Journal of Radioanalytical and Nuclear Chemistry最新文献

Sorption of Mo(VI) from aqueous solutions onto nano zirconium hydroxide gels was studied using ⁹⁹Mo radiotracer. The acid–base titration curves showed that the prepared nano Zr(OH)₄ gels, Gel #1 and Gel #2, were amphoteric materials with points of zero charge (PZC’s) at pH 2.8 and 3.3, respectively. The highest distribution coefficients of molybdate(VI)-⁹⁹Mo between both gels (Gel #1 and Gel #2) and Cl⁻ media were achieved at pH 2. The maximum sorption capacities of Gel #1 and Gel #2 were found to be 165.7 ± 7.5 and 195.4 ± 8.1 mg Mo/g, respectively. The prepared ⁹⁹Mo/^99mTc chromatographic column generator based on Gel #2 (achieving the higher Mo capacity) showed a good performance; the ^99mTc elution yield was 82.7 ± 2.0%, pH of the eluate ranged from 5 to 6.8, and ⁹⁹Mo breakthrough in the eluted ^99mTc was 0.005 ± 0.002% with a radiochemical purity of 97.3 ± 0.9% (as ^99mTcO₄⁻).

This study delineates the intrinsic composition of naturally occurring radioactive material (NORM) waste and affirms the viability of the carbothermal reduction method for the transformation of Ba(²²⁶Ra)SO₄ into Ba(²²⁶Ra)S. The waste was solubilized using ethylenediaminetetraacetic acid, and its constituents were determined employing X-ray diffraction and inductively coupled plasma-atomic emission spectrometry, identifying barium sulfate (BaSO₄) as the predominant component at a weight percentage of 67.13%. Thermodynamic calculations of the carbothermal reduction process were conducted utilizing the HSC Chemistry software, followed by systematic kinetic validation experiments with BaSO₄ as a proxy for Ba(²²⁶Ra)SO₄. The results demonstrate that carbothermal reduction of BaSO₄ initiates at temperatures surpassing 776 °C. The conversion efficiency of BaSO₄ to BaS is markedly influenced by temperature, with the rate escalating from 47.48% to 89.83% as the temperature is incremented from 850 °C to 950 °C. This method effectively converts the very insoluble NORM waste into readily soluble forms of Ba and Ra.

The removal of Cs and Sr from high level radioactive waste is very important for ecological protection. However, simultaneous immobilization of Cs and Sr is rarely reported. In this work, a perovskite structure CsSr₂Ta₃O₁₀ was synthesized by molten salt method. CsSr₂Ta₃O₁₀ has good thermal stability up to 900 °C at least. Under the γ irradiation of Co-60, most of the material maintained its structural integrity. CsSr₂Ta₃O₁₀ demonstrates a wide range of pH durability, where Cs is stable in the pH range from 4 to 12 and Sr from 2 to 12. Its frame structure remains stable in the pH range from 2 to 12 and will not be decomposed. Further sintering of CsSr₂Ta₃O₁₀ ceramic waste forms results in a high density of 93% − 95%. Moreover, leaching experiments conclude that the long-term leaching rates of Cs and Sr begin to stabilize after 14 days, reaching the order of 10⁰ and 10⁻³ g·m⁻²·d⁻¹. These results provide a possibility for the simultaneous immobilization of Cs and Sr.

The study evaluated the presence of anthropogenic and natural radionuclides in wheat samples close to nuclear facilities of Dera Ghazi Khan by using gamma ray spectrometry. The average activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K found to be 1.60, 2.41 and 108.22 Bq/kg, respectively. The estimated average values for the internal hazard index, radium equivalent, radiological doses and cancer risk factor were found to be within acceptable ranges. The study discovered no substantial health concerns from consuming edible grains because their concentrations were within the permissible limits established by UNSCEAR.

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The advent of multifunctional nanoparticles has significantly transformed the landscape of image-guided drug delivery (IGDD) in nuclear medicine. This review presents a detailed examination of the progress and applications of these nanoparticles within the field. It discusses combining imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) with targeted drug delivery platforms, highlighting the nanoparticles’ ability to improve drug bioavailability and therapeutic outcomes. Additionally, the review addresses the challenges related to their translation into clinical practice. By analyzing recent studies and advancements, it seeks to provide insights into the potential of multifunctional nanoparticles for enhancing IGDD in nuclear medicine.

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This paper explores the feasibility of using U–Th isochrons as a tool to help interpret ²³⁰Th–²³⁴U model ages derived from uranium metal samples. We introduce the basic concepts of the isochron, including the conditions required to produce a meaningful isochron from U–Th isotope data. Then, using examples from cast uranium metal samples, show how isochrons can be used to guide our understanding of the assumption of purification in a ²³⁰Th–²³⁴U model-age, and provide additional age data that can used to aid nuclear forensic investigations.

Uranium tailings reservoir is a huge radon source. Aiming at the complexity and uncertainty of radon exhalation law, a prediction method of radon exhalation based on variational mode decomposition (VMD) is proposed. The uranium tailings reservoir model was constructed by the shrinkage method, and the natural environment simulation and radon exhalation rate monitoring were carried out for 180 days in a uranium tailings reservoir in South China. The monitoring value of radon exhalation rate is decomposed into three components with different physical meanings by VMD, and the long short-term memory neural network model (LSTM) is established to predict the trend of radon exhalation. The ELMAN neural network model is established with external environmental factors as input, and the lag effect of environmental indicators on radon exhalation rate is specially considered. The results show that the VMD-LSTM-ELMAN method can accurately reflect the precipitation law of radon exhalation and has better prediction accuracy.

Radionuclides released during radiological or nuclear accident or attack can cause long-term environmental contamination and health problems in exposed persons so rapid decontamination is of great importance in order to reduce negative consequences. Radiological decontamination method should be efficient for a wide range of radionuclides in different conditions and on different surfaces, may not produce large amounts of secondary waste and should be inexpensive. Wide variety of physical and chemical methods for radiological decontamination is available but so far none provides unique solution. This paper provides an overview of currently used, still under development and new emerging radiological decontamination methods with a critical review on their advantages, limitations and disadvantages.

This study aims to measure radioactivity levels in soil samples extracted from the surroundings of Konya Beyşehir Lake in Turkey and to determine radiological risk parameters based on this data. Gamma-ray spectrometry was used to detect activity concentrations of ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs in soil samples. The average measured activity concentrations of these radionuclides detected in soil samples were 32 Bq/kg for ²²⁶Ra, 47 Bq/kg for ²³²Th, 350 Bq/kg for ⁴⁰K, and 6.5 Bq/kg for ¹³⁷Cs. By utilizing these activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K obtained from the measurements, the absorbed gamma dose rate (D), the annual effective dose equivalent (AEDE), the radium-equivalent activity (Ra_eq), and the excess lifetime cancer risk (LCR) were assessed. According to the calculation of the radiation hazard index in this research, it was understood that calculated radiological parameters for this region were within acceptable limits suggested by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR).

Sixteen oil and gas facilities in Pakistan were characterised for evaluation of Naturally Occurring Radioactive Material (NORM). This first-of-its-kind study may determine the need to establish national regulatory requirements for NORM activities. Gamma dose rates at each site and specific activities of ²²⁶Ra, ²²⁸Ra and ⁴⁰K in samples of scale, sludge, produced water, and soil by gamma spectrometry were measured. Subsequently, Annual Effective Doses due to external exposure were estimated. Results were found below the exemption levels. Based on maximum levels of ²²⁶Ra in sludge and scale along with radionuclides buildup over time, facilities were advised to regularly assess NORM.