Journal of Radioanalytical and Nuclear Chemistry最新文献

A neutron depth profiling (NDP) system was established at a cold neutron beam of China Advanced Research Reactor (CARR). In the recent years, we have upgraded the CARR NDP facility and made considerable advancements in spectral deconvolution methodology and related experiments. In 2023 CARR has been operational for over 100 days, conducting various experiments utilizing the NDP apparatus. These experiments encompassed several objectives: measurement thin films thickness, Li transportation and distribution in cathode materials and B distribution in semiconductor materials.

A graphitic carbon nitride adsorbent (g-CNA) has been developed for the removal of uranium from water. Experiments revealed that g-CNA exhibited a U(VI) adsorption capacity of 312.5 mg g⁻¹, reaching equilibrium within 30 min at pH 6.0. The Langmuir isotherm fit confirmed the monolayer U(VI) adsorption. Pseudo-second-order kinetics indicated that U(VI) and g-CNA concentrations influenced the reaction rate, with electrostatic interactions involved in the adsorption mechanism. Thermodynamic studies indicated spontaneous exothermic adsorption of U(VI) on g-CNA. The adsorption efficiency of g-CNA remained stable with the electrolytes, and the adsorbed U(VI) was removed with HCl, confirming its potential for U(VI) remediation.

The activity concentrations of ²²⁶Ra, ²¹⁰Pb, and ²¹⁰Po in soil samples were measured in the Gogi region of Yadgiri district, Karnataka, South India, which is a uranium mineralisation area with prospects for future mining. A total of 273 samples were analysed from 0–5, 5–15, and 15–30 km zones around Gogi, the common centre of all the zones. The activity concentrations of these radionuclides were similar to the global average values. A strong positive correlation was found between the activity concentration values of ²²⁶Ra, ²¹⁰Pb and ²¹⁰Po. Negative correlations were found between the activity concentrations of these radionuclides and soil characteristics such as cation exchange capacity (CEC), organic matter content (OMC), and pH.

This study investigates accurate dose mapping for gamma irradiators, particularly for broad-beam radiation types. The main objectives are to identify the most suitable algorithm by comparing Monte Carlo simulations and measurements, analyzing factors such as standard error, dosimeter placement, and environmental influences. Key findings show that certain algorithms and dosimeter setups yield higher accuracy and reliability in dose mapping. The study concludes that integrating software-based and measurement approaches enhances dose distribution precision, providing valuable insights for quality control and process optimization. This research contributes significantly to improved efficiency in gamma irradiation applications across various industries.

The migration and enrichment of rare earth after mining activities pose a significant environmental threat to the surrounding habitants. We conducted a study at the Zhuxi watershed to analyze the rare earth element distribution in the topsoil after mining activities. Our findings reveal that the rare earth elements content in the top soil of the watershed shows a decreasing trend from the eastern area to the western area. The distribution of each element indicated that the crust abundance had the greatest influence. Mining activities can affect the fractionation of rare earth elements. The ecological risk assessment of rare earth elements necessitates comprehensive assessments, as the geoaccumulation method weakens the impact of a single element.

A practical, rapid, and reliable method for the ultra-trace determination of ⁹⁰Sr by triple quadruple collision/reaction cell inductively coupled plasma mass spectrometry (CRC–ICP–MS/MS) has been developed. Suitable sample preparation was investigated, and the chemical separation has been achieved with the decontamination factor over 1 × 10⁵ for interfering nuclide ⁹⁰Zr. The concentrations of ⁹⁰Sr in two kinds of samples were determined successfully, with the average values of 7.2 ± 0.7 fg·g⁻¹, 5.0 ± 0.5 fg·g⁻¹, respectively. The ratios of ⁹⁰Sr to ⁸⁸Sr were 5.2 × 10^–8, 2.2 × 10^–9, respectively, and the instrumental detection limit of ⁹⁰Sr was 0.09 pg·g⁻¹.

In this study tritium exposure was assessed through urine samples analysis by the determination of tritium concentration and effective dose of selected 25 laboratory radiation workers in non-nuclear power plant (non-NPP) facility and 15 people of general public in Jakarta. The samples were mixed with activated charcoal, filtered, and distilled before analysis using liquid scintillation counter. It is revealed that the concentration of tritium levels in urine varied substantially depending not only on the job category but also their water intake, metabolism, and environment. These findings are important as reference data for evaluating the radiological impact on the population from future tritium contamination in Indonesia.

Developing efficient adsorbents is key to mitigate radioactive contamination in coal mine wastewater and improve uranium extraction. This study processed local Photinia × fraseri Dress into biochar via high-temperature carbonization. Microwave irradiation yielded modified biochar, then treated under alkaline conditions and dilute sulfuric acid to produce PDC-M-K and PDC-M-H. The study found that PDC-M-K and PDC-M-H had U(VI) adsorption capacities of 79.6 and 116.3 mg U/g ads, with utilization rates of 69.3% and 75.6%, respectively. Their adsorption selectivity for U(VI) was 66.5% and 72.8%. Indicating that modified biochar effectively adsorbs U(VI) from wastewater, providing a reference for future studies.

In the geological disposal of nuclear waste, the simultaneous reduction of diffusion rate of cationic and anionic radioactive species is essential. Natural calcium-bentonite only reduces the diffusion rate of cations, not anions. In this study, the half of calcium ions is bentonite was exchanged to silver ions to reduce diffusion rates of both of radioactive cation (¹³⁷Cs⁺) and anions (³⁶Cl⁻, ¹³¹I⁻) at the same time. This is due to the precipitation of silver halides in the interlayer space. The diffusion rate of both anionic and cationic radioactive species are small in compacted the silver-calcium bentonite.

The radioactive nuclide ²²⁵Ac is one of the few promising candidates for cancer treatment by targeted-(alpha)-therapy, but worldwide production of ²²⁵Ac faces significant limitations. In this work, the Isotope Separation On-Line method was used to produce actinium by irradiating targets made of uranium carbide and thorium carbide with 1.4-GeV protons. Actinium fluoride molecules were formed, ionized through electron impact, then extracted and mass-separated as a beam of molecular ions. The composition of the mass-selected ion beam was verified using time-of-flight mass spectrometry, (alpha)- and (gamma)-ray decay spectrometry. Extracted quantities of (^{225}textrm{Ac}^{19}textrm{F}_2^{+}) particles per (upmu)C of incident protons were (3.9(3)times 10^7) from a uranium carbide target and (4.3(4)times 10^7) for a thorium carbide target. Using a magnetic mass separator, the long-lived contamination ²²⁷ Ac is suppressed to (<5.47times 10^{-7}) (95% confidence interval) with respect to ²²⁵Ac by activity. Measured rates scale to collections of 108 kBq(upmu)A(^{-1})h(^{-1}) of directly produced (^{225}textrm{Ac}^{19}textrm{F}_2^{+}).