XRD) and scanning electron microscopy (SEM). SEM analysis shows the glass-ceramics prepared by HP sintering exhibit a relatively denser microstructure compared with GCs prepared by SS method, and energy dispersive spectroscopy (EDS) confirms that the salt waste is mainly incorporated into the ceramic phase. In addition, the product consistency tests (PCT) confirm that the HP samples are chemically durable with relatively lower normalized Sr, Si and Ca leach rates (sim)10(^{-4})–10(^{-3}) g/m(^{3}), indicating that HP GCs exhibit higher chemical durability than SS GCs.

Yttrium-90 (⁹⁰Y), a beta-emitting radionuclide with suitable half-life and radiation energy, is considered an ideal therapeutic nuclide and has been used for the treatment of inflammatory joint diseases, relapsed or refractory B-cell non-Hodgkin's lymphoma, and liver metastases of colorectal cancer. It has great potential for application in nuclear medicine. In this work, stable isotopes were employed to simulate the production conditions of curie-level Y-90 in a system with a Sr/Y concentration ratio of 20,000. The electrolysis was conducted with 0.1 M NH₄NO₃ as the supporting electrolyte, pH adjusted to 2.5, and a current density of 100 mA/cm² applied for 3 h, resulting in a Y recovery rate exceeding 98%. Meanwhile, by adjusting the cathode cleaning step, a theoretical purification factor of (6.8 ± 0.8) × 10⁵ was achieved in the simulated secondary electrodeposition. Based on this, a six-step process was developed for the simulated production of 2.4 Ci of ⁹⁰Y per day and 2.4 Ci per week. The obtained Y recovery liquid theoretically conformed to the requirements for medicinal application.

Automation significantly expands the analytical capacity of the laboratories, which perform instrumental neutron activation analysis on a large number of samples. Based on the existing experience and the need to implement new equipment and capabilities, specialized software for automating instrumental neutron activation analysis at the Regata facility of the IBR-2 reactor was developed. A database managed by Microsoft SQL Server for data import, storage, and export was created. The system also enables the storage of results obtained for other elemental analysis techniques (inductively coupled plasma optical emission spectroscopy, atomic absorption spectrometry, direct mercury analyzer). An overview of the user interface and capabilities of the new software is presented.

^99mTc is the most widely used radionuclide in medical diagnostics and typically obtained from high-specific-activity (HSA) ⁹⁹Mo produced in nuclear reactors. However, recent reactor shutdowns have led to supply shortages and prompted efforts to implement alternative production methods. One promising approach is neutron activation of ⁹⁸Mo, which yields low-specific-activity (LSA) ⁹⁹Mo. Since conventional Al₂O₃-based ⁹⁹Mo/^99mTc generators are designed for HSA ⁹⁹Mo, adaptations are required for LSA ⁹⁹Mo usage. In this study, we evaluated the feasibility of modifying existing Al₂O₃-based ⁹⁹Mo/^99mTc generators for use with LSA ⁹⁹Mo, anticipating production at the planned high brilliance neutron source (HBS) at Forschungszentrum Jülich. Key modifications included adjustments to the amount of Al₂O₃ on the column and the elution volume of ^99mTc to enhance ⁹⁹Mo adsorption and ^99mTc elution efficiency. The performance of the modified “mock-up” system was compared with a standard clinical generator. The results demonstrated that only minor modifications are required for LSA ⁹⁹Mo to be effectively utilized in a future generator, with elution efficiencies remaining comparable to conventional generators, while maintaining parameters like size, form, number, activity of the individual generator comparable. However, ⁹⁹Mo breakthrough levels exceeded regulatory limits, highlighting the need for further optimization. Nevertheless, these findings support the feasibility of using LSA ⁹⁹Mo in clinical applications with minimal changes to existing infrastructure.

Acacia saligna (Labill.) is a widely used ornamental tree recognized for its economic as forage and environmental benefits. This investigation was carried out to measure the contents of several chemical elements in A. saligna phyllodes, using neutron activation analysis. Results reveal that A. saligna had substantial levels of Ca, K, Na, and Fe. The levels of potentially toxic elements such as As, Br, and Sb were below DTLs and within safe limits. The majority of essential elements were adequate to meet the daily requirements of livestock. These findings suggest that A. saligna can support the basic nutrient needs of ruminants.

This study introduces a novel, physics-informed, and calibration-friendly hybrid machine learning framework for the rapid and accurate prediction of the Full Energy Peak (FEP) efficiency in High-Purity Germanium (HPGe) detectors. To overcome the limitations of conventional “black-box” models, our two-stage approach first represents the FEP efficiency curve using a physically interpretable logarithmic polynomial. Subsequently, machine learning models were trained to predict the polynomial coefficients directly from the detector geometric parameters using a comprehensive dataset generated via Monte Carlo simulations. Among the various algorithms tested, the Generalized Linear Model yielded superior performance, achieving R² values of 0.975–0.992 for the coefficients. While raw model predictions showed expected variability, a key feature of our framework (a single-point calibration protocol using one known efficiency value) dramatically improved accuracy, reducing the mean absolute percentage error by an average of 80% on the independent test data. The calibrated model was further validated using an experimental detector. The entire framework was deployed as a user-friendly online platform, enabling researchers to instantly generate and calibrate efficiency curves. Our work successfully harmonizes interpretability, speed, and accuracy, offering a powerful tool for the design, optimization, and routine calibration of HPGe detectors.