Search

Herein we have developed solvent extraction method for thorium(IV) with 0.15 M N-n decylaniline in xylene from 0.5 M H2SO4. Physicochemical parameters like acid concentration, amine concentration, equilibrium time, phase ratio, diluent, loading capacity to name a few were optimized for the quantitative extraction of thorium(IV). The back-extraction of thorium(IV) from organic phase was done with 0.1 M nitric acid and determined complexometrically. To extend the utility of this method, binary and ternary mixture separation, extraction of thorium(IV) from monazite sand and gas mantle are also investigated. [ABSTRACT FROM AUTHOR]

Nuclear grade zirconium and hafnium are important materials in nuclear power plants, which are usually produced with solvent extraction and separation technology. In this paper, the preferential extracting hafnium was successfully achieved by the selective complexation of the selected organic acids. Hydrochloric acid concentration, organic acid concentration, D2EHPA concentration were investigated to explore the optimum extraction conditions. Increasing acidity and extractant concentration was not conducive to the separation of zirconium and hafnium, while organic acid could effectively improve the separation factor, which was verified by ATR-FTIR spectroscopy. The largest separation factor, 9.936, for hafnium over zirconium was obtained. [ABSTRACT FROM AUTHOR]

This research demonstrates two methods of quantifying ion yield efficiency using an inductively coupled plasma mass spectrometer. The mass spectrometer is used as a means of separation where individual decay mass-chains are isolated (i.e., implanted) onto a conductive substrate. Quantifying the ion yield of this recovery process is crucial to understanding the abundance of the separated isotope present in the unseparated starting sample. The first method measured the accumulated charge directly incident on the conductive substrate in real-time while the second method performed a full chemical analysis of the substrate after dissolution. Our previous results demonstrated and compared these quantification methods with a multi-element standard of stable isotopes. This research expands on previous results and utilizes the stable mass ion yield to quantify trace amounts of the (radioactive) isotope of interest present in the sample. The mass-separated radioactive isotopes were fission products produced from thermal neutron irradiation of a highly enriched 235U foil. Five peak-yield mass chains were targeted. The results indicate good correlation between the two methods of measuring the ion yield and imply that coupling this method with traditional radiometric counting can result in an accurate means of quantifying radioactive isotopes. The final results we report here are within 1-sigma of the published cumulative fission yields. [ABSTRACT FROM AUTHOR]

A separation procedure was developed and implemented for the isolation of gold (Au) and platinum (Pt) radionuclides from deuteron irradiated Pt using tri-butyl phosphate (TBP) resin. Computational modeling and experimental results of the Au and Pt radionuclide production were reported and compared to literature values. Results of the separation procedure demonstrated a Pt recovery of 98 ± 2% and a Au recovery of 92 ± 7%, in their respective fractions (n = 4 ± 1σ) The decontamination factors were 2900 ± 500 for Au removal from the Pt fraction and 830 ± 30 for Pt removal from the Au fraction (n = 4 ± 1σ). [ABSTRACT FROM AUTHOR]

A crown-ether based extraction chromatography resin, Eichrom Pb, has been characterized for separations of the flerovium (Fl) pseudo-homolog Hg. Previous results on the batch uptake of Pb(II) and Sn(IV) are compared with newly investigated Hg(II) in HCl matrices. It was determined that all three elements can be strongly retained by the resin at different HCl concentrations. To assess the feasibility for performing an experiment on the chemical properties of Fl using this resin the extraction kinetics were studied. A separation method for the isolation of the homologs Pb(II) and Sn(IV) and pseudo-homolog Hg(II) has been established using 2 mL pre-packed Pb resin columns under vacuum flow. [ABSTRACT FROM AUTHOR]

Salophen modified biochar fibers derived from Luffa cylindrica sponges were prepared and subsequently studied as a potential U(VI) adsorbent by batch-type experiments. The material was characterized by spectroscopic and microscopic methods, which revealed no significant changes of the textural properties upon modification. The material presents extraordinarily high maximum adsorption capacity values (qmax) for U(VI) even under acidic conditions (714 g kg−1 at pH 3 and 833 g kg−1 at pH 5.5). This increased affinity is attributed to the selective binding of U(VI) by salophen and could be of particular interest for the adsorption of uranium from process solutions and industrial wastewaters. [ABSTRACT FROM AUTHOR]

A test was conducted to separate Cd from Cd/LiCl-KCl salt using a stainless steel basket with holes 0.5 mm in size. A thermal cycle test of Cd in the mesh basket was repeated 15 times to confirm the containment property. U was recovered from a bare Cd-U alloy via distillation at a low temperature of around 400-500 °C in a morphology of porous particles, showing no evidence for the bumping of the Cd-U alloy. The U recovery efficiency at a kg-scale reached 100%. [ABSTRACT FROM AUTHOR]

The applicability of MnO2-resin for the selective separation of Ra(II) from aqueous solutions containing also U(VI) and Eu(III) has been investigated as a function of solution pH and salinity. The measurements were performed by LSC for radium and by spectrophotometry for uranium and europium, using Arsenazo-III. According to the experimental results the maximum chemical recovery of the MnO2-resin for Ra(II) is observed in the pH range between 5 and 7 and selective separation of Ra(II) from aqueous solutions can be triggered by adjusting solution pH and salinity. [ABSTRACT FROM AUTHOR]

Lead-bismuth eutectic (LBE) is the proposed material for use as converter targets in the ISOL facilities globally. In this paper, an LBE target was irradiated with 22 MeV proton beam for 7.6 h to produce 203,204,205,206Bi, 203Pb along with 207Po. Separation of bulk Pb and Bi has been carried out using Aliquat-336 (tricaprylmethylammonium chloride), TOA (trioctyl amine) and DOWEX-1 as extractants. Bi was selectively extracted to the organic/solid phase leaving Pb in aqueous medium. High separation factor between Pb and Bi was observed when 0.5 M TOA and 1 M HNO3 were used as organic and aqueous phase respectively. [ABSTRACT FROM AUTHOR]

A method for analyzing 3H, 36Cl, 22Na, 133Ba and 134Cs from simulated groundwater (SGW) samples was introduced. Gamma emitting radionuclides 22Na, 133Ba and 134Cs were measured by using an HPGe-detector. Beta emitting 3H and 36Cl were separated from gamma emitting 22Na, 133Ba and 134Cs. AgCl precipitation was used for the separation of 36Cl from SGW samples with yields of 98 ± 2%. 3H was separated by distillation with recoveries of 97 ± 3%. This method was used for the determination of activity concentrations of 3H, 36Cl, 22Na, 133Ba and 134Cs in SGW samples collected from an in situ through diffusion experiment. [ABSTRACT FROM AUTHOR]

A new method consisting of methanol-methyl isobutyl ketone (MIBK)-water extraction and open-column cation exchange chromatography followed by HPLC was developed for the separation of total, residual, lipid-soluble, and five water soluble arsenic species including AsB, MMA, DMA, As(III), and As(V) in selected Canadian seafood samples. The mass fractions of arsenic were determined by neutron activation analysis with a detection limit of less than 20 µg kg−1. The method was validated by analyzing reference materials. The MIBK phase contained most of the lipid-soluble arsenic and indicated a linear relationship between the lipid content and lipid-soluble arsenic. [ABSTRACT FROM AUTHOR]

We have developed a combined sequential chemical separation procedure and multiple ion counting ICP-MS measurement method for isotopic measurements of Am in environmental samples. This, in conjunction with established resin bead TIMS measurements for Pu and Np, allows us to measure long-lived Pu-Np-Am nuclides in environmental samples on a single solution aliquot. This single aliquot method reduces time lines and maximizes sample utility for the measurements, improving sensitivity, precision, and accuracy over prior methods. We have evaluated this new method with environmental reference materials and have obtained accurate results on samples with > 3E6 atoms 241Am. [ABSTRACT FROM AUTHOR]

This study shows a membrane containing a protonated manganese dioxide powder that is able to continually extract tritium from light water at room temperature. The method of using membrane-supplied protons through a proton conductive polymer film from acidic aqueous solution was remarkably effective at maintaining a continual extraction of tritium from light water, compared to the use of the protonated manganese dioxide powder alone. The extraction mechanism of tritium might be based on the prior oxidation of OT− at the interface of protonated manganese dioxide and water via neutralization between H+/T+ and OH−/OT−. [ABSTRACT FROM AUTHOR]

The use of carbon dioxide (CO2) as a reaction cell gas for separation and trace analysis of uranium and plutonium by inductively coupled plasma mass spectrometry was investigated. For the analysis of the resultant UO2+ product ion, it was shown that quantitative determination of uranium concentration was achievable within ± 7% uncertainty for samples containing plutonium. In addition, uranium isotope ratios were measured within ± 12% for standard reference materials of several enrichments. This was achieved in both nitric acid and digested cellulose filter paper solutions—a common nuclear forensic sample substrate. However, non-linearity and long term signal instability was observed for plutonium at the high flow rate of CO2 and tuning parameters required to minimise uranium interferences. Therefore, plutonium analysis was not achievable. [ABSTRACT FROM AUTHOR]

The increasing complexity of oil and gas reservoirs demands an accurate understanding of formation composition and mineralogy. Geochemical well logging based on prompt gamma neutron activation analysis technique (PGNAA) plays a crucial role in determining elemental concentrations, identifying lithology and improving the evaluation of matrix properties. The accuracy of elemental concentrations dictates the accuracy of other derived parameters. Elemental standard gamma ray spectra, which are predetermined for each instrument in the research and development phase, can be obtained by experimental measurements. These standards are the foundation of the processing of the neutron induced gamma ray spectroscopy and are considered to be fixed for each instrument. By using Monte Carlo numerical modelling, the standard gamma ray spectra of individual elements under different conditions are calculated. The results show that variation of borehole size, drilling mud types and other logging conditions have impacts on the shapes of the standard libraries. Therefore, if only one set of fixed standard spectra is utilized in processing measured spectra, the accuracy of elemental concentrations is affected. To address this problem, a model for compensating for the effect of logging conditions on the shapes of standard spectra is proposed. A field example is illustrated to validate the proposed method and result shows that the agreement between computed elemental weight fractions and XRF core analysis results is improved by using the introduced method. [ABSTRACT FROM AUTHOR]

This paper reports the result of process development studies on separation of Sr(II) from Eu(III) in 4 M nitric acid using supported liquid membrane (SLM). The process utilizes addition of 18-crown-6 for masking of Sr(II), followed by their transport across SLM with TEHDGA as carrier molecule. The optimized process shows complete transport of Eu(III) in about 60 min, leaving pure Sr(II) in the feed compartment. The Sr(II) and Eu(III), both in pure form are valuable in medical and industrial radiation technology applications. [ABSTRACT FROM AUTHOR]

In this work, we report the distribution ratios of Zr(IV), Co(II), Sb(V) and Nb(V) using polyaniline in HCl, HF, oxalic acid and HF + HCl solutions. Distribution ratios were determined by batch method using radiotracer technique. Further, the separation factors and the %-uptake of metal ions were calculated and compared. Among the media studied, separation factors for Co(II), Sb(V) and Nb(V) with respect to Zr(IV) were the highest in 1 M HCl and the values are 52, 108 and 404 respectively. The results of this study can be utilized for designing an ion-exchange process for the decontamination of zircaloy pressure tubes used in the Pressurized Heavy Water Reactors. [ABSTRACT FROM AUTHOR]

Barium and strontium contents of alkaline-earth fission products in simulated oxide fuel were quantitatively analyzed during electrolytic reduction and salt distillation. Electrolytic reduction of the simulated oxide fuel was conducted at 650 °C in molten Li2O-LiCl salt. The residual salt was then separated by salt distillation at 900 °C. Ba and Sr were partially separated from the simfuel and accumulated in the salt during oxide reduction. Ba and Sr levels of 0.21-0.56 wt% of their initial simfuel masses were found in the distilled salt; 2.28-3.34 wt% were found in the fuel remaining after the salt distillation. [ABSTRACT FROM AUTHOR]

Solvent extraction of Ga(III) from hydrochloric acid solution using CYANEX 921 in sulfonated kerosene as a modified diluent has been discussed. The factors affecting the extraction of gallium have been investigated. The sulfonation of kerosene was found to enhance the separation of gallium from the interfering ions and was examined using IR spectroscopy. The process was found to be exothermic with decrease in the randomness of the system and the extracted species was suggested to be HGaCl4·3L¯, where L¯ refers to the CYANEX 921. The developed method was applied for the separation of Ga(III) from copper and zinc in chloride solution that result during production of 66/68Ga from the cyclotron. [ABSTRACT FROM AUTHOR]

A new procedure has been developed for isolating no-carrier-added 197m,gHg from 20 to 25 MeV α-particle irradiations of high purity Pt foils. A previously published procedure for isolation of 197m,gHg from 12 to 15 MeV proton irradiations of Au foils has been further characterized. From these procedures two separate methods have been established to isolate, with high separation factors, 197m,gHg from Pt to Au target materials. [ABSTRACT FROM AUTHOR]

This study describes a new and rapid procedure for radiostrontium determination in milk samples based on the use of plastic scintillation resins (PS resins). The proposed method reduces the time of analysis by at least 2 h by combining separation and measurement preparation into a single step and optimizing the pre-treatment steps. The method is robust and reproducible, with good total recoveries (65% on average) and a relative bias for total radiostrontium activity (89Sr + 90Sr) below 7%. The minimum detectable activity for 100 mL of milk sample measured for 60 min is about 0.34 Bq L-1. The proposed method can quantify radiostrontium content in 5 h, which makes it suitable for use in emergency situations. [ABSTRACT FROM AUTHOR]

The extraction behaviour of Am(III) and other metal ions present in the fast reactor simulated high- level liquid waste (FR-SHLLW) was studied using a modifier-free solvent phase composed of N,N-di-octyl-2-hydroxyacetamide (DOHyA) in n-dodecane. Quantitative extraction of Am(III) was achieved with the co-extraction of all lanthanides, Y(III) and Mo(VI) in the first five stages of a 20-stage mixer-settler. During the stripping run with 0.5 M HNO, Am(III), Ln(III) and Y(III) were quantitatively transferred to the aqueous product in three stages. The other extracted metal ions were retained in organic phase. The results showed that the extraction performance of DOHyA was superior to other amide extractant systems reported in the literature. [ABSTRACT FROM AUTHOR]

Magnetic sepiolite was synthesized by chemical precipitation of Fe and Fe at sepiolite suspension. Removal kinetics of U(VI) on sepiolite and magnetic sepiolite can be well fitted by pseudo-second-order and pseudo-first-order kinetic models, respectively. At pH < 5.0, U(VI) removal on sepiolite significantly decreased with increasing ionic strength, whereas U(VI) removal on magnetic sepiolite was independent of ionic strength. The maximum removal capacity of sepiolite and magnetic sepiolite at pH 5.0 and 298 K calculated from Langmuir model were 28.17 and 74.63 mg/g, respectively. XANES spectra suggested that U(VI) was partly reduced to U(IV) at long-term conditions. [ABSTRACT FROM AUTHOR]

In this study, I PET positron emitter was produced by 29.5 MeV protons irradiation of natural tellurium electroplated on a nickel-coated copper substrate at a current of 150.3 μA h. The routinely separation method of ion-exchange chromatography was adopted and 93% efficiency was achieved for this process. The average yield of I at the End of Bombardment (EOB) was 3.9 MBq/μA h (0.105 mCi/μA h). Additionally, the production process was simulated by the FLUKA, and the yield of 4.3 MBq/μA h (0.116 mCi/μA h) was estimated at the EOB for produced I. A reasonable agreement was achieved between the simulation results and experimental data. [ABSTRACT FROM AUTHOR]

Pure and complete fractions of neodymium, samarium, europium, gadolinium and dysprosium were isolated by means of high performance ion chromatography, using a cation exchange column and gradient elution with alpha-hydroxyisobutyric acid solutions (α-HIBA). Intermediate precision and robustness of the isolation method was investigated, identifying eluent pH as the most important parameter. Investigation of the elution behaviour of the most important fission and activation products and actinides indicated that preventing the accumulation of cesium on the cation exchange column required further isocratic elution with a higher concentrated α-HIBA solution after elution of the lanthanides. A sample matrix free of carbon was achieved by means of acid digestion, followed by UV photo-oxidation, resulting in samples suitable for mass spectrometric analysis. [ABSTRACT FROM AUTHOR]

Multi-channel inductively coupled plasma mass spectrometry and multi-collector ICPMS were used for effective bulk analysis techniques of environmental samples with high thorium contents. A desolvating nebulizer system was adopted to reduce the ThH/Th formation rate, which was evaluated using U/Th mixture solution. A UTEVA-based chemical separation method, with adjustment of the separation parameters for uranium and thorium, allowed for effective separation of uranium. The separation yields for uranium and thorium were estimated from the elution profiles of various U/Th mixture solutions. Bulk analysis of uranium in simulated samples with high thorium contents was performed to validate the improved analytical procedures. [ABSTRACT FROM AUTHOR]

This work describes a radiochemical separation procedure for the determination of gold (Au), platinum (Pt), tantalum (Ta), and tungsten (W) activation in the presence of fission products. Chemical separations result in a reduction in the minimum detectable activity by a factor of 287, 207, 141, and 471 for Ta, W, Pt, and Au respectively, with greater than 90% recovery for all elements. These results represent the highest recoveries and lowest minimum detectable activities for Ta, W, Pt, and Au from mixed fission-activation product samples to date, enabling considerable refinement in the measurement uncertainties for neutron fluences in highly complex sample matrices. Graphical Abstract: [ABSTRACT FROM AUTHOR]

We herein present a suquential procedure for separation of nuclides such as Fe, Nb, Ni, Sr, and Tc from activated carbon and stainless steel samples orignating from low and intermediate level of radioactive waste. Initially, iron was removed through the precipitation of Fe(OH) upon the addition of NHOH. The recoveries of Fe and Nb in the precipitate were 98.4 ± 2.9 and 98.5 ± 0.52%, respectively, while those of Ni, Re, and Sr in the supernatant were 74.0 ± 4.0, 96.7 ± 1.2, and 79.6 ± 1.2%, respectively. However, due to the especially low recovery of Re from the supernatant following anion exchange chromatography, the Fe precipitate was removed after the separation of Re by anion exchange chromatography. Our results indicate that this procedure is suitable for providing pure nuclides from waste samples to allow the measurement of their radioactive activities. [ABSTRACT FROM AUTHOR]

A membrane filtration device was prepared, and its stability under different seasonal conditions typical of northern China was studied. Strontium removal efficiency was investigated and membrane filtration mechanism was determined. At 12 °C strontium removal efficiency was the best and the highest decontamination factor was 942. Membrane filtration step significantly decreased the strontium concentration. Experimental data were well fit by an intermediate pore blocking model. Tiny particles in the pores and on the membrane surface acted as seed. At 29 °C a compressible cake layer formed on the membrane surface, alleviating membrane fouling but without an obvious strontium removal effect. [ABSTRACT FROM AUTHOR]

A thin foil of lead-bismuth eutectic (LBE) has been bombarded with 18 MeV proton beam. Production of Bi along with Pb was observed. This paper reports the separation of bulk Pb and Bi from LBE target based on their differential precipitation properties. The irradiated foil in HNO medium was evaporated to dryness and after addition of deionised water, Bi precipitated out while Pb remained in supernatant with < 5% contamination from Bi, establishing a clear separation of the bulk Bi from bulk Pb with a separation factor > 86,000. [ABSTRACT FROM AUTHOR]

Influence of various parameters affecting the extraction of La(III) from acidic nitrate medium has been analysed. The extraction of 99.1% La(III) from 0.01 mol/L HNO and 1 M NaNO has been obtained using 0.3 mol/L Cyanex 921 in petrofin. The ∆ H , ∆ S calculated from temperature variation experiments and were found to be negative. Stripping has been effectively achieved using low concentrations of HCl and HSO. Separation of La(III) from other lanthanides (Ce, Pr, Nd, Sm) has shown maximum separation factor for La-Sm pair. Modelling of data has been performed using MLR, ANN and ANFIS. [ABSTRACT FROM AUTHOR]

The EURO-grouped actinide extraction process has been developed to co-separate transuranic actinide elements from spent nuclear fuel, based on an organic solvent composed of two extractants, a diglycolamide (TODGA) and a malonamide (DMDOHEMA). This work aims to simplify the organic formulation, replacing the two extractants with a single modified diglycolamide. Batch experiments were carried out with the new formulation, investigating the extraction behaviour of transuranic elements and important FPs under high Pu loading. The solvent had a Pu loading capacity of > 30 g/L and yielded low distribution ratios for problematic elements, i.e., Sr, Zr, Mo and Fe for acidities up to 2 M HNO. Although further optimization is needed, the tested molecule is a very promising candidate for a simplified organic solvent for this type of separation. [ABSTRACT FROM AUTHOR]

An incident involving a radiation dispersal device (RDD) would most likely occur in an urban or metropolitan area. However, the majority of radiochemical separation schemes available have been developed for environmental samples that are not necessarily representative of those found in an urban environment. Sr is one of the possible radioisotopes that could be used in an RDD. It is therefore important to find efficient and accurate ways to separate it from debris in the area of deployment. This research demonstrates that the presence of steel in dissolved samples shows no appreciable interference with extraction chromatographic separations. Instead, it indicates that the separation could actually be improved by the presence of the steel constituents. [ABSTRACT FROM AUTHOR]

Thorium is an unusual radionuclide in laboratory intercomparisons and when it appears, the number of participants providing results is small and the results provided are not reliable enough. These facts are particularly significant for environmental and industrial solid samples. In this work, we analyze the most suitable method for Th determination by alpha-particle spectrometry, evaluating technical points and also considering cost, time and chemical reagents used. This work is divided in two parts. This part 1 deals with the analysis of different radiochemical separation methods for Th isotopes. [ABSTRACT FROM AUTHOR]

The majority of radiochemical separation schemes available have been developed for environmental samples that are not necessarily representative of those found in an urban environment. However, it is much more likely that an incident involving a radiation dispersal device (RDD) would occur in an urban or metropolitan area. It is unclear if the currently available separation schemes would be effective in such an event. It is therefore important to determine if the current schemes would be adequate, or to find efficient and accurate ways to separate radiological material from urban debris. One important radiological material that could be used in an RDD is Sr. Part I of this work investigated the effects steel had on strontium separations, while this work investigates cement and concrete. This research demonstrates that the individual elements present in a cement and concrete sample matrix can give rise to significant interferences with extraction chromatographic separations. Solutions of the constituents mixed in representative ratios; however, show fewer problems. [ABSTRACT FROM AUTHOR]

An analytical method was established for the determination of plutonium isotopes in sediment and soil samples based on sector field ICP-MS and an improved anion-exchange procedure for Pu separation. A high U decontamination factor of 4 × 10 was obtained and the chemical yield of Pu was improved to be about 65%. The developed method was validated by the analysis of four soil and sediment reference materials, the analytical results agreed well with the certified and information values. We further applied this method to determine Pu isotopes in actual sediment and soil core samples for Pu source identification. [ABSTRACT FROM AUTHOR]

A method of separating beta spectra into each radionuclide spectrum was proposed in this study. Based on mathematical curve fits, the spectrum of each radionuclide was defined by using the maximum energy information and process to separate specific spectra from the whole spectrum. Information on P, Y, and Rh radionuclides from the International Commission on Radiation Units and Measurements was used for applying the proposed method. A relative error of less than 2% was achieved with the application of the method. [ABSTRACT FROM AUTHOR]

A separation method of Mo from Nb, Zr, and the matrix elements of rubble waste was modified to determine the content of Mo in metal waste. A separation scheme to treat 1 g of metal waste was established by optimizing the amount of ascorbic acid, the rinsing solution, and repeating of the procedure. A thin-layer source was prepared using direct drop deposition and evaporation to measure Mo content. Finally, Mo content in the metal waste generated at the Japan Power Demonstration Reactor was analyzed using the developed method. [ABSTRACT FROM AUTHOR]

This paper reports an analytical method for rapid sequential separation of Po and actinides (Pu, Am and U) in air filter samples. An extraction chromatographic column TEVA + TRU was used in the separation of Po and actinides from the filter matrix, followed by its determination using alpha spectrometry. TEVA resin is widely used in the separation of plutonium and neptunium from the environmental samples, in this work potential application of TEVA in the sequential separation of Po and plutonium from filter matrix has been evaluated. This new method is simple, robust and can be performed formed in a day. [ABSTRACT FROM AUTHOR]

A separation of Po, Bi and Pb using AG 50Wx8 and AG MP 50 cation exchange resins in an HCl medium was developed. A procedure in which Po(IV) elutes first in 0.2 M HCl, followed by Bi(III) in 0.4 M HCl and finally Pb(II) in 2 M HCl was established. The separation using AG 50Wx8 provides a much better elution profile than that of AG MP 50 with no overlap between the elution bands. This separation has the potential to be used as an isotope generator for producing Po from Pb. [ABSTRACT FROM AUTHOR]

The rapid measurement of Ra in steel samples is very important in the event of a radiological emergency. Ra ( T = 1600 y) is a natural radionuclide present in the environment and a highly toxic alpha-emitter. Due to its long life and tendency to concentrate in bones, Ra ingestion or inhalation can lead to significant committed dose to individuals. A new method for the determination of Ra in steel samples has been developed at the Savannah River Environmental Laboratory. The new method employs a rugged acid digestion method that includes hydrofluoric acid, followed by a single precipitation step to rapidly preconcentrate the radium and remove most of the dissolved steel sample matrix. Radium is then separated using a combination of cation exchange and extraction chromatography, and Ra is measured by alpha spectrometry. This approach has a sample preparation time of ~ 8 h for steel samples, has a very high tracer yield (> 88%), and removes interferences effectively. A Ba yield tracer is used so that samples can be counted immediately following the separation method, avoiding lengthy ingrowth times that are required in other methods. [ABSTRACT FROM AUTHOR]

A number of impregnated sorbents based on di-( tert-butyldibenzo)-18-crown-6 (DTBDB18C6) and di-( tert-butylcyclohexano)-18-crown-6 (DTBDCH18C6) was obtained using different diluents for the crown ether and the styrene-divinylbenzene support. Sorption characteristics of the sorbents in relation to cobalt ions and Co radionuclide in thiocyanate solutions were determined within the range of pH of 1-7. It was found the DTBDB18C6-based sorbents were the most efficient for the sorption of cobalt macro quantities whereas the DTBDCH18C6-based ones for the sorption of Co radionuclide, using nitrobenzene as a diluent. A possibility was shown of the complete cobalt desorption by hydrochloric and nitric acid solutions with the concentration of 0.1-1.0 mol L. [ABSTRACT FROM AUTHOR]

A new protocol for the rapid quantification of actinides (U, Th, Pu, Am and Np) and Sr in soil samples has been developed. This protocol includes three steps: (1) an alkaline fusion digestion, (2) an automated separation and (3) an on-line ICP-MS measurement. Eluted fraction containing strontium can be collected to quantify radiostrontium using off-line radiometric techniques. After an optimization of the separation protocol using a design of experiments, excellent figures of merit are achieved. These figures include high chemical recoveries (>80%) for all radionuclides investigated, low quantification limits for actinides and concordance between measured activities and reference values. This protocol allows the automated treatment (sample dissolution included) of up to 10 samples in 24 h. [ABSTRACT FROM AUTHOR]

The separation of americium(III) from europium(III) was achieved utilizing a bis-2,6-(5,6,7,8-tetrahydro-5,9,9-trimethyl-5,8-methano-1,2,4-benzotriazin-3-yl) pyridine (CA-BTP) chromatographic resin. The extraction chromatographic materials were prepared using various concentrations of CA-BTP. This new, hydrolytically stable extractant was impregnated on an inert polymeric support at 40% loading. The uptake of Am(III) and Eu(III) by this material from 0.1 to 4.0 M aqueous HNO solutions was measured. The resulting dry weight distribution ratios, D , indicated a strong preference for Am(III) with little affinity for Eu(III). These results are similar to recently reported solvent extraction studies indicating a maximum uptake of Am(III) in the 0.5-1.0 M HNO range. The resin preparation, performance, and characterization of the Am/Eu separation are reported herein. [ABSTRACT FROM AUTHOR]

Flotation tailings from copper production are deposits of copper and other valuable metals, such as Mo, V and U. New hydrometallurgical technologies are more economical and open up new possibilities for metal recovery. This work presents results of the study on the extraction of copper by mixed extractant consisting p-toluidine dissolved in toluene. The possibility of simultaneous liquid-liquid extraction of molybdenum and vanadium was examined. D2EHPA solutions was used as extractant, and recovery of individual elements compared for the representative samples of ore and copper flotation tailings. Radiometric methods were applied for process optimization. [ABSTRACT FROM AUTHOR]

We evaluated uranium bioleaching from low-grade, granite-type uranium ore using mixed acidophilic microbes from uranium mine leachate. A 4854-ton plant-scale heap bioleaching process achieved sustained leaching with a uranium leaching efficiency of 88.3% using a pH of 1.0-2.0 and an Fe dosage of 3.0-5.5 g/L. Acid consumption amounted to 25.8 g HSO kg ore. Uranium bioleaching follows a diffusion-controlled kinetic model with a correlation coefficient of 0.9136. Almost all uranium was dissolved in aqueous solution, except those encapsulated in quartz particles. Therefore, heap bioleaching by mixed acidophilic microbes enables efficient, economical, large-scale recovery of uranium from low-grade ores. [ABSTRACT FROM AUTHOR]

A procedure by using TEVA resin to preconcentrate and separate Tc in groundwater was developed. Tc was efficiently preconcentrated from 5000 mL of water sample at a flow rate of 50 mL min by using a 2 mL of TEVA resin column based on the high affinity of TcO with TEVA resin in 0.1 mol L HCl media. Tc was further purified by using another 2 mL of TEVA resin column and determined by ICP-MS. The developed procedure was validated by the spiked samples and applied to Tc analysis in monitor well water samples. [ABSTRACT FROM AUTHOR]

An adsorption-coagulation-microfiltration (A-C-MF) hybrid process using copper ferrocyanide (CuFC) as the adsorbent was developed in this study for the removal of cesium from water. The effect of coagulant on cesium removal by CuFC adsorption was investigated. A simpler calculation method for determining the CuFC dosage was established based on the Freundlich adsorption isotherms. Although the volume of treated water was 1.32 times higher for the A-C-MF process than the adsorption-microfiltration (A-MF) process, the cake layer and membrane pore resistances in the former were both lower than those in the latter due to the coagulation process. [ABSTRACT FROM AUTHOR]

A LabVIEW-based software for the control of the fully automated multi-sequential flow injection analysis Lab-on-Valve (MSFIA-LOV) platform AutoRAD performing radiochemical analysis is described. The analytical platform interfaces an Arduino-based device triggering multiple detectors providing a flexible and fit for purpose choice of detection systems. The different analytical devices are interfaced to the PC running LabVIEWVI software using USB and RS232 interfaces, both for sending commands and receiving confirmation or error responses. The AUTORAD platform has been successfully applied for the chemical separation and determination of Sr, an important fission product pertinent to nuclear waste. [ABSTRACT FROM AUTHOR]

For separating americium from lanthanides, a macroporous silica-based polymeric adsorbent (HDEHP/SiO-P) was prepared in this study. Using this adsorbent, the adsorption characteristics of Am(III) and lanthanides were investigated in HNO solutions. The obtained results displayed that heavy lanthanides had greater adsorption towards HDEHP/SiO-P than Ce(III) and Am(III). The adsorption behavior of Am(III) was found to be similar with Ce(III) in 0.1-0.3 M HNO solutions. The adsorption kinetics of Gd(III) and Ce(III) reached equilibrium within 2 h and fitted well with the pseudo-second-order kinetic model. [ABSTRACT FROM AUTHOR]