Thorium Metal Research Articles

Recent Advances in Low Valent Thorium and Uranium Chemistry

The synthesis, isolation, and characterisation of well-defined low-valent actinide complexes are reviewed with a main focus on compounds featuring uranium and thorium metal centres in formal oxidation states ≤ +3. The importance of the ligand environment in enabling access to these highly reactive species, as well as its influence on ground state electronic configurations and their reactivity, are emphasised. Furthermore, we highlight cyclic voltammetry (C.V.) studies as a more widely used method that can guide the synthesis of these highly reducing species.

Temperature Dependence of the Ring Opening of Cyclopropene Imines on Thorium Metallocenes.

The reactions of two highly strained cyclopropenimine ligands L1H and L2H (L1H = N1,N1,N2,N2-tetraisopropyl-3-iminocycloprop-1-ene-1,2-diamine, L2H = N1,N1,N2,N2-tetracyclohexyl-3-iminocycloprop-1-ene-1,2-diamine) with three thorium precursors Cp*2ThCl2, Cp*2Th(Cl)(CH3), and Cp*2Th(CH3)2 were studied. At -20 °C, L1H and L2H react with Cp*2ThCl2 to form Th1 (Th1 = Cp*2ThCl2(L1H)) and Th2 (Th2 = Cp*2ThCl2(L2H)), respectively, where the neutral ligand coordinates to the thorium metal center. Coordination of the ligand to the thorium metal center introduces aromaticity at the cyclopropene ring of the ligand. Reaction at room temperature results in the ring opening of the ligand to form Th3 (Th3 = Cp*2ThCl2((Z)-2,3-bis(diisopropylamino)acrylonitrile) and Th4 (Th4 = Cp*2ThCl2((Z)-2,3-bis(dicyclohexylamino)acrylonitrile), where the cyclopropenimine converts into a nitrile and coordinates to the thorium metal center. Reaction of L1H and L2H with Cp*2Th(Cl)(CH3) and/or Cp*2Th(CH3)2 at -20 °C results in a rapid methanolysis reaction and forms Cp*2Th(L1/L2)(CH3/Cl)-type complexes Th5 (Th5 = Cp*2Th(L1)(CH3)), Th6 (Th6 = Cp*2Th(L2)(CH3), Th7 (Th7 = Cp*2Th(L1)(Cl), and Th8 (Th8 = Cp*2Th(L2)(Cl). On the other hand, at room temperature, these reactions result in a ring opening of the ligand. Room-temperature reaction of L1H and L2H with Cp*2Th(CH3)2 results in Th9 (Th9 = Cp*2Th(CH3)((Z)-3-imino-N1,N1,N2,N2-tetraisopropylbut-1-ene-1,2-diamine) and Th10 (Th10 = Cp*2Th(CH3)((Z)-3-imino-N1,N1,N2,N2-tetracyclohexylbut-1-ene-1,2-diamine). Similarly, at room temperature, L1H and L2H react with Cp*2Th(Cl)(CH3) to form Th11 (Th11 = Cp*2Th(Cl)((Z)-3-imino- N1,N1,N2,N2-tetraisopropylbut-1-ene-1,2-diamine) and Th12 (Th12 = Cp*2Th(Cl)((Z)-3-imino-N1,N1,N2,N2-tetracyclohexylbut-1-ene-1,2-diamine). The ring-opening reaction is assisted by the nucleophilic attack of the thorium-coordinated methyl group to the highly strained cyclopropene imine carbon.

Synthesis and characterization of metal–organic frameworks based on thorium for the effective removal of 2,4-dichlorophenylacetic pesticide from water: Batch adsorption and Box-Behnken Design optimization, and evaluation of reusability

This study aimed to assess the effectiveness of thorium metal–organic frameworks (Th-MOF) as an adsorbent for the removal of the hazardous herbicide 2,4-dichlorophenylacetic (2,4-D) from aqueous solutions. The experimental results convincingly demonstrate Th-MOF's capability as an adsorbent, effectively eliminating 2,4-D from water. The material's properties were thoroughly examined using SEM, TEM, PXRD, XPS, FT-IR, and BET studies, revealing a substantial surface area of 1122.12 m2/g, indicative of its potential for high adsorption capacity. Surface charge analysis indicated a positive charge below the point of zero charge (5.2) and a negative charge above it, influencing the adsorption behavior. The study explored the impact of pH on adsorption equilibrium through batch experiments, providing insights into the environmental factors affecting the adsorption process. In summary, this research highlights Th-MOF as a promising adsorbent for 2,4-D removal, contributing valuable insights into its characteristics and performance in water treatment applications. The significance of our findings lies in the clear impact of variations in solution pH on the adsorption behavior observed in the study. We conducted a detailed investigation into the effectiveness of 2,4-dichlorophenylacetic acid (2,4-D) adsorption on Th-MOF, employing pseudo-second-order kinetic models to unravel the kinetics of the process. The Langmuir isotherm model proved to be a reliable predictor of the adsorption mechanism, highlighting a chemisorption process throughout. Intriguingly, our study revealed that the entire adsorption–desorption process was characterized by an endothermic and spontaneous nature, as indicated by the calculated thermodynamic parameters (ΔH°), (ΔS°), and (ΔG°) when utilizing Th-MOF as the adsorbent. Furthermore, the artificially synthesized Th-MOF adsorbent showcased exceptional flexibility and cyclability, successfully undergoing up to six adsorption–desorption cycles. This versatility underscores the potential practical applications of Th-MOF in water treatment processes, emphasizing its effectiveness and recyclability for sustainable environmental remediation efforts. In a scaled-down laboratory demonstration of wastewater treatment, we evaluated the efficacy of the developed adsorbent. The interaction mechanism between Th-MOF and 2,4-dichlorophenylacetic acid (2,4-D) was closely examined, considering factors like H-bonding, π-π interaction, pore filling, or electrostatic contact. The Th-MOF adsorbent demonstrated its capability for efficient water filtration and industrial wastewater management. Our study is noteworthy for pioneering the method for removing 2,4-D from wastewater samples using the Th-MOF adsorbent. Results revealed maximum 2,4-D adsorption onto Th-MOF at a pH of 4, reaching 358.3 mg.g − 1. Further exploration assessed removal efficacy from real samples and the sustained performance of the adsorbent through more than six cycles, with attention to its regeneration potential. The optimization of adsorption outcomes was achieved through the utilization of the Box-Behnken Design. This analysis underscores the practical application and sustainability of Th-MOF in addressing real-world wastewater treatment challenges.

Non-covalent interactions orchestrated distinct molecular arrangements along different axes within the novel mixed ligand thorium metal complex: Experimental and theoretical insights

This study presents the crystallographic analysis of a defect-free single crystal of a novel thorium metal complex, revealing its intricate three-dimensional molecular structure. The crystal was found to belong to space group C2/c, containing six mononuclear complexes in each unit cell. The central metal atom exhibited a ten-coordinated distorted sphenocoronal capped square antiprismatic geometry, forming bidendate bonds with 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3‑dione) (TFTBD) and a 1,10 phenanthrene (Phe) ligand groups. Intriguingly, the crystal displayed a nonplanar geometry and featured various non-covalent interactions within its structure, both intra and intermolecular, enhancing its overall stability. Notably, intramolecular interactions involving CH⋯F/S/O bonds led to the formation of unique synthons, further substantiated by NCI analysis. Intermolecular interactions, such as CH⋯F, CH⋯Cg, and π⋯π interactions, played a crucial role in the crystal packing, resulting in the formation of two-dimensional molecular zig-zag chains, linear layers and hexagonal arrangements on the crystallographic ab-, bc-, and ca-planes respectively.

Analysis of iron-rich hydrochloric acid solutions for uranium, thorium, rare-earth elements and other heavy metals

A simple solvent extraction method is described for the separation of trace elements including uranium (U), thorium (Th) and rare-earth elements (REEs) from industrially processed iron-rich hydrochloric acid solutions. Iron (Fe) causes severe spectral interference during the analysis of trace elements using inductively coupled plasma optical emission spectrometer (ICP-OES) and U by light-emitting diode (LED)-based fluorimeter (LEDF). The spectral interferences of Fe on trace elements are studied and documented. Sequential solvent extractions using methyl isobutyl ketone (MIBK) effectively removed the highly interfering Fe from these processed acid solutions, thereby enabling accurate and sensitive determination of Cd, Zn, Pb, Co, Ni, Cr, V, Cu, Sr, Zr, Ti, REEs including radioactive elements like U and Th. Solvent extraction parameters like the number of extractions, aqueous-organic ratio and acidity have been optimized for removal of Fe. The accuracy of the method has been established by analyzing synthetically prepared hydrochloric acid solutions by spiking-recovery method. Ion exchange separation of REEs using Dowex 50 × 8 cation exchange resin has been also studied and reported. The precision obtained has been well within ± 10% RSD for elements having concentration above 10 mg L−1 and ± 15% for elements having concentration below 10 mg L−1 for replicate (n = 5) measurements.

Estimating 225Ac yield in thorium metal targets

In this work we estimate the yield of the radioisotope ^{225}Ac in a thorium metal target geometry similar to that described by Roberston et al.. We do so in three different yet complimentary studies. In the first study, we pose a three-way coupled time-dependent model describing beam position, temperature field, and local growth of the activity of the radioisotope and solve this numerically. In the second study, we present an analytical solution of the model equations for a generalized solid target in the “beam-thin” limit, i.e. where only a small fraction of the incoming energy of the proton beam is deposited into the thorium material. In the third study, we use the insight gained from the analytical solution and describe an operating strategy to maximize yield by modulating the beam flux temporally.

Isotopes illustrate vertical transport of anthropogenic Pb by reversible scavenging within Pacific Ocean particle veils

Reversible scavenging, the oceanographic process by which dissolved metals exchange onto and off sinking particles and are thereby transported to deeper depths, has been well established for the metal thorium for decades. Reversible scavenging both deepens the elemental distribution of adsorptive elements and shortens their oceanic residence times in the ocean compared to nonadsorptive metals, and scavenging ultimately removes elements from the ocean via sedimentation. Thus, it is important to understand which metals undergo reversible scavenging and under what conditions. Recently, reversible scavenging has been invoked in global biogeochemical models of a range of metals including lead, iron, copper, and zinc to fit modeled data to observations of oceanic dissolved metal distributions. Nonetheless, the effects of reversible scavenging remain difficult to visualize in ocean sections of dissolved metals and to distinguish from other processes such as biological regeneration. Here, we show that particle-rich "veils" descending from high-productivity zones in the equatorial and North Pacific provide idealized illustrations of reversible scavenging of dissolved lead (Pb). A meridional section of dissolved Pb isotope ratios across the central Pacific shows that where particle concentrations are sufficiently high, such as within particle veils, vertical transport of anthropogenic surface-dissolved Pb isotope ratios toward the deep ocean is manifested as columnar isotope anomalies. Modeling of this effect shows that reversible scavenging within particle-rich waters allows anthropogenic Pb isotope ratios from the surface to penetrate ancient deep waters on timescales sufficiently rapid to overcome horizontal mixing of deep water Pb isotope ratios along abyssal isopycnals.

Investigation of the Thermal Properties of Alkali Metal Thorium Phosphates and Their Application for the Sorption of Uranyl Ion from Acidic Medium

AbstractThermo physical properties of potassium, rubidium and cesium thorium phosphate compounds were investigated. All compounds were synthesized by conventional solid state method. Formation of orthorhombic AMThP3O10, tetragonal AM2Th(PO4)2 and monoclinic AMTh2(PO4)3; [AM=K, Rb and Cs] was confirmed using Powder X‐ray diffraction (XRD) technique. Structural study of CsThP3O10 was carried out for the first time from Rietveld refinement of XRD data. Thermal stability of all compounds was established using Thermogravimetric analysis (TGA) technique. When heated at 1673 K for 30 h in air, all the compounds decompose to ThO2. High temperature X‐ray diffraction (HT‐XRD) data of the compounds, synthesized during present study, were collected in an inert atmosphere from ambient to 973 K and their thermal expansion coefficients were calculated. These compounds show positive thermal expansion up to 973 K. Molar heat capacities for all phosphates were measured between 300–863 K using Differential Scanning Calorimeter. Alkali metal thorium phosphates, AMThP3O10 and AMTh2(PO4)3, showed efficient uptake of uranyl ion from aqueous acidic medium predominantly following Langmuir isotherm and Webber Morris intra particle diffusion kinetics.

Recovery of Uranium, Thorium, and Other Rare Metals from Eudialyte Concentrate by a Binary Extractant Based on 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and Methyl Trioctylammonium Nitrate

Eudialyte-group minerals are of scientific interest as important concentrators of rare elements (mainly Zr and REE) in agpaitic alkaline rocks and a potential source of REE, Zr, Hf, Nb, and Ta for industrial use. Extraction of uranium(VI), thorium(IV), zirconium(IV), hafnium(IV), titanium(IV), and scandium(III) by a binary extractant based on 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and methyl trioctylammonium nitrate from eudialyte breakdown solutions is studied. Extraction isotherms were obtained and exhaustive extraction was investigated. It is shown that uranium, thorium, hafnium, zirconium, scandium, and titanium are almost completely recovered in two-stage extraction by a mixture of 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and methyltrioctylammonium nitrate in 1,2-dichloroethane. Quantitative characteristics were compared for uranium(VI), thorium(IV), zirconium(IV), hafnium(IV), titanium(IV), and scandium(III). It was shown that the extraction efficiency of the metals by the binary extractant based on 1,5-bis[2-(hydroxyethoxyphosphoryl)-4-ethylphenoxy]-3-oxapentane and methyltrioctylammonium nitrate in 1,2-dichloroethane is much higher in comparison with the commercially available tributyl phosphate.

Toward Constraining Sources of Lithogenic Metals in the Northern Gulf of Mexico

AbstractNorth African dust is known to be deposited in the Gulf of Mexico, but its deposition rate and associated supply of lithogenic dissolved metals, such as the abiotic metal thorium or the micronutrient metal iron, have not been well‐quantified. 232Th is an isotope with similar sources as iron and its input can be quantified using radiogenic 230Th. By comparing dissolved 232Th fluxes at three sites in the northern Gulf of Mexico with upwind sites in the North Atlantic, we place an upper bound on North African dust contributions to 232Th and Fe in the Gulf of Mexico, which is about 30% of the total input. Precision on this bound is hindered by uncertainty in the relative rates of dust deposition in the North Atlantic and the northern Gulf of Mexico. Based on available radium data, shelf sources, including rivers, submarine groundwater discharge, and benthic sedimentary releases are likely as important if not more important than dust in the budget of lithogenic metals in the Gulf of Mexico. In other words, it is likely there is no one dominant source of Th and Fe in the Gulf of Mexico. Finally, our estimated Fe input in the northern Gulf of Mexico implies an Fe residence time of less than 6 months, similar to that in the North Atlantic despite significantly higher supply rates in the Gulf of Mexico.

ThC2@C82 versus Th@C84: unexpected formation of triangular thorium carbide cluster inside fullerenes.

Synthesis of the first thorium-containing clusterfullerenes, ThC2@C s (6)-C82 and ThC2@C2(5)-C82, is reported. These two novel actinide fullerene compounds were characterized by mass spectrometry, single-crystal X-ray diffraction crystallography, UV-vis-NIR spectroscopy, and theoretical calculations. Crystallographic studies reveal that the encapsulated ThC2 clusters in both C s (6)-C82 and C2(5)-C82 feature a novel bonding structure with one thorium metal center connected by a C[triple bond, length as m-dash]C unit, forming an isosceles triangular configuration, which has not been hitherto observed for endohedral fullerenes or for solid phase thorium carbides. Electronic structure calculations assign a formal electronic structure of [Th4+(C2)2-]2+@[C82]2-, with pronounced donation bonding from (C2)2- to Th4+, secondary backbonding from the fullerene to thorium and Th-C double bond character in both compounds. This work presents a new family of endohedral fullerenes, MC2@C2n-2, being unexpected isomers of MC2n , and provides broader understanding of thorium bonding.

Removal of lanthanum, cerium and thorium metal ions from aqueous solution using ZrT hybrid ion exchanger

In this paper, a hybrid exchanger, zirconium triethylenetetramine (ZrT), of the class of tetravalent metal acid (TMA) salts, has been synthesized by the sol–gel method. In the present work, an attempt has been to investigate the sorption behavior of lanthanum, cerium, and thorium metal ions towards ZrT exchanger in various electrolytes media with different concentrations. In order to understand the uptake behavior of ZrT, parametric studies, kinetic and thermodynamic studies have been investigated. Distribution studies data revealed the feasibility of binary lanthanide separations using ZrT and show possibility of its promising use as an efficient ion exchanger in the treatment of water containing radioactive metal waste. In general, the decay storage or ion exchange treatment is used for the treatment of aqueous waste generated from the low nuclear power reactor. As per the report (IAEA-TECDOC-654, 1992), such nuclear aqueous waste generated is found acidic in view of used acidic chemicals during the process. The use of ZrT will be effective or in other words, ZrT can be a potential candidate to be used as an ion-exchange material for the treatment of such nuclear aqueous waste, after optimizing the process parameters, in particular maintaining the pH in the range of 4–5.

Constructing Well-Defined and Robust Th-MOF-Supported Single-Site Copper for Production and Storage of Ammonia from Electroreduction of Nitrate.

A combined technique of production and storage of ammonia (NH3) from electroreduction of nitrate (NO3–) through one material is highly desirable but remains a huge challenge. Herein, we proposed a proof-of-concept strategy for combined NH3 production and storage from electroreduction of NO3– through elaborately designing a single-site CuII-bipyridine-based thorium metal–organic framework (Cu@Th-BPYDC). Noticeably, the single CuII site, anchored by a solid–liquid postsynthetic metalation within Th-BPYDC, shows a novel square coordination structure, as determined by the single-crystal X-ray diffraction. This strongly implies its enormous potential as an open metal site and consequently enables excellent performance in electroreduction of NO3– for NH3 production, giving 92.5% Faradaic efficiency and 225.3 μmol h–1 cm–2 yield. Impressively, we can further use Cu@Th-BPYDC material to effectively capture the previously produced NH3 from electroreduction of NO3–, affording an uptake up to 20.55 mmol g–1 at 298 K at 1 bar. The results in this work will outline a new direction toward the combined technique for advanced electrocatalysis such as gas production plus storage/or separation.

Interpenetration Control in Thorium Metal-Organic Frameworks: Structural Complexity toward Iodine Adsorption.

The rational design and synthesis of metal-organic frameworks with well-controlled interpenetration have been active research areas of inquiry, particularly for porosity-related applications. Herein, we extend the use of the ligand steric modulation strategy to initiate the first study of the interpenetration control of thorium-based MOFs. The approximate "hardness" of the Th4+ cation, which was conjugated with aromatic substitutions and delicately modified synthetic conditions, allows for the crystallization of single crystals of seven new Th-MOFs with five distinct topologies. Solvothermal reactions of Th(NO3)4 with the triphenyl H2TPDC ligand under variable conditions exclusively gave rise to an interpenetrated Th-MOF with a hex topology, namely Th-SINAP-16. Modifications of the ligand sterics with two pendant methyl groups to 2',5'-Me2TPDC2- and 2,2″-Me2TPDC2- afforded two noninterpenetrated UiO-68-type Th-MOFs (Th-SINAP-17 and Th-SINAP-20, respectively) with record-high pore volumes (74.8% and 75.3%, respectively) among all the thorium MOFs. Moreover, another four Th-MOFs Th-SINAP-n (n = 18, 19, 21, and 22) with three different topologies were obtained by a simple synthetic modulation. Notably, Th-SINAP-16 and Th-SINAP-21 represent the second rare examples of interpenetrated Th-MOFs reported to date. These findings revealed the unprecedented structural complexity and synthetic accessibility of Th-MOFs among all tetravalent metal containing MOFs. Such features make Th-MOFs as an ideal platform to elucidate the structure-property relationship for various applications, e.g. iodine adsorption.

Thermo physical properties and pressure induced phase transition in thorium and uranium sesquicarbide (Th2C3, U2C3)

Carbides of actinide metals thorium and uranium are the potential candidates as a nuclear fuel for generation IV advanced reactors. With the aim to search for new probable structures under high pressures and to determine the thermo mechanical properties of two candidates Th2C3 and U2C3 of actinide–carbon system, the ab initio calculations in conjunction with an evolutionary structure search algorithm have been performed up to the pressure range of 200 GPa. Apart from reproducing the already established bcc structure at zero pressure, the calculations could predict the existence of some new high pressure phases such as orthorhombic structures (SG No. 69, Fmmm) and (SG No. 65, Cmmm) at 62 GPa and 120 GPa, respectively, for Th2C3 and triclinic phase (SG No. 2, P1¯) at 57 GPa for U2C3. In U2C3, the effect of including the Hubbard potential (GGA + U = 3 eV) and spin–orbit coupling on structural, electronic, vibrational properties, and pressure induced phase transitions has also been studied. Furthermore, to substantiate the stability of the high pressure structures so predicted by comparing the enthalpies, the elastic and lattice dynamic stability analysis has also been carried out. Additionally, the high temperature thermo-physical properties of Th2C3 and U2C3 in the cubic phase derived from the present lattice dynamic calculations within quasiharmonic approximations have been compared with the experimental data reported in the literature.

Tensile stress and related Th-U-REE mineralizations in the granite of Wadi Ras Abda, North Eastern Desert, Egypt

The main rock types exposed at Wadi Ras Abda area are subduction-related older granite intruded by fine-grained alkali feldspar granite (microgranite intrusions). These rock types are dissected by acidic dykes (rhyolite) and basic dykes (basalt and dolerite) with their associated pegmatites and quartz veins. Ras Abda microgranite is highly radioactive and this radioactivity is structurally related. The thorium, uranium, and rare metal mineralization are distinguished within the microgranite intrusions along fault zones that are trending N40° E with high dipping angle reaching to 86°. It shows radioactive measurements ranging from 500 to 9500 ppm and showing visible secondary uranium and thorium minerals in addition to the deposition of black rare metal minerals. Uranothorite, thorite, and secondary uranium minerals (uranophane) are the main radioactive minerals at Wadi Ras Abda area, in addition to the rare earth–bearing mineral (REE) fergusonite. Six events are affected in W. Ras Abda area. Each event begins with compression (CP) and then extensional (EXT) phase of deformation. These events were arranged chronologically basing on field relations from the oldest to the youngest as following: WNW-ESE (CP), NNE-SSW (EXT), E-W (CP), N-S (EXT), NE-SW (CP), NW-SE (EXT), NNE-SSW to N-S (CP), WNW-ESE to E-W (EXT), NW-SE to NNW-SSE (CP), ENE-WSW to NE-SW (EXT) and ENE-WSW (CP), and NNW-SSE (EXT). The WNW-ESE to E-W–directed tensile stress reactivated faults and induced new faults along which the mineralized fluids flow. It is recognized that the low-stress regions in the vicinity of faults and their associated tension joints, along contacts between microgranite and older granite, are favorable locations for alterations and Th-U and REE mineralization.

Thhorium Metal–Organic Framework Showing Proton Transformation from [NH2(CH3)2]+ to the Carboxyl Group to Enhance Porosity for Selective Adsorption of D2 over H2 and Ammonia Capture

In this work, we report a novel thorium metal–organic framework, [NH2(CH3)][Th2(H2O)2(L)3] (namely, ECUT-36, H3L = 4,4′,4′′-nitrilotribenzoic acid), built on a new Th2 building block, showing a 3,9...

Thorium Utilization in Pressurized Water Reactors Using Bimetallic Thorium-Zirconium Alloy Cladding

A fuel rod design consisting of a bimetallic cladding tube of thorium metal bonded to a zirconium alloy and containing seed fuel in the interior space is proposed for thorium utilization in pressurized water reactors. The design mitigates the severe thermal penalty that arises in radial microheterogeneous designs when thorium is present as an oxide. The level of thorium loading has an important effect on the achievable discharge exposure as too high a loading results in a large reactivity penalty that is not compensated by rapid enough 233U breeding. In the bimetallic cladding design, the level of thorium loading could be adjusted by varying the thorium metal thickness, and analyses are presented to evaluate optimal levels of thorium loading. Results of cases for higher levels of initial seed loading are presented with a view to extending exposure and reducing the number of discharged assemblies. Liquid metal bonding the seed fuel–cladding gap is preferable as it reduces the seed fuel temperature and at the same time provides more room for fuel swelling. Helium bonding the gap is also possible with a seed fuel modified by an inert matrix. Both approaches need data for fuel thermal modeling, swelling, and fission gas release at high burnup not currently available.

Highly Sensitive Determination of Bisphenol A in Bottled Water Samples by HPLC after Its Extraction by a Novel Th-MOF Pipette-Tip Micro-SPE.

In this study, a novel thorium metal organic framework was synthesized, characterized and used as a sorbent for very efficient pipette tip micro solid-phase extraction of bisphenol A in bottled drinking water samples using high-performance liquid chromatography as detecting instrument. Parameters which influence extraction efficiency such as pH, sample volume, amount of sorbent, type and volume of eluent, number of aspirating and dispensing cycles for extraction and elution, and volume of the sample solution were studied and optimized. A linear calibration curve was obtained in the range of 0.002-0.456ngmL-1 (r2=0.996) with a detection limit of 0.0010ngmL-1. Repeatability of batch-to-batch extraction was better than 5.0% and a reproducibility of 3.2% for real samples obtained.

Selective Separation of Radium and Actinium from Bulk Thorium Target Material

A complete scheme for the selective separation of actinium and radium isotopes from bulk 232Th target material will be presented. The process may be applicable to the production of 225Ac and 227Ac via proton spallation on thorium targets. Thorium metal is dissolved in sulfuric acid with small amounts of HF. Actinium and radium are retained on cation exchange resin from the sulfate medium, while neutral and anionic thorium sulfate complexes are rejected. Targeting the minor components (Ac,Ra) allows use of much smaller chromatographic columns than traditional nitrate based systems which target the bulk thorium. Additionally, the primary separation is performed from 0.1M Th, 0.6M sulfate, pH 1-2 instead of the more corrosive 3-8M HNO3 typically employed in solvent extraction or anion exchange based thorium separations. Actinium and radium are recovered from the cation exchange resin in a small volume of 5M HNO3 and directly purified via extraction chromatography with UTEVA and DGA resins without feed adjustment or evaporation. The radium fraction can be further processed following ingrowth of 225Ac from 225Ra to produce additional 225Ac free from any potential 227Ac impurity. The flowsheet has been tested at the Canadian Nuclear Laboratory (CNL) on 25 gram solid thorium targets irradiated at Fermi Lab. -Bond, A.H., Horwitz, E.P., McAlister, D.R., 2006. A Multicolumn Selectivity Inversion Generator for the Production of High Purity Actinium-225 for Use in Therapeutic Nuclear Medicine, United States patent number 7,087,206. (Licensed to NorthStar Medical Radioisotopes) -D.R. McAlister, E.P. Horwitz, “Selective Separation of Radium and Actinium from Bulk Thorium Target Material on Strong Acid Cation Exchange Resin from Sulfate Media,” Applied Radiation and Isotopes, 140, 18-23 (2018).