Volume 113, Issue 9

Zirconium is widely used in the nuclear industry as a cladding material for nuclear reactors and loading nuclear fuel. From the perspective of safety and the economy, the recovery of zirconium from cladding waste at low temperatures is of strategic significance for nuclear energy. This work studied the electrochemical behavior of Zr(IV) and the separation of Zr metal in a low-temperature LiCl–KCl–CsCl molten salt system at 573 K (300 °C). Zr(IV) ion was reduced to metallic Zr through a two-step four-electron reaction process Zr(IV) → Zr(III) → Zr on the W electrode. The diffusion coefficients of Zr(IV) on the W electrode calculated by cyclic voltammetry and chronoamperometry were 5.805 × 10 −5  cm 2  s −1 and 2.861 × 10 −5  cm 2  s −1 , respectively. Furthermore, the reaction activation energy of the Zr(III)/Zr(0) pair was measured to be 34.52 kJ mol −1 by the Tafel method. Then, the electrochemical recovery of Zr was accomplished on the W electrode by potentiostatic electrolysis at −2.0 V or galvanostatic electrolysis at 0.01 A, and two zirconium-containing products with the dendritic and flakes morphologies were obtained accordingly. This study provides a new low-temperature molten salt system for the reprocessing of zirconium cladding and shows the application potential of low-temperature molten salts LiCl–KCl–CsCl for spent fuel reprocessing.

The efficient separation of 137 Cs from high-level liquid waste (HLLW) is of great significance for the development of nuclear energy. However, for columns commonly used in the industry, ion exchangers need to be loaded on the resin matrix, which is typically not resistant to strong acids. Consequently, a particle-reinforced ion exchange resin (PR AWP-CA) was designed and prepared. In PR AWP-CA, the active component (ammonium phosphotungstate) and particle reinforcer were encapsulated by carrier resin (calcium alginate). The formulation of was optimized by preparing the resin with different content. The results show that PR AWP-CA has great mechanical strength, high acid resistance and excellent selectivity. In 3 mol/L nitric acid, the adsorption equilibrium was reached after only 2 h. Cs could be selectively separated, and the recovery of cesium was greater than 98 % when the extraction of interference elements was close to 0. The cesium separation ability of the resin was stable in 3.0 mol/L nitric acid at 25–55 °C. PR AWP-CA exhibited good compressive resistance in column experiment. After five cycles, the resin could still present high adsorption capacity. A particle reinforced ion exchange resin, suitable for the separation of cesium in high level radioactive waste liquid, was successfully obtained.

This study aimed to develop a novel material for dual-modality SPECT/MRI. MnFe 2 O 4 nanoparticles (NPs) were synthesized via a green method using Elaeis guineensis Jacq. extracts (leaf extract – ELE and empty fruit bunches extract – EFBE) at an optimal calcination temperature of 400 °C. Characterization by FTIR, XRD, SEM, TEM, SAED, TGA, and VSM revealed NPs with an average size of 28.6 ± 9.6 nm and a magnetization value of 38.2 emu/g. The optimal conjugation with human serum albumin (HSA) was achieved at a 1:1 ratio, yielding approximately 0.388 ± 0.049 mg per mg of HSA. Radiolabeling of [ 99m Tc]Tc-HSA-MnFe 2 O 4 NPs was characterized using HPLC and TLC to assess impurities, demonstrating radiochemical purity exceeding 99 % across various media, including PBS, saline, water and human serum. Further studies are necessary to evaluate the biological profiles using in vitro and in vivo assays.

Mononuclear [Mn(L)Cl 2 (H 2 O) 2 ].1½H 2 O ( 1 ), [Cu(L)Cl 2 (H 2 O) 2 ] ( 2 ) and [Cu(L)Br 2 (H 2 O) 2 ].2H 2 O ( 3 ) complexes were obtained via reaction of N , N ’-(1,2-phenylene) bis (2-aminobenzamide ( L ) with Mn(II), Cu(II) halides, respectively. The structure of these metal chelates were confirmed using the various microanalyses and physiochemical tools as molar conductance, FT–IR spectra, thermogravimetric analysis (TG/DTG), UV–Vis, EPR, magnetic moment measurements, 3D molecular modeling and X–ray diffraction. The ligand forms hexacoordinated complexes having octahedral stereochemistry for all complexes. Gamma ray irradiation was applied to solid samples of complexes to examine the possible structure changes with γ –ray exposures (hereafter pointed to as 1A, 2A, 3A, respectively). The physical and chemical changes observed for γ –irradiated samples were examined by the same tools utilized for the as-prepared complexes. Spectroscopic results showed distortion of complex structure by γ –ray irradiation. TG/DTG results indicated that, thermal stability for all irradiated samples is not greatly affected by the applied γ -ray irradiation dose. The thermodynamic properties of the decomposition processes ( E a , A, ΔH*, ΔS*, and ΔG* ) were calculated from TGA using the Coats-Redfern equations. The results of XRD showed that, all samples are in nanoscale size and γ -ray irradiation altered the crystallite size. Also, dc solid-state electrical conductivity was performed and the activation energy were computed. Furthermore, the in vitro antimicrobial property for the ligand and all complexes before and after irradiation have been tested. The results showed that some complexes possessed good activity and irradiation enhanced the bioactivity of some complexes.

Aiming at enhancing the characters of the synthetic rubber (NBR) to fulfill the required measures of many applications, this work aims to study the impact of both, carbon black at a constant concentration of 40 phr and organomontmorillonite clay (nanoclay) at varying loading levels (0, 3, 7 and 10) phr, as reinforcing fillers within the acrylonitrile-butadiene rubber (NBR) matrix. The surfactant, N-cetyl-N, N, N-trimethyl ammonium bromide (CTAB), was applied to modify the superficial properties of the clay. Modified montmorillonite possesses desirable intercalating behavior within the rubber matrix, regarded as effective reinforcing filler that can replace other fillers. TEM, FT-IR, XRD and EDX methods were used to characterize the developed organomontmorillonite. Similarly, the nanocomposites mechanical, electrical, acoustic and thermal stability properties were investigated.

This research prepared novel glasses of (20 + x )BaO + (19 + y )PbO 2 + (59- x - y )B 2 O 3 + 2Er 2 O 3 , since x and y = 0, 2, 4, 6 mol% via melt-quenching and the gamma-ray shielding capability was determined by experimental and theoretical techniques. The experimental and Phy-X LAC values are close, thus suggesting that investigation’s setup was accurate. As a result of the contents of BaO and PbO 2 in sample BPBE-4 (x and y = 6 mol%) which has the highest amount as well as the highest density, the sample’s linear attenuation coefficient (LAC) value is consistently the highest throughout the energy level. This indicates a strong attenuating power. Whereas, sample BPBE-1 (x and y = 0 mol%) shows the lowest LACs both theoretical and experimental values owing to the lowest concentrations of BaO and PbO 2 mole percentage in its structure. The three radiation shielding layers, half value layer (HVL), tenth value layer (TVL) and mean free path (MFP) at 0.662 MeV for the sample BPBE-1 are 1.757, 5.836, and 2.535 cm respectively. For sample BPBE-4, it shows the lowest values for radiation shielding layers (1.519, 5.045, and 2.191 cm for HVL, TVL, and MFP) making it the best shielding material.

This study focused on developing new high-transparency, non-lead radiation shielding in barium zinc aluminum borosilicate glasses formulated as x BaO-17SiO 2 -(20- x ) ZnO–58B 2 O 3 –5Al 2 O 3 , where (0 ≤ x ≤ 12 mol %) of BaO. The density was measured according to Archimedes’ principle. Theoretical radiation shielding values were calculated with the Phy-X program. Findings revealed that the density and radiation shielding results increased as BaO increased. The Linear Attenuation coefficient (LAC), effective electron density (N eff ) effective atomic number (Z eq ), and electronic cross-section (ECS) variation as follow: G5 > G4 > G3 > G2 > G1. The Half value layer (HVL) and mean free path (MFP) variation as follow: G1 > G2 > G3 > G4 > G5. Consequently, a shield with a higher BaO content has better attenuation properties. The study found that among the analyzed glass samples, the G5 sample offered the highest efficiency in radiation protection. This highlights the potential of the synthesized glasses as promising candidates for applications requiring efficient fast neutron attenuation.