Volume 112, Issue 2

Morphological analysis of uranium materials has proven to be a key signature for nuclear forensic purposes. This study examines the morphological changes to magnesium diuranate (MDU) and sodium diuranate (SDU) during reduction in a 10 % hydrogen atmosphere with and without steam present. Impurity concentrations of the materials were also examined pre and post reduction using energy dispersive X-ray spectroscopy combined with scanning electron microscopy (SEM-EDX). The structures of the MDU, SDU, and UO x samples were analyzed using powder X-ray diffraction (p-XRD). Using this method, UO x from MDU was found to be a mixture of UO 2 , U 4 O 9 , and MgU 2 O 6 while UO x from SDU were combinations of UO 2 , U 4 O 9 , U 3 O 8 , and UO 3 . By SEM, the MDU and UO x from MDU had identical morphologies comprised of large agglomerates of rounded particles in an irregular pattern. SEM-EDX revealed pockets of high U and high Mg content distributed throughout the materials. The SDU and UO x from SDU had slightly different morphologies. The SDU consisted of massive agglomerates of platy sheets with rough surfaces. The UO x from SDU was comprised of massive agglomerates of acicular and sub-rounded particles that appeared slightly sintered. Backscatter images of SDU and related UO x materials showed sub-rounded dark spots indicating areas of high Na content, especially in UO x materials created in the presence of steam. SEM-EDX confirmed the presence of high sodium concentration spots in the SDU and UO x from SDU. Elemental compositions were found to not change between pre and post reduction of MDU and SDU indicating that reduction with or without steam does not affect Mg or Na concentrations. The identification of Mg and Na impurities using SEM analysis presents a readily accessible tool in nuclear material analysis with high Mg and Na impurities likely indicating processing via MDU or SDU, respectively. Machine learning using convolutional neural networks (CNNs) found that the MDU and SDU had unique morphologies compared to previous publications and that there are distinguishing features between materials created with and without steam.

Uranium concentration and uranium isotopic content are two important and critical parameters for any nuclear fuel fabrication facilities. In the present study emphasis has been given on the usage of high resolution gamma ray spectrometric (HR-GRS) technique with HPGe detector for the determination of uranium and 235 U content in uranium process stream samples. The work has been carried out with an aim to give quick analytical feedback to production facility and also to minimize the generation of analytical waste. These are important requirements for any industrial lab with high analytical load attached to production facility. In this paper a simple and a non-destructive testing (NDT) method has been described for quantification of uranium and 235 U content in samples received from UO 2 fuel production facilities using HR-GRS technique with high purity germanium (HPGe) detector. A 185.7 keV line of 235 U has been used for quantification of uranium in process solutions containing 1  g/L to 600 g/L of uranium covering both aqueous and organic process stream solutions. The results have been compared with that of Davies and Gray method. The limitations associated with gamma ray emitted from daughter products of 238 U and self-induced or self-excited X-ray fluorescence lines of uranium have also been studied. Multi Group Analysis of Uranium (MGAU) software code has been used for measurement of 235 U content in variety of samples. The results obtained are compared with that of results by thermal ionization mass spectrometer (TIMS).

Plastic packaging waste is considered a serious threat to the environment due to its non-biodegradable nature. Transforming plastic waste into active carbons using pyrolysis methods could be a valuable option to solve the challenge of plastic waste. Synthesized active carbon was differentiated using zeta potential, particle size, SEM, BET, and DSC. This study also investigates the use of obtained active carbons for U(VI) removal from commercial phosphoric acid. The kinetics of adsorption were found to follow the pseudo-second-order model and intra-particle diffusion as one of the controlling mechanisms. Langmuir, and Freundlich, isotherms were employed to explore the equilibrium data. Furthermore, thermodynamic investigations revealed that uranium uptake is an endothermic, feasible, and spontaneous process. The present study concludes that plastic waste-based activated carbon could be employed as a low-cost alternative to commercial activated carbon for uranium removal from phosphoric acid and the production of green fertilizers.

Acetonitrile is widely used as a solvent in synthesizing various fluorine-18 positron emission tomography (PET) radiotracers. Acetonitrile is classified as a Class II residual solvent, and due to its inherent toxic properties, the quantity of residual acetonitrile in drug products has to be limited. When working under Good Manufacturing Practices (GMP) during the radiosynthesis of a radiotracer, the aim is to control all solvent concentrations contained in the ready-to-use product. All products must meet predetermined specifications. Rarely, these limits may be exceeded. To avoid eliminating the entire batch, applying a straightforward time-based technique would be desirable to allow the majority of the product to be safely used. This technique should be based on determining a specific time and volume for which the radiotracer can be utilized in the patients after completing quality control analysis. Here, we report a very simple Excel sheet program based on existing mathematical equations that calculates the exact time and volume at which the radiotracer product can be safely administered to a patient.

The surface soil samples were collected from Northwest Turkey. The activity concentrations of 226 Ra, 232 Th, and 40 K were measured using an HPGe gamma-spectroscopy system. The activity concentrations of 226 Ra, 232 Th, and 40 K in the soils were found to be in the range of 11.78 ± 1.12–43.89 ± 14.94, 3.19 ± 2.01–88.22 ± 0.92, 362.81 ± 5.94–829.27 ± 12.38 Bq kg −1  d.w., respectively. The Surfer program was used to obtain 3-dimensional maps of the specific activities. Radium Equivalent Activity (Ra eq ), Absorbed Gamma Dose Rate ( D ), Annual Effective Dose Equivalent (AEDE), The Excess Life Time Cancer Risk (ELCR), External ( H ex ) and Internal ( H in ) Hazard Indexes, Annual Gonadal Dose Equivalent (AGDE), and Activity Utilization Index (AUI) were calculated and compared with the recommended values. Pearson’s correlation analysis (PCA) and factor analysis (FA) were utilized to analyze the data and indicate between the radiological parameters. The analysis showed that the total radiation was mainly caused by 226 Ra and 232 Th.

We conducted a comprehensive assessment of the Kattakurgan reservoir, alongside adjacent wells and boreholes, to measure the concentrations of natural radionuclides, heavy metals, and associated radiological hazards. Using NaI(Tl) crystal scintillation gamma spectrometers, we determined radionuclide levels in water and sediment. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for heavy metal analysis. Our results showed radionuclide concentrations in reservoir water for 226 Ra (0.8 Bq/L), 232 Th (0.4 Bq/L), and 40 K (0.4 Bq/L) were within the limits set by the World Health Organization (WHO). In contrast, deep well water samples showed elevated 226 Ra concentrations (1.5 Bq/L). Sediment samples’ radionuclide levels were in line with UNSCEAR guidelines. Barium was the most notable heavy metal, with a concentration of 68.08 μg/L. While most radiation hazard indices remained within safety limits, the gamma index recorded a value of 1.057 Bq/kg. Our research provides valuable data for water quality assessment. The methods described can be applied to other reservoir studies. Regular monitoring is recommended for continuous safety evaluation, and further studies on biotic samples are suggested to enhance understanding of the reservoir’s ecosystem health.