Journal of Radioanalytical and Nuclear Chemistry最新文献

This study reconstructs sediment accumulation rates in two lakes of the Vosges Mountains (northeastern France): Gérardmer (urban catchment) and Longemer (forested catchment). Sediment cores collected in 2013 were dated using ²¹⁰Pb, ¹³⁷Cs, and ²⁴¹Am, with the CRS model validated by fallout markers from 1963 to 1986. Results show a rise in mass accumulation rates from 0.02 ± 0.013 g cm⁻² yr⁻¹ in the late nineteenth century to nearly 0.200 ± 0.028 g cm⁻² yr⁻¹ by 2020, with synchronous fluctuations linked to regional climate but different amplitudes due to catchment conditions. Gérardmer shows sharper peaks caused by urbanisation, while Longemer records smoother variations under forest cover. These findings underline the combined influence of climate forcing and land use on lake sedimentation and confirm the value of a multi-isotope approach for recent environmental reconstructions.

Intercomparison exercises (IE) are a way for laboratories to test their analytical performance. In case of difficult-to-measure (DTM) radionuclide analysis, participation in IEs are important due to the lack of reference materials. This paper reports the results from an IE focusing on non-volatile DTM analysis in homogenised high activity steel. The IE was carried out according to the ISO 13528 standard, in which the performances are assessed using z score. The z scores were generally acceptable. The experimental results were compared with activation calculation results showing wide range of compatibility.

Measurement of ¹⁸⁵W is difficult by gamma spectroscopy due to the low intensity of the only gamma emission line. This work investigated the use of ICP-MS/MS, as an alternative to gamma spectroscopy for the quantification of ¹⁸⁵W. Stable standards were analyzed using NH₃/He and NO reaction gases to determine the interference removal from stable isotope interferences (e.g., ¹⁸⁵Re⁺ and ¹⁸⁴W¹H⁺) prior to analysis which can hinder quantification of ¹⁸⁵W. The NH₃/He and NO reaction gas methods achieved absolute detection limits for ¹⁸⁵W of 3.9 × 10⁷ and 9.9 × 10⁶ atoms, respectively. An irradiated W sample was analyzed by dilution using the NH₃/He method and following chemical separation using the NO method with both methods showing good agreement with GEA (gamma emission analysis). This work reports the first analyses of ¹⁸⁵W using ICP-MS/MS and demonstrates the utility of ICP-MS/MS for the measurement of activation products for nuclear forensics, even those with relatively short half-lives that may have previously been thought impossible at such levels.

This study reports the use of domestically produced ¹⁷⁷Lu for radiosynthesis and the characterization of [¹⁷⁷Lu]Lu-PEG-modified DOTA as a stable and hydrophilic precursor for targeted radiopharmaceuticals. The conjugate was synthesized by coupling DOTA-NHS ester and SH-PEG-NH₂ to form an amide, followed by radiolabeling with [¹⁷⁷Lu]LuCl₃ produced in the G.A. Siwabessy multipurpose reactor, Indonesia. Optimal labeling conditions (pH 5.0, 80°C, 1:2 molar ratio, 10 min) resulted in > 99% radiochemical purity and excellent in vitro stability in PBS (pH 7.4) for up to 168 h at 4°C and 25°C. PEGylation significantly increased the hydrophilicity, as indicated by the lower log D value (− 1.996 ± 0.028) compared to [¹⁷⁷Lu]Lu-DOTA without PEGylation (− 1.933 ± 0.057). These results indicate that DOTA modified with [¹⁷⁷Lu]Lu-PEG is a promising, stable, and highly hydrophilic platform suitable for bioconjugation with tumor-targeting biomolecules in theranostic applications. This study highlights the feasibility of utilizing locally produced ¹⁷⁷Lu for the development of advanced radiopharmaceuticals, supporting national self-reliance in nuclear medicine.

The management of Sr-90, a long-lived fission product with high mobility and radiotoxicity, poses significant challenges for nuclear waste disposal. This study investigates reactive spark plasma sintering (R-SPS) of kaolin and strontium carbonate mixtures for effective Sr-90 immobilization. The R-SPS process at 1000 °C enables formation of stable ceramic matrices incorporating strontium into SrAl₂Si₂O₈ and Sr₂Al₂SiO₇ crystalline phases. XRD, SEM, and TG/DTA analysis confirmed homogeneous matrices with uniform strontium distribution and dense microstructure. Leaching tests showed a Sr²⁺ migration rate of 1.79 × 10⁻⁵ g·cm⁻²·day⁻¹, indicating good chemical durability. The results suggest that kaolin-based ceramic matrices produced via R-SPS offer a promising approach for safe Sr-90 immobilization with reduced waste volumes and improved handling safety.

In this study, we developed a method to measure radon daughter aerosols size distributions by combining wire mesh screens with an inertial impactor in a parallel sampling setup. The deviations between theoretical and actual cut-off diameters across the six channels were within 10%. Under high radon conditions, the concentrations of 218Po, ²¹⁴Pb, ²¹⁴Bi, and their equilibrium equivalent concentration (EEC) increased progressively with cut-off diameter. Both experimental data and EM algorithm simulations revealed a bimodal size distribution. These results demonstrate that the method provides high-resolution activity data for accurate respiratory deposition modeling.

This study examines uranium-contaminated soil from a mining area in eastern China and uses Solanum nigrum L. as the test plant to evaluate the effect of Stenotrophomonas sp. on enhancing its remediation capacity. The results show that Stenotrophomonas sp. increases uranium accumulation in the aboveground and underground tissues of S. nigrum L. by 11.13–77.32% and 8.85–28.61%, respectively, and reduces rhizospheric uranium concentrations by up to 42.46%. Inoculation also enhances photosynthesis, osmotic adjustment, antioxidant activity, rhizospheric soil organic acids, and soil enzyme activities. These findings indicate that Stenotrophomonas sp. strengthens the remediation efficiency of S. nigrum L., providing theoretical support and technical guidance for the remediation of uranium-contaminated soils.

This study investigated the heavy metal (loid) and radionuclide contamination in the soil at a remediated oil drilling site. Radionuclide activity concentrations were within acceptable levels, while elevated concentrations were detected for Cd, Hg, Zn, As, and Cu. Positive matrix factorization identified four distinct sources: oil drilling, remediation process, industrial activities, and natural sources. The radiological risk indices indicated no significant gamma radiation hazard, and non-carcinogenic and carcinogenic indices were within the acceptable levels. The spatial distribution maps of health risk indices followed the distribution pattern of the five heavy metal(loid)s, revealing a single hotspot.

This study investigates alanine, glycine, and glutamine as high-dose gamma radiation dosimeters using diffuse reflectance spectroscopy (DRS). DRS provides a non-invasive, cost-effective method for rapid dose estimation. Amino acid powders were irradiated from 0.1 to 100 kGy, and their reflectance spectra in the range of 300 to 510 nm, were analysed. Non-linear dose–response curves were observed, with alanine, glycine, and glutamine showing peak sensitivities at different dose ranges. Measurements were within ± 6.3% suggesting good reproducibility, stability over time and temperature, and unaffected by dose fractionation. These results highlight amino acids' potential for reliable, long-term radiation dosimetry in routine monitoring applications.