Uranium

Imine-linked covalent organic frameworks (COFs) usually show high crystallinity and porosity, while vinyl-linked COFs have excellent semiconducting properties and stability. Therefore, achieving the advantages of imine- and vinyl-linkages in a single COF material is highly interesting but remains challenging. Herein, we demonstrate the fabrication of a layer-blocked COF (LB-COF) heterogeneous film that is composed of imine- and vinyl-linkages through two successive surface-initiated polycondensations. In brief, the bottom layer of imine-linked COF film was constructed on an amino-functionalized substrate via Schiff-base polycondensation, in which the unreacted aldehyde edges could be utilized for initiating aldol polycondensation to prepare the second layer of vinyl-linked COF film...

Fission products may interact with structural materials in various nuclear energy applications and cause their mechanical performance to deteriorate. Therefore, it is important to study the effects of different fission products on the mechanical properties of structural materials. In this work, nickel was chosen as a model structural material system and dilute amounts of uranium and fission product impurities X = (Tc, Te, Sb, Ce, Eu, and U) up to 4 at % were used. Density functional theory (DFT) calculations were utilized to assess the effects of these substitutional impurities on the elastic behavior of the metal...

BACKGROUND: There is a noticeable lack of information on the levels of both non-essential and essential trace elements in women aged over 50. The main objective of this study is to investigate trace element concentrations and explore the influence of sociodemographic factors and dietary sources of exposure in this demographic. METHODS: We analyzed 19 trace elements, including manganese, cobalt, copper, zinc, molybdenum, chromium, nickel, arsenic, strontium, cadmium, tin, antimony, cesium, barium, tungsten, mercury, thallium, lead, and uranium, using ICP-MS...

Developing effective adsorbents for uranium extraction from natural seawater is strategically significant for the sustainable fuel supply of nuclear energy. Herein, stable and low-cost supramolecular complexes (PA-bPEI complexes) were facilely constructed through the assembly of phytic acid and hyperbranched polyethyleneimine based on the multiple modes of electrostatic interaction and hydrogen bonding. The PA-bPEI complexes exhibited not only high uptake (841.7 mg g-1 ) and selectivity (uranium/vanadium selectivity = 84...

Based on the monitoring data of 137 Cs and 90 Sr in Tian Bay in 2005-2023, the impacts of the operation of Tianwan Nuclear Power Plant on the marine ecosystem were assessed. The 137 Cs and 90 Sr activity concentrations in the seawater and sediment varied within the background ranges. The radiation dose rates derived from 137 Cs and 90 Sr for the marine organisms ranged from 2.4 × 10-5 to 2.2 × 10-4 nGy/h, it was far below the most conservative screening dose rate (10 μGy/h)...

Residues generated from the uranium purification process, characterized by a high uranium content, pose a significant challenge for recovery through leaching and present a considerable environmental threat. After using XRD and SEM-mapping characterization analysis combined with the BCR continuous graded extraction test to analyze the content of different states of uranium, it was found that the main reason why the uranium in the residue was difficult to leach because it was encapsulated by SiO2 crystals. Using NH4 HF2 as a leaching agent, a leaching study of uranium in the residue was carried out, and the results showed that the H+ and F- produced by NH4 HF2 could react with SiO2 , destroying the crystal lattice of SiO2 and causing the encapsulated uranium to come into contact with the leaching agent, facilitating the leaching of uranium in the residue...

Advances in nuclear power reactors include the use of mixed oxide fuel, containing uranium and plutonium oxides. The high-temperature behaviour and structure of PuO2-x above 1,800 K remain largely unexplored, and these conditions must be considered for reactor design and planning for the mitigation of severe accidents. Here, we measure the atomic structure of PuO2-x through the melting transition up to 3,000 ± 50 K using X-ray scattering of aerodynamically levitated and laser-beam-heated samples, with O/Pu ranging from 1...

The radiation dose of workers in underground uranium mines mainly comes from radon and radon progeny. To ensure a healthy and safe work environment, it is necessary and urgent to optimize the design of ventilation systems. As such, based on the simplified radon diffusion-advection migration model of the rocks, this paper proposes 1) two methods for determining the radon exhalation rate modified by pressure drop, 2) three methods for calculating radon activity concentration of single-branch, and 3) the novel adjustment algorithm and solving procedures for calculating and adjusting the radon activity concentration in ventilation networks by modifying the radon exhalation rate, demonstrated on a specific ventilation network in a simulated underground uranium mine with calculation and analysis via MATLAB...

In this work, we report a pyrazole-based porous organic polymer (namely, ECUT-POP-2) for extraction of uranium. ECUT-POP-2 affords a high uranium extraction capacity of up to 1851 mg/g, excellent selectivity, and good reusability, suggesting its superior application in treating uranium-containing wastewater and acquring nuclear fuel.

Polynuclear metal hydride clusters play important roles in various catalytic processes, with most of the reported polynuclear metal hydride clusters adopting a polyhedral three-dimensional structure. Herein, we report the first example of a planar tetranuclear uranium hydride cluster [(CpCMe2CMe2Cp)U]4(μ2-H)4(μ3-H)4 (U4H8). It was synthesized by reacting an ansa-bis(cyclopentadienyl) ligand-supported uranium chloride precursor [(CpCMe2CMe2Cp)U]3(μ2-Cl)3(μ3-Cl)2 with NaHBEt3. The presence of hydrides in U4H8 was confirmed by NMR spectroscopy and its reactivity with phenol and carbon tetrachloride...

The removal of uranyl ions (UO2 2+ ) from water is challenging due to their chemical stability, low concentrations, complex water matrix, and technical limitations in extraction and separation. Herein, a novel molybdenum disulfide/graphene oxide heterojunction (MoS2 /GO-H) is developed, serving as an effective electrode for capacitive deionization (CDI). By combining the inherent advantages of electroadsorption and electrocatalysis, an innovative electroadsorption-electrocatalysis system (EES) strategy is introduced...

Energy and environmental issues make the generation of H2 O2 and the separation of U(VI) from water very important topics. In this work, we disclosed a low-cost, high-efficiency method for separating U(VI) from water based on the naturally formed catalyst (red volcanic stone powders, RVSP) of Ca(Al2 Si2 O8 )/Fe2 O3 heterojunction through a piezocatalytic pathway induced by ultrasonication. The charges were found to be elevatedly separated due to the formation of the heterojunction. It is found that under ultrasonication, charges were effectively separated and then reacted with water to form H2 O2 with a high yield of 196...

The influence of uranium (U) mining on the fungal diversity (FD) and communities (FC) structure was investigated in this work. Our results revealed that soil FC richness and FD indicators obviously decreased due to U, such as Chao1, observed OTUs and Shannon index (P<0.05). Moreover, the abundances of Mortierella, Gibberella, and Tetracladium were notably reduced in soil samples owing to U mining activities (P<0.05). In contrast, the abundances of Cadophora, Pseudogymnoascus, Mucor, and Sporormiella increased in all soil samples after U mining (P<0...

Ionic liquids (ILs) have significant potential for eco-friendly extraction of uranium from aqueous solutions, which is critical for nuclear technology, fuel cycle management, and environmental protection. This study examines the impact of the adjustable hydrophobic/hydrophilic properties of ILs on the removal of uranium(VI) (UO2 2+ ) from aqueous solutions utilizing both a novel hydrophilic IL (1-butoxyethyl-1-methylmorpholinium butoxyethylphosphite - Mor1-2O4 -BOEP) and 1-heptyl-1-methylmorpholinium heptylphosphite (Mor1-7 -HP) as an example of a hydrophobic IL with a similar structure...

This study employs time series forecasting, specifically Seasonal Auto-Regressive Integrated Moving Average, to predict the radiological impact of uranium mining in Mika, Nigeria. By utilizing meteorological data to model the dispersion of radioactive emissions to receptors, allowing for a comprehensive assessment of potential health and environmental consequences. The study observed a slight change in the Total Effective Dose Equivalent (TEDE) at the nearest residence northeast receptor between the actual and the forecasted data...

Nuclear power plays a pivotal role in the global energy supply. The adsorption-based extraction of uranium from seawater is crucial for the rapid advancement of nuclear power. The phosphorus nitride imide (PN) nanotubes were synthesized in this study using a solvothermal method, resulting in chemically stable cross-linked tubular hollow structures that draw inspiration from the intricate snowflake fractal pattern. Detailed characterization showed that these nanotubes possess a uniformly distributed five-coordinated nanopocket, which exhibited great selectivity and efficiency in binding uranium...

As a decay product of uranium series, 210 Pb spreads widely in the nature and imposes strong radiological and chemical toxicity. It is vital to establish reliable and efficient radioanalytical methods for 210 Pb determination to support environment and food radioactivity monitoring programs. This article critically reviews analytical methods developed for determining 210 Pb in environmental and biological samples, especially new development in recent years. Techniques applied throughout different analytical steps including sample pretreatment, separation, purification, and detection are summarized and their pros and cons are discussed to provide a holistic overview for 210 Pb environmental and biological assay...

Reentrant superconductivity is an uncommon phenomenon in which the destructive effects of magnetic field on superconductivity are mitigated, allowing a zero-resistance state to survive under conditions that would otherwise destroy it. Typically, the reentrant superconducting region derives from a zero-field parent superconducting phase. Here, we show that in UTe2 crystals extreme applied magnetic fields give rise to an unprecedented high-field superconductor that lacks a zero-field antecedent. This high-field orphan superconductivity exists at angles offset between 29o and 42o from the crystallographic b to c axes with applied fields between 37 T and 52 T...

Presentation of baseline data on terrestrial gamma radiation (TGR) levels is crucial for assessing the annual effective dose received by the public due to natural radiation exposure. Cumulative doses from various sources can become significant, warranting a spatial understanding of TGR distribution. Few countries have comprehensively mapped TGR on a national scale, often facing challenges due to remote or inaccessible regions. This study investigated the influence of weathered soil groups on TGR dose rates in Sarawak-Borneo, Malaysia, to facilitate insights for TGR projection and isodose mapping...

The role of tannins (TA), a well-known abundant and ecologically friendly chelating ligand, in metal capture has long been studied. Different kinds of TA-containing adsorbents are synthesized for uranium capture, while most adsorbents suffer from unfavorable adsorption kinetics. Herein, the design and preparation of a TA-containing 2D crosslinked network adsorbent (TANP) is reported. The ≈1.8-nanometer-thick TANP films curl up into micrometer-scale pores, which contribute to fast mass transfer and full exposure of active sites...