Study of an X-ray fluorescence thin film method for the determination of uranium in low activity solutions

International Nuclear Information System (INIS)

Diaz-Guerra, J. P.

1980-01-01

The application of the X-ray fluorescence thin film technique to the uranium determination in nitric solutions for a concentration range from 1 g/l to 100 g/l and activity levels under 5 mCi/ml is studied. The most suited excitation and measurement conditions are also studied and the uranium matrix effect correction, which is performed through the double dilution, α U U interaction coefficient calculation and internal standard methods, is discussed. The specimen preparation is satisfactorily accomplished by using P.V.C. filters fixed on aluminium supports. (Author) 18 refs

Determination of uranium in urine by fluorometry

International Nuclear Information System (INIS)

Afsar, M.; Aziz, A.; Mubarak, M.A.

1978-01-01

The report describes fluorometric determination of traces of uranium in the urine of mine workers and persons handling uranium. After preliminary treatment uranium is extracted by solvent extraction with TBP:MIBK mixtures. An aliquot of the extracted solution is fused with high carbonate flux at 650 0 C in platinum dishes. The fluorescence of fused sample is measured using a fluorometer. Various fusion parameters are discussed. The procedure for the operation and calibration of fluorometer is also described

Relative probabilities of the uranium isotopes for thorium x-ray emission and fluorescence of uranium x-rays

International Nuclear Information System (INIS)

Parker, J.L.

1991-01-01

Both thorium x-rays from decaying uranium isotopes and self-fluoresced uranium x-rays are prominent in high-resolution gamma-ray spectra of uranium-bearing materials. Useful application of the information carried by those x-rays has been curtailed because the probabilities of the uranium isotopes for thorium x-ray emission and for uranium x-ray fluorescence have not been known. By analyzing enrichment-meter geometry spectra from uranium oxide standards whose enrichments ranged from 0.7% to 91%, relative values, primarily, have been obtained for the probabilities of both processes. Thorium x-ray emission is very heavily dominated by 235 U. In all ordinarily occurring uranium isotopic distributions, thorium x-rays may be used as a valid 235 U signature. The probability for a thorium K α1 x-ray to be emitted in the decay of a 235 U atom is 0.048 ±0.002. In infinitely thick uranium oxide materials, the relative ratios of effectiveness for self-fluorescence, on a per unit mass basis, are approximately 234 U : 235 U : 236 U : 238 U = 1.13 : 1.00 : 0.52 : 0.028. on a per decay basis, the approximate ratios are 0.00039 : 1.00 : 0.017 : 0.18. These results imply that, contrary to what has often been stated, gamma rays are far more important than alpha particles in the self-fluorescence of uranium. Because of the importance of gamma-ray self-fluorescence, the uranium x-ray yield will be somewhat influenced by the size, shape, and composition of the materials. 4 refs., 1 fig

Laser-fluorescence determination of trace uranium in hot spring water, geothermal water and tap water in Xi'an Lishan region

International Nuclear Information System (INIS)

Ma Wenyan; Zhou Chunlin; Han Feng; Di Yuming

2002-01-01

Using the Laser-Fluorescence technique, an investigation was made, adopting the standard mix method, on trace uranium concentrations in hot spring water and geothermal water from Lishan region, and in tap water from some major cities in Shanxi province. Totally 40 samples from 27 sites were investigated. Measurement showed that the tap water contains around 10 -6 g/L of uranium, whose concentrations in both hot spring water and geothermal water are 10 -5 g/L. Most of samples are at normal radioactive background level, some higher contents were determined in a few samples

Laser fluorescence spectroscopy of sputtered uranium atoms

International Nuclear Information System (INIS)

Wright, R.B.; Pellin, M.J.; Gruen, D.M.; Young, C.E.

1979-01-01

Laser induced fluorescence (LIF) spectroscopy was used to study the sputtering of 99.8% 238 U metal foil when bombarded by normally incident 500 to 3000 eV Ne + , Ar + , Kr + , and O 2 + . A three-level atom model of the LIF processes is developed to interpret the observed fluorescent emission from the sputtered species. The model shows that close attention must be paid to the conditions under which the experiment is carried out as well as to the details of the collision cascade theory of sputtering. Rigorous analysis shows that when properly applied, LIF can be used to investigate the predictions of sputtering theory as regards energy distributions of sputtered particles and for the determination of sputtering yields. The possibility that thermal emission may occur during sputtering can also be tested using the proposed model. It is shown that the velocity distribution (either the number density or flux density distribution, depending upon the experimental conditions) of the sputtered particles can be determined using the LIF technique and that this information can be used to obtain a description of the basic sputtering mechanisms. These matters are discussed using the U-atom fluorescence measurements as a basis. The relative sputtering yields for various incident ions on uranium were also measured for the first time using the LIF technique. A surprisingly high fraction of the sputtered uranium atoms were found to occupy the low lying metastable energy levels of U(I). The population of the sputtered metastable atoms were found approximately to obey a Boltzman distribution with an effective temperature of 920 +- 100 0 K. 41 references

Major constituent quantitative determination in uranium alloys by coupled plasma atomic emission spectrometry and X ray fluorescence wavelength dispersive spectrometry

International Nuclear Information System (INIS)

Oliveira, Luis Claudio de; Silva, Adriana Mascarenhas Martins da; Gomide, Ricardo Goncalves; Silva, Ieda de Souza

2013-01-01

A wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometric method for determination of major constituents elements (Zr, Nb, Mo) in Uranium/Zirconium/Niobium and Uranium/Molybdenum alloy samples were developed. The methods use samples taken in the form of chips that were dissolved in hot nitric acid and precipitate particles melted with lithium tetraborate and dissolved in hot nitric acid and finally analyzed as a solution. Studies on the determination by inductively coupled plasma optic emission spectrometry (ICP OES) using matched matrix in calibration curve were developed. The same samples solution were analyzed in both methods. The limits of detection (LOD), linearity of the calibrations curves, recovery study, accuracy and precision of the both techniques were carried out. The results were compared. (author)

Determination of trace uranium by resonance fluorescence method coupled with photo-catalytic technology and dual cloud point extraction.

Science.gov (United States)

Li, Jiekang; Li, Guirong; Han, Qian

2016-12-05

In this paper, two kinds of salophens (Sal) with different solubilities, Sal1 and Sal2, have been respectively synthesized, and they all can combine with uranyl to form stable complexes: [UO2(2+)-Sal1] and [UO2(2+)-Sal2]. Among them, [UO2(2+)-Sal1] was used as ligand to extract uranium in complex samples by dual cloud point extraction (dCPE), and [UO2(2+)-Sal2] was used as catalyst for the determination of uranium by photocatalytic resonance fluorescence (RF) method. The photocatalytic characteristic of [UO2(2+)-Sal2] on the oxidized pyronine Y (PRY) by potassium bromate which leads to the decrease of RF intensity of PRY were studied. The reduced value of RF intensity of reaction system (ΔF) is in proportional to the concentration of uranium (c), and a novel photo-catalytic RF method was developed for the determination of trace uranium (VI) after dCPE. The combination of photo-catalytic RF techniques and dCPE procedure endows the presented methods with enhanced sensitivity and selectivity. Under optimal conditions, the linear calibration curves range for 0.067 to 6.57ngmL(-1), the linear regression equation was ΔF=438.0 c (ngmL(-1))+175.6 with the correlation coefficient r=0.9981. The limit of detection was 0.066ngmL(-1). The proposed method was successfully applied for the separation and determination of uranium in real samples with the recoveries of 95.0-103.5%. The mechanisms of the indicator reaction and dCPE are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Trace-element analysis of uranium ores by x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Coetzee, P.P.; De Villiers, W.v Z.

1985-01-01

The determination of seventeen trace elements (As, Ba, Co, Cr, Cu, Mo, Nb, Ni, Pb, Sr, Th, U, V, Y, Zn, and Zr) in uranium ores by x-ray fluorescence spectrometry was investigated. For the elements with analyte lines in the vicinity of the U-L lines, large overlap corrections were necessary and only a few completely interference-free background positions were available. Consequently, the Feather and Willis method was used for determining the background intensity at the peak positions as well as mass absorption coefficients. As a result of the presence of the U-L absorption edges, both primary and secondary mass absorption coefficients had to be used for matrix corrections. Furthermore, it was observed that the background intensity in the region of the uranium lines increased with increasing uranium content of the sample, instead of the expected decrease due to the increasing mass absorption coefficient. This was attributed to the scattering of uranium lines in the spectrometer chamber. A method was developed to correct the measured intensities for this effect. The contribution from the scattering of uranium lines to the measured intensity at the various 20 positions was determined on samples with different uranium concentrations and for which the mass absorption coefficients and concentrations of the various elements were known

Uranium concentrate analysis by X-ray fluorescence spectroscopy

International Nuclear Information System (INIS)

Diaz-Guerra, J.P.; Bayon, A.; Roca, R.

1978-01-01

The determination of As, Ca, Fe, Mo, P, S, Si. Th, V and U in uranium concentrates by X-ray fluorescence spectroscopy has been studied. As and U are determined in nitric solutions and for the rest of elements analysis is performed by a bead fusion technique using Li 2 B 4 O 7 and Li 2 CO 3 as fluxes. Although the uranium matrix minimizes the absorption and enhancement effects, because of the content variations of this element it is advisable to operate at a constant level of U 3 O 8 . Despite the high matrix absorption and the large dilution of the samples, sensitivity and speed are found to be satisfactory as the result of the use of a high sensitivity automatic spectrometer. The spectral interferences of Mo on S and P, and of Pb on As have been particularly considered. (author) [es

Determination of trace metals in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Salvador, V.L.R.; Imakuma, K.

1988-04-01

A method is described for the simultaneous determination of low concentrations of Ca, Cr, Cu, Fe, Mn and Ni in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry, without the use of chemical treatment. The lower limits of detection range from 2 μg g -1 for nickel and manganese to 5 μg g -1 for copper. Samples are prepared in the form of double-layer pellets with boric acid as a binding agent. Standards are prepared in a U 3 O 8 matrix, which is more chemically stable than UO 2 and has similar matrix behaviour. The correlation coefficients for calibration curves are better than 0.999. Erros range from 2.4 % for chromium to 6.8 % for nickel. (author) [pt

Determination of uranium traces in nuclear cans of nuclear reactors

International Nuclear Information System (INIS)

Acosta L, E.; Benavides M, A.M.; Sanchez P, L.

1996-01-01

To quantify the uranium content as impurity can be found in zirconium alloys and zircaloy, utilized to construct the sheaths containing fuels of the reactors of nuclear plants. The determination by fluorescence spectroscopy was employed as quality control measurement, at once the corrosion resistance, diminish with the increase of the uranium content in the alloys. (Author)

Uranium speciation in biofilms studies by laser fluorescence techniques

International Nuclear Information System (INIS)

Arnold, Thuro; Grossmann, Kay; Baumann, Nils

2010-01-01

Biofilms may immobilize toxic heavy metals in the environment and thereby influence their migration behaviour. The mechanisms of these processes are currently not understood, because the complexity of such biofilms creates many discrete geochemical microenvironments which may differ from the surrounding bulk solution in their bacterial diversity, their prevailing geochemical properties, e.g. pH and dissolved oxygen concentration, the presence of organic molecules, e.g. metabolites, and many more, all of which may affect metal speciation. To obtain such information, which is necessary for performance assessment studies or the development of new cost-effective strategies for cleaning waste waters, it is very important to develop new non-invasive methods applicable to study the interactions of metals within biofilm systems. Laser fluorescence techniques have some superior features, above all very high sensitivity for fluorescent heavy metals. An approach combining confocal laser scanning microscopy and laser-induced fluorescence spectroscopy for study of the interactions of biofilms with uranium is presented. It was found that coupling these techniques furnishes a promising tool for in-situ non-invasive study of fluorescent heavy metals within biofilm systems. Information on uranium speciation and uranium redox states can be obtained.

Fluorometric determination of uranium in natural waters

International Nuclear Information System (INIS)

Hues, A.D.; Henicksman, A.L.; Ashley, W.H.; Romero, D.

1977-03-01

Duplicate 200-μl aliquots of the water samples, as received, are transferred by means of Eppendorf pipettors onto 0.4-g pellets of 2 percent LiF-98 percent NaF flux, contained in platinum dishes. The pellets are dried under heat lamps; then fused over special propane burners. The fused pellets are transferred to a Galvanek-Morrison fluorometer, where they are excited with ultraviolet radiation and the fluorescence is measured. The uranium is calculated by comparing the measured fluorescence with that of other pellets, carried through the same procedure, which contain aliquots of standard uranium solutions. The sensitivity of the method is about 0.2 ppB of uranium, and the precision is approximately 15 relative percent in the 0.2- to 10-ppB uranium concentration range

Preparation of uranium standard solutions for x-ray fluorescence analysis

International Nuclear Information System (INIS)

Wong, C.M.; Cate, J.L.; Pickles, W.L.

1978-03-01

A method has been developed for gravimetrically preparing uranium nitrate standards with an estimated mean error of 0.1% (1 sigma) and a maximum error of 0.2% (1 sigma) for the total uranium weight. Two source materials, depleted uranium dioxide powder and NBS Standard Reference Material 960 uranium metal, were used to prepare stock solutions. The NBS metal proved to be superior because of the small but inherent uncertainty in the stoichiometry of the uranium oxide. These solutions were used to prepare standards in a freeze-dried configuration suitable for x-ray fluorescence analysis. Both gravimetric and freeze-drying techniques are presented. Volumetric preparation was found to be unsatisfactory for 0.1% precision for the sample size of interest. One of the primary considerations in preparing uranium standards for x-ray fluorescence analysis is the development of a technique for dispensing a 50-μl aliquot of a standard solution with a precision of 0.1% and an accuracy of 0.1%. The method developed corrects for variation in aliquoting and for evaporation loss during weighing. Two sets, each containing 50 standards have been produced. One set has been retained by LLL and one set retained by the Savannah River project

EDXRF and TXRF determination of gallium in gallium-uranium matrix

International Nuclear Information System (INIS)

Misra, N.L.; Sanjay Kumar, S.; Dhara, Sangita; Aggarwal, S.K.; Venugopal, V.

2009-01-01

Energy Dispersive X-Ray Fluorescence (EDXRF) and Total Reflection X-ray Fluorescence (TXRF) methods for determination of Gallium in Gallium-Uranium matrix have been developed. For EDXRF determinations, 200 μL of standards/samples mixed with internal standard copper were dispersed on 30 mm diameter absorbent sheet so that it behaves like a thin film of the sample. The Gallium amounts in samples were determined from their EDXRF spectra using a calibration plot. For TXRF determinations, samples were taken on flat polished quartz sample supports and Gallium was determined in conventional way. For EDXRF and TXRF determinations, the average precision and accuracy obtained for Ga determinations was better than 3% (1σ). (author)

Laser induced uranium fluorescence as an analytical method

International Nuclear Information System (INIS)

Krutman, I.

1985-01-01

A laser induced fluorescence system was developed to measure uranium trace level amounts in aqueous solution with reliable and simple materials and electronics. A nitrogen pulsed laser was built with the storage energy capacitor directly coupled to laser tube electrodes as a transmission line device. This laser operated at 3Hz repetition rate with peak intensity around 21 Kw and temporal width of 4.5 x 10 -9 s. A sample compartment made of rigid PVC and a photomultiplier housing of aluminium were constructed and assembled forming a single integrated device. As a result of this prototype system we made several analytical measurements with U dissolved in nitric acid to obtain a calibration curve. We obtained a straight line from a plot of U concentration versus fluorescence intensity fitted by a least square method that produced a regression coefficient of 0.994. The lower limit of U determination was 30 ppb -+ 3.5%. (Author) [pt

Use of X-ray fluorescence in a laboratory for the treatment of uranium ores (1960); Utilisation de la fluorescence X dans un laboratoire de traitements de minerais d'uranium (1960)

Energy Technology Data Exchange (ETDEWEB)

Guillet, H [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

A brief description will be given of some aspects of the experience gained over a year during which X-ray fluorescence was used at the laboratory or the present Section Autonome d'Etudes, Recherches et Applications Chimiques of the Commissariat a l'Energie Atomique. First part. - Reproducibility of results. A standard is tested daily. The observations made during the months from december 58 to may 59 are described. Second part. - Study of two chemical treatment processes using X-ray fluorescence, without development of a detailed method of analysis. a) Acid lixiviation of uranium ores. The residues are analysed by X-Ray fluorescence directly in powder form. b) Fixation and elution of vanadium on ion exchange resin. Third part. - Method for the quantitative analysis of the uranium in solution. A method of analysis of the uranium in solution is described for concentrations between 30 {gamma}/cc and 600 {gamma}/cc, whatever may be the impurities present (except for the elements between Zn and Rb, and between Ir and Pa). (author) [French] On se propose de decrire brievement quelques aspects de l'experience acquise en une annee d'utilisation de fluorescence X au laboratoire de l'actuelle Section Autonome d'Etudes, Recherches et Applications chimiques du Commissariat a l'Energie Atomique. Premiere Partie. - Etude de la reproductibilite des resultats. Un standard est teste quotidiennement. On donne la description des observations faites durant les mois de decembre 58 a mai 59. Deuxieme Partie. - Etude de deux procedes de traitements chimiques au moyen de la fluorescence X sans mise au point de methode d'analyse elaboree. a) Liziviation acide de minerais d'uranium. Les residus sont analyses par fluorescence X directement sous forme pulverulente. b) Fixation et elution du vanadium sur resine echangeuse d'ions. Troisieme partie. - Methode d'analyse quantitative de l'uranium en solution. On decrit une methode d'analyse de l'uranium en solution pour des concentrations allant

Determination of niobium, tantalum, and uranium in tantalite-columbite ores by X-ray fluorescence spectrometry; Application de la spectrometrie de fluorescence de rayos X a la determination de niobium, tantale et uranium dans niobiotantalites

Energy Technology Data Exchange (ETDEWEB)

Latorre, O; Bermudez Polonio, J

1964-07-01

A simple and quick procedure is carried out to determine niobium, tantalum and uranium employing the internal standard technique; zinc as internal standard for tantalum and molybdenum for niobium and uranium were selected. Some inter element effects were studied and the ratios. (Author)

Transition probability of the 5971-A line in neutral uranium from collision-induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Gagne, J.M.; Mongeau, B.; Demers, Y.; Pianarosa, P.

1981-01-01

From collision-induced fluorescence spectroscopy measurements, we have determined the transition probability Aof the 5971-A transition in neutral uranium. Our value, A 5971 = (5.9 +- 1.8) x 10 5 sec -1 , is, within experimental error, in good agreement with the previous determination of Corliss, A 5971 = (7.3 +- 3.0) x 10 5 sec -1 [J. Res. Nat. Bur. Stand. Sect. A 80,1 (1976)

Characterization of uranium in bituminized radioactive waste drums by self-induced X-ray fluorescence

International Nuclear Information System (INIS)

Pin, Patrick; Perot, Bertrand

2013-06-01

This paper reports the experimental qualification of an original uranium characterization method based on fluorescence X rays induced by the spontaneous gamma emission of bituminized radioactive waste drums. The main 661.7 keV gamma ray following the 137 Cs decay produces by Compton scattering in the bituminized matrix an intense photon continuum around 100 keV, i.e. in the uranium X-ray fluorescence region. 'Self-induced' X-rays produced without using an external source allow a quantitative assessment of uranium as 137 Cs and uranium are homogeneously mixed and distributed in the bituminized matrix. The paper presents the experimental qualification of the method with real waste drums, showing a detection limit well below 1 kg of uranium in 20 min acquisitions while the usual gamma rays of 235 U (185 keV) or 238 U (1001 keV of 234m Pa in the radioactive decay chain) are not detected. The relative uncertainty on the uranium mass assessed by self-induced X-ray fluorescence (SXRF) is about 50%, with a 95% confidence level, taking into account the correction of photon attenuation in the waste matrix. This last indeed contains high atomic numbers elements like uranium, but also barium, in quantities which are not known for each drum. Attenuation is estimated thanks to the peak-to-Compton ratio to limit the corresponding uncertainty. The SXRF uranium masses measured in the real drums are in good agreement with long gamma-ray spectroscopy measurements (1001 keV peak) or with radiochemical analyses. (authors)

Thin film-XRF determination of uranium following thin-film solid phase extraction

Energy Technology Data Exchange (ETDEWEB)

Hassan, Jalal, E-mail: jalalhassan@ut.ac.ir [Department of Toxicology, Faculty of Veterinary Medicine, University of Tehran (Iran, Islamic Republic of); Hosseini, Seyed M.; Mozaffari, Shahla [Department of Chemistry, Payame Noor University, Tehran (Iran, Islamic Republic of); Jahanparast, Babak; Karbasi, Mohammad H. [Iranian Mineral Processing Research Center, Ministry of Industry and Mineral, Karaj (Iran, Islamic Republic of)

2014-07-01

A sensitive method based on the preconcentration of uranium on modified filter paper (thin film) has been developed to determinate this element in water and soil samples by wavelength dispersive X-ray fluorescence. Uranium (VI) extraction from nitric acid medium by trioctyl phosphine (TOPO) from 100 mL of sample was carried out. The effects of nitric acid concentration, TOPO concentration and sample breakthrough on uranium extraction were investigated in this study. The proposed method provided good linearity from 7 to 1000 μg and the limit of detection (LOD), based on a signal-to noise ratio (S/N) of 3, was 2.5 μg. (author)

Spectrophotometric determination of trace uranium in phosphate ore samples from kurum and uro areas, Nuba mountains, Sudan

International Nuclear Information System (INIS)

Mohamed, A. A.; Ali, A. H.; Altayeb, M. A. H.

2004-01-01

A method was proposed for the spectrophotometric determination of uranium content in phosphate ores. the method is based on the use of nitrogen (v) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 425 nm. The procedure was used for the determination of trace uranium content in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in Sudan. X-ray fluorescence technique was employed for the assessment of the method used. The spectrophotometric method results show a high similarity with those obtained by XRF technique. This agreement indicates that the procedure proposed here has been successfully applied for the determination of uranium in phosphate ores. (Author)

Determination of uranium, thorium and potassium contents of rock samples in Yemen

International Nuclear Information System (INIS)

Abdulrahman Abdul-Hadi; Wedad Al-Qadhi; Enayat El-Zeen

2011-01-01

Uranium, thorium and potassium contents in 16 different rock samples from various sites in Republic of Yemen were determined using three different techniques of analysis: γ-spectrometry, Instrumental neutron activation analyses (INAA) and X-ray fluorescence (XRF). The concentration range for thorium, uranium and potassium were found to be from 9,810 ± 272 to 3.6 ± 1.3 ppm, 1,072 ± 40 to 1.2 ± 0.7 ppm and 11 ± 1 to 0.26 ± 0.05%, respectively. (author)

Fluorescence spectral imaging as a tool for locating uranium deposited on surfaces - 16089

International Nuclear Information System (INIS)

Monts, David L.; Wang, Guangjun; Su, Yi; Jang, Ping-Rey; Waggoner, Charles A.

2009-01-01

In the environment, metallic uranium readily oxidizes to form uranium compounds that contain the uranyl (UO 2 +2 ) moiety. For more than a hundred and fifty years, it has been known that when illuminated with ultraviolet (UV) light, uranyl compounds exhibit characteristic fluorescence in the visible region (450-650 nm). We report our efforts to develop a transportable, quantitative Fluorescence Spectral Imaging (FSI) system as a tool for locating and quantifying uranyl compounds dispersed in soils and on other surfaces. A project is underway to develop a set of sensors to locate expended depleted uranium (DU) rounds and to process soil and debris to recover the material from domestic firing ranges. The FSI system can also be utilized to monitor excavation of DU munitions and separation of uranyl compounds from soils. FSI images are acquired by illuminating a surface with a UV light and using a narrow band pass filter on a camera, recording an image of the resulting fluorescence. The FSI image provides both spatial and spectral information. The FSI system is described and its performance characterized using field samples. (authors)

Uranium separation and concentration from ground waters on TIO-PAN sorbent and determination by TRLFS

International Nuclear Information System (INIS)

Raindl, Jakub; Spendlikova, Irena; Nemec, Mojmir; Sebesta, Ferdinand; Zavadilova, Alena; John, Jan

2011-01-01

A new sorbent, viz. hydrated titanium dioxide embedded on a polyacrylonitrile solid support, was tested for the title purpose. Uranium so separated was eluted with 0.1M HCl. Uranium concentrations before and after sorption/elution were determined by time resolved laser induced fluorescence spectroscopy (TRLFS ). The study is aimed at the development of a method suitable for sample preparation for Accelerator Mass Spectrometry (AMS) measurements and at determining the 236 U/U ratio (in cooperation with the VERA facility at the University of Vienna, Austria)

Spatially resolved analyses of uranium species using a coupled system made up of confocal laser-scanning microscopy (CLSM) and laser induced fluorescence spectroscopy (LIFS)

International Nuclear Information System (INIS)

Brockmann, S.; Grossmann, K.; Arnold, T.

2014-01-01

The fluorescent properties of uranium when excited by UV light are used increasingly for spectroscope analyses of uranium species within watery samples. Here, alongside the fluorescent properties of the hexavalent oxidation phases, the tetra and pentavalent oxidation phases also play an increasingly important role. The detection of fluorescent emission spectrums on solid and biological samples using (time-resolved) laser induced fluorescence spectroscopy (TRLFS or LIFS respectively) has, however, the disadvantage that no statements regarding the spatial localisation of the uranium can be made. However, particularly in complex, biological samples, such statements on the localisation of the uranium enrichment in the sample are desired, in order to e.g. be able to distinguish between intra and extra-cellular uranium bonds. The fluorescent properties of uranium (VI) compounds and minerals can also be used to detect their localisation within complex samples. So the application of fluorescent microscopic methods represents one possibility to localise and visualise uranium precipitates and enrichments in biological samples, such as biofilms or cells. The confocal laser-scanning microscopy (CLSM) is especially well suited to this purpose. Coupling confocal laser-scanning microscopy (CLSM) with laser induced fluorescence spectroscopy (LIFS) makes it possible to localise and visualise fluorescent signals spatially and three-dimensionally, while at the same time being able to detect spatially resolved, fluorescent-spectroscopic data. This technology is characterised by relatively low detection limits from up to 1.10 -6 M for uranium (VI) compounds within the confocal volume. (orig.)

Speciation of bioaccumulated uranium(VI) by Euglena mutabilis cells obtained by laser fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Brockmann, Sina; Bernhard, Gert [Technical Univ. Dresden (Germany). Radiochemistry; Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V., Dresden (Germany). Inst. of Resource Ecology; Arnold, Thuro [Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V., Dresden (Germany). Inst. of Resource Ecology

2014-07-01

The ability of Euglena mutabilis cells - a unicellular protozoan with a flexible pellicle, which is typically found in acid mine drainage (AMD) environments - to bioaccumulate uranium under acid conditions was studied in batch sorption experiments at pH 3 and 4 using Na{sub 2}SO{sub 4} and NaClO{sub 4} as background media. It was found that axenic cultures of Euglena mutabilis Schmitz were able to bioaccumulate in 5 days 94.9 to 99.2% of uranium from a 1 x 10{sup -5} mol/L uranium solution in perchlorate medium and 95.1 to 95.9% in sodium sulfate medium, respectively. The speciation of uranium in solution and uranium bioaccumulated by Euglena mutabilis cells, were studied by laser induced fluorescence spectroscopy (LIFS). The LIFS investigations showed that the uranium speciation in the NaClO{sub 4} systems was dominated by free uranyl(VI) species and that the UO{sub 2}SO{sub 4} species was dominating in the Na{sub 2}SO{sub 4} medium. Fluorescence spectra of the bioaccumulated uranium revealed that aqueous uranium binds to carboxylic and/or (organo)phosphate groups located on the euglenid pellicle or inside the Euglena mutabilis cells. Reduced uranium immobilization rates of 0.93-1.43 mg uranium per g Euglena mutabilis biomass were observed in similar experiments, using sterile filtrated AMD waters containing, 4.4 x 10{sup -5} mol/L uranium. These lower rates were attributed to competition with other cations for available sorption sites. Additional LIFS measurements, however, showed that the speciation of the bioaccumulated uranium by the Euglena mutabilis cells was found to be identical with the uranium speciation found in the bioaccumulation experiments carried out in Na{sub 2}SO{sub 4} and NaClO{sub 4} media. The results indicate that Euglena mutabilis has the potential to immobilize aqueous uranium under acid condition and thus may be used in future as promising agent for immobilizing uranium in low pH waste water environments. (orig.)

Speciation of bioaccumulated uranium(VI) by Euglena mutabilis cells obtained by laser fluorescence spectroscopy

International Nuclear Information System (INIS)

Brockmann, Sina; Bernhard, Gert; Helmholtz-Zentrum Dresden-Rossendorf; Arnold, Thuro

2014-01-01

The ability of Euglena mutabilis cells - a unicellular protozoan with a flexible pellicle, which is typically found in acid mine drainage (AMD) environments - to bioaccumulate uranium under acid conditions was studied in batch sorption experiments at pH 3 and 4 using Na 2 SO 4 and NaClO 4 as background media. It was found that axenic cultures of Euglena mutabilis Schmitz were able to bioaccumulate in 5 days 94.9 to 99.2% of uranium from a 1 x 10 -5 mol/L uranium solution in perchlorate medium and 95.1 to 95.9% in sodium sulfate medium, respectively. The speciation of uranium in solution and uranium bioaccumulated by Euglena mutabilis cells, were studied by laser induced fluorescence spectroscopy (LIFS). The LIFS investigations showed that the uranium speciation in the NaClO 4 systems was dominated by free uranyl(VI) species and that the UO 2 SO 4 species was dominating in the Na 2 SO 4 medium. Fluorescence spectra of the bioaccumulated uranium revealed that aqueous uranium binds to carboxylic and/or (organo)phosphate groups located on the euglenid pellicle or inside the Euglena mutabilis cells. Reduced uranium immobilization rates of 0.93-1.43 mg uranium per g Euglena mutabilis biomass were observed in similar experiments, using sterile filtrated AMD waters containing, 4.4 x 10 -5 mol/L uranium. These lower rates were attributed to competition with other cations for available sorption sites. Additional LIFS measurements, however, showed that the speciation of the bioaccumulated uranium by the Euglena mutabilis cells was found to be identical with the uranium speciation found in the bioaccumulation experiments carried out in Na 2 SO 4 and NaClO 4 media. The results indicate that Euglena mutabilis has the potential to immobilize aqueous uranium under acid condition and thus may be used in future as promising agent for immobilizing uranium in low pH waste water environments. (orig.)

Chronocoulometric determination of trace levels of uranium in rocks

International Nuclear Information System (INIS)

Cantagallo, M.I.C.; Gutz, I.G.R.

1990-01-01

The chronocoulometric method for the determination of trace levels of uranium, based on the catalytic nitrate reduction was applied with real and synthetic samples. Reference materials with complex matrices like rocks were first solubilized by hot digestion under pressure in a PTFE bomb. When necessary, an adapted liquid-liquid extraction procedure was used for previous separation of interferents. The obtained results are in good agreement with the values obtained with other techniques such as X-ray fluorescence, mass spectrometry -isotope dilution and apithermal activation analysis. (author) [pt

Development of Fluorescence Spectral Imaging for Location of Uranium Deposited on Surfaces

International Nuclear Information System (INIS)

Monts, D.L.; Wang, G.; Su, Y.; Jang, P.R.; Waggoner, Ch.A.

2009-01-01

surface with a UV light and using a narrow band pass filter on a camera, recording an image of the resulting fluorescence. This system has the potential to also be utilized to monitor excavation of DU munitions and separation of uranyl compounds from soils. For the first-generation prototype FSI system, images acquired with '443-nm' radiation have greater intensity than those acquired with '400-nm' radiation; however, use of '400-nm' radiation permits better discrimination. FSI images enable smaller amounts of uranyl compounds to be detected than does traditional Spectral Imaging (SI) detection. A second-generation, transportable, FSI system is currently under development and is being extensively characterized so that quantitative determinations can be made of the amount of uranium present. In order to characterize the output of the new flood illumination system, a spectrum has been recorded that reveals that light in the 410- to 525-nm region is very efficiently blocked. However, the mercury 546-nm, 577-nm, and 615-nm transitions are partially transmitted by the flood light filtering system. Consequently, it is desirable to monitor fluorescence from the uranyl 488-nm and 509-nm emission bands rather than the 560-nm and 587-nm emission bands in order to avoid detecting light from the flood illumination system. (authors)

Standard test method for determination of low concentrations of uranium in oils and organic liquids by X-ray fluorescence

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This test method covers the steps necessary for the preparation and analysis by X-ray fluorescence (XRF) of oils and organic solutions containing uranium. Two different preparation techniques are described. 1.2 The procedure is valid for those solutions containing 20 to 2000 μg uranium per mL as presented to the spectrometer for the solution technique and 200 to 50 000 μg uranium per g for the pellet technique. 1.3 This test method requires the use of an appropriate internal standard. Care must be taken to ascertain that samples analyzed by this test method do not contain the internal standard or that this contamination, whenever present, has been corrected for mathematically. Such corrections are not addressed in this procedure. Care must be taken that the internal standard and sample medium are compatible; that is, samples must be miscible with tri-n-butyl phosphate (TBP) and must not remove the internal standard from solution. Alternatively, a scatter line may be used as the internal standard. 1....

Analytical method of uranium (IV) and uranium (VI) in uranium ores and uranium-bearing rocks

International Nuclear Information System (INIS)

Shen Zhuqin; Zheng Yongfeng; Li Qingzhen; Zhong Miaolan; Gu Dingxiang

1995-11-01

The best conditions for keeping the original valences of uranium during the dissolution and separation procedure of geological samples (especially those micro uranium-bearing rock) were studied. With the exist of high concentration protectants, the sample was decomposed with concentration HF at 40 +- 5 degree C. The U(VI) was dissolved completely and formed stable complex UO 2 F 2 , the U(IV) was precipitated rapidly and carried by carrier. Quantitative separation was carried out immediately with suction. The decomposition of sample and separation of solid/liquid phases was completed within two minutes. After separation, the U(IV) and U(VI) were determined quantitatively with laser fluorescence or voltametry respectively according to the uranium content. The limit of detection for this method is 0.7 μg/g, RSD is 10.5%, the determinate range of uranium is 2 x 10 -6 ∼10 -1 g/g. The uranium contents and their valence state ratio were measured for more than one hundred samples of sand stone and granite, the accuracy and precision of these results are satisfactory for uranium geological research. (12 tabs.; 11 refs.)

LED vs laser fluorimetry: a comparative study for the determination of uranium in natural waters

International Nuclear Information System (INIS)

Shenoy, N.; Parab, H.; Sounderajan, S.; Kiran Kumar; Kumar, S.D.; Reddy, A.V.R.

2015-01-01

Measurement of uranium in water samples has acquired considerable importance ever since its occurrence in drinking water sources was reported. Among the various methods available for uranium quantification at ultra trace levels, laser fluorimetry (LF) method is the method of choice due to its simplicity, speed and high sensitivity compared to other analytical techniques. This technique is based on the measurement of fluorescence of uranium complexes in aqueous solution. Recently, laser source has been replaced by light emitting diode (LEDs) in the fluorimeter systems. In comparison to laser source, LED source is, cost effective, generates less heat and has extended lifetime. Herein, authors have presented a comparison of LED based fluorimeter (Quantalase, Indore, India) and laser fluorimeter (CAT, Indore, India) for the determination of uranium in natural waters

Fluorimetric determination of uranium in water

International Nuclear Information System (INIS)

Acosta L, E.

1992-02-01

The fluorimetric method for the determination of microquantities of uranium in water is described. This method covers the determination of uranium in water in the interval from 0.2 to 50 ppm on 50 ml. of radioactive base sample. These limits can be variable if the volume of the aliquot one of the base sample is changed, as well as the volume of the used aliquot one for to the final determination of uranium. (Author)

A comparative study on determination of composition of uranium thorium mixed oxides by tube and radioisotope excited EDXRF

International Nuclear Information System (INIS)

Dhara, Sangita; Sanjay Kumar, S.; Misra, N.L.; Aggarwal, S.K.; Singh, Ajit Kumar; Lodha, G.S.

2009-01-01

Energy Dispersive X-ray Fluorescence (EDXRF) methods for determination of uranium and thorium in their mixed oxide matrices using tube and radioisotope excitation sources have been developed. The methodology involves preparation of mixed oxide calibration/sample mixtures of uranium and thorium oxides, mixing of fixed amount of internal standard Yttrium in form of Yttrium oxide, pelletizing these mixtures after thorough mixing and recording their EDXRF spectra using Rh target as well as 109 Cd radioisotope source. The samples were analysed for uranium and thorium on the basis of calibration plots

Uranium speciation in plants

International Nuclear Information System (INIS)

Guenther, A.; Bernhard, G.; Geipel, G.; Reich, T.; Rossberg, A.; Nitsche, H.

2003-01-01

Detailed knowledge of the nature of uranium complexes formed after the uptake by plants is an essential prerequisite to describe the migration behavior of uranium in the environment. This study focuses on the determination of uranium speciation after uptake of uranium by lupine plants. For the first time, time-resolved laser-induced fluorescence spectroscopy and X-ray absorption spectroscopy were used to determine the chemical speciation of uranium in plants. Differences were detected between the uranium speciation in the initial solution (hydroponic solution and pore water of soil) and inside the lupine plants. The oxidation state of uranium did not change and remained hexavalent after it was taken up by the lupine plants. The chemical speciation of uranium was identical in the roots, shoot axis, and leaves and was independent of the uranium speciation in the uptake solution. The results indicate that the uranium is predominantly bound as uranyl(VI) phosphate to the phosphoryl groups. Dandelions and lamb's lettuce showed uranium speciation identical to lupine plants. (orig.)

Uranium hexafluoride. Bromine spectrophotometric determination

International Nuclear Information System (INIS)

Anon.

Bromine determination in hydrolized uranium hexafluoride by reduction of bromates by ferrous sulfate, oxidation of bromides by potassium permanganate to give bromine which is extracted into carbon tetrachloride and transformed in eosine for spectrophotometry at 510 nm. The method is suitable for determining 5 to 150 ppm with respect to uranium [fr

Monitoring the mass of UF6 gas and uranium deposits in aluminium pipes using X-ray fluorescence and X-ray transmission gauges

International Nuclear Information System (INIS)

Packer, T.W.; Smith, S.M.

1984-12-01

In order to determine the enrichment of UF 6 gas in centrifuge plant pipework it is necessary to measure the mass of the gas (pressure) and the mass per unit area of any uranium deposited on the pipe. This paper shows that it is possible to determine the pressure of the UF 6 gas in pipes 120 mm in diameter using an energy-dispersive X-ray fluorescence spectrometer. Results are also given of transmission measurements made using a low power X-ray generator operated at two different applied voltages. A method of using the two measurements to determine the mass per unit area of deposited uranium is described. (author)

A gravimetric and an X-ray fluorescence method for the determination of rubidium in Rb2U(SO4)3

International Nuclear Information System (INIS)

Mudher, K.D.S.; Krishnan, K.; Jayadevan, N.C.

1993-01-01

Chemical characterization of rubidium uranium(IV) trisulfate, RB 2 U(SO 4 ) 3 , a new chemical assay standard for uranium requires accurate analysis of rubidium. A gravimetric and an X-ray fluorescence method (XRF) for the determination of rubidium in this compound are described. In the gravimetric method, rubidium is determined as Rb 2 Na[Co(NO 2 ) 6 ].H 2 O without separating uranium with a precision of the order of ±0.5%. In the XRF method, the concentration ratio of rubidium to uranium, C Rb /C U , is determined in the solid samples by the binary ratio method using calibration between intensity ratios (I Rb /I U ) and concentration ratios (C Rb /C U ). (author) 6 refs.; 2 figs.; 3 tabs

Determination of uranium in liquid samples

International Nuclear Information System (INIS)

Macefat, Martina R.; Grahek, Zeljko; Ivsic, Astrid G.

2008-01-01

Full text: Uranium is a natural occurring radionuclide and the first member of natural radioactive chains which makes its determination in natural materials interesting from geochemical and radioecological aspect. It can be quantitatively determined as element and/or its radioisotopes by different spectrometric methods (ICP-MS, spectrophotometry, alpha spectrometry). It is necessary to develop inexpensive, rapid and sensitive methods for the routine analysis. Therefore, in this paper, development of a new method for the isolation of uranium from liquid samples and subsequent determination by spectrophotometry and ICP-MS will be described. It is possible to isolate uranium from drinking and seawater using extraction chromatography or mixed solvent ion exchange. Uranium can be strongly bound on the TRU extraction chromatographic resin from nitric acid (chemical recovery is 100%) and can be separated from other interfering elements, while separation from thorium, which can be also strongly bound on this resin, is possible with hydrochloric acid. It is also possible to separate uranium from thorium on the anion exchanger Amberlite CG-400 (NO 3 - form) because uranium is much more weakly bound on this exchanger from alcoholic solutions of nitric acid. After the separation uranium is determined by ICP-MS and by spectrophotometric method with arsenazo III (λ max =652 nm). Developed method enables selection of the optimal mode of isolation for the given purposes. (author)

Determination of uranium and thorium during chemical treatment of monazite

International Nuclear Information System (INIS)

El-Nadi, Y.A.; Daoud, J.A.; Aly, H.F.; Kregsamer, P.

2000-01-01

Total reflection x-ray fluorescence (TXRF) is a very useful technique for both qualitative and quantitative analysis because of its high detection power and its needed to small sample volumes (less than 100 μl are sufficient). In this work TXRF was used to determine the initial concentrations of the elements included in monazite sand and following up the chemical steps for treatment of monazite with special attention to uranium and thorium concentration as well as lanthanides. The results were compared to those obtained from EDXRF and ICP-MS techniques. (author)

Uranium determination in dental ceramics

International Nuclear Information System (INIS)

Jacobson, I.; Gamboa, I.; Espinosa, G.; Moreno, A.

1984-01-01

There are many reports of high uranium concentration in dental ceramics, so they require to be controlled. The SSNTD is an optional method to determine the uranium concentration. In this work the analysis of several commercial dental ceramics used regularly in Mexico by dentists is presented. The chemical and electrochemical processes are used and the optimal conditions for high sensitivity are determined. CR-39 (allyl diglycol polycarbonate) was used as detector. The preliminary results show some materials with high uranium concentrations. Next step will be the analysis of equivalent dose and the effects in the public health. (author)

Determination of trace amounts of uranium in a reprocessing plant by solution spectrofluorimetry

International Nuclear Information System (INIS)

Mauchien, P.; Cauchetier, Ph.

1983-01-01

To establish inventory tables accurately and satisfy safeguards requirements - and also to ensure satisfactory operation of a reprocessing plant - it is essential to determine the uranium content of numerous solutions where the uranium is present only in trace quantities. For this purpose a method is proposed which relies on the fluorescence of uranyl solutions exposed to ultra-violet radiation. After a brief theoretical summary, the parameters which influence the measurements most strongly are enumerated: medium, temperature, nature of the matrix, and choice of wavelength of the incident radiation. It is then apparent that the measurement must be performed by internal calibration (using the proportional addition method) and that it is useful to obtain a fluorescence spectrum which enables us to verify the presence of uranium. The applications of this method at the La Hague plant are described, where it has been used since October 1981 by shift teams, notably to check the following points: the attack acid (before receiving the fuel), the foot of the first-cycle column, the carbonated solvent washing solution and the solutions of the effluent treatment unit. It is in fact used throughout the plant, even for checking uranium in PuO 2 oxide. The method makes it possible to avoid organic reagents such as pyridine and, in many cases, cumbersome effluent-generating separations. Determinations are possible - to give one example - by simple dilution in the fission-product concentrates and in plutonium solutions where the Pu/U ratio is as great as 1000/1. In pure solutions the detection limit with the equipment used at present is a few μg per litre in the measuring tank. In general, the accuracy is a few per cent. (author)

A new automatic analyzer for uranium determination

International Nuclear Information System (INIS)

Xia Buyun; Zhu Yaokun; Wang Bin; Cong Peiyan; Zhang Lan

1992-08-01

An intellectual automatic analyzer for uranium based on the principle of flow injection analysis (FIA) has been developed. It can directly determine the uranium solution in range of 0.02 to 500 mg/L without any pre-process. A chromatographic column with extractant, in which the trace uranium is concentrated and separated, has special ability to enrich uranium, is connected to the manifold of the analyzer. The analyzer is suited for trace uranium determination in varies samples. The 2-(5-bromo-2-pyridylazo)-5-diethyl-aminophenol (Br-PADAP) is used as color reagent. Uranium is determined in aqueous solution by adding cation surfactant, cetyl-pyridinium bromide (PCB). The rate of analysis is 30 to 90 samples per hour. The relative standard deviation of determination is 1% ∼ 2%. The analyzer has been used in factories and laboratory, and the results are satisfied. The determination range can easily be changed by using a multi-function auto-injection valve that changes the injection volume of the sample and channels. So, it could adopt varies FIA operation modes to meet the needs of FIA determination for other substance. The analyzer has universal functions

Applications of fluorescence techniques to the study of uranium in homogeneous and heterogeneous environments: hydrolysis and photo-reduction reactions on titanium dioxide

International Nuclear Information System (INIS)

Eliet, Veronique

1996-01-01

This thesis describes the use of Time-Resolved Fluorescence to characterise the spectroscopy of hydroxo-complexes of hexavalent Uranium, and to study photochemical reactions involving these species at mineral/water interfaces. The instrumentation used comprised of either an excimer laser coupled to an optical multichannel analyser OMA or a Nd-YAG laser coupled to a stroboscopic photomultiplier. The hydrolysis of Uranium at a constant temperature of 25 deg. C, has been studied in the pH ranges 0-5 and 9-12. Deconvolution of spectra and fluorescence decay curves for Uranium yielded individual fluorescence spectra and decay times for uranyl UO 2 2+ and its hydroxo-complexes UO 2 OH + , (UO 2 )2(OH) 2 2+ , (UO 2 ) 3 (OH) 5 + et UO 2 (OH) 3 - . The comparison of fluorescence efficiencies for the various species showed that the complex (UO 2 )2(OH) 2 2+ is up to 85 times more fluorescent than uranyl, depending on the emission wavelength. Further, investigations of fluorescence decays as a function of temperature in the pH range 0-6, yielded activation energies for the various Uranium hydroxo species. The knowledge gained in homogeneous media served in the study of the photochemical behaviour of Uranium in suspensions of the semi-conductor mineral, TiO 2 . After UV-light absorption, charge carriers formed at the mineral surface were found to reduce hexavalent Uranium to the tetravalent oxidation state. Time-Resolved Fluorescence Spectroscopy has been used to monitor the kinetics of the oxidation state change. A reaction mechanism is proposed on the basis of results obtained by studying the kinetics of the process at different values of pH The role of humic substances on the heterogeneous redox reaction has also been examined. (author) [fr

Optimization of experimental conditions in uranium trace determination using laser time-resolved fluorimetry

International Nuclear Information System (INIS)

Baly, L.; Garcia, M.A.

1996-01-01

At the present paper a new sample excitation geometry is presented for the uranium trace determination in aqueous solutions by the Time-Resolved Laser-Induced Fluorescence. This new design introduces the laser radiation through the top side of the cell allowing the use of cells with two quartz sides, less expensive than commonly used at this experimental set. Optimization of the excitation conditions, temporal discrimination and spectral selection are presented

Enhancement of uranyl fluorescence using trimesic acid: Ligand sensitization and co-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Maji, S. [Chemistry Group, Materials Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Viswanathan, K.S., E-mail: vish@igcar.gov.in [Chemistry Group, Materials Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

2011-09-15

Trimesic acid (TMA) was shown to sensitize and enhance uranyl fluorescence in aqueous medium, with the enhancement being a maximum at pH 5.0. Fluorescence spectra and lifetime data together suggest that TMA complexes with uranyl (UO{sub 2}{sup 2+}). The fluorescence of UO{sub 2}{sup 2+} in its acid complex is further enhanced by more than two orders of magnitude following the addition of Y{sup 3+}; a process referred to as co-fluorescence, leading to the possibility of detecting uranium at sub ng/mL level. The present study demonstrates, for the first time, fluorescence enhancement of the uranyl species due to co-fluorescence. - Highlights: > Trimesic acid was shown to sensitize and enhance the fluorescence of uranium in aqueous medium. > This ligand also exhibited co-fluorescence of uranium with Y{sup 3+}. > To the best of our knowledge this is the first report of co-fluorescence in uranium. > The enhancement of uranium fluorescence, resulted in detection limits in the ng/mL regime.

Introduction to the problems of uranium analysis

International Nuclear Information System (INIS)

Suschny, O.

1983-08-01

Brief information is given on different techniques used for recognition, separation and determination of uranium. The analytical methods dealt with are: radiometry, neutron activation analysis, delayed neutron counting, X-ray fluorescence analysis, fluorimetry, spectral photometry, gravimetry, and volumetry. Selection of a suitable method for determining uranium in geochemical surveys is also discussed

X-Ray Fluorescence Spectrometry. II Determination of Uranium in ores; Espectrometria de fluorescencia de Rayos X. II-Aplicacion a la determinacion de uranio en minerales

Energy Technology Data Exchange (ETDEWEB)

Bermudez Polonio, J; Crus Castillo, F. de la; Fernandez Cellini, R

1961-07-01

A method of analysis of uranium in ores by X-ray spectrometry was developed, using the internal standard technique. Strontium was found to be the most suitable internal standard for general use. A Norelco Philips X-ray fluorescent spectrometer was used in this work, equipped with a lithium fluoride crystal acting as a diffraction grating analyzer. The intensity of the uranium-L {alpha}{sub 1} spectral line is calculated and related to corresponding strontium-K{sub {alpha}} spectral line, both detected with a Scintillation Counter. (Author) 31 refs.

Uranium fluorides analysis. Titanium spectrophotometric determination

International Nuclear Information System (INIS)

Anon.

Titanium determination in uranium hexafluoride in the range 0.7 to 100 microgrammes after transformation of uranium fluoride in sulfate. Titanium is separated by extraction with N-benzoylphenylhydroxylamine, reextracted by hydrochloric-hydrofluoric acid. The complex titanium-N-benzoylphenylhydroxylamine is extracted by chloroform. Spectrophotometric determination at 400 nm [fr

Report on intercomparisons S-14, S-15, and S-16 of the determination of uranium and thorium in thorium ores

International Nuclear Information System (INIS)

Pszonicki, L.; Hanna, A.N.; Suschny, O.

1983-06-01

Twenty-nine laboratories from 18 countries took part in this intercomparison, organized by the IAEA's Analytical Quality Control Service, to help laboratories engaged in this task to check the reliability of their results. An additional aim was to establish the concentrations of thorium and uranium in three large batches of thorium ores and certifying them as reference materials. The evaluation was based on 438 individual results (108 laboratory means) for thorium, and on 412 individual results (106 laboratory means) for uranium. The number of laboratory means per element and per sample varied from 34 to 38. The methods most frequently used in the determination of both elements were neutron activation analysis and radiometry. They were followed by spectrophotometry and X-ray fluorescence analysis for thorium and by fluorimetry, X-ray fluorescence analysis and spectrophotometry for uranium determination, respectively. The relative uncertainty of all computed overall medians which were used as the best estimations of true values, does not exceed +-10% and +-5% for the concentration values below and above 0.1%, respectively

Isotopic ratio method for determining uranium contamination

International Nuclear Information System (INIS)

Miles, R.E.; Sieben, A.K.

1994-01-01

The presence of high concentrations of uranium in the subsurface can be attributed either to contamination from uranium processing activities or to naturally occurring uranium. A mathematical method has been employed to evaluate the isotope ratios from subsurface soils at the Rocky Flats Nuclear Weapons Plant (RFP) and demonstrates conclusively that the soil contains uranium from a natural source and has not been contaminated with enriched uranium resulting from RFP releases. This paper describes the method used in this determination which has widespread application in site characterizations and can be adapted to other radioisotopes used in manufacturing industries. The determination of radioisotope source can lead to a reduction of the remediation effort

Uranium determination in water

International Nuclear Information System (INIS)

Prudenzo, E.J.; Puga, Maria J.; Cerchietti, Maria L.R.; Arguelles, Maria G.

2005-01-01

In our laboratory, a procedure has been assessed to determine uranium content of water in normal situations. The method proposed without sample pre-treatment, is simple and rapid. Uranium mass is measured by fluorimetry. For calculation of detection limit (Ld) and quantification level (Lq) we used blank samples and the results were analyzed for different statistical test. The calculation of total propagated uncertainty and sources contribution on real samples are presented. (author)

Efficient isotope ratio analysis of uranium particles in swipe samples by total-reflection x-ray fluorescence spectrometry and secondary ion mass spectrometry

International Nuclear Information System (INIS)

Esaka, Fumitaka; Watanabe, Kazuo; Fukuyama, Hiroyasu; Onodera, Takashi; Esaka, Konomi T.; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu

2004-01-01

A new particle recovery method and a sensitive screening method were developed for subsequent isotope ratio analysis of uranium particles in safeguards swipe samples. The particles in the swipe sample were recovered onto a carrier by means of vacuum suction-impact collection method. When grease coating was applied to the carrier, the recovery efficiency was improved to 48±9%, which is superior to that of conventionally-used ultrasoneration method. Prior to isotope ratio analysis with secondary ion mass spectrometry (SIMS), total reflection X-ray fluorescence spectrometry (TXRF) was applied to screen the sample for the presence of uranium particles. By the use of Si carriers in TXRF analysis, the detection limit of 22 pg was achieved for uranium. By combining these methods with SIMS, the isotope ratios of 235 U/ 238 U for individual uranium particles were efficiently determined. (author)

Extraction/fluorometric determination of uranium with rhodamine B and 2-thenoyltrifluoroacetone

International Nuclear Information System (INIS)

Naganuma, Takeshi; Tuzuki, Satoshi; Jin, Jiye.

1990-01-01

A method for the fluorometric determination of uranium, based on a solvent extraction of an ion associate formed between Rhodamine B cation and 2-thenoyltrifluoroacetone(TTA)-metal chelate anion with benzene, is described. The procedure for the construction of the calibration curve is as follows. Varying amounts of uranium standard solution and 2 ml of 2 M ammonium acetate buffer solution are mixed. The solution is adjusted at pH 6.0 and 10 ml of 0.3 % Rhodamine B are added. It is then shaken for 5 min with 10 ml of 0.01 M TTA benzene solution. The fluoresence of the organic phase is measured at 545 nm (excitation) and 570 nm (emission) for uranyl-TTA-Rhodamine B complex. The fluorescence intensity is linearly related to the concentration of uranyl ion in the range of 0.05 ppm ot 1 ppm. (author)

Titrimetric determination of uranium in tributyl phosphate

International Nuclear Information System (INIS)

Sobkowska, A.

1978-01-01

The titrimetric method involving the reduction of U(VI) to uranium(IV) by iron(II) in phosphoric acid, selective oxidation of the excess of iron(II) and potentiometric titration with dichromate was directly used for the determination of uranium in tributyl phosphate mixtures. The procedure was applied to solutions containing more than 2 mg of uranium in the sample but the highest precision and accuracy were obtained in the range from 20 to 200 mg of uranium. Dibutyl phosphate and monobutyl phosphate as well as the other radiolysis products of TBP had no influence on the results of determinations. (author)

Thorium determination by X-ray Fluorescence Spectrometry in simulated thorex process solutions

International Nuclear Information System (INIS)

Yamaura, M.; Matsuda, H.T.

1989-01-01

The X-ray fluorescence method for thorium determination in aqueous and organic (TBP-n-dodecane) solutions is described. The thin film-technique for sample preparation and a suitable internal standard have been used. Some parameters as analytical line, internal standard, filter paper, paper geometry, sample volume and measurement conditions were studied. Uranium, fission products, corrosion products and thorex reagent components were studied as interfering elements in the thorium analysis, as well as the matrix effect by using the thorex process simulated solutions the method to thorium determination in irradiated thorium solutions was applied. (M.J.C.) [pt

Total reflection X-ray spectroscopy as a rapid analytical method for uranium determination in drainage water

International Nuclear Information System (INIS)

Matsuyama, Tsugufumi; Sakai, Yasuhiro; Izumoto, Yukie; Imaseki, Hitoshi; Hamano, Tsuyoshi; Yoshii, Hiroshi

2017-01-01

Uranium concentrations in drainage water are typically determined by α-spectrometry. However, due to the low specific radioactivity of uranium, the evaporation of large volumes of drainage water, followed by several hours of measurements, is required. Thus, the development of a rapid and simple detection method for uranium in drainage water would enhance the operation efficiency of radiation control workers. We herein propose a novel methodology based on total reflection X-ray fluorescence (TXRF) for the measurement of uranium in contaminated water. TXRF is a particularly desirable method for the rapid and simple evaluation of uranium in contaminated water, as chemical pretreatment of the sample solution is not necessary, measurement times are typically several seconds, and the required sample volume is low. We herein employed sample solutions containing several different concentrations of uranyl acetate with yttrium as an internal standard. The solutions were placed onto sample holders, and were dried prior to TXRF measurements. The relative intensity, otherwise defined as the net intensity ratio of the Lα peak of uranium to the Kα peak of yttrium, was directly proportional to the uranium concentration. Using this method, a TXRF detection limit for uranium in contaminated water of 0.30 μg/g was achieved. (author)

Study of uranium contamination of ground water in Punjab using X-ray fluorescence technique

International Nuclear Information System (INIS)

Alrakabi, Muhanad; Singh, Gurjeet; Bhalla, Atul; Kumar, Sunil; Kumar, Sanjeev; Rai, Bimal; Singh, N.; Shahi, J.S.; Mehta, D.; Srivastava, Alok

2010-01-01

A number of reports have appeared in public media about uranium ingestion being a possible cause for cancer and increased birth rate abnormalities among children in the Malwa region of Punjab state in India. These reports link problems like cancer and Autism, with the presence of uranium in the ground waters of Malwa region. The concentration of uranium in drinking water from sources as varied as ground water, canal water supply and reverse osmosis system have been investigated using X-ray fluorescence technique. Samples from the thermal power plants in the regions and nearby ground waters were also analyzed to identify the source of contamination. The samples were collected with assistance of the officials from the Government of Punjab. More than half a litre of each of the water samples was dried at 60 deg-80 deg in an oven. Residue was collected using larger quantities of water samples in case of RO water samples. The elemental analysis of the residue was carried out using the Energy-Dispersive X-Ray Fluorescence (EDXRF) spectrometer consisting of an 42 Mo-anode X-ray tube (Panalytical, 2.5 kW) as an excitation source and a Si(Li) detector. A combination of selective absorbers of 30 Zn, 38 Sr, and 39 Y was used in the incident beam for improving the detection limit for Uranium by reducing the background and removing the 42 Mo K X-rays. The detection limit in ppb/litre depends upon the amount of residue

Use of scattered media to determine lanthanides and actinides in natural water: application to uranium

International Nuclear Information System (INIS)

Reiller, P.

1993-11-01

This thesis has three parts; in the first one we present the general knowledge necessary to the understanding of phenomena to which we are going to be confronted: analysis by laser spectrofluorimetry with temporal resolution, chemistry in aqueous solution of uranium, fluorescence properties of uranium, chemistry of surfactants and their appliance in fluorescence exaltation; principle of ultrafiltration and application to ultrafiltration assisted by micella. In the second part, we will study the spectral and temporal properties of fluorescence with surfactants in the framework of using laser spectrofluorimetry with temporal resolution. In the last part, we will interest in the coupling of spectrofluorimetry and ultrafiltration assisted by micella

Determination of uranium in uranium metal, uranium oxides, and uranyl nitrate solutions by potentiometric titration

International Nuclear Information System (INIS)

Tucker, H.L.; McElhaney, R.J.

1983-01-01

A simple, fast method for the determination of uranium in uranium metal, uranium oxides, and uranyl nitrate solutions has been adapted from the Davies-Gray volumetric method to meet the needs of Y-12. One-gram duplicate aliquots of uranium metal or uranium oxide are dissolved in 1:1 HNO 3 and concentrated H 2 SO 4 to sulfur trioxide fumes, and then diluted to 100-mL volume. Duplicate aliquots are then weighed for analysis. For uranyl nitrate samples, duplicate aliquots containing between 50 and 150 mg of U are weighed and analyzed directly. The weighed aliquot is transferred to a Berzelius beaker; 1.5 M sulfamic acid is added, followed in order by concentrated phosphoric acid, 1 M ferrous sulfate, and (after a 30-second interval) the oxidizing reagent. After a timed 3-minute waiting period, 100 mL of the 0.1% vanadyl sulfate-sulfuric acid mixture is added. The sample is then titrated past its endpoint with standard potassium dichromate, and the endpoint is determined by second derivative techniques on a mV/weight basis

Study of an X-ray fluorescence thin film method for the determination of uranium in low activity solutions; Estudio de un metodo de fluorescencia de rayos X en capa delgada para la determinacion del uranio en soluciones de baja actividad

Energy Technology Data Exchange (ETDEWEB)

Diaz-Guerra, J P

1980-07-01

The application of the X-ray fluorescence thin film technique to the uranium determination in nitric solutions for a concentration range from 1 g/l to 100 g/l and activity levels under 5 mCi/ml is studied. The most suited excitation and measurement conditions are also studied and the uranium matrix effect correction, which is performed through the double dilution, {alpha}{sub U}U interaction coefficient calculation and internal standard methods, is discussed. The specimen preparation is satisfactorily accomplished by using P.V.C. filters fixed on aluminium supports. (Author) 18 refs.

On the interaction of uranium with the bioligands citric acid and glucose

International Nuclear Information System (INIS)

Steudtner, Robin

2011-01-01

For a better understanding of the actinide behaviour in human (in term of metabolism, retention, excretion) and in geological and biological systems, it is of prime importance to have a good knowledge of the relevant speciation. In model systems the chemical behaviour of uranium regarding complex formation and redox reaction were investigated. On this basis determinates thermodynamics constants and redox behaviour are used to prognoses a safety assessment for the respective system. The pentavalent uranium(V) is a metastable intermediate in natural redox system between uranium(IV) and uranium(VI). In this study the uranium(V) fluorescence was detected by laser spectroscopic methods (λ ex = 255 nm) for the first time. The peak maxima (λ ex = 255 nm) of luminescence spectrum of the photo reduced U(V) in aqueous perchlorate/2-propanol solution was detected at 440 nm and a fluorescence lifetime of 1.1 ± 0.02 μs was calculated. The stable aqueous uranyl(V)-tricarbonate complex was characterized by fluorescence spectroscopy (λ ex = 255 nm and 408 nm). The known quench effects of carbonate could be minimized by coupling the laser fluorescence system with the low temperature technique. The resulting U(V) fluorescence emission bands were detected between 375 nm and 445 nm. The peak maxima were identified at 401.5 nm (λ ex = 255 nm) and 413.0 nm (λ ex = 408 nm). The fluorescence lifetime of the uranyl(V)-carbonate species was determined at 153 K as 120 ± 0.1 μs (λ ex = 255 nm). In addition the fluorescence of uranium(V) was verifies by confocal laser scanning microscopy. The oxidation process from uranium(IV) to uranium(VI) was investigated on solid uraninite (UO 2 ) and uranium(IV) tetra chloride (UCl 4 ) and a 1 x 10 -2 M uranium(IV) sulphate (U IV SO 4 ) solution. By continuous oxygen transfer the uranium(IV) was oxidized slowly to uranium(VI). The temporal process was studied by the confocal laser scanning microscopy using an excitation wavelength of 408 nm. The

Uranium determination in different compositions

International Nuclear Information System (INIS)

Bulyanitsa, L.S.; Ivanova, K.S.; Ryzhinskij, M.V.; Alekseeva, N.A.; Solntseva, L.F.; Shereshevskaya, I.I.

1978-01-01

For clarifying the suitability of two different methods of analysis for determining uranium without its previous purification, the analysis of uranium carbides (UC, UC 2 , UC - ZrC) and alloys (U - Al, U - Zr - Nb, U- Ti) has been carried out. Dissolution of the compositions examined was carried out either after previous calcining (UC, UC 2 ) or fusion with KHSO 4 (UC - ZrC), or in phosphoric acid (alloys). The first method, a variant of potentiometric titration, has been modified for small amounts of uranium. Titration was carried out on a semiautomatic titrating unit. The uranium amount per titration is about 4 to 5 mg. The second method of analysis is the coulombmetric titration at a constant current intensity. The quantity of uranium per titration was equal to 1 - 3 mg. The statistical processing of the results obtained was carried out by a dispersion analysis that allowed to reveal the influence of separate factors, such as method of analysis, type of composition, the non-uniformity of a sample, the enumerated factors influencing the dispersion of the analysis results. It has been shown that the both methods are equally suitable for analysis of the uranium compounds examined

Rapid determination of uranium in natural waters by fthermal emission mass spectrometry

International Nuclear Information System (INIS)

Ferguson, J.R.; Caylor, J.D.; Rogers, E.R.; Cole, S.H.

1977-03-01

A method has been developed to rapidly analyze natural water samples for part-per-trillion (ng/l) concentrations of uranium using a custom-built thermal-emission mass spectrometer. The filtered water sample is spiked with 233 U as an internal standard and extracted with a 2 percent solution of TOPO (trioctylphosphine oxide) in carbon tetrachloride. An aliquot of the organic phase is evaporated and the uranium in the residue extracted with aqueous ammonium carbonate. A 5j-μl aliquot is taken and dried on a flat uranium concentration of 3 ng/l will yield a count rate greater than three times the standard deviation, plus the mean of the background, and is defined as the lowest determinable concentration. The standard deviation of the method is 3 percent at accuracy of the method has been evaluated by comparing the results with a fluorescence procedure. There is very good agreement for water samples with uranium concentrations from 200 to 1000 ng/l. The mass spectrometer is a 6-in. -radius, 60-degree-sector instrument equipped for ion counting and having a vacuum system allowing rapid sample changing while maintaining a high source vacuum. A multiplexer and high-voltage s witch provide synchronized peak switching and scaler gating for monitoring three isotopes of uranium 238, 235, and 233. With this instrument, an analyst can achieve an analysis rate in excess of 50 samples per eight-hour shift

Direct determination of uranium in soil, rock, ore and biological samples by laser-induced fluorometry

International Nuclear Information System (INIS)

Li Qingzhen; Zhang Yanan

1993-03-01

A laser-induced fluorometric method with modified J-22 anti-interferent fluorescent reagent for directly determining the uranium in soil, rock, ore, geochemical, biological and other samples has been studied. The effects of external ions and dilution law of sample are examined in detail. A method for correcting inner effect is proposed. A mixed solution of 0.25% NaOH-10% J-22 is prepared which can be added to the sample cuvette for direct measurement without any pre-adjustment of acidity. Therefore, it is much simpler for operation and reduces the loss and contamination of uranium. By changing the laser fluorometer sensitivity (400 ∼ 200), up to 3000 ng uranium in the cuvette can be detected. Thus, both analytical accuracy and detectable range are improved. This method is simple, rapid, accurate and applicable to various uranium-bearing samples. The detection limit is better than 0.05 μgU/g. The relative standard deviation is ≤+-5% for the rock reference samples of 0.95, 84.8, 669 and 7240 μgU/g

Determination of uranium by a gravimetric-volumetric titration method

International Nuclear Information System (INIS)

Krtil, J.

1998-01-01

A volumetric-gravimetric modification of a method for the determination of uranium based on the reduction of uranium to U (IV) in a phosphoric acid medium and titration with a standard potassium dichromate solution is described. More than 99% of the stoichiometric amount of the titrating solution is weighed and the remainder is added volumetrically by using the Mettler DL 40 RC Memotitrator. Computer interconnected with analytical balances collects continually the data on the analyzed samples and evaluates the results of determination. The method allows to determine uranium in samples of uranium metal, alloys, oxides, and ammonium diuranate by using aliquot portions containing 30 - 100 mg of uranium with the error of determination, expressed as the relative standard deviation, of 0.02 - 0.05%. (author)

Determination of microamounts of uranium in waste solutions

International Nuclear Information System (INIS)

Birringer, K.J.; Netzer, S.; Kuhn, E.; Groll, P.

1975-07-01

A method for the determination of microamounts of uranium in presence of high amounts of fission and corrosion products is described. Uranium is separated by reversed-phase chromatography on a small column, packed with Voltalef micro and impregnated with TOPO. For the direct photometric determination uranium is eluted by TAM dissolved in ethanol/pyridine. The efficiency of the separation, using a suitable scrub-solution, was tested with solutions of simulated inactive fission and corrosion products. The reproducibility of the method, with 24 μg of uranium, is +- 2,5%. (orig.) [de

Study of uranium contamination of ground water in Punjab using X-ray fluorescence technique

Energy Technology Data Exchange (ETDEWEB)

Alrakabi, Muhanad; Singh, Gurjeet; Bhalla, Atul; Kumar, Sunil; Kumar, Sanjeev; Rai, Bimal; Singh, N; Shahi, J S; Mehta, D [Department of Physics, Panjab University, Chandigarh (India); Srivastava, Alok [Department of Chemistry, Panjab University, Chandigarh (India)

2010-07-01

A number of reports have appeared in public media about uranium ingestion being a possible cause for cancer and increased birth rate abnormalities among children in the Malwa region of Punjab state in India. These reports link problems like cancer and Autism, with the presence of uranium in the ground waters of Malwa region. The concentration of uranium in drinking water from sources as varied as ground water, canal water supply and reverse osmosis system have been investigated using X-ray fluorescence technique. Samples from the thermal power plants in the regions and nearby ground waters were also analyzed to identify the source of contamination. The samples were collected with assistance of the officials from the Government of Punjab. More than half a litre of each of the water samples was dried at 60 deg-80 deg in an oven. Residue was collected using larger quantities of water samples in case of RO water samples. The elemental analysis of the residue was carried out using the Energy-Dispersive X-Ray Fluorescence (EDXRF) spectrometer consisting of an {sup 42}Mo-anode X-ray tube (Panalytical, 2.5 kW) as an excitation source and a Si(Li) detector. A combination of selective absorbers of {sup 30}Zn, {sup 38}Sr, and {sup 39}Y was used in the incident beam for improving the detection limit for Uranium by reducing the background and removing the {sup 42}Mo K X-rays. The detection limit in ppb/litre depends upon the amount of residue

Polarography applied to the determination of uranium oxide composition; Application de la polarographie a la determination de la composition d'oxydes d'uranium

Energy Technology Data Exchange (ETDEWEB)

Nens, C; Canton, C; Molina, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, Departement de Chimie, Services d' Etudes Chimiques et d' Analyse, Service d' Etudes Analytiques, Section de Chimie Analytique du Plutonium et d' Electroanalyse

1967-03-01

An analytical method based on conventional polarography has been developed, for the determination of the O/U ratio in uranium oxides. The dissolution of the samples is effected by means of molten ammonium bifluoride. After a transfer to aqueous solution, polarography is used to determine the oxide composition by measurement of both the hexavalent and the total uranium. (author) [French] Une methode d'analyse utilisamt la polarographie conventionnelle a ete mise au point pour la determination du rapport O/U dans les oxydes d'uranium. La mise en solution des echgantillons est realisee en milieu de bifluorure d'ammonium fondu. Apres passage en salution aqueuse, la polarographie permet d'atteindre la composition de l'oxyde par determination de l'uranium hexavalent et de l'uranium total. (auteur)

Studies on the determination of uranium by potentiometry

International Nuclear Information System (INIS)

Venkataramana, P.; John, Mary; Nair, P.R.; Kasar, U.M.; Natarajan, P.R.

1981-01-01

A potentiometric method for the determination of uranium standardised earlier has been in use for the chemical quality control of plutonium fuels. The method involves the reduction of U(VI) in phosphoric acid medium and titration of U(IV) against Cr(VI). An extension of the range of the quantity of uranium determined by the same method is reported here. The precisions have been evaluated at 13 concentration levels. 20 titrations were carried out at each concentration. the precision at 20 μg level was found to be 3.8% while it was better than 0.03% at concentrations ranging from 20 mg upto 200 mg. At 100 mg and 200 mg of uranium the total volume of the reagent solutions was 50 ml while in other cases it was 25 ml. The effects of a few impurities on the uranium determination were also studied for the 2-5 mg range of uranium. (author)

The use of room temperature phosphorescence for the determination of uranium in tin-tailings mineral samples

International Nuclear Information System (INIS)

Meor Yusof bin Meor Sulaiman

1988-01-01

The possibility of using phosphorescence technique in determining uranium in mineral samples and its comparison with that of fluorescence using high carbonate flux is presented. Samples used are tin-tailings mineral such as monazite, xenotime, ilmenite and zircon. The calibration graph obtained shows a linear relationship between the concentration range of 0-55 ppm U. From here, analysis of the standard showed that the result obtained and that of the certified value are consistent. HN0 3 :H 2 SO 4 (1:3) and phosphoric acid leaching methods are tried and the results show that phosphoric acid is the better method for phosphate mineral. Comparison of the results obtained from this technique and that of the direct and extraction methods of fluorimetry are also made. Phosphorescence is found to be a better method in determining uranium in this type of samples. (author)

Fluorimetric determination of uranium in zirconium and zircaloy alloys

International Nuclear Information System (INIS)

Acosta L, E.

1991-05-01

The objective of this procedure is to determine microquantities of uranium in zirconium and zircaloy alloys. The report also covers the determination of uranium in zirconium alloys and zircaloy in the range from 0.25 to 20 ppm on 1 g of base sample of radioactive material. These limit its can be variable if the size of the used aliquot one is changed for the final determination of uranium. (Author)

Precision determination of uranium in uranium oxide by constant-current coulometry

International Nuclear Information System (INIS)

Xu Laili; Wang Chunhuan.

1990-01-01

A method of constant-current coulometric titration for determination of uranium in uranium oxide is described. This method involves preliminary reduction of U (VI) in H 2 SO 4 -H 3 PO 4 medium by Cr (II) as a reductant, followed by air oxidation of excess of Cr (II), addition of solid K 2 Cr 2 O 7 in quantity slightly more than that of the required for quantitative oxidation of U (IV) and final titration of excess of K 2 Cr 2 O 7 with the electrogenerated Fe (II). The endpoint is determined amperometrically. The effect of various factors on the sample treatment and reduction-oxidation processes has been examined. The precision of the method as indicated by the standard deviation of an individual observation is less than 0.01% for l gram uranium oxide

Uranium hexafluoride and uranyl nitrate. Ionometric determination of bromine

International Nuclear Information System (INIS)

Anon.

Bromine was determined in uranium hexafluoride. The method is suitable for determining 2 to 20 ppm with respect to uranium. Bromides are oxidized by potassium permanganate to give bromine which is extracted into carbon tetrachloride, reduced by ascorbic acid and determined by ionometry [fr

A rapid method for the determination of uranium in ores and carbonaceous materials by x-ray-fluorescence spectrometry

International Nuclear Information System (INIS)

Tolmay, R.T.; Jacobs, J.J.

1980-01-01

The determination of uranium by a non-fusion method in a wide range of uranium-bearing materials, e.g. ores, coals, and resins, is described. Matrix effects are corrected for by dilution and fine grinding of the sample with coarse river sand and application of a technique for background correction. The linear calibration range is up to 1000 p.p.m. of U 3 O 8 . It was found that the suitable dilution of resins with river sand and fine grinding makes it possible for up to 6 per cent U 3 O 8 to be determined. Ten samples can be analysed in two-and-a-half hours. The precision and accuracy is 5 and 2 per cent at U 3 O 8 concentrations of 500 and 2000 p.p.m. respectively. The laboratory method, a listing of the computer programme required for the calibration and calculation of the U 3 O 8 concentrations, and instructions for the calculation of the error in the determination are given in the appendices [af

Determination of uranium and plutonium by sequential potentiometric titration

International Nuclear Information System (INIS)

Kato, Yoshiharu; Takahashi, Masao

1976-01-01

The determination of uranium and plutonium in mixed oxide fuels has been developed by sequential potentiometric titration. A weighed sample of uranium and plutonium oxides is dissolved in a mixture of nitric and hydrofluoric acids and the solution is fumed with sulfuric acid. After the reduction of uranium and plutonium to uranium(IV) and plutonium(III) by chromium(II) sulfate, 5 ml of buffer solution (KCl-HCl, pH 1.0) is added to the solution. Then the solution is diluted to 30 ml with water and the pH of the solution is adjusted to 1.0 -- 1.5 with 1 M sodium hydroxide. The solution is stirred until the oxidation of the excess of chromium(II) by air is completed. After the removal of dissolved oxygen by bubbling nitrogen through the solution for 10 minutes, uranium (IV) is titrated with 0.1 N cerium(IV) sulfate. Then, plutonium is titrated by 0.02 N cerium(IV) sulfate. When a mixture of uranium and plutonium is titrated with 0.1 N potassium dichromate potentiometrically, the potential change at the end point of plutonium is very small and the end point of uranium is also unclear when 0.1 N potassium permanganate is used as a titrant. In the present method, nitrate, fluoride and copper(II) interfere with the determination of plutonium and uranium. Iron interferes quantitatively with the determination of plutonium but not of uranium. Results obtained in applying the proposed method to 50 mg of mixtures of plutonium and uranium ((7.5 -- 50))% Pu were accurate to within 0.15 mg of each element. (auth.)

Methods of Uranium Determination in solutions of Tributyl Phosphate and Kerosene

International Nuclear Information System (INIS)

Petrement Eguiluz, J.; Palomares Delgado, F.

1962-01-01

A new analytical method for the determination of uranium in organic solutions of tributyl phosphate and kerosene is proposed. In this method the uranium is reextracted from the aqueous phase by reduction with cadmium in acid solution. The uranium can be determined in this solution by the usual methods. In case of very diluted solutions, a direct spectrophtometrical determination of uranium in the organic phase with dibenzoylmethane is proposed. (Author) 21 refs

Uranium prospecting; La prospection de l'uranium

Energy Technology Data Exchange (ETDEWEB)

Roubault, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

This report is an instruction book for uranium prospecting. It appeals to private prospecting. As prospecting is now a scientific and technical research, it cannot be done without preliminary studies. First of all, general prospecting methods are given with a recall of fundamental geologic data and some general principles which are common with all type of prospecting. The peculiarities of uranium prospecting are also presented and in particular the radioactivity property of uranium as well as the special aspect of uranium ores and the aspect of neighbouring ores. In a third part, a description of the different uranium ores is given and separated in two different categories: primary and secondary ores, according to the place of transformation, deep or near the crust surface respectively. In the first category, the primary ores include pitchblende, thorianite and rare uranium oxides as euxenite and fergusonite for example. In the second category, the secondary ores contain autunite and chalcolite for example. An exhaustive presentation of the geiger-Mueller counter is given with the presentation of its different components, its functioning and utilization and its maintenance. The radioactivity interpretation method is showed as well as the elaboration of a topographic map of the measured radioactivity. A brief presentation of other detection methods than geiger-Mueller counters is given: the measurement of fluorescence and a chemical test using the fluorescence properties of uranium salts. Finally, the main characteristics of uranium deposits are discussed. (M.P.)

Determination of uranium and plutonium in urine of people working with regenerated uranium

International Nuclear Information System (INIS)

Golutvina, M.M.; Ryzhova, E.A.

1987-01-01

Method of determining uranium and plutonium content in urine with their combined presence up to α-activity ratio Pu:U=1:100 is developed. The method is based on extraction chromatographic separation of nuclides using trimethyloctylammonium nitrate and their subsequent α-spectrometric determination. The coefficient of plutonium purification from uranium makes up 750. Chemical yield of Pu is 72±6%, U-76±8%. The method sensitivity is 0.2 decompositions per minute for a sample

Determination of uranium in samples containing bulk aluminium

International Nuclear Information System (INIS)

Das, S.K.; Kannan, R.; Dhami, P.S.; Tripathi, S.C.; Gandhi, P.M.

2015-01-01

The determination of uranium is of great importance in PUREX process and need to be analyzed at different concentration ranges depending on the stage of reprocessing. Various techniques like volumetry, spectrophotometry, ICP-OES, fluorimetry, mass spectrometry etc. are used for the measurement of uranium in these samples. Fast and sensitive methods suitable for low level detection of uranium are desirable to cater the process needs. Microgram quantities of uranium are analyzed by spectrophotometric method using 2-(5- bromo-2-pyridylazo-5-diethylaminophenol) (Br-PADAP) as the complexing agent. But, the presence of some of the metal ions viz. Al, Pu, Zr etc. interferes in its analysis. Therefore, separation of uranium from such interfering metal ions is required prior to its analysis. This paper describes the analysis of uranium in samples containing aluminium as major matrix

Determination of Uranium and Thorium in Drinking and Seawater

International Nuclear Information System (INIS)

Rozmaric Macefat, M.; Gojmerac Ivsic, A.; Grahek, Z.; Barisic, D.

2008-01-01

Uranium and thorium are the first members of natural radioactive chain which makes their determination in natural materials interesting from geochemical and radioecological aspect. They are quantitatively determined as elements by spectrophotometric method and/or their radioisotopes by alpha spectrometry and ICP-MS. It is necessary to develop inexpensive, rapid and sensitive methods for the routine researches because of continuous monitoring of the radioactivity level. Development of a new method for the isolation of uranium and thorium from liquid samples and subsequent spectrophotometric determination is described in this paper. It is possible to isolate uranium and thorium from drinking and seawater using extraction chromatography or ion exchange chromatography. Uranium and thorium can be strongly bound on the TRU extraction chromatographic resin from 3 mol dm -3 HNO 3 (chemical recovery is 100 percent) and separated from other interfering elements (sodium, potassium, calcium, strontium etc). Their mutual separation is possible by using anion exchanger Amberlite CG-400 (NO 3 - form). From alcoholic solutions of nitric acid thorium can be strongly bound on the anion exchanger while uranium is much more weakly bound which enables its separation from thorium. After the separation, uranium and thorium are determined by spectrophotometric method with arsenazo III at 652 nm and 662 nm respectively. Developed method enables selection of the optimal mode of isolation for the given purposes.(author)

Fluorometric analysis for uranium in natural waters

International Nuclear Information System (INIS)

Waterbury, G.R.

1977-01-01

A fluorometric method is used for the routine determination of uranium at 0.2 to parts-per-billion (ppB) concentrations in natural surface waters. Duplicate 200-μl aliquots of the water samples are pipetted onto 0.4-g pellets of 98 percent NaF-2 percent LiF flux contained in platinum dishes. The pellets are dried under heat lamps and fused over special propane burners. The fused pellets are subjected to ultraviolet radiation and the fluorescence is measured in a fluorometer. The lower limit of detection is 0.2 ppB of uranium, and the precision is about 15 relative percent in the 0.2 to 10 ppB uranium concentration range. Two analysts determine uranium in 750 to 900 samples per week using this method. Samples containing solids or more than 19 ppB of uranium are analyzed by a delayed neutron counting method

Determination of uranium by an amperometric method

International Nuclear Information System (INIS)

John, Mary; Venkataramana, P.; Vaidyanathan, S.; Natarajan, P.R.

1981-01-01

An amperometric method has been standardised for the determination of uranium. Uranium is reduced to its quadrivalent state in concentrated phosphoric acid medium with ferrous iron. The excess iron is destroyed with nitric acid in presence of Mo(VI). The medium is diluted and U(IV) is titrated with standard potassium dichromate to an amperometric end point using a pair of identical plantinum wires as electrodes. The reagent volumes and uranium quantities have been scaled down to 30 ml. and 2-5 mg of uranium in the present work with a view to minimising the problems associated with recovery of plutonium. The results are quantitative with an R.S.D. of 0.2% in the present version of weight based titrations. (author)

Trace determination of uranium in fertilizer samples by total ...

Indian Academy of Sciences (India)

Uranium is reported to be present in phosphate fertilizers. The recovery of uranium from the fertilizers is important because it can be used as fuel in nuclear reactors and also because of environmental concerns. For both these activities suitable method of uranium determinations at trace levels in these fertilizers are required.

Standard test methods for analysis of sintered gadolinium oxide-uranium dioxide pellets

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 These test methods cover procedures for the analysis of sintered gadolinium oxide-uranium dioxide pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Section Carbon (Total) by Direct CombustionThermal Conductivity Method C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Chlorine and Fluorine by Pyrohydrolysis Ion-Selective Electrode Method C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Gadolinia Content by Energy-Dispersive X-Ray Spectrometry C1456 Test Method for Determination of Uranium or Gadolinium, or Both, in Gadolinium Oxide-Uranium Oxide Pellets or by X-Ray Fluorescence (XRF) Hydrogen by Inert Gas Fusion C1457 Test Method for Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction Isotopic Uranium Composition by Multiple-Filament Surface-Ioni...

Determination of isotopic uranium in food and water

International Nuclear Information System (INIS)

Baratta, E.J.; Mackill, P.

2001-01-01

The U.S. Food and Drug Administration (FDA) conducts surveys of foods both domestic and imported for the presence of radioactivity. It does not routinely analyze for the actinides, specifically uranium, as it has been shown by previously by studies as reported by WELFORD and others that the concentration in food is very low. This was the result of a 'Tri-City' study. However, at specific sites, the FDA has been requested to analyze for uranium. The concern is that either 'enriched' or 'depleted' uranium has been introduced into the environment and possibly contaminated the food supply. In addition some concern has been raised that water from wells or other sources used for processing food may contain uranium, both natural, depleted or enriched. Methodology for the determination of isotopic uranium, specifically for uranium-238 (depleted) and/or uranium-235 (enriched) in the analyses of food and water samples and the results of these surveys are discussed. (author)

Application of chronocoulomentry for trace levels uranium determination using catalytic nitrate reduction on mercury electrode

International Nuclear Information System (INIS)

Cantagallo, M.I.C.

1988-01-01

With the aim of improving the sensitivity of the electro-analytical determination of uranium at trace levels, the uranium catalyzed reduction of nitrate on mercury electrodes was used and the technique of chronocoulometry was compared with other voltammetric techniques. The catalytic process offers high sensitivity in comparison with uranyl reduction in absence of nitrate. The chronocoulometry, virtually unexplored for analytical applications, was found to be specially well suited for determinations based on this kind of electrode process, when using current integration times in the range of several seconds. Under these conditions the interference from diffusion controlled faradaic processes is reduced to a minimum. Several experimental parameters were investigated (eletrolyte composition, potential program, integration time, blank correction, temperature, previous separation) and adequate conditions were selected for the analytical determination of pure and real samples. The proposed method was applied and evaluated with real and, when necessary, an adapted liquid-liquid extraction procedure was used. Reference materials with complex matrices like rocks were first solubilized by hot digestion under pressure. The obtained results are in good agreement with the values obtained with other techniques such as X-ray fluorescence, mass spectrometry-isotope dilution and epithermal netron activation analysis. (author) [pt

Spectrochemical method of uranium determination in sea water

International Nuclear Information System (INIS)

Koval'chuk, L.I.; Koryukova, V.P.; Andrianov, A.M.

1979-01-01

A spectrochemical method of uranium determination in sea water is reported. The method involves the use of hydrated titanium oxide as a concentrator and a substrate for the analysis. The uranium-containing concentrate mixed with carbon powder (1:1) is burned in the alternating current ark (i=15 A) and the spectra are recorded by a diffraction spectrometer. The analytical line of uranium is 2865.14 A. The variation coefficient is 12%

The determination of uranium in pyrite samples

International Nuclear Information System (INIS)

Jacobs, J.J.

1979-01-01

An existing method for the determination of uranium in rocks and minerals is examined for the determination of uranium in materials containing pyrite. The results are comparable with those obtained by a spectrophotometric method, the precision (relative standard deviation) of the method for standards with U 3 O 8 contents of 1500 and 300 p.p.m. being 0,03 and 0,08 respectively when prepared in pyrite, and 0,15 and 0,06 respectively when made up with inert diluent. Full details of the procedure are given in accompanying appendices [af

Measurement of isotope shift of recycled uranium by laser induced fluorescence spectroscopy

International Nuclear Information System (INIS)

Oba, Masaki; Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi

1999-07-01

Isotope shift of the recycled uranium atoms including the 236 U was measured by laser induced fluorescence method. Eight even levels at 2 eV and three odd levels at 4 eV were measured with isotope shifts among 238 U, 236 U and 235 U obtained. As for the measurement of the 4 eV levels, the Doppler free two photon absorption method was used, and the hyperfine structure of the 235 U was analyzed simultaneously. The isotope shift of 234 U was also observed in the three transition. (J.P.N.)

Trace determination of uranium in fertilizer samples by total ...

Indian Academy of Sciences (India)

the fertilizers is important because it can be used as fuel in nuclear reactors and also because of en- vironmental concerns. ... The amounts of uranium in four fertilizer samples of Hungarian origin were determined by ... TXRF determination of uranium from phosphate fertilizers of Hungarian origin and the preliminary results ...

Anion-exchange enrichment and spectrophotometric determination of uranium in sea-water

International Nuclear Information System (INIS)

Kuroda, Rokuro; Oguma, Koichi; Mukai, Noriko; Iwamoto, Masatoshi

1987-01-01

A method is proposed for the determination of uranium in sea-water. The uranium is strongly sorbed on a strongly basic anion-exchange resin (Cl - form) from acidified sea-water containing sodium azide (0.3M) and is easily eluted with 1M hydrochloric acid. Uranium in the effluent can be determined spectrophotometrically with Arsenazo III. The combined method allows easy and selective determination of uranium in sea-water without using a sophisticated adsorbent. The overall recovery and precision are satisfactory at the 3 μg/1. level. (author)

Uranium prospecting; La prospection de l'uranium

Energy Technology Data Exchange (ETDEWEB)

Roubault, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

This report is an instruction book for uranium prospecting. It appeals to private prospecting. As prospecting is now a scientific and technical research, it cannot be done without preliminary studies. First of all, general prospecting methods are given with a recall of fundamental geologic data and some general principles which are common with all type of prospecting. The peculiarities of uranium prospecting are also presented and in particular the radioactivity property of uranium as well as the special aspect of uranium ores and the aspect of neighbouring ores. In a third part, a description of the different uranium ores is given and separated in two different categories: primary and secondary ores, according to the place of transformation, deep or near the crust surface respectively. In the first category, the primary ores include pitchblende, thorianite and rare uranium oxides as euxenite and fergusonite for example. In the second category, the secondary ores contain autunite and chalcolite for example. An exhaustive presentation of the geiger-Mueller counter is given with the presentation of its different components, its functioning and utilization and its maintenance. The radioactivity interpretation method is showed as well as the elaboration of a topographic map of the measured radioactivity. A brief presentation of other detection methods than geiger-Mueller counters is given: the measurement of fluorescence and a chemical test using the fluorescence properties of uranium salts. Finally, the main characteristics of uranium deposits are discussed. (M.P.)

Uranium Age Determination by Measuring the 230Th / 234U Ratio

International Nuclear Information System (INIS)

LAMONT, STEPHEN P.

2004-01-01

A radiochemical isotope dilution mass spectrometry method has been developed to determine the age of uranium materials. The amount of 230Th activity, the first progeny of 234U, that had grown into a small uranium metal sample was used to determine the elapsed time since the material was last radiochemically purified. To preserve the sample, only a small amount of oxidized uranium was removed from the surface of the sample and dissolved. Aliquots of the dissolved sample were spiked with 233U tracer and radiochemically purified by anion-exchange chromatography. The 234U isotopic concentration was then determined by thermal ionization mass spectrometry. Additional aliquots of the sample were spiked with 229Th tracer, and the thorium was purified using two sequential anion-exchange chromatography separations. The isotopic concentrations of 230Th and 232Th were determined by TIMS. The lack of any 232Th confirmed the assumption that all thorium was removed from the uranium sample at the time of purification. The 230Th and 234U mass concentrations were converted to activities and the 230Th/234U ratio for the sample was calculated. The experimental 230Th/234U ratio showed the uranium in this sample was radiochemically purified in about 1945. Isotope dilution thermal ionization mass spectrometry has sufficient sensitivity to determine the age of 100 samples of uranium. This method could certainly be employed as a nuclear forensic method to determine the age of small quantities of uranium metal or salts. Accurate determination of the ultra-trace 230Th radiochemically separated from the uranium is possible due to the use of 229Th as an isotope dilution tracer. The precision in the experimental age of the uranium could be improved by making additional replicate measurements of the 230Th/234U isotopic ratio or using a larger initial sample

Analytical procedure for the titrimetric determination of uranium in concentrates

International Nuclear Information System (INIS)

Florence, T.M.; Pakalns, P.

1989-01-01

In 1964 Davis and gray published a titrimetric method for uranium which does not require column reductors, electronic instruments or inert atmospheres, and is sufficiently selective to enable uranium to be determined without prior separation. The method involves reduction of uranium (VI) to (IV) by ferrous sulphate in concentrated phosphoric acid medium. The excess ion (II) is then selectively oxidised by nitric acid using molybdenum catalyst. After addition of sulphuric acid and dilution with water, the uranium (IV) is titrated with standard potassium dichromate, using barium diphenylamine sulphonate indicator. This method has been found to be simple, precise and reliable, and applicable to a wide range of uranium-containing materials. The method given here for determining uranium in concentrates is essentially that of Davies and Gray. Its applications, apparatus, reagents, procedures and accuracy and precision are discussed. 10 refs

Determination of uranium, thorium and radium isotope ratio

International Nuclear Information System (INIS)

Sokolova, Z.A.

1983-01-01

The problems connected with the study of isotope composition of natural radioactive elements in natural objects are considered. It is pointed out that for minerals, ores and rocks the following ratios are usually determined: 234 U/ 238 U, 230 Th/ 238 U, 226 Ra/ 238 U, 228 Th/ 230 Th, 228 Th/ 232 Th and lead isotopes; for natural waters, besides the enumerated - 226 Ra/ 228 Ra. General content of uranium and thorium in the course of isotope investigations is determined from separate samples, most frequently by the X-ray spectral method, radium content - by usual radiochemical method, uranium and radium content in waters -respectively by calorimetric and emanation methods. Radiochemical preparation of geologic powder and aqueous samples for isotope analysis is described in detail. The technique of measuring and calculating isotope ratios (α-spectrometry for determining isotope composition of uranium and thorium and emanation method for determining 226 Ra/ 228 Ra) is presented

Uranium(VI) speciation by spectroscopy

International Nuclear Information System (INIS)

Meinrath, G.

1997-01-01

The application of UV-Vis and time-resolved laser-induced fluorescence (TRLF) spectroscopies to direct of uranium(VI) in environmental samples offers various prospects that have, however, serious limitations. While UV-Vis spectroscopy is probably not sensitive enough to detect uranium(VI) species in the majority of environmental samples, TRLFS is principially able to speciate uranium(VI) at very low concentration levels in the nanomol range. Speciation by TRLFS can be based on three parameters: excitation spectrum, emission spectrum and lifetime of the fluorescence emission process. Due to quenching effects, the lifetime may not be expected to be as characteristics as, e.g., the emission spectrum. Quenching of U(VI) fluorescence by reaction with organic substances, inorganic ions and formation of carbonate radicals is one important limiting factor in the application of U(VI) fluorescence spectroscopy. Fundamental photophysical criteria are illustrated using UV-Vis and fluorescence spectra of U(VI) hydrolysis and carbonato species as examples. (author)

Determination of the oxygen-metal-ratio of uranium-americium mixed oxides

International Nuclear Information System (INIS)

Bartscher, W.

1982-01-01

During the dissolution of uranium-americium mixed oxides in phosphoric acid under nitrogen tetravalent uranium is oxidized by tetravalent americium. The obtained hexavalent uranium is determined by constant potential coulometry. The coulombs measured are equivalent to the oxygen in excess of the minimum composition of UO 2 x AmO 1 . 5 . The total uranium content of the sample is determined in a subsequent coulometric titration. The oxygen-metal ratio of the sample can be calculated for a given uranium-americium ratio. An excess of uranium dioxide is necessary in order to suppress the oxidation of water by tetravalent americium. The standard deviation of the method is 0.0017 O/M units. (orig.) [de

Speciation and spectrophotometric determination of uranium in seawater

Directory of Open Access Journals (Sweden)

M. KONSTANTINOU

2004-06-01

Full Text Available A series of ion-exchange and extraction procedures for the separation of uranium from seawater samples and subsequent spectrophotometric determination of uranium in seawater by means of arsenazo(III is described. According to the measurements performed by means of traced samples at every stage of separation, the yield of the pre-analytical procedures is generally over 90% and the separation of uranium very selective. The mean uranium concentration in seawater samples collected from five different coastal areas in Cyprus was found to be 3.2 ± 0.2 & micro; g L-1. Uranium in seawater is stable in its hexavalent oxidation state and UO2 (CO334- is the predominant species under normal coastal conditions (pH ≥ 8, EH ≥ 0.35 mV, 1 atm and 0.03% CO2.

Determination of uranium in industrial and environmental samples. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

El-Sweify, F H; Shehata, M K; Metwally, E M; El-Shazly, E A.A.; El-Naggar, H A [Nuclear Chemistry Department, Hot Laborities Center, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

The phosphate ores used at `Abu zaabal fertilizer and chemical company` for the production of some chemicals and fertilizers contain detectable amounts of uranium. In this study, the content of uranium in samples of different products of fertilizers, gypsum, and phosphate ore were determined using NAA, and gamma ray spectroscopy of the irradiated samples. Another method based on measuring the natural radioactivity of {sup 238} U series for non-irradiated samples using gamma-ray spectroscopy was also used for determine uranium content in the samples. In the NAA method, the content of U(ppm) in the samples was been computed from the photopeak activity of the lines = 106.1, 228.2, and 277.5 KeV of {sup 239} Np induced in the irradiated samples, and the uranium standard simultaneously irradiated. the gamma-ray spectra, and the decay curves are given. In the second method the gamma-ray spectra of the natural radioactivity of the samples and uranium standard were measured. The gamma-transition of energies 295.1, 251.9 KeV for {sup 214} Pb; 609.3, 768.4, 1120.3, 1238.1 KeV for {sup 214} Bi were determined. The uranium {sup 23U} traces in drainage water was also determined spectrophotometrically using arsenazo-III after preconcentration of uranium from the pretreated drainage water in column packed with chelex-100 resin. The recovery was found to be 90 {+-} 5%. 11 figs., 3 tabs.

Analysis of uranium and its compounds. Ruthenium spectrographic determination

International Nuclear Information System (INIS)

Anon.

Ruthenium determination in uranium and its compounds, suitable for content greater than 0.1 ppm with respect to uranium, by dissolution in sulfuric acid and addition of palladium as an internal standard, separation of the precipitated ruthenium, in the presence of gold, by reduction with zinc, the precipitate is calcined and ruthenium is determined by spectrography [fr

Simultaneous determination of actinides by x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Cohen, V.H.

1990-01-01

The x-ray spectrometric simultaneous determination of uranium and plutonium in simulated Purex Process solutions is described. The method is accomplished by intensity measurements of the L α sub(1) lines. The thin film technique for sample preparation and thorium as an internal standard had been used. An evaporation technique had been also tested for low concentration uranium solutions. In the measurement range 0,05 - 130 U g/L, 0,5 - 20 Pu g/L linear calibration curves were effected. The standard deviation in the concentration range 10 to 130 g/L was 3,5%, 4% in the 1 to 10 g/L and 13% in 0,05 to 1 g/L for uranium determination and 4% for plutonium determination in the range of 1 to 20 g/L. The sensitivity of the method was about 3,62 μg to U and 3,95 μg to Pu. Uranium and plutonium do not reciprocally interfere with one another until U/Pu ≅ 90 m/m. The fission product as interfering elements were also verified. Finally, uranium and plutonium were determined in simulated Purex Process solutions within the requested accuracy for control method. (author)

Determination of chlorine in nuclear-grade uranium compounds

International Nuclear Information System (INIS)

Yang Chunqing; Liu Fuyun; Huang Dianfan

1988-01-01

The determination of chlorine in nuclear-grade uranium compounds is discribed. Chlorine is separated from uranium oxide pyrohydrolytically with stream of wet oxygen in a furnace at 800 ∼ 900 deg C. Chlorine is volatilized as hydrochloric acid, absorbed in a dilute alkaline solution and measured with chlorine-selective electrode. This method covers the concentration range of 10 ∼ 500 pm chlorine in uranium oxide. Precision of at least ± 10% and recovery of 85 ∼ 108% have been reported

Simultaneous determination of a binary mixture: kinetic method for determination of uranium and vanadium

International Nuclear Information System (INIS)

Jianhua, W.; Ronghuan, H.

1993-01-01

A kinetic method for simultaneous determination of a binary mixture is proposed, and a procedure for simultaneous determination of uranium (IV) and vanadium (IV) is established based on their inductive effect on chromium (VI)-iodide redox reaction in a weak acidic medium. The reaction was monitored by FIA-spectrophotometry using the I 3 - -starch complex as indicator. The calibration graphs are linear for uranium (IV) and vanadium (IV) within the range of 0 ∼ 3.6 μg/ml and 0 ∼ 2.5 μg/ml respectively. Most foreign ions, except for iron (II) and antimony (III), do not interfere with the determination. The uranium and vanadium content in different samples was determined, and the results were satisfactory. (author). 2 tabs., 2 figs., 9 refs

Spatially resolved analyses of uranium species using a coupled system made up of confocal laser-scanning microscopy (CLSM) and laser induced fluorescence spectroscopy (LIFS); Ortsaufgeloeste Analyse von Uranspezies mittels einem Gekoppelten System aus Konfokaler Laser-Scanning Mikroskopie (CLSM) und Laser Induzierter Fluoreszenzspektroskopie (LIFS)

Energy Technology Data Exchange (ETDEWEB)

Brockmann, S. [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. (VKTA), Dresden (Germany); Grossmann, K.; Arnold, T. [Helmholtz-Zentrum Dresden-Rossendorf e.V. (Germany). Inst. fuer Ressourcenoekologie

2014-01-15

The fluorescent properties of uranium when excited by UV light are used increasingly for spectroscope analyses of uranium species within watery samples. Here, alongside the fluorescent properties of the hexavalent oxidation phases, the tetra and pentavalent oxidation phases also play an increasingly important role. The detection of fluorescent emission spectrums on solid and biological samples using (time-resolved) laser induced fluorescence spectroscopy (TRLFS or LIFS respectively) has, however, the disadvantage that no statements regarding the spatial localisation of the uranium can be made. However, particularly in complex, biological samples, such statements on the localisation of the uranium enrichment in the sample are desired, in order to e.g. be able to distinguish between intra and extra-cellular uranium bonds. The fluorescent properties of uranium (VI) compounds and minerals can also be used to detect their localisation within complex samples. So the application of fluorescent microscopic methods represents one possibility to localise and visualise uranium precipitates and enrichments in biological samples, such as biofilms or cells. The confocal laser-scanning microscopy (CLSM) is especially well suited to this purpose. Coupling confocal laser-scanning microscopy (CLSM) with laser induced fluorescence spectroscopy (LIFS) makes it possible to localise and visualise fluorescent signals spatially and three-dimensionally, while at the same time being able to detect spatially resolved, fluorescent-spectroscopic data. This technology is characterised by relatively low detection limits from up to 1.10{sup -6} M for uranium (VI) compounds within the confocal volume. (orig.)

Uranium determination in soil samples using Eichrom resins

International Nuclear Information System (INIS)

Marabini, S.; Serdeiro, Nelidad H.

2003-01-01

Traditionally, the radiochemical methods for uranium activity determination in soil samples by alpha spectrometry, use some techniques like solvent extraction, precipitation and ion exchange in the separation and purification stages. In the last years, some new materials have been developed for using in extraction chromatography, specific for actinides determinations. In the present method the long and tedious stages were eliminated, and the reagents consumption and concentration were minimised. This new procedure was applied to soils since it is one of the most complex matrices. In order to reduce time and chemical reagents, the soil samples up to 0,5 g were leached with nitric, hydrofluoric and perchloric acids in hermetic sealed recipients of Teflon at 150 C degrees during 5 hours. UTEVA Eichrom resin was used for uranium separation and purification. The uranium activity concentration was determined by alpha spectrometry. Several standard samples were analysed and the results are presented. (author)

Standard test method for analysis of uranium and thorium in soils by energy dispersive X-Ray fluorescence spectroscopy

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This test method covers the energy dispersive X-ray fluorescence (EDXRF) spectrochemical analysis of trace levels of uranium and thorium in soils. Any sample matrix that differs from the general ground soil composition used for calibration (that is, fertilizer or a sample of mostly rock) would have to be calibrated separately to determine the effect of the different matrix composition. 1.2 The analysis is performed after an initial drying and grinding of the sample, and the results are reported on a dry basis. The sample preparation technique used incorporates into the sample any rocks and organic material present in the soil. This test method of sample preparation differs from other techniques that involve tumbling and sieving the sample. 1.3 Linear calibration is performed over a concentration range from 20 to 1000 μg per gram for uranium and thorium. 1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units in parentheses are for information only. 1.5 This standard...

Determination of the stoichiometric ratio uranium dioxide samples

International Nuclear Information System (INIS)

Moura, Sergio Carvalho

1999-01-01

The determination of the O/U stoichiometric ratio in uranium dioxide is an important parameter in order to qualify nuclear fuels. The excess oxygen in the crystallographic structure can cause changes in the physico-chemical properties of this compound such as variation of the thermal conductivity alterations, fuel plasticity and others, affecting the efficiency of this material when it is utilized as nuclear fuel in the reactor core. The purpose of this work is to evaluate methods for the determination of uranium oxide samples from two different production processes, using gravimetric, voltammetric and X-ray diffraction techniques. After the evaluation of these techniques, the main aspect of this work is to define a reliable methodology in order to characterize the behavior of uranium oxide. The methodology used in this work consisted of two different steps: utilization of gravimetric and volumetric methods in order to determine the ratio in uranium dioxide samples; utilization of X-ray diffraction technique in order to determine the lattice parameters using patterns and application of the Rietveld method during refining of the structural data. As a result of the experimental part of this work it was found that the X-ray diffraction analysis performs better and detects the presence of more phases than gravimetric and voltammetric techniques, not sensitive enough in this detection. (author)

Uranium metal and uranium dioxide powder and pellets - Determination of nitrogen content - Method using ammonia-sensing electrode. 1. ed.

International Nuclear Information System (INIS)

1994-01-01

This International Standard specifies an analytical method for determining the nitrogen content in uranium metal and uranium dioxide powder and pellets. It is applicable to the determination of nitrogen, present as nitride, in uranium metal and uranium dioxide powder and pellets. The concentration range within which the method can be used is between 9 μg and 600 μg of nitrogen per gram. Interference can occur from metals which form complex ammines, but these are not normally present in significant amounts

Determination of Oxygen - to - Uranium Ratio in Hyperstoichio - Metric Uranium Dioxide. RCN Report

International Nuclear Information System (INIS)

Tolk, A.; Lingerak, W.A.

1970-09-01

For the determination of the O/U ratio in hyperstoichiometric uranium dioxide we prefer the following chemical procedure. The sample is dissolved in concentrated phosphoric acid without change in valence of the uranium. Then the amount of U (VI) present in the solution is titrated with a Fe (II) - standard solution in phosphoric acid. The titrimetric end-point is detected following the ''dead-stop-end-point'' procedure. When special precautions are made the O/U value can be determined with an accuracy and precision of + 0.0001 0/U units when 500 mg sample aliquots are used. (author)

Titrimetric determination of uranium

International Nuclear Information System (INIS)

Florence, T.M.

1989-01-01

Titrimetric methods are almost invariably used for the high precision assay of uranium compounds, because gravimetric methods are nonselective, and not as reliable. Although precipitation titrations have been used, for example with cupferron and ferrocyanide, and chelate titrations with EDTA and oxine give reasonable results, in practice only redox titrations find routine use. With all redox titration methods for uranium a precision of 01 to 02 percent can be achieved, and precisions as high as 0.003 percent have been claimed for the more refined techniques. There are two types of redox titrations for uranium in common use. The first involves the direct titration of uranium (VI) to uranium (IV) with a standard solution of a strong reductant, such as chromous chloride or titanous chloride, and the second requires a preliminary reduction of uranium to the (IV) or (III) state, followed by titration back to the (VI) state with a standard oxidant. Both types of redox titrations are discussed. 4 figs

Automated controlled-potential coulometric determination of uranium

International Nuclear Information System (INIS)

Knight, C.H.; Clegg, D.E.; Wright, K.D.; Cassidy, R.M.

1982-06-01

A controlled-potential coulometer has been automated in our laboratory for routine determination of uranium in solution. The CRNL-designed automated system controls degassing, prereduction, and reduction of the sample. The final result is displayed on a digital coulometer readout. Manual and automated modes of operation are compared to show the precision and accuracy of the automated system. Results are also shown for the coulometric titration of typical uranium-aluminum alloy samples

Process of quantity determination of uranium by chromatography in liquid zone

International Nuclear Information System (INIS)

Muller, J.P.; Cojean, J.; Daubizit, M.

1993-01-01

The invention concerns a process of quantity determination of uranium by chromatography in liquid zone, usable to determine the quantity of uranium traces. Solutions to be treated can be aqueous or organic

Simple and selective method for determination of microgram quantities of uranium-238 in urine

International Nuclear Information System (INIS)

Pavlovskaya, N.A.; Martakova, P.I.

1977-01-01

A technique has been developed and described to determine microgram quantities of uranium-238 in urea. The subject of the technique is as follows: urea (50-500 ml) is acidified with hydrochloric acid, and uranium(6) is quantitatively isolated by its coprecipitation with methylviolet rhodanide; the precipitate is separated by centrifuging and mineralized in the presence of nitric and chloric acids; then uranium (6) is reduced into uranium(4) and its amount is determined photoelectrocolorimetrically using the ''arsenazo 3'' reagent. The limiting amount of uranium in a sample being determined is 10 -6 . For a sample volume of 500 ml sensitivity of the technique of uranium determination is 2x10 -9 g/ml. Titanium, thorium and niobium do not interfere with determination of uranium

Spectrographic determination of microconstituents in uranium tetrafluoride

International Nuclear Information System (INIS)

Paula Reino, L.C. de; Lordello, A.R.

1982-11-01

A espectrographic method for the direct determination of impurities in uranium tetrafluoride (UF 4 ) was developed. The major impurities introduced during the preparation of UF 4 (Fe, Ni, Cr) and other impurities introduced in the prior stages of this preparation were determined. Spectrochemical carriers were used to suppress the uranium distillation during excitation, because fluoride compound is more volatile the refractory matrix (U 3 O 8 ). Better results were obtained using as carrier a mixture of 20% MgO and 10% MgO and 10% NaCl, concerning to the UF 4 matrix. The sensibilities for some of those impurities are in the ppm level. (Author) [pt

Uranium determination in phosphatized materials by drop electrode polarography

International Nuclear Information System (INIS)

Sequeira, F.M.C. de; Abrao, A.

1987-01-01

An uranium determination procedure in phosphate rocks and crude phosphoric acid is outlined polarography is used. Uranium is previously separedted by extraction with tri-n-byte phosphate 10%-petroleum ether using aluminium nitrate as salting out agent. (M.L.J.) [pt

Determination of carbon in uranium and its compounds

International Nuclear Information System (INIS)

Perez-Garcia, M. M.

1972-01-01

This paper collects the analytical methods used our laboratories for the determination of carbon in uranium metal, uranate salts and the oxides, fluorides and carbides of uranium. The carbon is usually burned off in a induction or resistance oven under oxygen flow. The CO 2 is collected in barite solution. Where it is backtitrated with potassium biphthalate. (Author)

The determination of phosphorus in uranium minerals and resulting solutions

International Nuclear Information System (INIS)

Petrement Eguiluz, J. C.; Parellada Bellod, R.; Fernandez Cellini, R.

1964-01-01

Interferences of several elements present in Spanish uranium minerals in the phosphorus determination by the spectrophotometrical method of the molibdovanada te phosphoric acid are studied. A method is described with a previous separation of these element by a cationic resin. This method is successfully applied to the phosphorus determination in acid or alkaline lixiviation solutions of uranium minerals, as well as in the evaluates of ion exchange resins used used technically for the concentration of solutions with a low uranium content. (Author) 11 refs

Simultaneous determination of plutonium and uranium in environmental samples

International Nuclear Information System (INIS)

Jiao Shufen

1993-01-01

Plutonium and uranium in a plant sample ash was simultaneously determined by using anion exchange resin columns, and concentrated hydrochloric acid and nitric acid. At the final stage of the determination of the nuclides, each of them was electrodeposited together with a little amount of molybdenum carrier onto a stainless steel plate and measured by α-ray spectrometer. The recoveries of uranium and plutonium from the plant samples determined by adding internal standard 236 Pu which was 100% and 63%, respectively

Laser-time resolved fluorimetric determination of trace of boron in U3O8

International Nuclear Information System (INIS)

Xu Yongyuan; Wang Yulong; Wang Qin

1988-01-01

In this work, a laser-time resolved fluorimetric determinatin of trace of boron in U 3 O 8 had been developed. The boron complex with dibenzoyl methane (DBM) in a suitable medium is excited by a small nitrogen laser and emits the delay fluorescence with lifetime of 2 ms which is much longer than that of the fluorescence of uranium. Since the fluorescence of uranium doesn't interfere with determination of boron in the time resolved fluorimetric method boron need not be separated from uranium in advance. Thus the determination is very rapid and simple. The limit of determination is 0.02 ngB/ml. When 10 mgU is taken, 0.01 ppm of boron in uranium can be determined. Several samples of U 3 O 8 with boron content from 0.04 to 0.5 ppm have been determined by using this method. The results of determination have been accordant with other methods

Thorium determination by x-ray fluorescence spectrometry in simulated thorex process solutions

International Nuclear Information System (INIS)

Yamaura, M.; Matsuda, H.T.

1991-11-01

The X-ray fluorescence method for thorium determination in aqueous and organic (TBP/n-dodecane) solutions is described. The thin film technique for sample preparation and a suitable internal standard had been used. The best conditions for Thorium determination had been established studying some parameters as analytical line, internal standard, filter paper, paper geometry, sample volume and measurement conditions. With the established conditions, thorium was concentration range of to 200 g Th/L and in organic solutions (2-63g Th/L) with 1,5% of precision. The accuracy of the proposed method was 3% in aqueous and organic phases. The detection limit was 1,2μg thorium for aqueous solutions and 1,4μg for organic solutions. Uranium, fission products, corrosion products and Thorex reagent components were studied as interfering elements in the thorium analysis. The matrix effect was also studied using the Thorex process simulated solutions. Finally, the method was applied to thorium determination in irradiated thorium solutions with satisfactory results. (author)

Applications of optical fiber to remote laser fluorescence analysis

International Nuclear Information System (INIS)

Kim, Cheol Jung; Shin, Jang Soo; Lee, Sang Mock; Kim, Jeong Moog; Kim, Duk Heon; Hong, Seok Kyung

1991-12-01

Fluorescence analysis using time-resolved laser fluorimetry has been used for trace uranium analysis because this method shows high sensitivity and low detection limit and is less matrix dependent than any other fluorimetric measurement. By this time, the uranium analyses in the solution of reprocessing process or high radioactive area have been primarily analyzed by sampling of the solution, but recently, a study on a remote uranium fluorescence analysis using optical fiber has been setting out based on the development of an optical fiber with radiation resistivity and of an advanced laser excitation source. Laser fluorimetry developed by our laboratory for trace uranium analyses in uranium handling process or in urine samples of workers in a nuclear facility has been used in our institute since 1988. A development of the system for remote control of uranium fluorescence analysis will be expected to contribute to an on-line uranium concentration monitoring in the cooling water of reconversion stream. In this report, we summarize the information related to fluorescence analyses and remote fluorescence monitoring methods established by foreign countries and our laboratory. We also present a future research direction for remote on-line monitoring of uranium in conversion or reconversion process. (Author)

Aftermath of Uranium Ore Processing on Floodplains: Lasting Effects of Uranium on Soil and Microbes

Science.gov (United States)

Tang, H.; Boye, K.; Bargar, J.; Fendorf, S. E.

2016-12-01

A former uranium ore processing site located between the Wind River and the Little Wind River near the city of Riverton, Wyoming, has generated a uranium plume in the groundwater within the floodplain. Uranium is toxic and poses a threat to human health. Thus, controlling and containing the spread of uranium will benefit the human population. The primary source of uranium was removed from the processing site, but a uranium plume still exists in the groundwater. Uranium in its reduced form is relatively insoluble in water and therefore is retained in organic rich, anoxic layers in the subsurface. However, with the aid of microbes uranium becomes soluble in water which could expose people and the environment to this toxin, if it enters the groundwater and ultimately the river. In order to better understand the mechanisms controlling uranium behavior in the floodplains, we examined sediments from three sediment cores (soil surface to aquifer). We determined the soil elemental concentrations and measured microbial activity through the use of several instruments (e.g. Elemental Analyzer, X-ray Fluorescence, MicroResp System). Through the data collected, we aim to obtain a better understanding of how the interaction of geochemical factors and microbial metabolism affect uranium mobility. This knowledge will inform models used to predict uranium behavior in response to land use or climate change in floodplain environments.

Nuclear energy - Uranium dioxide powder and sintered pellets - Determination of oxygen/uranium atomic ratio by the amperometric method. 2. ed.

International Nuclear Information System (INIS)

2007-01-01

This International Standard specifies an analytical method for the determination of the oxygen/uranium atomic ratio in uranium dioxide powder and sintered pellets. The method is applicable to reactor grade samples of hyper-stoichiometric uranium dioxide powder and pellets. The presence of reducing agents or residual organic additives invalidates the procedure. The test sample is dissolved in orthophosphoric acid, which does not oxidize the uranium(IV) from UO 2 molecules. Thus, the uranium(VI) that is present in the dissolved solution is from UO 3 and/or U 3 O 8 molecules only, and is proportional to the excess oxygen in these molecules. The uranium(VI) content of the solution is determined by titration with a previously standardized solution of ammonium iron(II) sulfate hexahydrate in orthophosphoric acid. The end-point of the titration is determined amperometrically using a pair of polarized platinum electrodes. The oxygen/uranium ratio is calculated from the uranium(VI) content. A portion, weighing about 1 g, of the test sample is dissolved in orthophosphoric acid. The dissolution is performed in an atmosphere of nitrogen or carbon dioxide when sintered material is being analysed. When highly sintered material is being analysed, the dissolution is performed at a higher temperature in purified phosphoric acid from which the water has been partly removed. The cooled solution is titrated with an orthophosphoric acid solution of ammonium iron(II) sulfate, which has previously been standardized against potassium dichromate. The end-point of the titration is detected by the sudden increase of current between a pair of polarized platinum electrodes on the addition of an excess of ammonium iron(II) sulfate solution. The paper provides information about scope, principle, reactions, reagents, apparatus, preparation of test sample, procedure (uranium dioxide powder, sintered pellets of uranium dioxide, highly sintered pellets of uranium dioxide and determination

Determination of geochemical and anthropogenic uranium sources in soil and tailing

International Nuclear Information System (INIS)

Stojanovic, M.; Potpara, D.; Tesmanovic, L.

2002-01-01

The origin of uranium in soil (geochemical or anthropogenic) influences the degree of its accessibility to plants. Uranium originating from the geochemical sources is much less, if not quite inaccessible to plants. On the other hand uranium accumulated in soil as a result of anthropogenic activity (use of phosphate fertilisers, dissemination of flying ash from the thermal power plants, dissemination of mining wastes, disposal of nuclear waste and use of ammunition produced from depleted uranium) is most often present in forms much more accessible to plants. The aim of this work was to determine the efficiency of different methods of uranium extraction from soil (used to determine the 'mobile' and accessible contents) which could give the answer on the level of its accessibility to plants, and to determine uranium distribution in various chemical fractions by the method of fractional extraction.The applied method of fractional extraction is based on the idea that all metals form bonds of different strength with the solid phase of soil and such bonds can be completely broken under the effect of reagents such as: 0.1M CaCl 2 (pH - 7.0) for extraction of water-soluble and alternately adsorbed forms of metals; 1M CH 3 COONa (pH - 5.0) for the extraction of specifically adsorbed forms of metals bonded to carbonates; 0.04M hydroxylamine hydrochloride in 25% CH 3 COOH (pH - 3.0) for extraction of metals bonded to Fe and Mn oxide; 0.02M HNO 3 in 30% H 2 O 2 for metals bonded to organic matter. Structurally bonded forms of metals in silicates are determined from the difference of the total uranium content and sum of the metal quantity from the first four fractions. Determination of uranium content in samples was performed by the fluorimetric method. (author)

Standardization of solvent extraction procedure for determination of uranium in sea water

International Nuclear Information System (INIS)

Maity, Sukanta; Dusane, C.B.; Sahu, S.K.; Pandit, G.G.

2014-01-01

Marine ecosystem is becoming polluted by heavy metals and naturally occurring radionuclides due to rapid industrialization and human activities. Many contaminants such as heavy metals and naturally occurring radionuclides though occur at extremely low concentration in sea water, are accumulated by marine organisms and concentrations in their body tissue can be hundreds of times greater than sea water. As human being consume different marine organisms like biota, can lead potential health problem to human being. Uranium is a naturally occurring radioactive element which is important for nuclear technology. However, mineral resources for uranium are limited. Seawater is a major source of uranium. The total estimated quantity of uranium in seawater is around four and a half billion tones. Thus, the oceans have the potential to become the most eco-friendly and long sustainable resource for uranium. A number of countries in the world are in search of techniques to recover uranium from seawater economically. For this purpose and also for the environmental monitoring, the determination of uranium in seawater is very much important. Seawater contains very high concentrations of salts and its uranium content is very low. Accordingly, the separation and preconcentration of uranium is usually involved in the analytical procedures used for the determination of uranium in seawater. In the present study solvent extraction procedure was adopted for the determination of uranium in sea water collected from different locations across Thane Creek area, Mumbai, India

Field technique for the measurement of uranium in natural waters

Energy Technology Data Exchange (ETDEWEB)

Robbins, J C [Scintrex Ltd., Concord, Ontario

1978-05-01

An analytical method suitable for field determination of trace levels of uranium in natural waters is described. Laser UV radiation causes persistent fluorescence of a uranyl complex. Electronic gating substantially rejects detection of short-lived natural organic matter fluorescence. Further work is required on effects of interferences in samples with complex matrices and interpretative aids such as concurrent conductivity and organic content measurements.

Determination of uranium in the red blood cells of the workers in the chemical processing of uranium ore

International Nuclear Information System (INIS)

Nosek, J.; Simkova, M.; Kukula, F.; Musil, K.

1975-04-01

Neutron activation analysis was used in determining uranium in the venous blood erythrocytes of controls and of workers exposed to occupational hazards in a uranium chemical treatment plant. While 4.1 +- 2.6 ppb of uranium was found in dry matter of the erythrocytes in controls, 6.5 +- 2.1 ppb of uranium was ascertained in dry matter of the erythrocytes in occupationally exposed workers of a wet preparation plant, and 37.2 +- 20.2 ppb of uranium in the erythrocytes in workers of a dry cleaning plant. (author)

On the interaction of uranium with the bioligands citric acid and glucose; Zur Wechselwirkung von Uran mit den Bioliganden Citronensaeure und Glucose

Energy Technology Data Exchange (ETDEWEB)

Steudtner, Robin

2011-10-26

For a better understanding of the actinide behaviour in human (in term of metabolism, retention, excretion) and in geological and biological systems, it is of prime importance to have a good knowledge of the relevant speciation. In model systems the chemical behaviour of uranium regarding complex formation and redox reaction were investigated. On this basis determinates thermodynamics constants and redox behaviour are used to prognoses a safety assessment for the respective system. The pentavalent uranium(V) is a metastable intermediate in natural redox system between uranium(IV) and uranium(VI). In this study the uranium(V) fluorescence was detected by laser spectroscopic methods ({lambda}{sub ex} = 255 nm) for the first time. The peak maxima ({lambda}{sub ex} = 255 nm) of luminescence spectrum of the photo reduced U(V) in aqueous perchlorate/2-propanol solution was detected at 440 nm and a fluorescence lifetime of 1.1 {+-} 0.02 {mu}s was calculated. The stable aqueous uranyl(V)-tricarbonate complex was characterized by fluorescence spectroscopy ({lambda}{sub ex} = 255 nm and 408 nm). The known quench effects of carbonate could be minimized by coupling the laser fluorescence system with the low temperature technique. The resulting U(V) fluorescence emission bands were detected between 375 nm and 445 nm. The peak maxima were identified at 401.5 nm ({lambda}{sub ex} = 255 nm) and 413.0 nm ({lambda}{sub ex} = 408 nm). The fluorescence lifetime of the uranyl(V)-carbonate species was determined at 153 K as 120 {+-} 0.1 {mu}s ({lambda}{sub ex} = 255 nm). In addition the fluorescence of uranium(V) was verifies by confocal laser scanning microscopy. The oxidation process from uranium(IV) to uranium(VI) was investigated on solid uraninite (UO{sub 2}) and uranium(IV) tetra chloride (UCl{sub 4}) and a 1 x 10{sup -2} M uranium(IV) sulphate (U{sup IV}SO{sub 4}) solution. By continuous oxygen transfer the uranium(IV) was oxidized slowly to uranium(VI). The temporal process was

Determination of favourable areas for uranium prospecting in Bolivia

International Nuclear Information System (INIS)

Pardo, E.

1981-01-01

The most prominent geological, lithological, stratigraphic, orogenic, metallogenetic, palaeogeographic and geochemical features favourable for the concentration of uranium deposits in Bolivia are described. This is a generalized study of the features mentioned above and should provide guidelines for eventual better understanding of the geology of Bolivia in general and that of uranium in particular. The purpose here is to demonstrate rational planning, which should be followed by the determination of favourable areas for uranium exploration, by the Bolivian Nuclear Energy Commission/Comision Boliviana de Energia Nuclear (COBOEN), and to provide basic information for the drawing up of contracts with foreign and/or national organizations interested in investing in uranium exploration. (author)

Uranium in coral skeletons determined by epithermal neutron activation analysis

International Nuclear Information System (INIS)

Ohde, S.; Hossain, M.M.M.; Ozaki, H.; Masuzawa, T.

2003-01-01

A simple and non-destructive method has been proposed for the routine determination of uranium by epithermal neutron activation analysis in coral skeletons. Using a cadmium capsule, about 0.1-0.2 g samples were irradiated for 6 hours in the Triga Mark II Reactor. Measurements of γ-ray ( 239 Np via 239 U) were performed with each sample and standard after cooling for about three days. Compared with a non-destructive thermal NAA, the present method was found to improve the sensitivity because it reduced the intense Compton background induced by 24 Na. Uranium in coral standards was determined within 2% of analytical precision. The data obtained for the carbonate standards are mostly consistent with reported values. The present method could be usefully applied to determine uranium contents in fossil corals from the Funafuti Atoll in the Pacific. The distribution of uranium between seawater and coral skeletons is also discussed in order to understand the environmental media in which the coral grew. (author)

Fluorimetric determination of uranium in water; Determinacion fluorimetrica de uranio en aguas

Energy Technology Data Exchange (ETDEWEB)

Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

1992-02-15

The fluorimetric method for the determination of microquantities of uranium in water is described. This method covers the determination of uranium in water in the interval from 0.2 to 50 ppm on 50 ml. of radioactive base sample. These limits can be variable if the volume of the aliquot one of the base sample is changed, as well as the volume of the used aliquot one for to the final determination of uranium. (Author)

Determination of uranium in fissium-uranium alloy and in fissium dross

International Nuclear Information System (INIS)

Bodnar, L.Z.

1976-01-01

Dissolution and analysis techniques for fissium-uranium alloy and fissium dross are described. The fuming technique of dissolution effectively eliminated all interferring elements in the titration determination of U. The results from the semiquantitative analysis of fission dross by spark source mass spectrometry were tabulated

Sequential potentiometric determination of uranium and plutonium in a single aliquot

International Nuclear Information System (INIS)

Rao, V.K.; Charyulu, M.M.; Natarajan, P.R.

1983-01-01

A method is reported for sequential potentiometric determination of uranium and plutonium present is an aliquot. Plutonium is first determined by oxidizing it to the hexavalent state with perchloric acid followed by iron(II) reduction and titration of excess ferrous iron with chromium(VI). Uranium is subsequently determined by reduction to the quadrivalent state using titanium(III) and titration with vanadium(V). The interference of plutonium and iron(II) is eliminated by the addition of a mixture containing sulfamic acid, nitric acid, and molybdenum(VI). The results of the analysis of mixture containing 3-5 mg quantities of uranium and plutonium are reliable with errors less than 0.3% and 0.2%, respectively. The application of the method for the analysis of mixtures containing various amounts of uranium and plutonium has been examined. (author)

A discussion on several problems in determination of uranium ore grade criteria

International Nuclear Information System (INIS)

Zhu Zhixiang.

1991-01-01

The course of determination of uranium ore grade criteria in China is briefly introduced. The cut-off grade minimum industrial grade and allowable minimum average grade uranium ore bodies used in China are reviewed. The meanings and role of various grade criteria and their economic basis for determination in uranium exploration, mining and sorting are discussed and the author's ideas are given

Spectrophotometric determination of uranium using quercetin

International Nuclear Information System (INIS)

Barros, A.R.

1972-10-01

A spectrophotometric method for quantitative determination of uranium, using a flavone (quercetin) as complexing agent, is described. The method is based on the reaction between uranyl ion and alcoholic solution of quercetin with a complex formation of intense yellow color. (M.C.L.) [pt

Measurement of uranium quantities by fluorescence-X using neuronal techniques

International Nuclear Information System (INIS)

Vigneron, V.; Martinez, J.M.; Simon, A.C.; Junca, R.

1995-01-01

Layered neural networks are a class of models based on neural computation in biological systems. Connexionists models are made of a large number of simple computing structures, highly interconnected. The weights assigned to the connections enable the encoding of the knowledge required for a task. They can be trained to learn any input-output relation after selecting a suitable architecture. This method appears useful in those cases in which a simple operation and a fast response are needed, together with a reasonable accuracy. They are applied here to the automatic analysis of X-ray fluorescence spectra, obtained with plastic bottles irradiate by collimated beam of photons, emitted by a sealed source of iridium. The method could allow the surveillance of the measurement of uranium quantities in nuclear fuel cycles in processing plants. (authors). 11 refs., 4 figs

Kinetic analysis of pulsed laser induced phosphorescence for uranium determination

International Nuclear Information System (INIS)

Serdeiro, Nelida H.

2003-01-01

The laser induced kinetic phosphorescence allows the uranium determination in different kind of matrices, with a lower detection limit than those reached by other spectroscopic methods. It involves the uranyl ions excitation by a pulsed dye-laser source, followed by temporal resolution of the phosphorescence. This method is used for the determination of trace quantities of uranium in aqueous solution, with a suitable complexant agent, without chemical separation before the analysis. The objective of this paper is to present the results of uranium determinations in different standard samples, water, soil, filter and urine, and a comparison with other methods such as fluorimetry, alpha spectrometry and mass spectrometry. Moreover, the measurement conditions, the advantages and disadvantages, the sample preparation, the interferences and the detection limit are described. (author)

U(IV) fluorescence spectroscopy. A new speciation tool

Energy Technology Data Exchange (ETDEWEB)

Lehmann, Susanne; Brendler, Vinzenz [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Steudtner, Robin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

2017-06-01

We combined absorption and fluorescence spectroscopy to study the speciation of U(IV) in solution in concentrations down to 10{sup -6} M uranium. With our time-resolved laser-induced fluorescence setup we could determine the fluorescence decay time of U(IV) in perchloric as well as in chloric acid with 2.6 ± 0.3 ns at room temperature and 148.4 ± 6.5 ns at liquid nitrogen temperature. For the U(IV) sulfate system, we observed a bathochromic shift and a peak shape modification in the fluorescence spectra with increasing sulfate concentration in solution. Thus, the potential of U(IV) fluorescence for speciation analysis could be proven.

Determination of uranium concentration in an ore sample using laser-induced breakdown spectroscopy

International Nuclear Information System (INIS)

Kim, Y.-S.; Han, B.-Y.; Shin, H.S.; Kim, H.D.; Jung, E.C.; Jung, J.H.; Na, S.H.

2012-01-01

Laser-induced breakdown spectroscopy (LIBS) has been recognized as a promising technique for analyzing sensitive nuclear materials such as uranium, plutonium, and curium in a high-radiation environment, especially since the implementation of IAEA (International Atomic Energy Agency) safeguards. The uranium spectra of ore samples were quantitatively analyzed prior to analyzing sensitive materials in the nuclear industry. The purpose of this experiment is to extract quantitative information about the uranium in a uranium ore using a standard addition approach. The uranium ore samples containing different concentrations of U were prepared by mixing raw ore powder with natural uranium oxide powders. Calibration sets of 0.2, 0.4, 0.6, 0.8 and 1.0 wt.% uranium concentrations within the uranium ore sample were achieved. A pulsed and Q-switched Nd:YAG laser at a wavelength of 532 nm was used as a light source. An echelle spectrometer that covers a 190–420 nm wavelength range is used to generate a calibration curve and determine the detection limit of uranium in the ore matrix. The neutral atomic-emission peak at a wavelength of 356.659 nm indicated a detection limit of ∼ 158 ppm for uranium, and the uranium concentration was determined in a raw ore sample that has an unknown quantity of uranium. - Highlights: ► The feasibility of LIBS application to monitor uranium element was carried out. ► The detection limit of U in ore was determined by a standard additional approach. ► Quantitative analyses of U concentration in a natural uranium ore were performed.

Determination of uranium in organic phase by flow injection spectrophotometric analysis

International Nuclear Information System (INIS)

Yu Yiyun

1998-01-01

Based on the use of merging zone circuit and simulating a series of standard solution of uranium in organic phase, uranium in unknown organic phase sample was determined by flow injection spectrophotometry. A linear calibration graph was obtained with correlation coefficient of 0.999 for uranium concentration in organic phase over 10∼200 mg/L. Isopropyl alcohol was used as carrier solution. Mixing colour solution contains isopropyl alcohol, triethanolamine, masking reagent and Br-PADAP. The relative standard deviation of the method was better than +-5%. Determination of each sample can be completed in one minute. The method characteristic is: (1) using merging zone and simulating standard solution of uranium in organic phase, the method is sensitive and reliable; (2) even if the determined solution was in turbid condition, it can be quantitatively determined; (3) by means of solution replace technique, the tube of peristaltic pump can be used over a long period of time

Determination of uranium in ground water using different analytical techniques

International Nuclear Information System (INIS)

Sahu, S.K.; Maity, Sukanta; Bhangare, R.C.; Pandit, G.G.; Sharma, D.N.

2014-10-01

The concern over presence of natural radionuclides like uranium in drinking water is growing recently. The contamination of aquifers with radionuclides depends on number of factors. The geology of an area is the most important factor along with anthropogenic activities like mining, coal ash disposal from thermal power plants, use of phosphate fertilizers etc. Whatever may be the source, the presence of uranium in drinking waters is a matter of great concern for public health. Studies show that uranium is a chemo-toxic and nephrotoxic heavy metal. This chemotoxicity affects the kidneys and bones in particular. Seeing the potential health hazards from natural radionuclides in drinking water, many countries worldwide have adopted the guideline activity concentration for drinking water quality recommended by the WHO (2011). For uranium, WHO has set a limit of 30μgL-1 in drinking water. The geological distribution of uranium and its migration in environment is of interest because the element is having environmental and exposure concerns. It is of great interest to use an analytical technique for uranium analysis in water which is highly sensitive especially at trace levels, specific and precise in presence of other naturally occurring major and trace metals and needs small amount of sample. Various analytical methods based on the use of different techniques have been developed in the past for the determination of uranium in the geological samples. The determination of uranium requires high selectivity due to its strong association with other elements. Several trace level wet chemistry analytical techniques have been reported for uranium determination, but most of these involve tedious and pain staking procedures, high detection limits, interferences etc. Each analytical technique has its own merits and demerits. Comparative assessment by different techniques can provide better quality control and assurance. In present study, uranium was analysed in ground water samples

Determination of uranium in phosphorite by radiometric measurements and activation analysis

International Nuclear Information System (INIS)

Santos Amaral, R. dos.

1987-01-01

Uranium was determined by passive gamma ray counting in phosphate rocks in the range from 50 to 400 ppm U 3 O 8 . The measurements were carried out focusing on the 186 KeV gamma ray from the 235 U nuclide. The radioactive equilibrium of the 226 Ra in the uranium decay chain was investigated due its contribution in the 186 KeV compound 226 Ra 235 U photopeak. Therefore a simulataneous uranium determination through the 234 Th radionuclide demonstrate the equilibrium conditions. The results of the uranium analysis by the following methods: spectrophotometry, XRF and delayed neutrons from three independent laboratories were compared to evaluate the accuracy of the radioanalytical results. The uranium content was also determined by neutron activation analysis, followed by gamma measurement of the 239 Np formed by the 238 U (n,γ) 239 U reaction and 239 U beta decay and the fission products of 235 U. By the correlation of 239 Np, 99 Mo, 143 Ce, 131 I, and 133 I photopeak was measured the 238 U/ 235 U isotopic ratio. (author) [pt

Uranium determination using atomic spectrometric techniques: An overview

International Nuclear Information System (INIS)

Santos, Juracir S.; Teixeira, Leonardo S.G.; Santos, Walter N.L. dos; Lemos, Valfredo A.; Godoy, Jose M.; Ferreira, Sergio L.C.

2010-01-01

This review focuses on the determination of uranium using spectroanalytical techniques that are aimed at total determination such as flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma optical emission spectrometry (ICP-OES); and inductively coupled plasma mass spectrometry (ICP-MS) that also enables the determination of uranium isotopes. The advantages and shortcomings related to interferences, precision, accuracy, sample type and equipment employed in the analysis are taken into account, as well as the complexity and costs (i.e., acquisition, operation and maintenance) associated with each of the techniques. Strategies to improve their performance that employ separation and/or preconcentration steps are considered, with an emphasis given to solid-phase extraction because of its advantages compared to other preconcentration procedures.

Extractive spectrophotometric determination of uranium with malachite green

International Nuclear Information System (INIS)

Dubey, S.C.; Nadkarni, M.N.

1977-01-01

A sensitive spectrophotometric method based on the extraction of a uranium-benzoate-Malachite Green complex by chlorobenzene is described. The absorption maximum is at 635 nm and the molar absorptivity is 8.3 x 10 4 1. mole -1 cm -1 . A preliminary separation of uranium by extraction with methyl isobutyl ketone from acid-deficient aluminium nitrate solution is used to avoid interferences. An aliquot of the extract in then diluted with chlorobenzene and shaken with benzoate buffer containing Malachite Green (MG). The method has been applied for the determination of uranium in a synthetic leach solution. The complex extracted is probably [U0 2 (C 6 H 5 C00 3 - ][MG + ]. (author)

Determination of the uranium content of phosphate rocks

International Nuclear Information System (INIS)

Levin, R.; Ronen, S.

1977-03-01

A method is described for the spectrophotometric determination of uranium (VI) in the presence of various elements by extraction with 0.1M trioctylphosphine oxide (TOPO) dissolved in cyclohexane from 1.5M nitric acid. The colour is developed directly in the organic phase using Arsenazo I. The optical absorbance is measured at a wavelength of 600 nm. Possible interferences of accompanying elements can be eliminated by reduction with ascorbic acid and by screening with sodium fluoride. This method allows the determination of any uranium content, in the 20 to 200 μg range, of phosphate rocks containing up to 1 g (PO 4 ) 3-

Simultaneous determination of uranium and thorium with Arsenazo III by second-derivative spectrophotometry

International Nuclear Information System (INIS)

Kuroda, Rokuro; Kurosaki, Mayumi; Hayashibe, Yutaka; Ishimaru, Satomi

1990-01-01

A derivative spectrophotometric method has been developed for the simultaneous determination of microgram quantities of uranium and thorium with Arsenazo III in hydrochloric acid medium. The second-derivative absorbances of the uranium and thorium Arsenazo III complexes at 679.5 and 684.4 nm are used for their quantification. Uranium and thorium, both in the range 0.1-0.7 μg/ml have been determined simultaneously with good precision. The procedure does not require separation of uranium and thorium, and allows the determination of both metals in the presence of alkaline-earth metals and zirconium, but lanthanides interfere. (author)

Determination of uranium and its isotopic ratios in environmental samples

International Nuclear Information System (INIS)

Flues Szeles, M.S.M.

1990-01-01

A method for the determination of uranium and its isotopic ratios ( sup(235)U/ sup(238)U and sup(234U/ sup(238)U) is established in the present work. The method can be applied in environmental monitoring programs of uranium enrichment facilities. The proposed method is based on the alpha spectrometry technique which is applied after a purification of the sample by using an ionic exchange resin. The total yield achieved was (91 + 5)% with a precision of 5%, an accuracy of 8% and a lower limit of detection of 7,9 x 10 sup(-4)Bq. The uranium determination in samples containing high concentration of iron, which is an interfering element present in environmental samples, particularly in soil and sediment, was also studied. The results obtained by using artificial samples containing iron and uranium in the ratio 1000:1, were considered satisfactory. (author)

Determination of uranium in uranyl nitrate solutions of nuclear grade quality - Gravimetric method

International Nuclear Information System (INIS)

1990-01-01

This international Standard specifies a precise and accurate gravimetric method for determining the uranium content in uranyl nitrate product solutions of nuclear grade quality at concentrations above 100 g/l of uranium. Non-volatile impurities influence the accuracy of the method. Uranyl nitrate is converted into uranium octoxide (U 3 O 8 ) by ignition in air to constant mass at 900 deg. C ± 10 deg. C. Calculation of the uranium content in the sample using a gravimetric conversion factor which depends on the isotopic composition of the uranium. The isotopic composition is determined by mass spectrometry

Rapid uranium analysis by delayed neutron counting of neutron activated samples

International Nuclear Information System (INIS)

Papadopoulos, N.N.

1985-01-01

The uranium analyzer at the Nuclear Research Center ''Demokritos'' and the delayed neutron method have been used to determine the uranium content in lignite, in chemically enriched samples and in solutions of extractable uranium. The results are compared with data obtained by other methods. In the case of dissolved extractable uranium. The results are in good agreement with X-ray fluorescence data in the range 100 ppm to 2000 ppm while beyond these limits the discrepancies between neutron and spectrophotometric data are observed. The results for lignite samples are in good agreement with gamma spectrometric data. Discrepancies indicate that more extensive intercomparisons are needed to check the reliability of various methods

Determination of uranium in bench test by L_Ⅲ-absorption edge method

International Nuclear Information System (INIS)

Song You; Zheng Weiming; Liu Guijiao; Chen Chen

2014-01-01

By independent research L_Ⅲ--absorption edge densimeter, an analytical method for uranium sample with the concentration from 20 g/L to 200 g/L was developed. The fitting area for uranium measurement was determined through experiment. The left fitting area was 1659-1856 channel, and the right one was 2063-2280 channel. The uranium L_Ⅲ--absorption edge was at 1995 channel. The results show that the influence of HNO_3 concentration lower than 9 mol/L, Al and Fe concentration lower than 10 g/L was negligibly small. The uranium measurement precision is better than 0.5%, and the instrument stability is good. Some samples in bench test of uranium recovery were determined. The results are satisfactory. (authors)

Adsorptive stripping voltammetric determination of uranium with cephradine

International Nuclear Information System (INIS)

Ali, A.M.M.; Ghandour, M.A.; Khodari, M.

1995-01-01

Uranium adsorbed with cephradine is reduced on a hanging mercury drop electrode. This property was exploited in developing a highly sensitive stripping voltammetric procedure for the determination of uranium. A detection limit 2 x 10 -9 mol I -1 (0.5 μg I -1 ) of uranium ion is obtained with an 180 s accumulation time. Cyclic voltammetry was used to characterize the interfacial and redox behaviour. The effects of various parameters are discussed. Experimental conditions include the use of 5 x 10 -6 mol I -1 cephradine in 0.05 mol I -1 sodium perchlorate (pH ''approx ='' 6.5), an accumulation potential of 0.0 V versus SCE and a direct current stripping technique. The response is linear up to 5 x 10 -6 mol I -1 uranium and the relative standard deviation at 1 x 10 -7 mol I -1 ) UO 2+ is 4.4%. The effect of other metal ions was investigated. (author)

Pulp tissue in sex determination: A fluorescent microscopic study

Science.gov (United States)

Nayar, Amit; Singh, Harkanwal Preet; Leekha, Swati

2014-01-01

Aims: To determine and compare the reliability of pulp tissue in determination of sex and to analyze whether caries have any effect on fluorescent body test. Materials and Methods: This study was carried on 50 maxillary and mandibular teeth (25 male teeth and 25 female teeth), which were indicated for extraction. The teeth are categorized into 5 groups, 10 each (5 from males and 5 from females) on the basis of caries progression. The pulp cells are stained with quinacrine hydrochloride and observed with fluorescent microscope for fluorescent body. Gender is determined by identification of Y chromosome fluorescence in dental pulp. Results: Fluorescent bodies were found to be more in sound teeth in males as the caries increase the mean percentage of fluorescent bodies observed decreases in males. We also observed the fluorescent spots in females, and the value of the spot increases in female as the caries progresses, thereby giving false positive results in females. Conclusion: Sex determination by fluorescent staining of the Y chromosome is a reliable technique in teeth with healthy pulps or caries with enamel or up to half way of dentin. Teeth with caries involving pulp cannot be used for sex determination. PMID:25125912

Fluorimetric routine determination of uranium in urine samples

International Nuclear Information System (INIS)

Widua, L.; Schieferdecker, H.; Hezel, U.

With a modified RA 2 reflectance accessory for the Zeiss PMQII/PMQ3 spectrophotometer, uranium in urine was detected with higher sensitivity. A quick method is now available with a detection limit of <2 μg U/1 urine for the determination of possible uranium incorporations, whose sensitivity meets the requirements of radiation protection. Compared with other extraction methods, the instrument outlay and the required working time are small. The total error of the method is below 5 percent

Determination of uranium in clinical and environmental samples by FIAS-ICPMS

International Nuclear Information System (INIS)

Karpas, Z.; Lorber, A.; Halicz, L.; Gavrieli, I.

1998-01-01

Uranium may enter the human body through ingestion or inhalation. Ingestion of uranium compounds through the diet, mainly drinking water, is a common occurrence, as these compounds are present in the biosphere. Inhalation of uranium-containing particles is mainly an occupational safety problem, but may also take place in areas where uranium compounds are abundant. The uranium concentration in urine samples may serve as an indication of the total uranium body content. A method based on flow injection and inductively coupled plasma mass spectrometry (FIAS-ICPMS) was found to be most suitable for determination of uranium in clinical samples (urine and serum), environmental samples (seawater, wells and carbonate rocks) and in liquids consumed by humans (drinking water and commercial beverages). Some examples of the application of the FIAS-ICPMS method are reviewed and presented here

Applications of optical fiber to the remote fluorescence analysis

International Nuclear Information System (INIS)

Shin, Jang Soo; Kim, Duck Hueon; Lee, Soo Ho

1992-12-01

The laser fluorometer developed in 1987 has been used in real circumstances for trace uranium analysis. And, we have been trying to improve the instrument to be able to apply in analytical circumstances of remote measurement using optical fiber. The N 2 laser beam and the resulting fluorescence light could be successfully transmitted through a quartz-made optical fiber. The wavelength resolution and the fluorescence decay time resolution induced by pulsed N 2 laser were used to the uranium fluorescence analyses. The fluorescence of uranium in nitric acid medium was measured successfully using the system. The fluorescence signal was analysed using simplex method which is useful to deconvolute the mixed signals. An analytical method using thermal lens effect was developed. The method will be a complementary one for the fluorescence measurement. (Author)

Uranium determination by UV-Vis spectrophotometry in organic matrix

International Nuclear Information System (INIS)

Iwaki, Leonardo E.O.; Silva, Ieda S.; Oliveira, Luis C.

2013-01-01

Concentrations of uranium in the process samples provide essential information required for nuclear process monitoring. A large number of techniques have been developed to allow uranium determination, but each technique possesses some advantages and disadvantages and cannot be applied without difficulty to all samples. The ultraviolet visible spectrophotometry (UV-Vis) is widely method used in analytical industrial processes due to its simplicity, rapidity, low costs, low generation of analytical waste, easy calibration and operation. In this study, we describe a simple and fast quantification method to determination of a high amount of uranium in organic phase (TBP/kerosene) using UV-Vis spectrophotometry. The process sample was analyzed in UV-Vis and compared with inductively coupled plasma optical emission spectrometry (ICP OES) showing similar results in both methods. The statistical tests (Student-t and Fischer) showed that the both techniques they are equivalent. (author)

Extractive spectrophotometric determination of uranium with malachite green

Energy Technology Data Exchange (ETDEWEB)

Dubey, S C; Nadkarni, M N [Bhabha Atomic Research Centre, Bombay (India). Fuel Reprocessing Div.

1977-04-01

A sensitive spectrophotometric method based on the extraction of a uranium-benzoate-Malachite Green complex by chlorobenzene is described. The absorption maximum is at 635 nm and the molar absorptivity is 8.3 x 10/sup 4/1. mole /sup -1/ cm/sup -1/. A preliminary separation of uranium by extraction with methyl isobutyl ketone from acid-deficient aluminium nitrate solution is used to avoid interferences. An aliquot of the extract in then diluted with chlorobenzene and shaken with benzoate buffer containing Malachite Green (MG). The method has been applied for the determination of uranium in a synthetic leach solution. The complex extracted is probably (U0/sub 2/(C/sub 6/H/sub 5/C00/sub 3//sup -/)(MG/sup +/).

Potentiometric determination of milligram amounts of uranium by semiautomatic titrator

International Nuclear Information System (INIS)

Ryzhinskij, M.V.; Stepanov, A.V.; Preobrazhenskaya, L.D.; Solntseva, L.F.; Gromova, E.A.

1978-01-01

A semiautomatic titrator is described which allows gravimetriotentiometricc-p titrat mg amounts of substances. Milligram amounts of uranium (absolute contents and oxygen/uranium ratio) in U 3 O 8 were determined as an example of the titrator action. The relative standard deviation was less than 0.001

Optimal Fluorescence Waveband Determination for Detecting Defective Cherry Tomatoes Using a Fluorescence Excitation-Emission Matrix

Directory of Open Access Journals (Sweden)

In-Suck Baek

2014-11-01

Full Text Available A multi-spectral fluorescence imaging technique was used to detect defective cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA was applied to the fluorescence emission spectra of all regions at 410 nm excitation to determine the emission wavelengths for defect detection. The major emission wavelengths were 688 nm and 506 nm for the detection. Fluorescence images combined with the determined emission wavebands demonstrated the feasibility of detecting defective cherry tomatoes with >98% accuracy. Multi-spectral fluorescence imaging has potential utility in non-destructive quality sorting of cherry tomatoes.

Study and Elimination of the Interference of Aluminium on the Voltammetric Determination of Uranium with Chloranilic Acid. Application to the Determination of Uranium in Waters and Geological Samples

International Nuclear Information System (INIS)

Fernandez, C.; Sanchez, M.; Ballesteros, O.; Fernandez, M.; Clavero, M. A.; Gonzalez, A. M.

2000-01-01

The interference of aluminium during the voltammetric determination of uranium with 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid) has been investigated. The presence of aluminium originates a voltammetric signal due to its chloranilic acid complex at the same potential range as the uranium analytical signal appears. The interference of aluminium can be overcome by addition of an appropriate amount of sodium fluoride as complexing reagent. The determination of uranium by adsorptive stripping voltammetry (AdSV) can be carried out at concentration levels as low as 1 μg/L in the presence of 100 μg/L aluminium after the addition of 100μL of 0.1 mol/L NaF. The method can be applied to the determination of uranium in aluminium-containing waters and geological samples containing high aluminium levels. (Author) 19 refs

Indirect determination of uranium by atomic-absorption spectrophotometry using an air-acetylene flame

International Nuclear Information System (INIS)

Alder, J.F.; Das, B.C.

1977-01-01

An indirect method has been developed for the determination of uranium by atomic-absorption spectrophotometry using an air-acetylene flame. Use is made of the reduction of copper(II) by uranium(IV) followed by complex formation of the copper(I) ions so produced with neocuproine (2,9-dimethyl-1,10-phenanthroline) and finally the determination of copper in this complex by atomic-absorption spectrophotometry. The results show that the method can be recommended, provided that care is taken to ensure the complete reduction of uranium(VI) to uranium(IV). The sensitivity of the method is 4.9 μg of uranium and the upper limit 500 μg without dilution. (author)

Uranium in drinking water. A simple determination of uranium (VI) according to DIN standard 38406-17

International Nuclear Information System (INIS)

Haug, Sandro

2009-01-01

The number of reports on uranium loads in tap water and drinking water increases. Already for years, the organization Foodwatch e.V. (Berlin, Federal Republic of Germany) warns about to high concentrations of uranium in tap water. So far, only a limit value for mineral water exists in the Mineral Water Regulation which is suitable for the production of infant diet. This limit value amounts 2 microgram per litre. Temporarily, also in the policy a national limit value for uranium in drinking water is introduced. The Federal Office for Environment Protection (Dessau, FRG) designates a value of ten microgram uranium per litre of drinking water and mineral water as an approximate value. The effective control of water quality presupposes high-performance, simple and economical analysis methods. A particularly well suitable measuring technique for the determination of uranium(VI) in groundwater, raw water and drinking water is the voltammetry. In the last years, a national standard was compiled based on this measuring technique: DIN standard 38406-17

Sensitivity evaluation of the green alga Chlamydomonas reinhardtii to uranium by pulse amplitude modulated (PAM) fluorometry

International Nuclear Information System (INIS)

Herlory, Olivier; Bonzom, Jean-Marc; Gilbin, Rodolphe

2013-01-01

Highlights: •Our study addressed the toxicity thresholds of uranium on microalgae using PAM fluorometry. •The oxygen-evolving complex (OEC) of PSII was identified as the primary action site of uranium. •Uranium impaired the electron flux between the photosystems until almost complete inhibition. •Non-photochemical quenching was identified as the most sensitive fluorescence parameter. •PAM fluorometry provided a rapid and reasonably sensitive method for assessing stress response. -- Abstract: Although ecotoxicological studies tend to address the toxicity thresholds of uranium in freshwaters, there is a lack of information on the effects of the metal on physiological processes, particularly in aquatic plants. Knowing that uranium alters photosynthesis via impairment of the water photo-oxidation process, we determined whether pulse amplitude modulated (PAM) fluorometry was a relevant tool for assessing the impact of uranium on the green alga Chlamydomonas reinhardtii and investigated how and to what extent uranium hampered photosynthetic performance. Photosynthetic activity and quenching were assessed from fluorescence induction curves generated by PAM fluorometry, after 1 and 5 h of uranium exposure in controlled conditions. The oxygen-evolving complex (OEC) of PSII was identified as the primary action site of uranium, through alteration of the water photo-oxidation process as revealed by F 0 /F v . Limiting re-oxidation of the plastoquinone pool, uranium impaired the electron flux between the photosystems until almost complete inhibition of the PSII quantum efficiency (F ′ q /F ′ m , EC 50 = 303 ± 64 μg U L −1 after 5 h of exposure) was observed. Non-photochemical quenching (qN) was identified as the most sensitive fluorescence parameter (EC 50 = 142 ± 98 μg U L −1 after 5 h of exposure), indicating that light energy not used in photochemistry was dissipated in non-radiative processes. It was shown that parameters which stemmed from

Gas chromatographic method fr determination of carbon in metallic uranium

International Nuclear Information System (INIS)

Nikol'skij, V.A.; Markov, V.K.; Evseeva, T.I.; Cherstvenkova, E.P.

1983-01-01

Gas chromatographic device to determine carbon in metal uranium is developed. Burnout unite, permitting to load in the burnout tube simultaneously quite a few (up to 20) weight amounts of materials to be burned is a characteristic feature of the device. As a result amendments for control experiment and determination limit are decreased. The time of a single determination is also reduced. Conditions of carbon burn out from metal uranium are studied and temperature and time of complete extraction of carbon in the form of dioxide from weight amount into gaseous phase are established

Polarographic determination of uranium dioxide stoichiometry

International Nuclear Information System (INIS)

Viguie, J.; Uny, G.

1966-10-01

The method described allows the determination of small deviations from stoichiometry for uranium dioxide. It was applied to the study of surface oxidation of bulk samples. The sample is dissolved in phosphoric acid under an argon atmosphere; U(VI) is determined by polarography in PO 4 H 3 4.5 N - H 2 SO 4 4 N. U(IV) is determined by potentiometry. The detection limit is UO 2,0002 . The accuracy for a single determination at the 95% confidence level is ±20 per cent for samples with composition included between UO 2,001 and UO 2,01 . (authors) [fr

Determination of trace quantities of uranium in rocks mass spectrometric isotope dilution technique

International Nuclear Information System (INIS)

Kakazu, Mauricio Hiromitu

1980-01-01

A detailed experimental investigation on the thermionic emission of uranium deposited on a single flat type rhenium filament has been carried out. The study was aimed at determining the influence of various forms of deposition on the emission sensitivity and thermal stability of U + , UO + and UO 2 + ions. Based on these investigations, a technique, involving an addition of a small quantity of colloidal suspension of graphite on top of the uranyl nitrate sample deposited, was chosen because of its higher, emission sensitivity for uranium metal ions. The experimental parameters of the technique were optimised and the technique was employed in the determination of trace quantities of uranium in rock samples using mass spectrometric isotope dilution method. For the mass spectrometric isotope dilution analysis National Bureau of Standards uranium isotopic standard NBS-U 970 was employed as a tracer, where as the mass discrimination effect in the uranium isotope analysis was corrected using the uranium isotopic standard NBS-U500. Uranium was determined in each of the seven granite samples from Wyoming, USA and two USGS standard rocks. The precision of the analysis was found to be ±1% . The uranium values obtained on the rock samples were compared with the analyses of other investigators. Influence of the sample splitting on the uranium analysis was discussed in the light of the analytical results obtained.(author)

On the distribution of uranium in hair: Non-destructive analysis using synchrotron radiation induced X-ray fluorescence microprobe techniques

Energy Technology Data Exchange (ETDEWEB)

Israelsson, A., E-mail: axel.israelsson@liu.se [Department of Medical and Health Sciences, Linköping University, 58183 Linköping (Sweden); Eriksson, M. [Swedish Radiation Safety Authority, 17116 Stockholm (Sweden); Pettersson, H.B.L. [Department of Radiation Physics, Linköping University, 58183 Linköping (Sweden); Department of Medical and Health Sciences, Linköping University, 58183 Linköping (Sweden)

2015-06-01

In the present study the distribution of uranium in single human hair shafts has been evaluated using two synchrotron radiation (SR) based micro X-ray fluorescence techniques; SR μ-XRF and confocal SR μ-XRF. The hair shafts originated from persons that have been exposed to elevated uranium concentrations. Two different groups have been studied, i) workers at a nuclear fuel fabrication factory, exposed mainly by inhalation and ii) owners of drilled bedrock wells exposed by ingestion of water. The measurements were carried out on the FLUO beamline at the synchrotron radiation facility ANKA, Karlsruhe. The experiment was optimized to detect U with a beam size of 6.8 μm × 3 μm beam focus allowing detection down to ppb levels of U in 10 s (SR μ-XRF setup) and 70 s (SR confocal μ-XRF setup) measurements. It was found that the uranium was present in a 10–15 μm peripheral layer of the hair shafts for both groups studied. Furthermore, potential external hair contamination was studied by scanning of unwashed hair shafts from the workers. Sites of very high uranium signal were identified as particles containing uranium. Such particles, were also seen in complementary analyses using variable pressure electron microscope coupled with energy dispersive X-ray analyzer (ESEM–EDX). However, the particles were not visible in washed hair shafts. These findings can further increase the understanding of uranium excretion in hair and its potential use as a biomonitor. - Highlights: • Uranium at the fg level was detectable and the uranium distribution in single hair shafts was derived. • The uranium is located peripherally on the shafts in what seems to be a layer of approximately 10-15 μm thickness. • Uranium bearing particles were found on hairs that had not been washed.

Determination of plutonium and uranium in the same aliquot by potentiometric titration

International Nuclear Information System (INIS)

Karekar, C.V.; Chander, Keshav; Nair, G.M.; Natarajan, P.R.

1986-01-01

A potentiometric titration method was developed for the determination of plutonium and uranium in the same aliquot in nitric acid medium. Plutonium was first determined by oxidation to Pu(VI) by fuming with HClO 4 . Pu(VI) was reduced to Pu(IV) with known excess of Fe(II). Uranium in the same solution was determined by reduction to U(IV) with Fe(II) in H 3 PO 4 medium. For the quantity of plutonium and uranium in the range of 3-5 mg per aliquot a precision of +-0.2% and +-0.4%, respectively, was obtained. (author)

Polarographic determination of uranium dioxide stoichiometry; La determination polarographique de la stoechiometrie du dioxyde d'uranium

Energy Technology Data Exchange (ETDEWEB)

Viguie, J.; Uny, G. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Grenoble, 38 (France)

1966-10-01

The method described allows the determination of small deviations from stoichiometry for uranium dioxide. It was applied to the study of surface oxidation of bulk samples. The sample is dissolved in phosphoric acid under an argon atmosphere; U(VI) is determined by polarography in PO{sub 4}H{sub 3} 4.5 N - H{sub 2}SO{sub 4} 4 N. U(IV) is determined by potentiometry. The detection limit is UO{sub 2,0002}. The accuracy for a single determination at the 95% confidence level is {+-}20 per cent for samples with composition included between UO{sub 2,001} and UO{sub 2,01}. (authors) [French] La methode decrite permet de determiner les faibles ecarts a la stoechiometrie du dioxyde d'uranium. Elle a ete appliquee a l'etude de l'oxydation superficielle des echantillons. La mise en solution s'effectue dans l'acide phosphorique concentre sous atmosphere d'argon; U(VI) est dose par polarographie dans le milieu PO{sub 4}H{sub 3} 4,5 N et H{sub 2}SO{sub 4} 4 N; U(IV) est dose par potentiometrie. La limite de detection est UO{sub 2,0002}. La precision obtenue pour une determination au taux de certitude 0,95 est de l'ordre de 20 pour cent pour des echantillons dont la teneur est comprise entre UO{sub 2,001} et UO{sub 2,01}. (auteurs)

Determination of low carbon content in uranium

International Nuclear Information System (INIS)

Champeix, L.; Chevilliard, H.; Ponty, J.

1960-01-01

The method of carbon determination previously used for low carbon steels has been applied to uranium. Carbon contents down to a few tens p.p.m. and probably to a few p.p.m., can be determined with satisfactory precision, sensibility and accuracy. Reprint of a paper published in 'Memoires Scientifiques Rev. Metallurg.', LVI, n. 7, 1959, p. 657-662 [fr

Spectrophotometric determination of uranium and plutonium in nitric acid solutions at their co-presence

International Nuclear Information System (INIS)

Levakov, B.I.; Mishenev, V.B.; Nezgovorov, N.Yu.; Ryazanova, G.K.; Timofeev, G.A.

1986-01-01

The method of spectrophotometric determination of uranium (6) and plutonium (4) in nitric acid solutions is described. Uranium is determined by light absorption of the complex with arsenazo 3 in 0.05 mol/l nitric acid at λ=654 nm, plutonium - by light absorption of the complex with xylenol orange in 0.1 mol/l nitric acid at λ=540 nm. To disguise plutonium, tetravalent and certain trivalent elements DTPA is introduced into photometered solution for uranium determination. The relative root-mean square deviation of determination results does not exceed 0.03 in uranium concenration ranges 0.5-5 μg/ml, of plutonium -1-3 μg/ml

Spectrographic determination of impurities in uranium tetrafluoride

International Nuclear Information System (INIS)

Capdevila Perez, C.; Roca Adell, M.; Alvarez Gonzalez, F.

1967-01-01

A carrier distillation method for the determination of Ag, Al, As, B, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Si in uranium tetrafluoride was develop ped. the previous addition of 25% Y 2 3 prevents the excitation of uranium by conversion of the volatile UF 4 into U 3 0 8 during the arc discharge. NaCl or Ga 2 0 3 , containing Ge and V as internal standards, are used as carriers, and samples are arced in 10 Amp. d.c. arc in a graphite anode cup. 7 mm diameter, 10 mm deep, being the weight of charge 300 mg. (Author) 14 refs

Evaluation of methods for mathematical corrections in the determination of niobium and zirconium contents in U-Nb and U-Zr alloys by X-ray fluorescence analysis

International Nuclear Information System (INIS)

Salvador, V.L.R.; Sato, I.M.; Lordello, A.R.

1985-01-01

Methods for the determination of niobium and zirconium in U-Nb and U-Zr alloys with the X-ray fluorescence technique are described. The NbK sub(Ab) line, although not under the overlapping effect of the uranium lines as the NbK sub(β) line, although not under the overlapping effect of the uranium lines as the NbK sub(α) is, presents a more intensive absorption effect than this last one; on the other hand the ZrK sub(α) and ZrK sub(β) lines are under the overlapping effect of the uranium spectrum. Such interferences are mathematically corrected by means of relations between the intensities of the lines for the elements and those for the uranium. The technique for the preparation of the samples is the double layer pressed pellet. From the different corrections the best method has showed a precision of 5%. (Author) [pt

Evaluation of the LASL automated spectrophotometer for uranium determination at submilligram levels

International Nuclear Information System (INIS)

Hollen, R.M.; Jackson, D.D.; Rein, J.E.

1977-07-01

The LASL automated spectrophotometer, designed for determination of 1 to 14 mg of uranium and 0.5 to 14 mg of plutonium, has been evaluated for determination of lower levels of uranium to 0.12 mg. The essentially linear response of absorbance is maintained and the standard deviation for a single measurement is constant at about 0.013 mg of uranium, corresponding to a maximum uncertainty of about 10 percent at the 0.12-mg limit. The instrument was applied to the analysis of a series of low-level-concentration, 0.07- to 0.8-mg/ml uranium samples. The results were not statistically different from those obtained by a manual spectrophotometric method

Determination of uranium and plutonium in high active solutions by extractive spectrophotometry

International Nuclear Information System (INIS)

Subba Rao, R.V.; Damodaran, K.; Santosh Kumar, G.; Ravi, T.N.

2000-01-01

Plutonium and uranium was extracted from nitric acid into trioctyl phosphine oxide in xylene. The TOPO layer was analysed by spectrophotometry. Thoron was used as the chromogenic agent for plutonium. Pyridyl azoresorcinol was used as chromogenic agent for uranium. The molar absorption coefficient for uranium and plutonium was found to be 19000 and 19264 liter/mole-cm, respectively. The correlation coefficient for plutonium and uranium was found to be 0.9994. The relative standard deviation for the determination of plutonium and uranium was found to be 0.96% and 1.4%, respectively. (author)

Track Detection Technique Using CR-39 for Determining Depleted Uranium in Biological Specimens

International Nuclear Information System (INIS)

Murbat, S.M.

2013-01-01

Track detecting technique using CR-39 track detector has been implemented for determining depleted uranium concentration in biological specimens (tissues, bones, and blood) of patients infected with cancer diseases. Results were compared with specimens of patients infected with conventional diseases (noncancerous). Specimens were collected from middle and south of Iraq have been contaminated with depleted uranium in the Gulf war in 1991. Results show that this technique is efficient for determining depleted uranium concentration in biological specimens. It was found that all studies samples determine for patients infected with cancer diseases contain a high concentration of depleted uranium (more than the international standard) comparing with noncancerous diseases. Moreover, it was found that persons infected with Leukemia show more sensitive to uranium concentrations to induce the diseases (66-202 ppb), while (116- 1910 ppb) concentrations were needed for inducing cancer diseases in organs and tissues. Result confirmed the correlation between cancerous diseases and the munitions made of depleted uranium used in the Gulf war in 1991 leads to contaminate the Iraqi environment and causes a high risk against people in Iraq.

Micelle-mediated methodology for the preconcentration of uranium prior to its determination by flow injection

Energy Technology Data Exchange (ETDEWEB)

Fernandez Laespada, M E; Perez Pavon, J L; Moreno Cordero, B [Univ. de Salamanca (Spain). Dept. de Quimica Analitica, Nutricion y Bromatologia

1993-02-01

Cloud point extraction has been used for the preconcentration of uranium, prior to its determination by flow injection. The non-ionic surfactant employed was Triton X-114 and the reagent chosen to form a hydrophobic chelate of uranium was 1-(2-pyridylazo)-2-naphthol. The optimum conditions for the preconcentration and determination of uranium have been studied. This methodology has been applied to the determination of trace amounts of uranium in tap and river waters from Salamanca. (Author).

The Determination of Uranium and Trace Metal Impurities in Yellow Cake Sample by Chemical Method

International Nuclear Information System (INIS)

Busamongkol, Arporn; Rodthongkom, Chouvana

1999-01-01

The purity of uranium cake is very critical in nuclear-grade uranium (UO 2 ) and uranium hexafluoride (UF 6 ) production. The major element in yellow cake is uranium and trace metal impurities. The objective of this study is to determine uranium and 25 trace metal impurities; Aluminum, Barium, Bismuth, Calcium, Cadmium, Cobalt, Chromium, Copper, Iron, Potassium, Iithium, Magnesium, Manganese, Molybdenum, Sodium, Niobium, Nickel, Lead, Antimony, Tin, Strontium, Titanium, Vanadium, Zinc and Zirconium, Uranium is determined by Potassium dichromate titration, after solvent extraction with Cupferon in Chloroform, Trace metal impurities are determined by solvent extraction with Tributyl Phosphate in Carbon-tetrachloride ( for first 23 elements) and N-Benzoyl-N-Phenylhydroxylamine in Chloroform ( for last 2 elements), then analyzed by Atomic Absorption Spectrophotometer (AAS) compared with Inductively Couple Plasma Spectrophotometers (ICP). The accuracy and precision are studied with standard uranium octaoxide

Depleted uranium determination at the Novi Sad low level facility

International Nuclear Information System (INIS)

Bikit, I.; Slivka, J.; Krmar, M.; Veskovic, M.; Conkic, Lj.; Varga, E.

2002-01-01

Natural uranium determination in environmental samples at the low-level gamma-spectroscopy laboratory of the Faculty of Science in Novi Sad has more than 20 years long tradition. When the issue of depleted uranium emerged the experimental advantages of the measuring equipment (GMX type of HPGe detector with enhanced efficiency below 100 keV, and iron low level shielding) where fully exploited. A detection technique selective for depleted uranium was developed. The details of this method together with the results for about 100 samples (soil, plants, water, food) are presented, and discussed. (author)

Determination of metallic impurities in nuclearly pure uranium compounds by electrothermal spectrophotometry

International Nuclear Information System (INIS)

Franco, M.B.

1986-01-01

Atomic absorption spectrometry, with electrothermal atomization, has been used for the determination of Al, Cd, Cr, Fe, Mn and Ni in uranium oxide standards. The analysis were performed without sample dissolution and without uranium chemical separation. This technique is adequate for the qualification of nuclearly pure uranium, according to the standard specifications. (Author) [pt

Determination of uranium in urine by 2-spectrometry

International Nuclear Information System (INIS)

Duarte, C.L.; Szeles, M.S.-M.F.

1989-07-01

A comparative study is presented for two technics of preparation sources for the determination of uranium isotopes by α - spectrometry: electrodeposition and chemical stripping with polymeric membrane containing trioctylphosphine oxide (TOPO). A method is described for separation of uranium from urine with an ion-exchange column Dowex 1x8 (chloride form). The mean yield obtained for electrodeposition and TOPO deposition was 74% and 8,5% respectively. The TOPO deposition presented better resolution for 238 U and 234 U than electrodeposition. The global yield of the method obtained was 50%. (author) [pt

Determination of uranium by luminescent method (tablet variant)

International Nuclear Information System (INIS)

Sergeev, A.N.; Yufa, B.Ya.

1985-01-01

A new tablet variant of luminescent determination of uranium in rocks is developed. The analytical process includes the following operations: sample decomposition, uranium separation from luminescence quencher impurities, preparation of luminescent sample (tablet), photometry of the tablet. The method has two variants developed: the first one is characterized by a more hard decomposition, sample mass being 0.2 g; the second variant has a better detection limit (5x10 -6 %), the sample mass being 0.2-1 g. Procedures of the sample preparation for both variants of analysis are described

Uranium isotopic determination by alpha spectroscopy

International Nuclear Information System (INIS)

Acena, M.; Garcoa-Torano, E.

1979-01-01

A method for alpha-spectrometry determinations of uranium isotopes, using surface barrier detectors, is described. This method is based in the shape similarity of the most intense line groups for the nuclides 234 U, 235 U, 236 U and 238 U. The method yields analytical results sufficiently accurate in samples with 235 U contents lower than 25% in atoms. (author)

Fluorescent determination of neptunium in plutonium

International Nuclear Information System (INIS)

Alexandruk, V.M.; Babaev, A.S.; Dem'yanova, T.A.; Stepanov, A.V.

1991-01-01

This paper describes a new procedure for direct determination of Neptunium in Plutonium using laser induced time resolved fluorescence method. The procedure based on measurement of fluorescence intensity of Neptunium followed its concentration in effective layer of pellet of calcium fluoride. Detection limit of determination of Neptunium is 2 10 -12 g. At the level of Neptunium content in Plutonium more than 5 ppm relative standard deviation is equal 0.08-0.12. For carrying out of single measurement it is necessary neither more nor less 5 mkg Plutonium

Automated spectrophotometer for plutonium and uranium determination

International Nuclear Information System (INIS)

Jackson, D.D.; Hodgkins, D.J.; Hollen, R.M.; Rein, J.E.

1975-09-01

The automated spectrophotometer described is the first in a planned series of automated instruments for determining plutonium and uranium in nuclear fuel cycle materials. It has a throughput rate of 5 min per sample and uses a highly specific method of analysis for these elements. The range of plutonium and uranium measured is 0.5 to 14 mg and 1 to 14 mg, respectively, in 0.5 ml or less of solution with an option to pre-evaporate larger volumes. The precision of the measurements is about 0.02 mg standard deviation over the range corresponding to about 2 rel percent at the 1-mg level and 0.2 rel percent at the 10-mg level. The method of analysis involves the extraction of tetrapropylammonium plutonyl and uranyl trinitrate complexes into 2-nitropropane and the measurement of the optical absorbances in the organic phase at unique peak wavelengths. Various aspects of the chemistry associated with the method are presented. The automated spectrophotometer features a turntable that rotates as many as 24 samples in tubes to a series of stations for the sequential chemical operations of reagent addition and phase mixing to effect extraction, and then to a station for the absorbance measurement. With this system, the complications of sample transfers and flow-through cells are avoided. The absorbance measurement system features highly stable interference filters and a microcomputer that controls the timing sequence and operation of the system components. Output is a paper tape printout of three numbers: a four-digit number proportional to the quantity of plutonium or uranium, a two-digit number that designates the position of the tube in the turntable, and a one-digit number that designates whether plutonium or uranium was determined. Details of the mechanical and electrical components of the instrument and of the hardware and software aspects of the computerized control system are provided

Uranium analysis. Impurities determination by spark mass spectrometry

International Nuclear Information System (INIS)

Anon.

Determination of impurities in uranium, suitable for atomic content greater than 10 -8 , particularly adapted for a low content. The method is quantitative for metallic impurities and qualitative for non metallic impurities [fr

Analytical strategies for uranium determination in natural water and industrial effluents samples

International Nuclear Information System (INIS)

Santos, Juracir Silva

2011-01-01

The work was developed under the project 993/2007 - 'Development of analytical strategies for uranium determination in environmental and industrial samples - Environmental monitoring in the Caetite city, Bahia, Brazil' and made possible through a partnership established between Universidade Federal da Bahia and the Comissao Nacional de Energia Nuclear. Strategies were developed to uranium determination in natural water and effluents of uranium mine. The first one was a critical evaluation of the determination of uranium by inductively coupled plasma optical emission spectrometry (ICP OES) performed using factorial and Doehlert designs involving the factors: acid concentration, radio frequency power and nebuliser gas flow rate. Five emission lines were simultaneously studied (namely: 367.007, 385.464, 385.957, 386.592 and 409.013 nm), in the presence of HN0 3 , H 3 C 2 00H or HCI. The determinations in HN0 3 medium were the most sensitive. Among the factors studied, the gas flow rate was the most significant for the five emission lines. Calcium caused interference in the emission intensity for some lines and iron did not interfere (at least up to 10 mg L -1 ) in the five lines studied. The presence of 13 other elements did not affect the emission intensity of uranium for the lines chosen. The optimized method, using the line at 385.957 nm, allows the determination of uranium with limit of quantification of 30 μg L -1 and precision expressed as RSD lower than 2.2% for uranium concentrations of either 500 and 1000 μg L -1 . In second one, a highly sensitive flow-based procedure for uranium determination in natural waters is described. A 100-cm optical path flow cell based on a liquid-core waveguide (LCW) was exploited to increase sensitivity of the arsenazo 111 method, aiming to achieve the limits established by environmental regulations. The flow system was designed with solenoid micro-pumps in order to improve mixing and minimize reagent consumption, as well as

On the distribution of uranium in hair: Non-destructive analysis using synchrotron radiation induced X-ray fluorescence microprobe techniques

Science.gov (United States)

Israelsson, A.; Eriksson, M.; Pettersson, H. B. L.

2015-06-01

In the present study the distribution of uranium in single human hair shafts has been evaluated using two synchrotron radiation (SR) based micro X-ray fluorescence techniques; SR μ-XRF and confocal SR μ-XRF. The hair shafts originated from persons that have been exposed to elevated uranium concentrations. Two different groups have been studied, i) workers at a nuclear fuel fabrication factory, exposed mainly by inhalation and ii) owners of drilled bedrock wells exposed by ingestion of water. The measurements were carried out on the FLUO beamline at the synchrotron radiation facility ANKA, Karlsruhe. The experiment was optimized to detect U with a beam size of 6.8 μm × 3 μm beam focus allowing detection down to ppb levels of U in 10 s (SR μ-XRF setup) and 70 s (SR confocal μ-XRF setup) measurements. It was found that the uranium was present in a 10-15 μm peripheral layer of the hair shafts for both groups studied. Furthermore, potential external hair contamination was studied by scanning of unwashed hair shafts from the workers. Sites of very high uranium signal were identified as particles containing uranium. Such particles, were also seen in complementary analyses using variable pressure electron microscope coupled with energy dispersive X-ray analyzer (ESEM-EDX). However, the particles were not visible in washed hair shafts. These findings can further increase the understanding of uranium excretion in hair and its potential use as a biomonitor.

Laser based analytical spectroscopy of uranium

International Nuclear Information System (INIS)

Argekar, A.A.; Kulkarni, M.J.; Godbole, S.V.; Page, A.G.; Samuel, J.K.; Paranjape, D.B.; Singh Mudher, K.D.

1992-01-01

Analytical spectroscopy of uranium has been studied using a XeCl excimer laser, using the fluorescence emission of U(VI) ions doped in a solid solution of sodium fluoride (NaF) and sodium chloride (NaCl) in 3:2 proportion. An electronic circuitry involving time-gating of the photomultiplier tube and facility to integrate the analytical signal over ten laser pulses has been developed to enable laser operation and signal detection with high S/N ratio. The matrix enhanced U(VI) fluorescence emission is free from chemical and spectral interferences due to the concomitant presence of ten metallic elements generally associated with uranium. The digital signal output is highly precise and does not saturate upto 5 ppm uranium concentration. X-ray diffraction patterns obtained for uranium doped compounds at 2.5% and 10% dopant concentrations are broadly similar to that of Na 2 U 2 O 7 . The detailed studies have, however, revealed fine structure for individual peaks, thereby, revealing the formation of sodium fluoro-uranate complex which is responsible for the enhanced intensity of fluorescence emission. (author). 10 refs., 6 figs., 2 tabs

Determination of uranium by controlled-potential coulometry with platinum electrode

International Nuclear Information System (INIS)

Eppis, M.R.; Adelfang, P.

1990-01-01

In this work it was investigated the process by which is possible to determine uranium by means of a controlled-potential coulometry with a platinum electrode, using a reversible method, in presence of Pu(III) or Fe(II), that permits to analyze uranium and plutonium jointly with the same work electrode. The method has been adapted to be used in a standard electrochemical cell, without any modification. The determination occurs in five stages: 1) Uranium and iron reduction, with an electrolysis at -250mV vs standard calomel electrode (S.C.E.). 2) Electrolysis at +200 mV vs S.C.E. to remove the hydrogen generated in the former stage. 3) Oxidation of U(IV) to U(VI) and Fe(II) to Fe(III) by an electrolysis at +650 mV vs S.C.E. 4) Reduction of Fe(III) to Fe(II) at +200 mV vs S.C.E. 5) A new oxidation of Fe(II) to Fe(III) at +650 mV vs S.C.E. By difference between the integrated charge in the steps 3) and 5), the integrated charge corresponding to the uranium oxidation is obtained. It was necessary to determine: a) the potential and the time that is necessary to apply to realize quantitative electrochemical reduction of uranium. b) the dependence of the U/Fe concentration ratios. c) the weight of U contained in the aliqout and its influence on the method. The accuracy and precision of the method was studied and results with a standard deviation of 0.03% was obtained. Moreover, the method presents the following advantages: a) it is possible to determine U and Pu on the same aliquot; b) the process is reversible; c) the use of mercury in glove-box is avoided. (Author) [es

Determination of uranium traces in fuel cans of nuclear reactors

International Nuclear Information System (INIS)

Acosta L, C.E.; Benavides M, A.M.; Sanchez P, L.A.; Nava S, G.F.

1997-01-01

The objective of this work is to quantify the uranium content that as impurity can be found in zircon and zircaloy alloys which are used in the construction of fuel cans. The determination of this serves as a quality control measure due to that the increment of uranium content in alloy, diminishing the corrosion resistance. The fluorimetric method was used to do this determination. It is a very sensitive, reliable, rapid method also high reproducibility and repeatability as well as low detection limits (0.25 mg/kg). (Author)

Report on intercomparisons IAEA/S-17, S-18, and S-19 of the determinaton of uranium in uranium phosphate ores

International Nuclear Information System (INIS)

Pszonicki, L.; Hanna, A.N.; Suschny, O.

1984-08-01

The aim of the reported intercomparisons, organized by the IAEA's Analytical Quality Control Service, was to provide an opportunity to the participating laboratories to check the reliability of their results by comparing them with the results obtained by other laboratories. The participants were requested to determine the concentration of uranium in three samples of Brasilian uranium phosphate ores containing uranium of a low, a medium, and a large concentration. Twenty-four laboratories from 19 countries returned results. The analytical method most frequently used was radiometry of natural isotopes, followed by neutron activation analysis, fluorimetry, X-ray fluorescence and spectrophotometry. In general, the results can be considered as satisfactory. The relative confidence intervals of the medians extend in the range from -3% to +5%. The overall medians of all materials were accepted as reliable for certification

Radium 226 and uranium isotopes simultaneously determination in water samples using liquid scintillation counter

International Nuclear Information System (INIS)

Al-Masri, M.S.; Al-Akel, B.; Saaid, S.; Nashawati, A.

2007-04-01

In this work a method has been developed to determine simultaneously Radium 226 and Uranium isotopes in water samples by low back ground Liquid Scintillation Counter. Radium 226 was determined by its progeny Polonium 214 after one month of sample storage in order to achieve the equilibrium between Radium 226 and Polonium 214. Uranium isotopes were determined by subtracting Radium 226 activity from total alpha activity. The method detection limits were 0.049 Bq/L and 0.176 Bq/L for Radium 226 and Uranium isotopes respectively. The repeatability limits were ± 0.32 Bq/L and ± 0.9 Bq/L for Radium 226 and Uranium isotopes respectively. While relative errors were % 9.5 and %18.2 for Radium 226 and Uranium isotopes respectively. On the other hand, the report presented the results of different standard and natural samples.(author)

Sensitivity evaluation of the green alga Chlamydomonas reinhardtii to uranium by pulse amplitude modulated (PAM) fluorometry

Energy Technology Data Exchange (ETDEWEB)

Herlory, Olivier, E-mail: olivier.herlory@gmail.com [IRSN-Laboratoire d’Ecotoxicologie des Radionucléides, Centre de Cadarache, BP3, 13115 Saint Paul lez Durance (France); Bonzom, Jean-Marc, E-mail: jean-marc.bonzom@irsn.fr [IRSN-Laboratoire d’Ecotoxicologie des Radionucléides, Centre de Cadarache, BP3, 13115 Saint Paul lez Durance (France); Gilbin, Rodolphe, E-mail: rodolphe.gilbin@irsn.fr [IRSN-Laboratoire de Biogéochimie, Biodisponibilité et Transferts des Radionucléides, Centre de Cadarache, BP3, 13115 Saint Paul lez Durance (France)

2013-09-15

Highlights: •Our study addressed the toxicity thresholds of uranium on microalgae using PAM fluorometry. •The oxygen-evolving complex (OEC) of PSII was identified as the primary action site of uranium. •Uranium impaired the electron flux between the photosystems until almost complete inhibition. •Non-photochemical quenching was identified as the most sensitive fluorescence parameter. •PAM fluorometry provided a rapid and reasonably sensitive method for assessing stress response. -- Abstract: Although ecotoxicological studies tend to address the toxicity thresholds of uranium in freshwaters, there is a lack of information on the effects of the metal on physiological processes, particularly in aquatic plants. Knowing that uranium alters photosynthesis via impairment of the water photo-oxidation process, we determined whether pulse amplitude modulated (PAM) fluorometry was a relevant tool for assessing the impact of uranium on the green alga Chlamydomonas reinhardtii and investigated how and to what extent uranium hampered photosynthetic performance. Photosynthetic activity and quenching were assessed from fluorescence induction curves generated by PAM fluorometry, after 1 and 5 h of uranium exposure in controlled conditions. The oxygen-evolving complex (OEC) of PSII was identified as the primary action site of uranium, through alteration of the water photo-oxidation process as revealed by F{sub 0}/F{sub v}. Limiting re-oxidation of the plastoquinone pool, uranium impaired the electron flux between the photosystems until almost complete inhibition of the PSII quantum efficiency (F{sup ′}{sub q}/F{sup ′}{sub m}, EC{sub 50} = 303 ± 64 μg U L{sup −1} after 5 h of exposure) was observed. Non-photochemical quenching (qN) was identified as the most sensitive fluorescence parameter (EC{sub 50} = 142 ± 98 μg U L{sup −1} after 5 h of exposure), indicating that light energy not used in photochemistry was dissipated in non-radiative processes. It was shown

A gravimetric method for the determination of oxygen in uranium oxides and ternary uranium oxides by addition of alkaline earth compounds

International Nuclear Information System (INIS)

Fujino, Takeo; Tagawa, Hiroaki; Adachi, Takeo; Hashitani, Hiroshi

1978-01-01

A simple gravimetric determination of oxygen in uranium oxides and ternary uranium oxides is described. In alkaline earth uranates which are formed by heating in air at 800-1100 0 C, uranium is in the hexavalent state over certain continuous ranges of alkaline earth-to-uranium ratios. Thus, if an alkaline earth uranate or a compound containing an alkaline earth element, e.g. MgO, is mixed with the oxide sample and heated in air under suitable conditions, oxygen can be determined from the weight change before and after the reaction. The standard deviation of the O:U ratio for a UOsub(2+x) test sample is +-0.0008-0.001, if a correction is applied for atmospheric moisture absorbed during mixing. (Auth.)

Automated assay of uranium solution concentration and enrichment

International Nuclear Information System (INIS)

Horley, E.C.; Gainer, K.; Hansen, W.J.; Kelley, T.A.; Parker, J.L.; Sampson, T.E.; Walton, G.; Jones, S.A.

1992-01-01

For the first time, the concentration and enrichment of uranium solutions can be measured in one step. We have developed a new instrument to automatically measure the concentration and enrichment of uranium solutions through the adaptation of a commercial robot. Two identical solution enrichment systems are being installed in the Portsmouth Gaseous Diffusion Plant. These automated systems will reduce radiation exposure to personnel and increase the reliability and repeatability of the measurements. Each robotic system can process up to 40 batch and 8 priority samples in an unattended mode. Both passive gamma-ray and x-ray fluorescence (XRF) analyses are performed to determine total uranium concentration and 235 U enrichment. Coded samples are read by a bar-code reader to determine measurement requirements, then assayed by either or both of the gamma-ray and XRF instruments. The robot moves the sample containers and operates all shield doors and shutters, reducing hardware complexity. If the robots is out of service, an operator can manually perform all operations

Potentiometric determination of hexavalent uranium in uranium silicide samples

International Nuclear Information System (INIS)

Arlegui, Oscar

1999-01-01

The Chilean Nuclear Energy Commission's Department of Nuclear Materials has among its projects the production of fuels elements for nuclear reactors, and, therefore, the Chemical Analysis Laboratory must have a rapid and reliable method for uranium analysis, to control the uranium concentration during each stage of the production process. For this reason the Chilean Nuclear Energy Commission's Chemical Analysis Laboratory has validated a potentiometric method, which is a modification of the Davies and Gray method proposed by A.R. Eberle. This method uses the Potentiometric Titration Technique and is based on the direct and rapid reduction of uranium (VI) to Uranium (IV), in a concentrated phosphoric acid medium, with excess iron (II) used as a reducing agent. In this medium the excess iron (II) selectively oxidizes to iron (III) with nitric acid, using molybdenum (IV) as a catalyzer, the nitrous acid that is produced is eliminated by adding amidosulfuric acid. The solution is diluted with 1M sulfuric acid and the uranium (IV) obtained is titrated potentiometrically with potassium dichromate in the presence of vanadilic sulfate to obtain a better defined final titration point. The samples were softened with hydrochloric acid and nitric acid and later 50 ml were estimated in a 20% sulfuric acid medium. The analytical method was validated by comparing it with Certified Reference Material (C.R.M.) from the New Brunswick Laboratory (NBL), Metallic Uranium, CRM 112-A. The F Test and the T Test show that the value calculated is less than the tabulated value so the result is traceable to the reference material. The quantification limit, sensitivity, precision and accuracy were quantified for the method

Sensitivity evaluation of the green alga Chlamydomonas reinhardtii to uranium by pulse amplitude modulated (PAM) fluorometry.

Science.gov (United States)

Herlory, Olivier; Bonzom, Jean-Marc; Gilbin, Rodolphe

2013-09-15

Although ecotoxicological studies tend to address the toxicity thresholds of uranium in freshwaters, there is a lack of information on the effects of the metal on physiological processes, particularly in aquatic plants. Knowing that uranium alters photosynthesis via impairment of the water photo-oxidation process, we determined whether pulse amplitude modulated (PAM) fluorometry was a relevant tool for assessing the impact of uranium on the green alga Chlamydomonas reinhardtii and investigated how and to what extent uranium hampered photosynthetic performance. Photosynthetic activity and quenching were assessed from fluorescence induction curves generated by PAM fluorometry, after 1 and 5h of uranium exposure in controlled conditions. The oxygen-evolving complex (OEC) of PSII was identified as the primary action site of uranium, through alteration of the water photo-oxidation process as revealed by F0/Fv. Limiting re-oxidation of the plastoquinone pool, uranium impaired the electron flux between the photosystems until almost complete inhibition of the PSII quantum efficiency ( [Formula: see text] , EC50=303 ± 64 μg UL(-1) after 5h of exposure) was observed. Non-photochemical quenching (qN) was identified as the most sensitive fluorescence parameter (EC50=142 ± 98 μg UL(-1) after 5h of exposure), indicating that light energy not used in photochemistry was dissipated in non-radiative processes. It was shown that parameters which stemmed from fluorescence induction kinetics are valuable indicators for evaluating the impact of uranium on PSII in green algae. PAM fluorometry provided a rapid and reasonably sensitive method for assessing stress response to uranium in microalgae. Copyright © 2013 Elsevier B.V. All rights reserved.

Use of electrothermal atomization for determining metallic impurities in nuclearly pure uranium compounds

International Nuclear Information System (INIS)

Franco, M.B.

1986-01-01

Atomic absorption spectrometry with electrothermal atomization was used for the determination of Al, Cd, Cr, Fe, Mn, Mo and Ni as impurities in uranium oxide samples. The determinations were performed in solubilized samples both with and without uranium separation as well as in solid samples. (Author) [pt

Use of electrothermal atomization for determining metallic impurities in nuclearly pure uranium compounds

International Nuclear Information System (INIS)

Franco, M.B.

1985-01-01

Atomic absorption spectrometry with electrothermal atomization was used for the determination of Al, Cd, Cr, Fe, Mn, Mo and Ni as impurities in uranium oxide samples. The determinations were performed in solubilized samples both with and without uranium separation as well as in solid samples. (Author) [pt

Determination of uranium by direct titration with dipicolinic acid

International Nuclear Information System (INIS)

Baumann, E.W.

1984-01-01

Direct titration of uranium with dipicolinic acid, in the presence of Arsenazo I, is a simple, precise, and accurate method for uranium determination. The method is particularly attractive because it can be totally automated. Detecting the end point (color change from blue to pink) depends on the concentration range. For the Micro Method (1 to 20 ppM U in the solution titrated), the gradual color change is monitored spectrophotometrically. For the Macro Method (20 to 300 ppM), the end point is determined either visually or spectrophotometrically. The spectrophotometric end point is computed by fitting the titration curve. The relative standard deviation is +-1 to 3% for the Micro Method and +-0.3% for the Macro Method

Determination of uranium in plutonium--238 metal and oxide by differential pulse polarography

International Nuclear Information System (INIS)

Fawcett, N.C.

1976-01-01

A differential pulse polarographic method was developed for the determination of total uranium in 238 Pu metal and oxides. A supporting electrolyte of 0.5 M ascorbic acid in 0.15 N H 2 SO 4 was found satisfactory for the determination of 500 ppM or more of uranium in 10 mg or less of plutonium. A relative standard deviation of 0.27 to 4.3 percent was obtained in the analysis of samples ranging in uranium content from 0.65 to 2.79 percent. The limit of detection was 0.18 μg ml -1 . Peak current was a linear function of uranium concentration up to at least 100 μg ml -1 . Amounts of neptunium equal to the uranium content were tolerated. The possible interference of a number of other cations and anions were investigated

DIFFERENTIAL PULSE ANODIC STRIPPING VOLTAMMETRY FOR DETERMINATION OF SOME HEAVY METALS IN URANIUM

Directory of Open Access Journals (Sweden)

Saryati Saryati

2010-06-01

Full Text Available The direct determination of some metals impurity in uranium by using differential pulse anodic stripping voltammetry (DPASV method at a hanging mercury drop electrode and in a carbonate buffer media was developed. It was found that the carbonate buffer show the strongest affinity for uranium and gives the best separation between the DPASV peaks of heavy metals impurities. The carbonate concentration markedly affects the oxidation and reduction the major and the minor constituents of the uranium samples. In 0.1 M carbonate buffer solution pH 10, copper, bismuth, thalium, lead, cadmium, zinc, could be determined without the removal of the uranium matrix. Recovery and relative standard deviation (RSD of this method was in the range of 174% - 85.2% for recovery and 36.8% - 1.2% for RSD. The larger error of analytical result was obtained for Zn at low concentration. In general, the analytic results error and RSD decreased with increasing metals concentration.   Keywords: heavy metal determination, differential pulse anodic stripping voltammetry, uranium

Performance evaluation of indigenous controlled potential coulometer for the determination of uranium and plutonium

International Nuclear Information System (INIS)

Sharma, H.S.; Jisha, V.; Noronha, D.M.; Sharma, M.K.; Aggarwal, S.K.

2007-09-01

We have carried out performance evaluation of indigenously manufactured controlled potential coulometer for the determination of uranium and plutonium respectively in Rb 2 U(SO 4 ) 3 and K 4 Pu(SO 4 ) 4 chemical assay standards. The coulometric results obtained on uranium determination showed an insignificant difference as compared with the biamperometric results at 95% and 99.9% confidence levels while for plutonium determination showed a difference of -0.4% at 95% with respect to expected value. The results obtained show that indigenous coulometer is suitable for uranium and plutonium determination in chemical assay standards. (author)

Study on direct determination of uranium and efficient equilibrium factor by gamma-ray spectrometer

International Nuclear Information System (INIS)

Liu Chunkui

1990-01-01

The test principle, test set and surveying methods for conducting gamma-ray spectrometry on conveyer are presented. The conversion coefficient of the spectrometer has been found by using duallinear regression analysis of uranium and radon and their higher and lower bands of gamma-ray spectra. The efficient equilibrium factor can be quickly determined, and the direct determination of uranium in the non-equilibrium condition of uranium and radium can be made

Quantification of the effect of in-situ generated uranium metal on the experimentally determined O/U ratio of a sintered uranium dioxide fuel pellet

International Nuclear Information System (INIS)

Narasimha Murty, B.; Bharati Misra, U.; Yadav, R.B.; Srivastava, R.K.

2005-01-01

This paper describes quantitatively the effect of in-situ generated uranium metal (that could be formed due to the conducive manufacturing conditions) in a sintered uranium dioxide fuel pellet on the experimentally determined O/U ratio using analytical methods involving dissolution of the pellet material. To quantify the effect of in-situ generated uranium metal in the fuel pellet, a mathematical expression is derived for the actual O/U ratio in terms of the O/U ratio as determined by an experiment involving dissolution of the material and the quantity of uranium metal present in the uranium dioxide pellet. The utility of this derived mathematical expression is demonstrated by tabulating the calculated actual O/U ratios for varying amounts of uranium metal (from 5 to 95% in 5% intervals) and different O/U ratio values (from 2.001 to 2.015 in 0.001 intervals). This paper brings out the necessity of care to be exercised while interpreting the experimentally determined O/U ratio and emphasizes the fact that it is always safer to produce the nuclear fuel with oxygen to uranium ratios well below the specified maximum limit of 2.015. (author)

Extraction photometric determination of uranium (6) with use of malachite green

International Nuclear Information System (INIS)

Stepanenko, Yu.V.; Bagdasarov, K.N.; Shchemeleva, G.G.

1975-01-01

A study of the reaction between uranium (6) and malachite green in the presence of sodium benzoate has indicated that, in a weakly acid medium (pH 4.5 to 5.5), the reaction yields a poorly soluble greenish compound which tends to be extracted by a 1-to-1 mixture of benzene and chloroform. The compound comprises uranium, a benzoate and a malachite green in a ratio of 1/3/1. A method has been developed for an extraction-photometric determination of uranium in metallic lead

Extraction photometric determination of uranium (6) with use of malachite green

Energy Technology Data Exchange (ETDEWEB)

Stepanenko, Yu V; Bagdasarov, K N; Shchemeleva, G G [Rostovskij-na-Donu Gosudarstvennyj Univ. (USSR)

1975-12-01

A study of the reaction between uranium (6) and malachite green in the presence of sodium benzoate has indicated that, in a weakly acid medium (pH 4.5 to 5.5), the reaction yields a poorly soluble greenish compound which tends to be extracted by a 1-to-1 mixture of benzene and chloroform. The compound comprises uranium, a benzoate and a malachite green in a ratio of 1/3/1. A method has been developed for an extraction-photometric determination of uranium in metallic lead.

Various electroanalytical methods for the determination of uranium in different matrices

Directory of Open Access Journals (Sweden)

Alankar Shrivastava

2013-06-01

Full Text Available Uranium is a toxic material hence numerous body systems such as the kidney, brain, liver, and heart can be affected by uranium exposure. The main effect is kidney toxicity. Uranium is a naturally occurring element found in low levels in all rock, soil, and water. All uranium isotopes may also cause radiation hazards, thus without any doubt an analysis of such materials in the surrounding environment is very important. The presented review is a summarization of all electroanalytical techniques for the determination of uranium and its compounds in various matrices. Totally 43 different methods are found in our literature survey. Out of these three are polarographic, 25 potentiometry, five capillary electrophoresis and 28 voltametric methods are available in the literature. Interferences of different ions and applications in different matrices are also given for each method.

Radioactivity and the French uranium bearing minerals

International Nuclear Information System (INIS)

Guiollard, P.Ch.; Boisson, J.M.; Leydet, J.C.; Meisser, N.

1998-01-01

This special issue of Regne Mineral journal is entirely devoted to the French uranium mining industry. It comprises 4 parts dealing with: the uranium mining industry in France (history, uranium rush, deposits, geologic setting, prosperity and recession, situation in 1998, ore processing); radioactivity and the uranium and its descendants (discovery, first French uranium bearing ores, discovery of radioactivity, radium and other uranium descendants, radium mines, uranium mines, atoms, elements and isotopes, uranium genesis, uranium decay, isotopes in an uranium ore, spontaneous fission, selective migration of radionuclides, radon in mines and houses, radioactivity units, radioprotection standards, new standards and controversies, natural and artificial radioactivity, hazards linked with the handling and collecting of uranium ores, conformability with radioprotection standards, radioactivity of natural uranium minerals); the French uranium bearing minerals (composition, crystal structure, reference, etymology, fluorescence). (J.S.)

Determination of irradiated reactor uranium in soil samples in Belarus using 236U as irradiated uranium tracer.

Science.gov (United States)

Mironov, Vladislav P; Matusevich, Janna L; Kudrjashov, Vladimir P; Boulyga, Sergei F; Becker, J Sabine

2002-12-01

This work presents experimental results on the distribution of irradiated reactor uranium from fallout after the accident at Chernobyl Nuclear Power Plant (NPP) in comparison to natural uranium distribution in different soil types. Oxidation processes and vertical migration of irradiated uranium in soils typical of the 30 km relocation area around Chernobyl NPP were studied using 236U as the tracer for irradiated reactor uranium and inductively coupled plasma mass spectrometry as the analytical method for uranium isotope ratio measurements. Measurements of natural uranium yielded significant variations of its concentration in upper soil layers from 2 x 10(-7) g g(-1) to 3.4 x 10(-6) g g(-1). Concentrations of irradiated uranium in the upper 0-10 cm soil layers at the investigated sampling sites varied from 5 x 10(-12) g g(-1) to 2 x 10(-6) g g(-1) depending on the distance from Chernobyl NPP. In the majority of investigated soil profiles 78% to 97% of irradiated "Chernobyl" uranium is still contained in the upper 0-10 cm soil layers. The physical and chemical characteristics of the soil do not have any significant influence on processes of fuel particle destruction. Results obtained using carbonate leaching of 236U confirmed that more than 60% of irradiated "Chernobyl" uranium is still in a tetravalent form, ie. it is included in the fuel matrix (non-oxidized fuel UO2). The average value of the destruction rate of fuel particles determined for the Western radioactive trace (k = 0.030 +/- 0.005 yr(-1)) and for the Northern radioactive trace (k = 0.035 + 0.009 yr(-1)) coincide within experimental errors. Use of leaching of fission products in comparison to leaching of uranium for study of the destruction rate of fuel particles yielded poor coincidence due to the fact that use of fission products does not take into account differences in the chemical properties of fission products and fuel matrix (uranium).

Separation of uranium and other metals from commercial phosphoric acid by ion-exchange and voltammetric determination of uranium

International Nuclear Information System (INIS)

Ferreira, J.B.C.; Carvalho, F.M.S. de; Abrao, A.

1985-11-01

The separation of metals from crude commercial phosphoric acid is achieved by simple dilution and percolation through a strong cationic ion exchanger. Uranium, calcium, magnesium, manganese, iron and aluminum are quantitatively fixed by the exchanger and can be detected or analysed after their complete elution with 6 M HCI. Titanium and zirconium are only partially retained. Specially for its separation and determination uranium is retained selectively by the resin from the phosphoric acid-EDTA solution, the column is washed with water and then eluted with hydrochloric acid. Uranium is analyzed by voltametry with the hanging drop mercury electrode. (Author) [pt

Laser fluorimetric determination of uranium in environmental samples from Nile Delta and adjacent regions

International Nuclear Information System (INIS)

Shawky, S.; Ibrahiem, N.; Farouk, A.; Ghods, A.

1994-01-01

Total uranium content was determined in soil and plant samples obtained from various areas in the Nile Delta. Samples taken from east and west of the delta, Suez canal cities and from the Alexandria region were analysed using laser fluorimetry (LF). Uranium was extracted from digested samples with methyl-isobutyl ketone and measured using a laser fluorimeter. The radium content of the same soil samples was determined using gamma spectroscopy. The uranium content of plant samples was determined using LF, since this technique has a detection limit lower than that of GS. Uranium content in the samples varied between 0.6-4.4 μg/g for soil and 0.032-0.17 μg/g for plant tissue. (author)

Spectrofluorimetric determination of microquantities of aluminium in uranium

International Nuclear Information System (INIS)

Gomiero, L.A.; Nascimento, M.R.L. do; Abraao, A.

1976-01-01

A rapid and sensitive method for the separation and spectrofluorimetric determination of microamounts of aluminium in uranium compounds is described. In sodium carbonate solution at pH 9.5-10.0, the uranyl ion forms a very stable anionic complex with the carbonate ion. In these conditions, uranium is not extracted by a chloroform oxine solution, while alumium is isolated as the tris(oxinate)aluminium(III) form. The interferences are previously extracted with chloroform as diethylditiocarbomates in the same tris(oxinate)aluminum(III) pH extraction. The sensitivity is 0,005 μ Al/ml of organic phase and the relative standard deviation is 10% [pt

Potentiometric determination of uranium in simulated Purex Process solutions by acidiometry

International Nuclear Information System (INIS)

Cohen, V.H.; Matsuda, H.T.; Araujo, B.F. de; Araujo, J.A. de

1983-01-01

A potentiometric methods for sequential free acidity and uranium determination in simulated Purex Process solutions is described. An oxalate solution or a mixture of fluoride-oxalate pellets were used as complexing agent for free titration. Following this first equivalent point, uranium is determined-by indirect titration of H + liberated in the peruanate reaction. Some elements present in the standard fuel elements with a burn-up of 33.000 Mwd/t, neutron flux of 3,2 x 10 13 n.cm -2 .s -1 and cooling time of two years were considered as interfering elements in uranium analyses. As a substitute of Pu-IV, Th(NO 3 ) 4 solution was used. The method can be applied to aqueous and organic (TBP/diluent) solutions with 2% precision and 2% accuracy. (Autor) [pt

Potentiometric determination of uranium in simulated Purex Process solutions by acidiometry

Energy Technology Data Exchange (ETDEWEB)

Cohen, V H; Matsuda, H T; Araujo, B.F. de; Araujo, J.A. de

1984-01-01

A potentiometric methods for sequential free acidity and uranium determination in simulated Purex Process solutions is described. An oxalate solution or a mixture of fluoride-oxalate pellets were used as complexing agent for free titration. Following this first equivalent point, uranium is determined-by indirect titration of H/sup +/ liberated in the peruanate reaction. Some elements present in the standard fuel elements with a burn-up of 33.000 Mwd/t, neutron flux of 3,2 x 10/sup 13/n.cm/sup -2/.s/sup -1/ and cooling time of two years were considered as interfering elements in uranium analyses. As a substitute of Pu-IV, Th(NO/sub 3/)/sub 4/ solution was used. The method can be applied to aqueous and organic (TBP/diluent) solutions with 2% precision and 2% accuracy. (Autor).

Fluor determination by alkaline hydrolysis of the uranium and thorium fluorides

International Nuclear Information System (INIS)

Barrachina Gomez, L.; Gasco Sanchez, L.

1961-01-01

The alkaline hydrolysis of the uranium and thorium fluorides is studded and a new method for the determination of the fluoride, on the basis of a indirect volumetric titration with standard soda, is proposed. The compounds that may influence the hydrolysis of the uranium fluoride and that may be occasionally found in it as impurities are also studied. the method can be applied to the uranium fluoride except when there is a great quantity of F 2 UO 2 or UO 3 present in the sample. (Author) 20 refs

Nuclear fuel technology - Determination of uranium in solutions, uranium hexafluoride and solids - Part 2: Iron(II) reduction/cerium(IV) oxidation titrimetric method

International Nuclear Information System (INIS)

2004-01-01

This first edition of ISO 7097-1 together with ISO 7097-2:2004 cancels and replaces ISO 7097:1983, which has been technically revised, and ISO 9989:1996. ISO 7097 consists of the following parts, under the general title Nuclear fuel technology - Determination of uranium in solutions, uranium hexafluoride and solids: Part 1: Iron(II) reduction/potassium dichromate oxidation titrimetric method; Part 2: Iron(II) reduction/cerium(IV) oxidation titrimetric method. This part 2. of ISO 7097 describes procedures for determination of uranium in solutions, uranium hexafluoride and solids. The procedures described in the two independent parts of this International Standard are similar: this part uses a titration with cerium(IV) and ISO 7097-1 uses a titration with potassium dichromate

Nuclear fuel technology - Determination of uranium in solutions, uranium hexafluoride and solids - Part 1: Iron(II) reduction/potassium dichromate oxidation titrimetric method

International Nuclear Information System (INIS)

2004-01-01

This first edition of ISO 7097-1 together with ISO 7097-2:2004 cancels and replaces ISO 7097:1983, which has been technically revised, and ISO 9989:1996. ISO 7097 consists of the following parts, under the general title Nuclear fuel technology - Determination of uranium in solutions, uranium hexafluoride and solids: Part 1: Iron(II) reduction/potassium dichromate oxidation titrimetric method; Part 2: Iron(II) reduction/cerium(IV) oxidation titrimetric method. This part 1. of ISO 7097 describes procedures for the determination of uranium in solutions, uranium hexafluoride and solids. The procedures described in the two independent parts of this International Standard are similar: this part uses a titration with potassium dichromate and ISO 7097-2 uses a titration with cerium(IV)

AEC determines uranium enrichment policy

International Nuclear Information System (INIS)

Anon.

1992-01-01

The Advisory Committee on Uranium Enrichment of the Atomic Energy Commission (AEC) has submitted a report to AEC chairman concerning the promotion of the introduction of advanced material, high performance centrifuges to replace conventional metallic drum centrifuges, and the development of next generation advanced centrifuges. The report also called for the postponement until around 1997 of the decision whether the development should be continued or not on atomic vapor laser isotope separation (AVLIS) and molecular laser isotope separation (MLIS) processes, as well as the virtual freezing of the construction of a chemical process demonstration plant. The report was approved by the AEC chairman in August. The uranium enrichment service market in the world will continue to be characterized by oversupply. The domestic situation of uranium enrichment supply-demand trend, progress of the expansion of Rokkasho enrichment plant, the trend in the development of gas centrifuge process and the basic philosophy of commercializing domestic uranium enrichment are reported. (K.I.)

Determination of fluorine trace amounts in metallic uranium

Energy Technology Data Exchange (ETDEWEB)

Kukisheva, T N; Bolshakova, A S; Yefimova, N S

1976-05-01

A simple and rapid method was proposed for the determination of fluorine in metallic uranium without the removal of the latter. The method is based on the weakening of the color intensity of a complex of zirconium with xylenol orange in the presence of fluorine in a 1 N solution with respect to hydrochloric acid. For preparation for photometry, the solution to be analyzed is neutralized with ammonia to a pH of approximately 3. It is suggested that a complex of sulfosalicylic acid with uranium (VI) be used as the indicator in neutralization. The required acidity in the solution subjected to photometry is provided by the addition of a 5 N hydrochloric acid solution of zirconium. The coefficient of variation V/sub 15/ (at a fluorine content 3x10/sup -3/%) is 10%. In 7 h, 15-20 determinations can be performed.

Determining uranium speciation in Fernald soils by molecular spectroscopic methods

International Nuclear Information System (INIS)

Allen, P.G.; Berg, J.M.; Crisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.

1994-07-01

This progress report describes new experimental results and interpretations for data collected from October 1, 1992, through September 30, 1993, as part of the Characterization Task of the Uranium in Soils Integrated Demonstration of the Office of Technology Development, Office of Environmental Restoration and Waste Management of the US Department of Energy. X-ray absorption, optical luminescence, and Raman vibrational spectroscopies were used to determine uranium speciation in contaminated soils from the US DOE's former uranium production facility at Fernald, Ohio. These analyses were carried out both before and after application of one of the various decontamination technologies being developed within the Integrated Demonstration. This year the program focused on characterization of the uranium speciation remaining in the soils after decontamination treatment. X-ray absorption and optical luminescence spectroscopic data were collected for approximately 40 Fernald soil samples, which were treated by one or more of the decontamination technologies

Accurate and precise determination of small quantity uranium by means of automatic potentiometric titration

International Nuclear Information System (INIS)

Liu Quanwei; Luo Zhongyan; Zhu Haiqiao; Wu Jizong

2007-01-01

For high radioactivity level of dissolved solution of spent fuel and the solution of uranium product, radioactive hazard must be considered and reduced as low as possible during accurate determination of uranium. In this work automatic potentiometric titration was applied and the sample only 10 mg of uranium contained was taken in order to reduce the harm of analyzer suffered from the radioactivity. RSD<0.06%, at the same time the result can be corrected for more reliable and accurate measurement. The determination method can effectively reduce the harm of analyzer suffered from the radioactivity, and meets the requirement of reliable accurate measurement of uranium. (authors)

The use of voltammetry for determining uranium and associated elements in compounds of nuclear interest

International Nuclear Information System (INIS)

Carvalho, F.M.S. de.

1988-01-01

The determination of uranium and some trace elements found as impurities in nuclear materials by the voltammetric technique using the hanging mercury drop electrode is presented. Emphasis is given to the determination of uranium, of major interest. Europium and ytterbium are simultaneously determined in fractions of individual lanthanides. A procedure for the simultaneous determination of copper, cadmium, nickel and zinc in water, industrial effluents and uranium compounds is discussed. The advantage of the procedure is its simplicity and easiness of execution, with excellent precision and accuracy. (author) [pt

Measurement of plutonium in spent nuclear fuel by self-induced x-ray fluorescence

Energy Technology Data Exchange (ETDEWEB)

Hoover, Andrew S [Los Alamos National Laboratory; Rudy, Cliff R [Los Alamos National Laboratory; Tobin, Steve J [Los Alamos National Laboratory; Charlton, William S [Los Alamos National Laboratory; Stafford, A [TEXAS A& M; Strohmeyer, D [TEXAS A& M; Saavadra, S [ORNL

2009-01-01

Direct measurement of the plutonium content in spent nuclear fuel is a challenging problem in non-destructive assay. The very high gamma-ray flux from fission product isotopes overwhelms the weaker gamma-ray emissions from plutonium and uranium, making passive gamma-ray measurements impossible. However, the intense fission product radiation is effective at exciting plutonium and uranium atoms, resulting in subsequent fluorescence X-ray emission. K-shell X-rays in the 100 keV energy range can escape the fuel and cladding, providing a direct signal from uranium and plutonium that can be measured with a standard germanium detector. The measured plutonium to uranium elemental ratio can be used to compute the plutonium content of the fuel. The technique can potentially provide a passive, non-destructive assay tool for determining plutonium content in spent fuel. In this paper, we discuss recent non-destructive measurements of plutonium X-ray fluorescence (XRF) signatures from pressurized water reactor spent fuel rods. We also discuss how emerging new technologies, like very high energy resolution microcalorimeter detectors, might be applied to XRF measurements.

Voltametric determination of O:U relation in uranium oxide

International Nuclear Information System (INIS)

Carvalho, F.M.S. de; Abrao, A.

1988-07-01

Uranium oxide samples are dissolved in hot concentrated H 3 PO 4 - H 2 SO 4 mixture and the solution diluted with 1M H 2 SO 4 . One aliquot of such solution (A) is used to record the first voltamogram which gives the U(VI) content. To a second aliquot HNO 3 and H 2 O 2 is added to oxidise uranium to the hexavalent state (B) and the second voltamogram is recorded from 0.0 to 0.4 V X SCE. The O:U ratio in the original sample is calculated by the expression: O/U = 2.000 + [U (VI) soln.A/% U(VI) soln. B]. The method provides an accurate means for determining O to U ratios in high-purity uranium dioxide, fuel pellets and a variety of oxides prepared for developmental work on ceramic fuel materials. (author) [pt

Evaluation of kinetic phosphorescence analysis for the determination of uranium

International Nuclear Information System (INIS)

Croatto, P.V.; Frank, I.W.; Johnson, K.D.; Mason, P.B.; Smith, M.M.

1997-12-01

In the past, New Brunswick Laboratory (NBL) has used a fluorometric method for the determination of sub-microgram quantities of uranium. In its continuing effort to upgrade and improve measurement technology, NBL has evaluated the commercially-available KPA-11 kinetic phosphorescence analyzer (Chemchek, Richland, WA). The Chemchek KPA-11 is a bench-top instrument which performs single-measurement, quench-corrected analyses for trace uranium. It incorporates patented kinetic phosphorimetry techniques to measure and analyze sample phosphorescence as a function of time. With laser excitation and time-corrected photon counting, the KPA-11 has a lower detection limit than conventional fluorometric methods. Operated with a personal computer, the state-of-the-art KPA-11 offers extensive time resolution and phosphorescence lifetime capabilities for additional specificity. Interferences are thereby avoided while obtaining precise measurements. Routine analyses can be easily and effectively accomplished, with the accuracy and precision equivalent to the pulsed-laser fluorometric method presently performed at NBL, without the need for internal standards. Applications of kinetic phosphorimetry at NBL include the measurement of trace level uranium in retention tank, waste samples, and low-level samples. It has also been used to support other experimental activities at NBL by the measuring of nanogram amounts of uranium contamination (in blanks) in isotopic sample preparations, and the determining of elution curves of different ion exchange resins used for uranium purification. In many cases, no pretreatment of samples was necessary except to fume them with nitric acid, and then to redissolve and dilute them to an appropriate concentration with 1 M HNO 3 before measurement. Concentrations were determined on a mass basis (microg U/g of solution), but no density corrections were needed since all the samples (including the samples used for calibration) were in the same density

Study of resolution enhancement methods for impurities quantitative analysis in uranium compounds by XRF

Energy Technology Data Exchange (ETDEWEB)

Silva, Clayton P.; Salvador, Vera L.R.; Cotrim, Marycel E.B.; Pires, Maria Ap. F.; Scapin, Marcos A., E-mail: clayton.pereira.silva@usp.b [Instituto de Pesquisas Energeticas e Nucleares (CQMA/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente

2011-07-01

X-ray fluorescence analysis is a technique widely used for the determination of both major and trace elements related to interaction between the sample and radiation, allowing direct and nondestructive analysis. However, in uranium matrices these devices are inefficient because the characteristic emission lines of elements like S, Cl, Zn, Zr, Mo and other overlap characteristic emission lines of uranium. Thus, chemical procedures to separation of uranium are needed to perform this sort of analysis. In this paper the deconvolution method was used to increase spectra resolution and correct the overlaps. The methodology was tested according to NBR ISO 17025 using a set of seven certified reference materials for impurities present in U3O8 (New Brunswick Laboratory - NBL). The results showed that this methodology allows quantitative determination of impurities such as Zn, Zr, Mo and others, in uranium compounds. The detection limits were shorter than 50{mu}g. g{sup -1} and uncertainty was shorter than 10% for the determined elements. (author)

Study of resolution enhancement methods for impurities quantitative analysis in uranium compounds by XRF

International Nuclear Information System (INIS)

Silva, Clayton P.; Salvador, Vera L.R.; Cotrim, Marycel E.B.; Pires, Maria Ap. F.; Scapin, Marcos A.

2011-01-01

X-ray fluorescence analysis is a technique widely used for the determination of both major and trace elements related to interaction between the sample and radiation, allowing direct and nondestructive analysis. However, in uranium matrices these devices are inefficient because the characteristic emission lines of elements like S, Cl, Zn, Zr, Mo and other overlap characteristic emission lines of uranium. Thus, chemical procedures to separation of uranium are needed to perform this sort of analysis. In this paper the deconvolution method was used to increase spectra resolution and correct the overlaps. The methodology was tested according to NBR ISO 17025 using a set of seven certified reference materials for impurities present in U3O8 (New Brunswick Laboratory - NBL). The results showed that this methodology allows quantitative determination of impurities such as Zn, Zr, Mo and others, in uranium compounds. The detection limits were shorter than 50μg. g -1 and uncertainty was shorter than 10% for the determined elements. (author)

Total reflection X-ray Fluorescence determination of interfering elements rubidium and uranium by profile fitting

Science.gov (United States)

Dhara, Sangita; Khooha, Ajay; Singh, Ajit Kumar; Tiwari, M. K.; Misra, N. L.

2018-06-01

Systematic studies to assess the analytical parameters obtained in the total reflection X-ray fluorescence (TXRF) determinations of interfering elements Rb and U using profile fitting are reported in the present manuscript. The X-ray lines Rb Kα and U Lα having serious spectral interference (ΔE = 218 eV), have been used as analytical lines. The intensities of these X-ray lines have been assessed using profile fitting. In order to compare the analytical results of Rb determinations in presence of U, with and without U excitation, synchrotron radiation was tuned to energy just above and below the U Labs edge. This approach shall excite both Rb Kα and U Lα simultaneously and Rb Kα selectively. Finally, the samples were also analyzed with a laboratory based TXRF spectrometer. The analytical results obtained in all these conditions were comparable. The authenticity of the results was assessed by analyzing U with respect to Rb in Rb2U(SO4)3, a standard reference material for U. The average precision obtained for TXRF determinations was below 3% (RSD, n = 3, 1σ) and the percent deviation of TXRF values from the expected values calculated on the basis of sample preparation was within 3%.

New resin gel for uranium determination by diffusive gradient in thin films technique

International Nuclear Information System (INIS)

Gregusova, Michaela; Docekal, Bohumil

2011-01-01

A new resin gel based on Spheron-Oxin chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10 2 mg L -1 . The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel.

New resin gel for uranium determination by diffusive gradient in thin films technique

Energy Technology Data Exchange (ETDEWEB)

Gregusova, Michaela, E-mail: gregusova@iach.cz [Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Veveri 97, 602 00 Brno (Czech Republic); Docekal, Bohumil [Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Veveri 97, 602 00 Brno (Czech Republic)

2011-01-17

A new resin gel based on Spheron-Oxin chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10{sup 2} mg L{sup -1}. The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel.

Determination of uranium isotopes in urine

International Nuclear Information System (INIS)

Lellis, I.R.; Silva, D.V.F.M. Rey; Taddei, M.H.T.

2017-01-01

Variable concentrations of uranium occur naturally in waters, plant products and soils. Small amounts of this element are routinely incorporated by man. Occupationally exposed individuals (IOEs) are subject to the incorporation of higher amounts of uranium into their work routines. The effects on human health resulting from the incorporation of uranium in environmental doses are not very well established and are currently recognized as of little relevance. The incorporation resulting from occupational activities, where higher doses can be found, represents a health risk resulting from chemical damages to the kidneys. Considering that uranium is eliminated from the human body through urine and feces, and that the concentration in the urine can be obtained by means of radiochemical analyzes, this can be considered an efficient indirect method to verify the incorporation of this element. In the work the isotopes of 234 U, 235 U and 238 U were analyzed in urine samples of IOEs and the rate of uranium present in them was verified

Applications of inductively coupled plasma spectroscopy to geochemical reconnaissance for uranium exploration

International Nuclear Information System (INIS)

Cagle, G.W.; Butz, T.R.

1980-01-01

The analysis of large numbers of natural groundwater and stream sediment samples by Inductively Coupled Plasma (ICP) Spectroscopy has been applied to a geochemical reconnaissance program as part of the National Uranium Resource Evaluation Program. Approximately 25 elements have been determined in over 60,000 samples by ICP analysis. These data are combined with additional measurements obtained by atomic absorption, colorimetry, neutron activation, and fluorescence spectroscopy. Results are presented and interpreted in terms of the uranium favorability of areas in Texas where this survey has been completed

Uranium and thorium determination in water samples taken along River Kura

International Nuclear Information System (INIS)

Ahmadov, M.M.; Ibadov, N.A.; Safarova, K.S.; Humbatov, F.Y.; Suleymanov, B.A.

2014-01-01

Full text : In the present investigation, uranium and thorium concentration in rivers water of Azerbaijan has been measured using inductively coupled plasma mass spectrometry. The Agilent 7700x series ICP-MS applied for analysis of water samples. This method is based on direct introduction of samples, without any chemical pre-treatment, into an inductively coupled plasma plasma mass spectrometer. Uranium and thorium was determined at the mass mass numbers of 238 and 232 respectively using Bi-209 as internal standard. The main purpose of the study is to measure the level of uranium and thorium in water samples taken along river Kura

Standardization of solvent extraction procedure for determination of uranium in seawater

International Nuclear Information System (INIS)

Sukanta Maity; Sahu, S.K.; Pandit, G.G.

2015-01-01

Solvent extraction procedure using ammonium pyrolidine dithiocarbamate complexing agent in methyl isobutyl ketone organic phase and acid exchange back-extraction is described for the simultaneous quantitative pre-concentration of uranium in seawater followed by its determination by differential pulse adsorptive stripping voltammetry. Solvent extraction time is optimized for extraction of uranium from seawater. Solvent extraction efficiency for uranium in seawater at different pH was carried out. The method gives a recovery of 98 ± 2 % for 400 mL sample at pH 3.0 ± 0.02, facilitating the rapid and interference free analysis of seawater samples. (author)

Uranium and thorium determination in Santa Quiteria liquor by ICP-OES analysis

International Nuclear Information System (INIS)

Pedro Junior, A.; Rezende, Paulo R.; Carvalho, Leonel M.; Ferreira, Elizabeth de Massena

2009-01-01

The mineral source of Itataia located in Santa Quiteria (Ceara/Brazil) is a phosphorus uraniferous one, where uranium occurs in collophanite (fluoroapatite) form. Phosphate minerals of the apatite family make possible the uses of uranium as a byproduct. The sulfuric leaching of the phosphate rock in order to obtain phosphoric acid also permits uranium recovery. Thus, the liquor coming from the leaching contains high levels of phosphoric acid as well as elements like Mg, Fe, U, Zr, Th and some rare earths in significant concentrations. The direct determination of U and Th content of this liquor is essential to a rapid response in the uranium separation and purification together process by solvent extraction, aiming its use for commercial purposes, as nuclear industry fuel. In this study U and Th were determined by Inductively Coupled Plasma Spectrometry (ICP-OES) in several samples of liquor, in high concentrations of H 3 PO 4 in environment. Several ratios of U/Th and H 3 PO 4 concentrations were studied, in order to find the optimal conditions for the direct determination of U and Th, without need to prior separation. (author)

Carbon determination in uranium and its compounds

International Nuclear Information System (INIS)

Silva Queiroz, C.A. da; Abrao, A.

1982-01-01

Carbon content in uranium and its compounds, especially ceramic grade UO 2 , must be controlled rigorously. A method for the determination of carbon with the aid of commercial equipment which uses platinum as a catalyst for the oxidation of CO, and infrared cells for CO 2 measurement is described. The detection limit is 5μg C/g U and the determination range is 0.0005 to 5% C/U. The method is being used routinely to control the carbon content in nuclear fuel materials. (Author) [pt

Study on the determination of uranium by activation analysis with epithermal neutrons

International Nuclear Information System (INIS)

Atalla, L.T.

1977-01-01

A method is described that is applied to the determination of uranium in different types of materials, either by an entirely instrumental method or with the chemical separation of uranium-239, when the presence of interferences does not allow the instrumental analysis. The advantages and disadvantages in the use of epithermal neutrons in the activation of samples for a more selective activation of uranium-238 also presented. The instrumental method is tested through standart materials, accepted internationally. The possibility of uranium extraction with di-etil-hexilphosphoric acid is also presented and the choice of the former technique is justified. The sensitibility of the method is discussed as well as precision and accuracy through results obtained in the analysis of the standards and the calibration curve of uranium [pt

Application of the mass spectrometry-isotope dilution technique for the determination of uranium contents in rocks

International Nuclear Information System (INIS)

Kakazu, M.H.; Iyer, S.S.

1980-01-01

Application of the spectrometric isotope dilution technique for the accurate determination of parts per million range of uranium in rock samples is described. The various aspects of the method like sample dissolution, ion exchange separation, mass spectrometric procedures are discussed. A single filament ionization source was employed for the isotope analysis. A carbon reduction method was used to reduce uranium oxide ions to uranium metal ions. The tracer solution for isotope dilution was prepared from National Bureau of Standards uranium isotopic Standard NBS U-970. Uranium contents are meassured for nine rock samples and the values obtained are compared with the uranium values measured by others workers. Errors caused in the uranium determination due to sample splitting problems as well as the incomplete acid digestion of the samples are discussed. (Author) [pt

Determination of traces of uranium in sea water after separation by froth flotation

International Nuclear Information System (INIS)

Sekine, K.

1975-01-01

Uranium in sea water is separated by froth flotation of the uranium (VI)-Arsenazo III-Zephiramine ion-adduct and then determined by neutron activation or spectrophotometric method using the uranium(IV)-Arsenazo III complex. Results of the analysis of Pacific coastal samples by the two methods are in good agreement; an average value of 3.0μg U/per liter was obtained. (author)

Adsorptive differential pulse voltammetry for determination of uranium in sea water

International Nuclear Information System (INIS)

Khandekar, R.N.; Raghunath, R.

1990-01-01

An adsorptive stripping voltammetric procedure for direct determination of trace quantities of uranium in sea water is described. Optimal conditions include pH 6.7, 2 x 10 -5 M 8-hydroxyquinoline (oxine) and collection potential of -0.4V (vs Ag/AgCl) at hanging mercury drop electrode. With controlled adsorptive accumulation for one min. a detection limit of 2.8 x 10 -10 M uranium is obtained. The response is linear upto 7 x 10 -8 M uranium and the relative standard deviation at 4 x 10 -9 M uranium is 11.5%. The effect of possible interference from other metals has been investigated. The accuracy of the method has been tested by comparison with the results obtained by fluorimetric method. (author). 2 figs., 1 tab., 20 refs

Determination of chlorine in nuclear-grade uranium compounds by ion-selective electrode

International Nuclear Information System (INIS)

Yang Chunqing; Liu Fuyun; Huang Dianfan.

1989-01-01

The determination of microamount chlorine in nuclear-grade uranium compounds is described. Chlorine is separated from uranium oxide pyrohydrolytically with stream of wet oxygen in a furnace at 800-900 deg C. Chlorine is volatilized as hydrochloric acid, which then is absorbed in a dilute alkaline solution and measured with chlorine selective electrode. This method covers the concentration range of 10-500 ppm chlorine in uranium oxide. The relative standard diviation is better than 10% and recovery of 85-108% has been reported

Separation of chloride and fluoride from uranium compounds and their determination by ion selective electrodes

International Nuclear Information System (INIS)

Pires, M.A.F.; Abrao, A.

1982-01-01

Fluoride and chloride must be rigorously controlled in uranium compounds, especially in ceramic grade UO 2 . Their determination is very difficult without previous uranium separation, particularly when both are at a low concentration. A simple procedure is described for this separation using a strong cationic resin to retain the uranyl ion. Both anions are determined in the effluent solution. Uranium compounds of nuclear fuel cycle, especially ammonium diuranate, ammonium uranyl tricarbonate, sodium diuranate, uranium trioxide and dioxide and uranium peroxide are dissolved in nitric acid and the solutions are percolated through the resin column. Chloride and fluoride are determined in the effluent by selective electrodes, the detection limits being 0.02 μg F - /ml and 1.0 μg Cl - /ml. The dissolution of the sample, the acidity of the solution, the measurement conditions and the sensitivity of the method are discussed. (Author) [pt

Ion exchange separation of nitrate from uranium compounds and its determination by spectrophotometry and ion chromatography

International Nuclear Information System (INIS)

Pires, M.A.F.; Atalla, L.T.; Abrao, A.

1985-11-01

A procedure for the separation of nitrate from uranium compounds by retaintion of uranyl ion on a cationic ion exchanger and its determination in the effluent is described. Nitrate is analysed by the spectrometric method with 1-phenol-2,4-dissulphonic acid. This determination covers the 1 to 10 μg NO - 3 /mL range and requires an amount of 10 to 100 μg NO - 3 . The main interference is uranium (VI) due its own intense yellow color. This difficulty is overcome by the complete separation of UO 2 ++ with the cationic resin. Alternatively, the ion chromatography technique is used for the determination of nitrate in the effluent of the cationic resin. The determination was easily made by the comparison of the nitrate peak hights of the analyte and the standard solutions. The ion chromatography method is very sensitive (0,3 μg NO - 3 /mL), reproducible and suitable for routine analysis and permits the determination of fraction of part per million of nitrate in uranium. The results of nitrate determination using both spectrophotometric and ion chromatography techniques are compared. The method is being routinely applied for the quality control of uranium compounds in the fuel cycle, specially uranium oxide, ammonium diuranate, uranium peroxide and ammonium uranyl tricarbonate. (Author) [pt

Uranium isotopes determination in urine samples using alpha spectrometry and ICP-MS

International Nuclear Information System (INIS)

Rosa, Mychelle M.L.; Maihara, Vera A.; Tine, Fernanda D.; Santos, Sandra M.C.; Bonifacio, Rodrigo L.; Taddei, Maria HelenaT.

2015-01-01

The action of determining the concentration of uranium isotopes in biological samples, 'in vitro' bioassay, is an indirect method for evaluating the incorporation and quantification of these radionuclides internally deposited. When incorporated, these radionuclides tend to be disposed through excretion, with urine being the main source of data because it can be easily collected and analyzed. The most widely used methods for determination of uranium isotopes ( 234 U, 235 U and 238 U) are Alpha Spectrometry and ICP-MS. This work presents a comparative study for the determination of uranium isotopes using these two methodologies in real samples from occupationally exposed workers. In order to validate the methodology, a sample of the intercomparison exercise organized by PROCORAD (Association pour la Promotion du Controle de Qualite des Analyses de Biologie Medicale em Radiotoxicologie) was used, and the results were statistically compared applying the Student's t-test. (author)

The determination of uranium(VI) by flow-injection analysis

International Nuclear Information System (INIS)

Jones, E.A.

1985-01-01

A method is described for the direct determination of uranium(VI) in waste waters and acid leach liquors by use of a flow-injection procedure and spectrophotometric measurement with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (bromo-PADAP). The interference effects of several commonly occurring elements were studied. The calibration curve is linear over concentrations of uranium(VI) from 0,5 to 20 mg/1, and the precision obtained on a synthetic leach liquor was 0,019 (relative standard deviation). The procedure is rapid and convenient, and up to 40 samples can be analysed in an hour

Determination of uranium and plutonium in metal conversion products from electrolytic reduction process

International Nuclear Information System (INIS)

Lee, Chang Heon; Suh, Moo Yul; Joe, Kih Soo; Sohn, Se Chul; Jee, Kwang Young; Kim, Won Ho

2005-01-01

Chemical characterization of process materials is required for the optimization of an electrolytic reduction process in which uranium dioxide, a matrix of spent PWR fuels, is electrolytically reduced to uranium metal in a medium of LiCl-Li 2 O molten at 650 .deg. C. A study on the determination of fissile materials in the uranium metal products containing corrosion products, fission products and residual process materials has been performed by controlled-potential coulometric titration which is well known in the field of nuclear science and technology. Interference of Fe, Ni, Cr and Mg (corrosion products), Nd (fission product) and LiCl molten salt (residual process material) on the determination of uranium and plutonium, and the necessity of plutonium separation prior to the titration are discussed in detail. Under the analytical condition established already, their recovery yields are evaluated along with analytical reliability

Determination of carbon chlorine and fluorine in uranium dioxide

International Nuclear Information System (INIS)

Kijko, N.I.; Timofeev, G.A.

1983-01-01

Techniques of chlorine and fluorine determination and simultaneous determination of carbon and chlorine in electrolytic uranium dioxide are described. The method of chlorine and fluorine determination is based on their separation during oxide pyrohydrolysis with subsequent spectrophotometric analysis of condensate. Lower determination limits constitute 1 μg for chlorine, 0.5 μg for fluorine. Relative standard deviation when the content of impurities analyzed is 10 -3 % constitutes 0.05-0.07

Hydrazine determination in presence of uranium by modified spectrophotometric method

International Nuclear Information System (INIS)

Velavendan, P.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

2011-01-01

In the present work an indirect, sensitive and accurate method for the determination of hydrazine is described. The method is based on the formation of yellow coloured azine complex by post column derivatization of hydrazine with P-dimethylamino benzaldehyde. The formed yellow coloured complex is stable in acidic medium and has a maximum absorption at 460 nm. Interference due to uranium was studied and the method was applied for the determination of hydrazine in presence of uranium in aqueous stream of nuclear fuel reprocessing. A calibration graph was made for the concentration range of hydrazine from 0.05 ppm to 10 ppm with RSD 0.807% and correlation coefficient of 0.99996. (author)

Simultaneous determination of glycols based on fluorescence anisotropy

International Nuclear Information System (INIS)

Garcia Sanchez, F.; Navas Diaz, A.; Lopez Guerrero, M.M.

2007-01-01

Simultaneous determination of non-fluorescent glycols in mixtures without separation or chemical transformation steps is described. Two methods based in the measure of fluorescence anisotropy of a probe such as fluorescein dissolved in the analyte or analyte mixtures are described. In the first method, the anisotropy spectra of pure and mixtures of analytes are used to quantitative determination (if the fluorophor concentration is in a range where fluorescence intensity is proportional to concentration). In the second method, a calibration curve anisotropy-concentration based on the application of the Perrin equation is established. The methods presented here are capable of directly resolving binary mixtures of non-fluorescent glycols on the basis of differences on the fluorescence anisotropy of a fluorescence tracer. Best analytical performances were obtained by application of the method based on Perrin equation. This method is simple, rapid and allows the determination of mixtures of glycols with reasonable accuracy and precision. Detection limits are limited by the quantum yield and anisotropy values of the tracer in the solvents. Recovery values are related to the differences in anisotropy values of the tracer in the pure solvents. Mixtures of glycerine/ethylene glycol (GL/EG), ethylene glycol/1,2-propane diol (EG/1,2-PPD) and polyethylene glycol 400/1,2-propane diol (PEG 400/1,2-PPD) were analysed and recovery values are within 95-120% in the Perrin method. Relative standard deviation are in the range 1.3-2.9% and detection limits in the range 3.9-8.9%

Risk assessment applications for determining cleanup limits for uranium in treated and untreated soils

International Nuclear Information System (INIS)

Armstrong, A.Q.; Layton, D.W.; Rutz, E.E.

1994-01-01

Uranium-contaminated soils are present at various locations across the US where uranium was processed for nuclear fuels or atomic weapons. Important issues relative to such contamination include the assessment of potential health risks associated with human exposures to the residual uranium and the determination of safe levels of uranium in soils that have been treated by a given technology. This paper discusses various risk assessment considerations that must be dealt with when developing cleanup limits for uranium in treated and untreated soils. Key issues addressed include alternative land use scenarios, potential exposure pathways, characterization of the bioavailability of uranium compounds in food and water, a brief overview of health risks associated with uranium and its daughter products as well as a summary of considerations for development of risk-based cleanup limits for uranium in soils

Determination of the uranium content in phosphate fertilizers by the fission track registration technique

International Nuclear Information System (INIS)

Rocha, A.C.S. da.

1983-01-01

The application of fission track registration technique (SSNTD) to determine the uranium contents in phosphate fertilizers is dealt with. Samples were prepared by the wet method and the detector used was Makrofol Kg 10μm thick. The determination of uranium in phosphate fertilizer industry is of considerable interest in environmental control. The roots of vegetables tend to absorb and accumulate uranium form soil and so the human body could be contaminated. The phosphate fertilizers were originated from the phosphate-rich apatite deposits located in the high naturally radioactive areas of Araxa and Tapira in the state of Minas Gerais, Brazil. The results obtained ranged from 11.1 to 100ppm of uranium with a total error from 8.2 to 15.7%. The thorium contributions to the total track counting were discounted, though the actual concentrations of thorium in the samples were not determined. (Author) [pt

Impurities determination of uranium metal flame spectrophotometry and atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Rukihati.

1978-01-01

The atomic absorption flame spectrophotometry has been applied to the determination of chromium, copper, iron, lead, manganese and nickel in the metal of uranium. The first step to be done is to dissolve the uranium sample in nitric acid and then the uranium is extracted by a tributylphosphate-carbon tetrachloride solution. The aqueous phase which contains the chromium, copper, iron, lead, manganese and nickel is aspirated into an airacetylene flame. The results of this method are compared with the results of emission spectrographic method. It is found that this technique is competative to other methods in the sense that it is quite fast and accurate. (author)

Flame photometric determination of Na, K and Li in uranium compounds

International Nuclear Information System (INIS)

Sabato, S.F.; Lordello, A.R.

1985-01-01

A flame photometric method for the determination of Na, K and Li in uranium compounds is described. The uranium is separated by solvent extraction from hydrochloric acid medium with tri-butyl phosphate. Amounts of uranium in order of 20 μg/ml don't cause any interference in the photometric results. The element Na presents a residual concentration due to the contamination of the reagents. The relative standard deviation is about 10% for the three elements. The relative error varies with the concentration of the element and it is between 1 and 24% for Na, between O and 12% for K and between O and 33% for Li. (Author) [pt

Uranium isotopes determination in urine samples using alpha spectrometry and ICP-MS

Energy Technology Data Exchange (ETDEWEB)

Rosa, Mychelle M.L.; Maihara, Vera A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Tine, Fernanda D.; Santos, Sandra M.C.; Bonifacio, Rodrigo L.; Taddei, Maria HelenaT. [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

2015-07-01

The action of determining the concentration of uranium isotopes in biological samples, 'in vitro' bioassay, is an indirect method for evaluating the incorporation and quantification of these radionuclides internally deposited. When incorporated, these radionuclides tend to be disposed through excretion, with urine being the main source of data because it can be easily collected and analyzed. The most widely used methods for determination of uranium isotopes ({sup 234}U, {sup 235}U and {sup 238}U) are Alpha Spectrometry and ICP-MS. This work presents a comparative study for the determination of uranium isotopes using these two methodologies in real samples from occupationally exposed workers. In order to validate the methodology, a sample of the intercomparison exercise organized by PROCORAD (Association pour la Promotion du Controle de Qualite des Analyses de Biologie Medicale em Radiotoxicologie) was used, and the results were statistically compared applying the Student's t-test. (author)

Anodic dissolution polarography used for the direct determination of metals in uranium

International Nuclear Information System (INIS)

Bueno, L.A.O.; Abrao, A.

1976-01-01

An electrochemical method of analysis, consisting of pre-concentration and determination of the elements Cd, Pb, Tl, Bi and Cu, present as impurities in uranium salts has been developed. The anodic stripping polarography has been employed using a dropping mercury electrode. The interference of uranium itself in the determination of these elements was eliminated by changing its reduction potential to - 1,0V (with respect to the Ag/AgCl electrode), thus making possible the analysis of the elements that are reduced at more positive potentials. This was achieved by the addition of sufficient amount of K 2 CO 3 to the uranyl chloride solution (in the 4:1 carbonate to uranyl ratio) so as to form the uranyl tricarbonate ([UO 2 (CO 3 ) 3 ] 4- ) complex anion. The supporting electrolyte was the uranyl complex in K 2 CO 3 0,1M. The final concentration of uranium ranged from 2 to 5 g/l. The detection limits for the studied elements varied from 0,08 to 1,27 ppm (μg of the element/gU). This technique has proved to be very convenient since provides sensitivity and precision. The method makes possible the determination of mentioned elements directly in uranium solutions, avoiding any previous chemical separations [pt

Rapid determination of fluoride in uranyl nitrate solution obtained in conversion process of uranium tetrafluoride

International Nuclear Information System (INIS)

Levin, R.; Feldman, R.; Sahar, E.

1976-01-01

In uranium production the conversion of impure uranium tetrafluoride by sodium hydroxide was chosen as a current process. A rapid method for determination of fluoride in uranyl-nitrate solution was developed. The method includes precipitation of uranium as diuranate, separation by centrifugation, and subsequent determination of fluoride in supernate by titration with thorium nitrate. Fluoride can be measured over the range 0.15-2.5 gr/gr U, with accuracy of +-5%, within 15 minutes. (author)

Determination of trace uranium in human hair by nuclear track detection technique

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; En, Zinaida; Cho, Seung Yeon; Kang, Sang Hoon; Lee, Jae Ki

2001-01-01

The aim of this study is to describe a usefulness of nuclear analytical technique in assessing and comparing the concentration levels through the analysis of uranium using human hair sample in the field of environment. A fission track detection technique was applied to determine the uranium concentration in human hair. Hair samples were collected from two groups of people - a) workers not dealing with uranium directly, and b) workers possibly contaminated with uranium. The concentration of 235 U for the first group varied from <1 to 39 ng/g and the second group can be estimated up to the level of μg/g. Radiographs of heavy-duty work samples contained high dense 'hot spots' along a single hair. After washing in acetone and distilled water, external contamination was not totally removed. Insoluble uranium compounds were not completely washed out. The (n, f)-radiography technique, having high sensitivity, and capable of getting information on uranium content at each point of a single hair, is an excellent tool for environmental monitoring

Uncertainty estimation of uranium determination in urine by fluorometry

International Nuclear Information System (INIS)

Shakhashiro, A.; Al-Khateeb, S.

2003-11-01

In this study an applicable mathematical model is proposed for the estimation of uncertainty in uranium determination by fluorometry in urine sample. The study based on EURACHEM guide for uncertainty estimation. This model was tested on a sample containing 0.02 μg/ml uranium, where calculated uncertainty was 0.007 μg/ml. The sources of uncertainty were shown on fish-bone plane as the following: In addition, the weight of each uncertainty parameter was shown in a histogram: Finally, it was found that the estimated uncertainty by the proposed model was 3 to 4 time more that the usually reported standard deviation. (author)

Lignite utilisation for binding of radionuclides and uranium determination by adsorptive stripping chronopotentiometry

International Nuclear Information System (INIS)

Zavodska, L.

2010-01-01

This work in its first part deals with non-energetic use of young brown coal - lignite. The goal of the work was to perform a complex physical and chemical characterisation of the Slovak lignite (deposit Cary) which could contribute to rts use in binding of radionuclides in the environment. The characteristics of Slovak lignite were compared to leonardite (Gascoyne, USA) and Czech lignite (the area of Mikulcice). In the samples the residual humidity was determined. as well. as the content of ashes. representation of selected inorganic (As, Ba, Cd, Co, Cr, Cu, Ni, Pb and Zn) as well as organo-elements (C, H, N, 0, S) and crystalline forms of inorganic phase in lignite. The specific surface (BET isotherm) of lignite was determined, representation of total and free humic acids and their cation exchange capacity. The samples underwent al.so gamma-spectrometric analysis ( 40 K, 226 Ra, 228 Ac, 137 Cs and 60 Co). Using the radio-indicator method ( 85 Sr and 137 Cs) the kinetics of sorption of Cs + and Sr + ions in Slovak lignite was studied. The efficiency of sorption for both cations on lignite was evaluated on the basis of constructed sorption isotherms. The sorption of Cs + ions on Slovak lignite is more suitable for the Freundlich type of isotherm, in case of Sr + ions the sorption is better described by Langmuir isotherm. The results of sorption experiments on lignite in comparison with clinoptilolite and montmorillonite K-10 showed a more efficient sorption for Sr Ions. despite the more coarse-grained fraction of this matrix. This finding supports the possibility of lignite application for binding of a quite mobile radiostrontium, which may be applied for construction of radioactive waste repositories or for remediation of contaminated soils. The second part of the work deals with the development and validation of new fast and reliable electrochemical method of uranium determination in natural waters. It is based on physical adsorption of created complex of uranium

NGSI FY15 Final Report. Innovative Sample Preparation for in-Field Uranium Isotopic Determinations

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Thomas M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Meyers, Lisa [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-11-10

Our FY14 Final Report included an introduction to the project, background, literature search of uranium dissolution methods, assessment of commercial off the shelf (COTS) automated sample preparation systems, as well as data and results for dissolution of bulk quantities of uranium oxides, and dissolution of uranium oxides from swipe filter materials using ammonium bifluoride (ABF). Also, discussed were reaction studies of solid ABF with uranium oxide that provided a basis for determining the ABF/uranium oxide dissolution mechanism. This report details the final experiments for optimizing dissolution of U₃O₈ and UO₂ using ABF and steps leading to development of a Standard Operating Procedure (SOP) for dissolution of uranium oxides on swipe filters.

Determination of uranium in sea water by adsorptive differential pulse voltametry

International Nuclear Information System (INIS)

Khandekar, R.N.; Raghunath, Radha

1991-01-01

An adsorptive stripping voltametric procedure for direct determination of trace quantities of uranium in sea water has been described. Optimal conditions include pH 6.7, 2 x 10 -5 M 8-hydroxy quinoline (oxine) and collection potential of -0.4V (Vs Ag/AgCl) at hanging mercury drop electrode. With controlled adsorptive accumulation for one minute a detection limit of 2.8 x 10 -10 M uranium is obtained. The response is linear upto 7 x 10 -8 M uranium and the relative standard deviation at 4 x 10 -9 M is 11.5%. The effect of possible interference from other metals has been investigated. (author). 14 refs., 1 tab

Homogeneity and fissure determination in uranium bars with solid state nuclear track detectors

Energy Technology Data Exchange (ETDEWEB)

Castillo, F. (Universidad Nacional Autonoma de Mexico, Mexico City. Facultad de Ciencias); Gamboa, I.; Espinosa, G.; Tapia, A. (Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Fisica); Somogyi, G. (Magyar Tudomanyos Akademia, Debrecen. Atommag Kutato Intezete)

1984-01-01

A simple and efficient method for determining fissure and concentration inhomogeneity in uranium bars is the alpha-radiographic technique. In our present work uranium bars made by ININ (Mexico) were studied by using CR-39 track detectors. The space inhomogeneity in track density was measured by an optical densitometer. The presence of fissure is determined by a microfiche reader. Such a study takes only few hours and does not require sophisticated instrumentation.

Methods for oxygen/uranium ratio determination in substoichiometric uranium dioxide

International Nuclear Information System (INIS)

Baranov, V.G.; Godin, Yu.G.; S'edin, Yu.D.; Kosykh, V.G.; Nepryakhin, A.M.; Komarenko, F.F.; Kutyreva, G.A.

1994-01-01

Investigations are performed into a possibility to use the methods of thermal gravimetric analysis, gas chromatography, hydration-dehydration, and e.m.f. of high-temperature solid-electrode galvanic cell for determining O-U atomic ratio in UO 2-x . It is shown that the investigated methods have an analysis error of ± 0.001 O/U units. However, the e.m.f. method, which feature a high accuracy near stoichiometry can be applied only within the limits of UO 2-x homogeneity. A possibility is shown to expend the area of e.m.f. method application during the analysis of substoichiometric uranium dioxide. 9 refs.; 1 tab

Determination of uranium isotopes in environmental samples by anion exchange in sulfuric and hydrochloric acid media

International Nuclear Information System (INIS)

Popov, L.

2016-01-01

Method for determination of uranium isotopes in various environmental samples is presented. The major advantages of the method are the low cost of the analysis, high radiochemical yields and good decontamination factors from the matrix elements, natural and man-made radionuclides. The separation and purification of uranium is attained by adsorption with strong base anion exchange resin in sulfuric and hydrochloric acid media. Uranium is electrodeposited on a stainless steel disk and measured by alpha spectrometry. The analytical method has been applied for the determination of concentrations of uranium isotopes in mineral, spring and tap waters from Bulgaria. The analytical quality was checked by analyzing reference materials. - Highlights: • The method allows cost-effective determination of U isotopes. • High amounts of environmental samples can be analyzed. • High chemical yields, energy resolution and decontamination factors were achieved. • Uranium isotope concentrations in mineral waters from Bulgaria are presented.

Simple, cost effective method for determination of phosphorus in uranium ore concentrate

International Nuclear Information System (INIS)

Misra, U.B.; Ramamurty, Vasantha; Dutta, M.; Balaji Rao, Y.; Subba Rao, Y.

2015-01-01

In this paper determination of phosphate as phosphorus in uranium ore concentrate has been described. The method used is spectrophotometric determination of phosphorus as phospho-molybdenum blue complex. As uranyl ion do not absorb in 600-900 nm range of visible region in the present medium, the phosphomolybdenum blue complex formation which is having maximum absorbance at 825 nm is exploited for determination of phosphorus. The molar absorptivity coefficient with and without the presence of uranium matrix are 2.6048 x 10 4 and 2.6730 x 10 4 lmol -1 cm -1 . The effect of matrix is not evident from the experiment carried out. (author)

Determination of uranium-235 by differential gamma spectrometry

International Nuclear Information System (INIS)

Suner, A.A.; La Gamma de Batistoni, A.M.G.; Botbol, J.

1974-12-01

A method for the determination of U-235 contained in solutions of uranium, by gamma spectrometry with Ge(Li) detector is described. Ra-226 is coprecipitated in BaSO 4 . The activity at 186 keV is measured, substracted by the corresponding of a standard. The detection limit is 1% of increment of U-235 over the standard. (author)

Equilibria determination in uranium ores by alpha spectrometry

International Nuclear Information System (INIS)

Tormo Ferrero, M.J.

1976-01-01

A method for the measurement of the U-234/U-238 activities is described. The separation of the uranium from the interferring elements is carried out by ionic change with anionic resine, in chlorhydric-metanol-ascorbic acid medium. The method has been applied to different spanish ores in which the equilibrium state has been determined (author)

Applications of Qualitative Microanalysis to the Determination of Secondary Species Associated with Uranium; Application de la microanalyse qualitative a la determination des especes secondaires d'uranium

Energy Technology Data Exchange (ETDEWEB)

Agrinier, H

1959-02-01

Microanalytical techniques are described which allow rapid determinations of secondary species associated with uranium. They consist in exposing the constituent elements of the ores by means of characteristic microchemical reactions. Because of their rapidity and the small amount of apparatus needed, these techniques can be used either in the field or in the laboratory. (author) [French] Les techniques de microanalyse decrites dans cet ouvrage permettent la determination rapide des especes secondaires d'uranium. Elles consistent a mettre en evidence les elements constitutifs des mineraux par des reactions microchimiques caracteristiques. En raison de leur rapidite et du peu de materiel qu'elles necessitent, ces techniques peuvent etre utilisees aussi bien sur le terrain qu'au laboratoire. (auteur)

Gravimetric determination of uranium in SALE samples

International Nuclear Information System (INIS)

Anon.

1981-01-01

As a participant in the Safeguards Analytical Laboratory Evaluation (SALE) program, the Analytical Chemistry Laboratory at General Atomic routinely assays uranium dioxide and uranyl nitrate SALE samples for uranium content. Gravimetric methods are relatively easy and inexpensive to apply when the samples for uranium content. Gravimetric methods are relatively easy and inexpensive to apply when the samples are free from substantial amounts of metallic impurities. Clearly the gravimetric procedure alone is not specific for uranium and must be enhanced by the use of impurity corrections. Emission spectrography is used routinely as the technique of choice for making such corrections. In cases where it is essential to assay specifically for uranium, the modified Davies-Gray titration using a weighed titrant method is applied. In this paper some essential features of these gravimetric and titrimetric procedures are discussed

Determination of {sup 90}Sr in uranium fission products

Energy Technology Data Exchange (ETDEWEB)

Bajo, S; Tobler, L [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1996-02-01

A previously published radiochemical procedure for the determination of {sup 90}Sr in grass and soil has been successfully employed - with minor modifications - for the determination of this nuclide in a solution of uranium fission products. It is suitable for the determination of {sup 90}Sr in environmental materials following a nuclear accident. The procedure is based on tributylphosphate extraction of {sup 90}Y, precipitation of Y-oxalate, and counting in a proportional counter. (author) figs., tabs., 10 refs.

Development of a choronocoulometric method for determining traces of uranium using the catalytic nitrate reduction

International Nuclear Information System (INIS)

Cantagallo, M.I.C.; Gutz, I.G.R.

1990-01-01

With the aim of improving the sensitivity of the electroanalytical determination of uranium at trace levels. The uranium catalyzed reduction of nitrate on mercury electrode and the technique of chronocoulometry were used. Several experimental parameters were investigated (electrolyte composition, potential program, integration time, blank correction, temperature, previous separation) and adequate conditions were selected for the analytical determination. Under these conditions it was possible to exceed the best reported sensitivity for the catalytic determination, extending the detection limit to 3.10 -10 M. Exploratory study of the combination of this procedure with pre-concentration of uranium ions on the electrode revealed a detection limit ten limes lower. (author) [pt

Standard test method for the determination of uranium by ignition and the oxygen to uranium (O/U) atomic ratio of nuclear grade uranium dioxide powders and pellets

CERN Document Server

American Society for Testing and Materials. Philadelphia

2000-01-01

1.1 This test method covers the determination of uranium and the oxygen to uranium atomic ratio in nuclear grade uranium dioxide powder and pellets. 1.2 This test method does not include provisions for preventing criticality accidents or requirements for health and safety. Observance of this test method does not relieve the user of the obligation to be aware of and conform to all international, national, or federal, state and local regulations pertaining to possessing, shipping, processing, or using source or special nuclear material. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.4 This test method also is applicable to UO3 and U3O8 powder.

Determination of rare earth elements in uranium bearing samples using Inductively Coupled Plasma Mass Spectrometry (ICPMS)

International Nuclear Information System (INIS)

Mishra, S.; Chaudhury, P.; Pradeepkumar, K.S.; Sahoo, S.K.

2017-01-01

In the present study a methodology has been described for determination of REEs without involving separation and the method is successfully applied for determination of REE concentration in uranium ore as well as in soil samples from a uranium mining site

Direct determination of uranium in the organic phase D2EHPA-TOPO using XRF spectroscopy

International Nuclear Information System (INIS)

Stas, J.; Al-Merey, R.; Karajo, J.

2000-06-01

Three calibration curves have been carried out to determine uranium concentration in the organic phase (D2EHPA-TOPO) using XRF technique with Cd 109 as a primary exciting source. Copper was used as an internal standard, so the linear relation between relative intensity of uranium against its concentration has been obtained. The range of uranium concentrations studies are (0-100 μg.mL -1 ), (100-1000 μg.mL -1 ) and (1000-6500 μg.mL -1 ), which covered all uranium against its concentration concerning first and second cycles of uranium extraction from phosphoric acid. detection limit was found to be 1.1 μg/ml. The effect of different range of (0.2-0.6 M) D2EHPA and (0.025-0.15 M) TOPO and iron (0-500 μg.mL -1 ) on the accuracy and the precision of uranium determination have been studied and no effect was found. Unknown organic samples have been analyzed using XRF technique and compared with γ-ray, UV and volumetric techniques, obtained results were comparable. (Author)

Determination of oxygen in uranium compounds using sulfur monochloride

International Nuclear Information System (INIS)

Baudin, G.; Besson, J.; Blum, P.L.; Tran-Van, Danh

1964-01-01

The authors have described in an other paper (Anal. Chim. Acta, in press) a method for oxygen determination in uranium compounds, in which the sample is attacked by sulfur monochloride. The present paper is concerned with the experimental aspects of the method: apparatus procedure. (authors) [fr

Determination of uranium in coated fuel particle compact by potassium fluoride fusion-gravimetric method

International Nuclear Information System (INIS)

Ito, Mitsuo; Iso, Shuichi; Hoshino, Akira; Suzuki, Shuichi.

1992-03-01

Potassium fluoride-gravimetric method has been developed for the determination of uranium in TRISO type-coated fuel particle compact. Graphite matrix in the fuel compact is burned off by heating it in a platinum crucible at 850degC. The coated fuel particles thus obtained are decomposed by fusion with potassium fluoride at 900degC. The melt was dissolved with sulfuric acid. Uranium is precipitated as ammonium diuranate, by passing ammonia gas through the solution. The resulting precipitate is heated in a muffle furnace at 850degC, to convert uranium into triuranium octoxide. Uranium in the triuranium octoxide was determined gravimetrically. Ten grams of caoted fuel particles were completely decomposed by fusion with 50 g of potassium fluoride at 900degC for 3 hrs. Analytical result for uranium in the fuel compact by the proposed method was 21.04 ± 0.05 g (n = 3), and was in good agreement with that obtained by non-destructive γ-ray measurement method : 21.01 ± 0.07 g (n = 3). (author)

Elemental imaging of kidneys of adult rats exposed to uranium acetate

Energy Technology Data Exchange (ETDEWEB)

Homma-Takeda, S. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)], E-mail: shino_ht@nirs.go.jp; Terada, Y. [Japan Synchrotron Radiation Research Institute, Mikazuki, Hyogo 679-5198 (Japan); Nakata, A.; Sahoo, S.K.; Yoshida, S. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Ueno, S. [School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628 (Japan); Inoue, M. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Iso, H.; Ishikawa, T.; Konishi, T.; Imaseki, H. [Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shimada, Y. [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

2009-06-15

Concern about the toxicity of depleted uranium for military use has increased recently. Renal toxicity is the hallmark effect of uranium exposure. However, the dynamics and distribution of uranium in the kidney are not well understood. Here, we determined the precise distribution of uranium and essential elements in the rat kidney using microbeam scanning particle-induced X-ray emission (micro-PIXE) and synchrotron radiation X-ray fluorescence (SR-XRF). Uranium accumulation in the rat kidney reached a maximum at 1 day after the subcutaneous (s.c.) administration of 2 mg U/kg of uranium acetate and then gradually decreased. At 3 h after administration, uranium was distributed mainly in the proximal tubules of the inner zone of the cortex and in the outer stripe of the outer medulla, and absorbed by the proximal tubule epithelium. Iron was localized more in the inside of the outer medulla than uranium, while phosphorus, potassium, sulfur and zinc were equally distributed in the cortex and the outer stripe of the outer medulla. At 3 days after administration, the number of apoptotic cells increased and cells were lost from the proximal tubules. Uranium was detectable mainly in the outer stripe of the outer medulla at 15 days, suggesting that the renal distribution of uranium is site-selective and causes site-specific renal lesions.

Quantitative determination of uranium by SIMS

International Nuclear Information System (INIS)

Kuruc, J.; Harvan, D.; Galanda, D.; Matel, L.; Aranyosiova, M.; Velic, D.

2008-01-01

The paper presents results of quantitative measurements of uranium-238 by secondary ion mass spectrometry (SIMS) with using alpha spectrometry as well as complementary technique. Samples with specific activity of uranium-238 were prepared by electrodeposition from aqueous solution of UO 2 (NO 3 ) 2 ·6H 2 O. We tried to apply SIMS to quantitative analysis and search for correlation between intensity obtained from SIMS and activity of uranium-238 in dependence on the surface's weight and possibility of using SIMS in quantitative analysis of environmental samples. The obtained results and correlations as well as results of two real samples measurements are presented in this paper. (authors)

Automation of potentiometric titration for the determination of uranium in nuclear fuel materials

International Nuclear Information System (INIS)

Kelkar, Anoop; Pandey, Ashish; Kapoor, Y.S.; Kumar, Manish; Singh, Mamta; Fulzele, Ajeet; Prakash, Amrit; Afzal, Mohd; Panakkal, J.P.

2010-01-01

Advanced Fuel Fabrication Facility is fabricating various types of mixed oxide fuels, namely for PHWR, BWR, FBTR and PFBR. Precise determination of uranium in MOX fuel sample is important to get desired burn up in the reactor. The modified Davies and Gray method is routinely used for the potentiometric titration of uranium

Trace determination of uranium and thorium in biological samples by radiochemical neutron activation analysis

International Nuclear Information System (INIS)

Benedik, Ljudmila; Repinc, Urska; Byrne, Anthony R.; Stegnar, Peter

2002-01-01

Radiochemical neutron activation analysis (RNAA) is an excellent method for determining uranium and thorium; it offers unique possibilities for their ultratrace analysis using selective radiochemical separations. Regarding the favourably sensitive nuclear characteristics of uranium and of thorium with respect to RNAA, but the different half-lives of their induced nuclides, two different approaches were used. In the first approach uranium and thorium were determined separately via 239 U, 239 Np and 233 Pa. In the second approach these elements were 239 239 233 determined simultaneously in a single sample using U and/or Np and Pa. Isolation of induced nuclides was based on separation by extraction and/or anion exchange chromatography. Chemical yields were measured in each sample aliquot using added 235 U, 238 Np and 231 Pa radioisotopic tracers. (author)

Determination of Uranium plus Plutonium by Alpha spectrometry in different matrix

International Nuclear Information System (INIS)

Equillor, Hugo E.; Campos, Juan M.

2011-01-01

Usually, the determination of alpha emitters by alpha spectrometry is performed with a prior purification of each of the elements to be quantified. In this work, a methodology for the determination of uranium and plutonium isotopes as jointly described, in order to improve analytical processing times and measurement. The method includes purifying uranium and plutonium, and the subsequent electrodeposition for alpha spectrometry measurement. The technique is based on the use of TBP (tributyl phosphate) as extractant and easy to obtain reactants. It is applicable to various matrices, including water, filters and soils. In the conditions described, is applied to small aliquots of approximately 0.5 g of solid. The technique produces high quality electrodeposits. (authors) [es

Fluorimetrich determination of uranium in mineral samples and phosphoric solutions

International Nuclear Information System (INIS)

Pupo Gonzales, I.; Cuevillas, J.; Estevez, J.

1991-01-01

In this paper an analytical technique for the determination of uranium in different cuban minerals and acid leaching liquors of phosphorites is proposed. The method used for solid samples includes their disolution and further dilution of the solution obtained. For liquid samples dilution is the only intermediate step used. A study of HNO3 concentration (pH) was made in fluorimetric measurements. The method was applied to the uranium analysis in two IAEA standard reference samples (phosphate base), in natural phosphorites and a synthetic one, in clays and phosphoric liquors. The results agree with those obtained by other methods

Potentiometric determination of uranium with cobalt (3) acetate as oxidimetric titrant

International Nuclear Information System (INIS)

Muhammad, H.; Ishrat, P.; Zyka, J.

1972-01-01

A potentiometric method for the determination of uranium through the reduction of hexavalent to tetravalent state and its potentiometric oxidation in 8 N sulphuric acid with standard cobalt (3)-acetate has been worked out. The method is quite accurate with the error not exceeding 1% for mg amounts. Moreover an apparatus for preservation of reduced solution of uranium and its delivery for titrations has been designed. The same apparatus can be used for reducing and preserving solutions of strong reducing titrants. (author)

Alpha spectroscopic determination of plutonium and uranium in food, biological materials, and soils

International Nuclear Information System (INIS)

Frindik, O.

1980-07-01

An alpha-spectrometric method for the plutonium determination which was tested in different samples is described in detail. In particular, this method is capable of determining the very low plutonium levels found in food at present, and allow recoveries of 85-95% of the tracer added. Inorganic samples, such as soil samples for example, can be analyzed by using an abbreviated modification of the method. The measuring preparations show a high degree of spectral purity. Uranium can be separated during the analytical procedure and, after purification, can also be determined alpha-spectrometrically. 90-100% of the uranium are recovered. (orig.) [de

Determination of the uranium concentration in water samples by the technique of fission track recording

International Nuclear Information System (INIS)

Geraldo, L.P.

1979-01-01

The technique of fission track register was developed for the determination of micrograms of uranium. The Makrofol KG, a synthetic plastic made by Bayer, was used as the detector and the wet method was utilized. The detector calibration curve allows the determination of the uranium concentration in a sample within an interval from 8.0 to 0.4μgU/L, the total error ranging from 3.3% to 29.0% respectively. The method was used in the determination of the uranium content in various water samples, obtained from various sources like rivers, sea etc. in the state of Sao Paulo, Brazil. Results were compared with those obtained by other authors using different methods. The average concentration found in sea waters (3.27 +- 9.12μgU/l) by this method is compatible with the international average accepted value of 3.3μgU/l, irrespective of site and depth. The determination of the uranium content by fission track counting has proved to be very convenient. (Author) [pt

The rapid determination of americium curium, and uranium in urine by ultrafiltration

International Nuclear Information System (INIS)

Stradling, G.N.; Popplewell, D.S.; Ham, G.J.; Griffin, R.

1975-01-01

The rapid ultrafiltration method developed for the assay of plutonium has been extended to the determination of americium, curium and uranium in urine. The limits of detection for americium and curium, and uranium are 0.09 and 0.12 dm -1 l -1 respectively, and the analysis time excluding counting less than 2 hours. The method can therefor be effectively used as a rapid screening procedure. When the reference level for plutonium is exceeded, the α activity may require to be characterised. The single ultrafiltration technique must be modified for turbid urine samples. The method is inappropriate, except for uranium, when the urine contains DTPA. (author)

Final Technical Report - In-line Uranium Immunosensor

International Nuclear Information System (INIS)

Blake, Diane A.

2006-01-01

In this project, personnel at Tulane University and Sapidyne Instruments Inc. developed an in-line uranium immunosensor that could be used to determine the efficacy of specific in situ biostimulation approaches. This sensor was designed to operate autonomously over relatively long periods of time (2-10 days) and was able to provide near real-time data about uranium immobilization in the absence of personnel at the site of the biostimulation experiments. An alpha prototype of the in-line immmunosensor was delivered from Sapidyne Instruments to Tulane University in December of 2002 and a beta prototype was delivered in November of 2003. The beta prototype of this instrument (now available commercially from Sapidyne Instruments) was programmed to autonomously dilute standard uranium to final concentrations of 2.5 to 100 nM (0.6 to 24 ppb) in buffer containing a fluorescently labeled anti-uranium antibody and the uranium chelator, 2,9-dicarboxyl-1,10-phenanthroline. The assay limit of detection for hexavalent uranium was 5.8 nM or 1.38 ppb. This limit of detection is well below the drinking water standard of 30 ppb recently promulgated by the EPA. The assay showed excellent precision; the coefficients of variation (CV's) in the linear range of the assay were less than 5% and CV?s never rose above 14%. Analytical recovery in the immunosensors-based assay was assessed by adding variable known quantities of uranium to purified water samples. A quantitative recovery (93.75% - 108.17%) was obtained for sample with concentrations from 7.5 to 20 nM (2-4.75 ppb). In August of 2005 the sensor was transported to Oak Ridge National Laboratory, for testing of water samples at the Criddle test site (see Wu et al., Environ. Sci. Technol. 40:3978-3985 2006 for a description of this site). In this first on-site test, the in-line sensor was able to accurately detect changes in the concentrations of uranium in effluent samples from this site. Although the absolute values for the uranium

Determination of natural uranium in urine (233U)

International Nuclear Information System (INIS)

Jeanmaire, L.; Jammet, H.

1959-01-01

A procedure for the quantitative analysis of uranium in urine is described. The residue obtained by mineralization is dissolved in diluted hydrochloric acid. Uranium is separated by fixation on a permutit 50 column, elution with 0,2 M oxalic acid and electrodeposition on nickel. Uranium is then measured by α counting. It is thus possible to detect less than 1 pico-curie of uranium in the sample. (author) [fr

Liquid-solid extraction of uranium (VI) with TOPO - molten naphthalene and determination by laser fluorimetry in geological samples

International Nuclear Information System (INIS)

Kumar, Sanjay; Krishnakumar, M.; Patwardhan, A.A.

2007-01-01

A simple, rapid, sensitive, cost-effective and efficient method for separation of uranium using tri-n-octylphosphine oxide (TOPO)-molten naphthalene as solid phase extractant and its determination by laser fluorimetry in geological samples (rock, soil, sediment) was developed. Under optimum conditions, using 50 mg TOPO and 100 mg naphthalene, 50 - 5000 ng of uranium in 10 ml sample solution (3% (v/v) HNO 3 ) could be extracted quantitatively. The extracted uranium was stripped using tetra sodium pyrophosphate (5% (v/v) solution, pH adjusted to 7.0 with H 3 PO 4 ) and determined by laser fluorimetry. The influence of different acid concentrations, the amount of solid phase extractant, sample volumes, different stripping reagents, their volumes and effect of foreign ions on the extraction and determination of uranium (VI) were investigated. Synthetic samples of varying concentration as regards uranium were prepared and analysed. Recoveries ranging from 90% to 105% were obtained. The method was validated by analyzing four certified reference materials namely, BL-5, DH-1a, SY-2, SY-3 and the values obtained for uranium agreed well with the certified values. The method was also applied to the determination of uranium in geological samples (rock, soil and sediment) by laser fluorimetry and the results obtained compared favorably with those obtained from the pellet fluorimetry method. Following the proposed method, determination limit for uranium was found to be 1 μg/g with RSD ± 10%. (author)

Determination of molybdenum in uranium by differential pulse polarography

International Nuclear Information System (INIS)

Purwanto, A.; Iswani, G.S.

1996-01-01

The separation an determination of Mo (VI) in uranium dioxid (UO 2 ) samples by polarography method were studied. The determination of Mo(VI) was based on electrochemistry reduction of molybdenum (VI) quinolinolate complex (Mo VI O 2 Q 2 ). To decrease the matrix influence, this complex was extracted into chloroform. After chloroform phase was evaporate at room temperature, residues were dissolved with N,N-Dimethyl formamide (DMF). Potential wave reduction of Mo(VI) at -0,48 volt versus Ag/AgCl/KCl saturated in supporting electrolyte buffer acetate 1 M (1M CH 3 COOH-1M CH 3 COONH 4 ). Extraction was done in 0.3 M H 2 SO 4 media at optimum pH of 2.0 and 4 % oxine in 0.5 M H 2 SO 4 was used as complex compound. Extraction two times with 10 ml chloroform for 5 minutes each ratio of organic water was 1:5. This method was used to determine Mo (VI) in concentration range of 4.8 -12 μg in the presence of 200 mg uranium. It was found recovery of Mo (VI) was 95%. Mo (VI) contents in UO 2 samples determined by standard addition was 5.26±0.41 μg/g. (author)

Study of the oxidation state of arsenic and uranium in individual particles from uranium mine tailings, Hungary

International Nuclear Information System (INIS)

Alsecz, A.; Osan, J.; Palfalvi, J.; Torok, Sz.; Sajo, I.; Mathe, Z.; Simon, R.; Falkenberg, G.

2007-01-01

Uranium ore mining and milling have been terminated in the Mecsek Mountains (southwest Hungary) in 1997. Mine tailings ponds are located between two important water bases, which are resources of the drinking water of the city of Pecs and the neighbouring villages. The average U concentration of the tailings material is 71.73 μg/g, but it is inhomogeneous. Some microscopic particles contain orders of magnitude more U than the rest of the tailings material. Other potentially toxic elements are As and Pb of which chemical state is important to estimate mobility, because in mobile form they can risk the water basis and the public health. Individual U-rich particles were selected with solid state nuclear track detector (SSNTD) and after localisation the particles were investigated by synchrotron radiation based microanalytical techniques. The distribution of elements over the particles was studied by micro beam X-ray fluorescence (μ-XRF) and the oxidation state of uranium and arsenic was determined by micro X-ray absorption near edge structure (μ-XANES) spectroscopy. Some of the measured U-rich particles were chosen for studying the heterogeneity with μ-XRF tomography. Arsenic was present mainly in As(V) and uranium in U(VI) form in the original uranium ore particles, but in the mine tailings samples uranium was present mainly in the less mobile U(IV) form. Correlation was found between the oxidation state of As and U in the same analyzed particles. These results suggest that dissolution of uranium is not expected in short term period. (authors)

Simultaneous determination of radium and uranium in soil

International Nuclear Information System (INIS)

Yamamoto, Takashi; Yuki, Eiji; Ishida, Tatsuo

1977-01-01

Radium and uranium contents in soil are the fundamental indexes for natural radioactivity. In this connection, the simultaneous determination of Ra and U has been studied. To a soil sample, 133 Ba is added and the mixture is dried. It is decomposed with sulfuric and nitric acids. Then a Ba-carrier is added, and the insoluble residue (Ra analysis sample) and the solution (U analysis sample) are obtained for simultaneous determination of Ra and U. The rates of recovery of Ra and U in soil are both over 90%. (Mori, K.)

Development and performance of on-line uranium analyzers

International Nuclear Information System (INIS)

Ofalt, A.E.; O'Rourke, P.E.

1985-10-01

A diode-array spectrophotometer and and x-ray fluorescence analyzer were installed online in a full-scale prototype facility to monitor uranium loading and breakthrough of ion exchange columns. Uranium concentrations of 10 ppM in uranyl nitrate solutions can be detected online to improve process control and material accountability. 9 figs

Influence of biofilms on migration of uranium, americium and europium in the environment

International Nuclear Information System (INIS)

Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

2015-01-01

The report on the influence of biofilms on migration of uranium, americium and europium in the environment deals with the contamination problems of uranium mines such as SDAG WISMUT in Saxonia and Thuringia. In mine waters microorganisms form a complex microbiological biocoenosis in spite of low pH values and high heavy metal concentrations including high uranium concentrations. The analyses used microbiological methods like confocal laser scanning microscopy and molecular-biological techniques. The interactions of microorganism with fluorescent radioactive heavy metal ions were performed with TRLFS (time resolved laser-induced fluorescence spectroscopy).

The use of radiometric-logging techniques to determine uranium grade in certain mineralised Karoo boreholes

International Nuclear Information System (INIS)

Corner, B.; De Beer, G.P.

1976-05-01

During the period September-October 1975, 22 mineralised boreholes in nine different Karoo uranium occurrences were logged radiometrically with the aim of determining to what accuracy the actual uranium grade could be predicted from the gamma logs. The true uranium grades of the mineralised zones logged were known from existing chemical analyses. The results showed that the uranium grades could be predicted to an accuracy of better than 10% through the use of gamma-logging equipment calibrated at Pelindaba, provided that the ore was in equilibrium and that little or no thorium was present. Disequilibrium is, however, prevalent in the Karoo, and in the holes logged it occurred by depletion of uranium relative to its gamma-emitting daughter products. Such effects were mostly confined to the zone above the water table, and it is concluded that for Karoo-type occurrences, the high radiometric background levels observed over extended distances in some boreholes were indicative of radon-gas buildup, and hence of disequilibrium. It is further concluded that radiometric borehole logging can largely replace chemical analyses in the determination of uranium grade for ore-reserve calculations, although chemical checks for disequilibrium would always be necessary [af

The determination of uranium distribution homogeneity in the fuel plates with the uranium loading of 4.80 and 5.20 g/cm3 by X-Ray attenuation

International Nuclear Information System (INIS)

Supardjo; Rojak, A.; Boybul; Suyoto; Datam, A. S.

2000-01-01

The calibration of X-Ray intensity of the U 3 Si 2 -AI fuel plates with the uranium loading between 3.60 up to 5.20 g/cm 3 and varied thickness of AIMgSi1 reference block have been performed. The measurement with changing variable slit diameter and energy of X-Ray attenuation, are produced enough representative X-Ray intensity at 18 mm slit diameter and energy of 43 kV. From the correlation of X-ray intensities vs variation of uranium loading in the fuel plates and thickness of the AIMgSi1 materials, the equivalence of thickness of the AIMgSi1 block to the uranium loading of fuel plates are determined. By assuming that the tolerance of the homogeneity measurement is + 20 % from normal thickness staircase of the AIMgSi1 standard could be determined and than together with fuel plate were scanned to determine the uranium homogeneity. The test result on the U 3 Si 2 -AI fuel plates with uranium loading of 4.80 and 5.20 g/cm 3 (each 4 fuel plates) indicated that uranium distribution in the fuel plates is relatively homogeneous, with each maximum deviation being 6.30 % and 6.90%. It is showed that measurement method is relatively good, easy, and fast so that this method is suitable to control the uranium homogeneity in the fuel plate. (author)

Multisensor system for determination of iron(II), iron(III), uranium(VI) and uranium(IV) in complex solutions

International Nuclear Information System (INIS)

Legin, A.V.; Seleznev, B.L.; Rudnitskaya, A.M.; Vlasov, Yu.G.; Tverdokhlebov, S.V.; Mack, B.; Abraham, A.; Arnold, T.; Baraniak, L.; Nitsche, H.

1999-01-01

Development and analytical evaluation of a multisensor system based on the principles of 'electronic tongue' for the determination of low contents of uranium(VI), uranium(IV), iron(II) and iron(III) in complex aqueous media have been carried out. A set of 29 different chemical sensors on the basis of all- solid-state crystalline and vitreous materials with enhanced electronic conductivity and redox and ionic cross-sensitivity have been incorporated into the sensor array. Multidimensional data have been processed by pattern recognition methods such as artificial neural networks and partial least squares. It has been demonstrated that Fe(II) and Fe(III) contents in the range from 10 -7 to 10 -4 mol L -1 of total iron concentration can be determined with the average precision of about 25 %. U(VI) and U(IV) contents can been determined with the average precision of 10-40% depending on the concentration. The developed multisensor system can be applied in future for the analysis of mining and borehole waters as well other contaminated natural media, including on-site measurements. (author)

Thermoionic emission characteristics of uranium with application to its determination by MSID technique using 233U tracer

International Nuclear Information System (INIS)

Shihomatsu, H.M.; Iyer, S.S.

1988-01-01

Experimental details of the uranium determination in geological samples (50-1500 ppm range) by mass spectrometric isotope dilution technique (MSID) employing 233 U tracer are presented. For this purpose the thermoionic emission characteristics of uranium in various filament arrangements like simple plane, filament boat, double, are studied and the most efficient one selected for the isotope dilution analysis. The various experimental procedures involved in the MSID like sample dissolution, chemical separation and mass spectrometric analysis are developed and optimised. The experimental results on the uranium determination by MSID with 233 U tracer yielded precision and accuracy of 0,5% and 1% respectively. The importance of the sampling in the precise and accuracy determination of uranium in geological samples, where it is heterogeneously distributed, is discussed. (author) [pt

Uranium(VI) coordination polymers with pyromellitate ligand: Unique 1D channel structures and diverse fluorescence

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yingjie, E-mail: yzx@ansto.gov.au [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Bhadbhade, Mohan [Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW 2052 (Australia); Karatchevtseva, Inna [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Price, Jason R. [Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168 (Australia); Liu, Hao [Centre for Clean Energy Technology, School of Chemistry and Forensic Science, University of Technology Sydney, PO Box 123, Broadway, Sydney, NSW 2007 (Australia); Zhang, Zhaoming; Kong, Linggen [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Čejka, Jiří [Department of Mineralogy, National Museum, Václavské náměstí, 68, Prague 1, 115 79-CZ (Czech Republic); Lu, Kim; Lumpkin, Gregory R. [Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

2015-03-15

Three new coordination polymers of uranium(VI) with pyromellitic acid (H{sub 4}btca) have been synthesized and structurally characterized. (ED)[(UO{sub 2})(btca)]·(DMSO)·3H{sub 2}O (1) (ED=ethylenediammonium; DMSO=dimethylsulfoxide) has a lamellar structure with intercalation of ED and DMSO. (NH{sub 4}){sub 2}[(UO{sub 2}){sub 6}O{sub 2}(OH){sub 6}(btca)]·~6H{sub 2}O (2) has a 3D framework built from 7-fold coordinated uranyl trinuclear units and btca ligands with 1D diamond-shaped channels (~8.5 Å×~8.6 Å). [(UO{sub 2}){sub 2}(H{sub 2}O)(btca)]·4H{sub 2}O (3) has a 3D network constructed by two types of 7-fold coordinated uranium polyhedron. The unique μ{sub 5}-coordination mode of btca in 3 enables the formation of 1D olive-shaped large channels (~4.5 Å×~19 Å). Vibrational modes, thermal stabilities and fluorescence properties have been investigated. - Graphical abstract: Table of content: three new uranium(VI) coordination polymers with pyromellitic acid (H{sub 4}btca) have been synthesized via room temperature and hydrothermal synthesis methods, and structurally characterized. Two to three dimensional (3D) frameworks are revealed. All 3D frameworks have unique 1D large channels. Their vibrational modes, thermal stabilities and photoluminescence properties have been investigated. - Highlights: • Three new coordination polymers of U(VI) with pyromellitic acid (H{sub 4}btca). • Structures from a 2D layer to 3D frameworks with unique 1D channels. • Unusual µ{sub 5}-(η{sub 1}:η{sub 2}:η{sub 1}:η{sub 2:}η{sub 1}) coordination mode of btca ligand. • Vibrational modes, thermal stabilities and luminescent properties reported.

Cellular localization of uranium in the renal proximal tubules during acute renal uranium toxicity.

Science.gov (United States)

Homma-Takeda, Shino; Kitahara, Keisuke; Suzuki, Kyoko; Blyth, Benjamin J; Suya, Noriyoshi; Konishi, Teruaki; Terada, Yasuko; Shimada, Yoshiya

2015-12-01

Renal toxicity is a hallmark of uranium exposure, with uranium accumulating specifically in the S3 segment of the proximal tubules causing tubular damage. As the distribution, concentration and dynamics of accumulated uranium at the cellular level is not well understood, here, we report on high-resolution quantitative in situ measurements by high-energy synchrotron radiation X-ray fluorescence analysis in renal sections from a rat model of uranium-induced acute renal toxicity. One day after subcutaneous administration of uranium acetate to male Wistar rats at a dose of 0.5 mg uranium kg(-1) body weight, uranium concentration in the S3 segment of the proximal tubules was 64.9 ± 18.2 µg g(-1) , sevenfold higher than the mean renal uranium concentration (9.7 ± 2.4 µg g(-1) ). Uranium distributed into the epithelium of the S3 segment of the proximal tubules and highly concentrated uranium (50-fold above mean renal concentration) in micro-regions was found near the nuclei. These uranium levels were maintained up to 8 days post-administration, despite more rapid reductions in mean renal concentration. Two weeks after uranium administration, damaged areas were filled with regenerating tubules and morphological signs of tissue recovery, but areas of high uranium concentration (100-fold above mean renal concentration) were still found in the epithelium of regenerating tubules. These data indicate that site-specific accumulation of uranium in micro-regions of the S3 segment of the proximal tubules and retention of uranium in concentrated areas during recovery are characteristics of uranium behavior in the kidney. Copyright © 2015 John Wiley & Sons, Ltd.

Determination of nitrate in effluents from Uranium Extraction Plant

International Nuclear Information System (INIS)

Dudwadkar, Ayushi; Kumar, Sangita D.; Reddy, A.V.R.

2014-01-01

Determination of nitrate concentration in the effluent samples from Uranium Extraction Plant is required before its safe discharge. As the different streams are diluted with sea water these samples contain high concentration of chloride. The large concentration of chloride poses a challenge in the determination of nitrate; hence, matrix elimination is accomplished by adopting a sample pretreatment technique. The present study was carried out to develop a simple, accurate and rapid analytical methodology for the determination of nitrate in the above matrices. The quantitative determination of nitrate was accomplished using anion exchange chromatography with conductometric detection. (author)

Spectrophotometric determination of uranium traces in zircaloy-4 and zirconium sponge

International Nuclear Information System (INIS)

Correia, R.J.; Weber de D'Alessio, Ana; Zucal, R.H.

1980-01-01

The uranium contents of the zircaloy-4 which is used for the fabrication of the fuel cans for the PHWR Atucha and Embalse nuclear power stations must not exceed 3.ppM. A method was developed for performing that control, involving the separation of the uranium from its matrix by partition chromatography and its determination by spectrophotometry with Arsenazo (III). This method is applied within the range of 0.2 to 10 ppM, obtaining a relative standard deviation of 6% for U contents of 3 ppm. (M.E.L.) [es

Determination of crystal water in uranium tetrafluoride

International Nuclear Information System (INIS)

Cheng Yingfang

1991-01-01

A gravimetric method for measuring crystal water in uranium tetrafluoride is reported. Being convenient, reliable and quick, it can be used as a routine analytical method measure crystal water in uranium tetrafluoride, thorium tetrafluoride etc

Interlaboratory comparison exercise for the determination of uranium by potentiometric titration (first phase)

International Nuclear Information System (INIS)

Verdingh, V.; Le Duigou, Y.

1991-01-01

Upon request of the Esarda working group on low-enriched uranium conversion and fuel fabrication plants an interlaboratory comparison was organized, to assess the precision and accuracy concerning the determination of uranium by the potentiometric titration method. This report presents the results of the first phase of this exercise (pure uranyl-nitrate solutions). The solutions used in this intercomparison have been certified for their uranium content by the CBNM, Geel. Comparison of the laboratory results with the certified values shows excellent, good and fairly good agreement for many of the participating laboratories. 10 tabs., 5 figs., 10 refs

Precise coulometric titration of uranium in a high-purity uranium metal and in uranium compounds

International Nuclear Information System (INIS)

Tanaka, Tatsuhiko; Yoshimori, Takayoshi

1975-01-01

Uranium in uranyl nitrate, uranium trioxide and a high-purity uranium metal was assayed by the coulometric titration with biamperometric end-point detection. Uranium (VI) was reduced to uranium (IV) by solid bismuth amalgam in 5M sulfuric acid solution. The reduced uranium was reoxidized to uranium (VI) with a large excess of ferric ion at a room temperature, and the ferrous ion produced was titrated with the electrogenerated manganese(III) fluoride. In the analyses of uranium nitrate and uranium trioxide, the results were precise enough when the error from uncertainty in water content in the samples was considered. The standard sample of pure uranium metal (JAERI-U4) was assayed by the proposed method. The sample was cut into small chips of about 0.2g. Oxides on the metal surface were removed by the procedure shown by National Bureau of Standards just before weighing. The mean assay value of eleven determinations corrected for 3ppm of iron was (99.998+-0.012) % (the 95% confidence interval for the mean), with a standard deviation of 0.018%. The proposed coulometric method is simple and permits accurate and precise determination of uranium which is matrix constituent in a sample. (auth.)

Spectrographic determination of lanthanides in high-purity uranium compounds, after chromatographic separation by alumina-hydrofluoric acid

International Nuclear Information System (INIS)

Lordello, A.R.; Abrao, A.

1979-01-01

A method is presented for the determination of fourteen rare earth elements in high-purity uranium compounds by emission spectrography. The rare earths are chromatographically separated from uranium by using alumina-hydrofluoric acid. Lanthanum is used both as collector and internal standard. The technique of excitation involves a total consumption of the sample in a 17 ampere direct current arc. The range of determination is about 0.005 to 0.5 μg/g uranium. The coefficient of variation for Pr, Ho, Dy, Er, Tm, Lu, Gd and Tb amounts to 10%. (Author) [pt

Determination of the uranium concentration in soil solutions by the fission track registration technique

International Nuclear Information System (INIS)

Fernandes, G.P.

1980-02-01

The fission tracks registration technique was used to determine the uranium concentration in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. From the calibration curves obtained, it was possible to determine uranium concentrations in soil solutions, from 90 to 320 μg U/l, with an error between 9.4% and 4.0%, respectively. The method was applied to a few soil samples from Pocos de Caldas, Minas Gerais in Brazil. The uranium concentrations in the sample and residues were also determined by other methods to compare the results obtained; only one sample showed deviation from the results obtained by the fission tracks method. And this discrepancy was explained in a reasonable way. It was shown that the fission tracks technique can be used with sucess for application in soil solutions. (Author) [pt

Spectrographic determination of boron and silicon in uranium tetrafluoride: Study of the chemical reactions in the electrode cavity when ZnO is used as a uranium excitation suppressor

International Nuclear Information System (INIS)

Alduan, F. A.; Capdevila, C.; Roca, M.

1973-01-01

A method has been developed for determining traces of boron and silicon in uranium tetrafluoride. Use is made of zinc oxide to decrease the volatilization of uranium and achieve high sensitivities. The thermochemical reactions which occur in the anode cavity during the arcing process have been investigated. UO 2 and a uranium, zinc and fluorine compound, both less volatile than uranium tetrafluoride, are formed. (Author)

Spectrophotometric titrations: Application to the determination of some elements in uranium solutions

International Nuclear Information System (INIS)

L'Her, M.

1967-01-01

The aim of this work is the application of spectrophotometric titrations to the analysis of uranium-containing solutions. We have been led to examine the general principles involved in these titrations, and we give a brief outline of these principles. In the first part we deal therefore with spectrophotometric titrations from a general point of view, examining their fundamental principle, their practical execution as well as the various possibilities of the method. The advantage of the titration are examined, in particular that of lending itself simultaneous determination of two species. The possibility of applying these spectrophotometric titrations to the analysis of uranium-containing solutions is the subject of the second part of this report: the dosage of a few species in uranium (VI) solutions is described. To this second part is added an experimental appendix consisting of a description of the apparatus, as well as of the operational techniques used for certain titrations, in particular those involving solutions containing uranium. (author) [fr

Measurement of disequilibrium in uranium and geochemical cartography by XRF field measurements for uranium exploration in a roll-front context (Mongolia)

International Nuclear Information System (INIS)

Andre, G.; Licht, A.

2009-01-01

Exploration studies in the South-eastern Mongolia revealed uranium mineralisation associated with a roll-front development in sands and clays of the Sainshand formation (late Cretaceous). The authors report a field measurement campaign performed with a portable X-ray fluorescence apparatus which allows on-site analysis of 30 species including uranium. This on-site analysis of uranium contents quickly characterizes the equilibrium state of new sectors. Visualization of disequilibria informs on the genesis and on the evolution of the deposit. The tracking of elements like selenium, vanadium and molybdenum helps the understanding of uranium trap or release mechanisms

X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Ray, N.B.

1977-01-01

The principle, instrument and procedure of X-ray fluorescence spectrometry are described. It is a rapid, simple and sensitive method for the trace analysis of elements from sodium to uranium in powder, liquid or metal samples. (M.G.B.)

Analysis of uranium and of some of its compounds and alloys. Copper spectrophotometric determination

International Nuclear Information System (INIS)

Copper determination in uranium, uranium oxides (UO 2 , UO 3 , U 3 O 8 ), ammonium diuranate, U-Al-Fe alloy (700 ppm Al and 300 ppm Fe) and U-Mo alloy (1.1 percent Mo) by acid dissolution reduction of copper by hydroxylamine hydrochloride and formation of a complex with diquinolyle-2,2' amyl alcohol (pH value 6 to 7) and spectrophotometry at 550 nm. The method is applicable for copper content between 5 to 40 ppm in respect of uranium contained in the material [fr

Automatic chemical determination facility for plutonium and uranium

International Nuclear Information System (INIS)

Benhamou, A.

1980-01-01

A proposal for a fully automated chemical determination system for uranium and plutonium in (U, Pu)O 2 mixed oxide fuel, from the solid sample weighing operation to the final result is described. The steps completed to data are described. These include: test sample preparation by weighing, potentiometer titration system, cleaning and drying of glassware after titration. The process uses a Mettler SR 10 Titrator System in conjunction with others automatized equipment in corse of realization. Precision may reach 0.02% and is generally better than 0.1%. Accuracy in within +-0.1% of manual determination results or titration standards [fr

Development of the fission fragment track registration technique for the determination of the uranium contamination

International Nuclear Information System (INIS)

Tanaka, E.M.

1979-01-01

The Fission Fragment Track Registration Technique is developed to measure the uranium concentration about microgram of uranium per litre of liquid samples. The drying method of drops on the detector (Makrofol KG) and a special sampling procedure to avoid the cumbersome high density of tracks formation at the edge of the deposition surface as a 'ring' is adopted. The samples are irradiated by neutrons produced by the IEA-R1 Reactor (thermal neutron flux about 10 12 neutrons/cm 2 .s) inducing the uranium fission. The tracks registered by the fission fragments in the detector are chemically enlarged and counted by an automatic couting system. By this method the uranium concentrations ranging from 0,9 to 7,6 microgram of uranium per litre, can be determined with precisions between 2,7% the greater and 23% to the lower concentration. The uranium concentration measurements in human hair and urine are made showing that this method is very useful to control and detect eventual uranium contamination [pt

Simultaneous determination of uranium and plutonium in dissolver solution of irradiated fuel, using ID-TIMS. IRP-11

International Nuclear Information System (INIS)

Shah, Raju; Sasi Bhushan, K.; Govindan, R.; Alamelu, D.; Khodade, P.S.; Aggarwal, S.K.

2007-01-01

A simple sample preparation and simultaneous analysis method to determine uranium and plutonium from dissolver solution, employing the technique of Isotope Dilution Mass spectrometry has been demonstrated. The method used, co-elusion of Uranium and Plutonium from anion exchanger column after initial elution of major part of uranium in 1:5 HNO 3 in order to reduce the initial U/Pu ratio from 1000 to about 100-200 in the co-eluted fraction. Due to the availability of variable multi-collector system, different Faraday cups were adjusted to collect the different ion intensities corresponding to the different masses, during the simultaneous analysis of Uranium and Plutonium, loaded on Re double filament assembly. 233 U and PR grade Plutonium were used as spikes to determine Uranium and Plutonium from dissolver solution of irradiated fuel from research reactor. The possibility of getting the isotopic composition of uranium from the simultaneous analysis of co-eluted purified fraction of U and Pu from spiked aliquots is also explained. (author)

REIMEP-22 inter-laboratory comparison: "U Age Dating - Determination of the production date of a uranium certified test sample"

OpenAIRE

VENCHIARUTTI CELIA; VARGA ZSOLT; RICHTER Stephan; JAKOPIC Rozle; MAYER Klaus; AREGBE Yetunde

2015-01-01

The REIMEP-22 inter-laboratory comparison aimed at determining the production date of a uranium certified test sample (i.e. the last chemical separation date of the material). Participants in REIMEP-22 on "U Age Dating - Determination of the production date of a uranium certified test sample" received one low-enriched 20 mg uranium sample for mass spectrometry measurements and/or one 50 mg uranium sample for D-spectrometry measurements, with an undisclosed value for the production date. They ...

Fluorimetric determination of uranium in zirconium and zircaloy alloys; Determinacion fluorimetrica de uranio en aleaciones de zirconio y zircaloy

Energy Technology Data Exchange (ETDEWEB)

Acosta L, E [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

1991-05-15

The objective of this procedure is to determine microquantities of uranium in zirconium and zircaloy alloys. The report also covers the determination of uranium in zirconium alloys and zircaloy in the range from 0.25 to 20 ppm on 1 g of base sample of radioactive material. These limit its can be variable if the size of the used aliquot one is changed for the final determination of uranium. (Author)

Determination of impurities in uranium--niobium (7.5%)--zirconium (2.5%) alloy

Energy Technology Data Exchange (ETDEWEB)

Arragon, Y

1973-10-01

The determination of 11 impurities in uranium--niobium-- zirconium alloys was studied. Elements of which the alloy is composed are considered and information is given on the determination of niobium by niobic acid precipitation. Selective elimination of the three components is discussed. Two liquid-liquid extractions are used. The nioblum is separated by methylisobutylketone in a hydrochloric --hydrofluoric medium and the zirconium and uranium by tributyl phosphate in a nitric medium. The determination of trace elements using electrochemical methods is discussed. Anodic re-dissolution polarography or square wave polarography enabled six elements (cadmium, copper, lead, zinc, bismuth, and thallium) to be determined in a carbonate medium together with aluminium in tetraethylammonium perchlorate, molybdenum in nitric acid, ammonium nitrate, and tungsten in hydrochloric acid with added double sodium and potassium tartrate. Fluorine was determined using ionometric techniques with a specific electrode and carbon was titrated by conductometry after combustion of the sample in an oxygen current. (auth)

Determination of uranium in soil with emphasis on dose assessment

International Nuclear Information System (INIS)

Vidic, A.; Ilic, Z.; Deljkic, D.; Repinc, U.; Benedik, Lj.; Maric, S.

2005-01-01

Uranium is present naturally in the earth crust and has three isotopes with long half-lives. These isotopes are 2 38U (99.27% natural abundance), 2 35U (0.72% natural abundance) and 2 34U (0.006% natural abundance). Isotope 2 35U is a valuable fuel for nuclear power plants. During the manufacture of nuclear fuel the concentration of 2 35U is increased. Depleted uranium (DU) is a waste product of this enrichment process and typically contains about 99.8% 2 38U , 0.2% 2 35U and 0.0006% 2 34U in mass. Due to its high density and other physical properties, DU is used in munitions designed to penetrate armour plate. DU weapons were used during the Balkan war in Bosnia and Herzegovina. It was estimated, that nearly 10,000 projectiles were fired or 3 tonnes of DU used in BandH. The aim of this work was to determine uranium radioisotopes in soil and air collected in Hadzici (near Sarajevo). The investigated area is a former military base used for the production and maintenance of tanks and other heavy military vehicles. During a NATO attack in 1995, about 1,500 rounds were fired at the site. The specific activities of 2 38U found in soil ranged from 28 Bq/kg to 55 Bq/kg. We found higher specific activities in some foci, in the range from 143 Bq/kg to 810 Bq/kg. The specific activities of uranium isotopes in the air were determined using simple dust loading approach. The results served to calculate the annual effective dose that could be received by individual workers at the site and by general population from the surrounding area. Radioactivity measurements in the environment of Hadzici showed that the annual effective dose for general population was less than 20 micro Sv.(author)

Plutonium oxides and uranium and plutonium mixed oxides. Carbon determination

International Nuclear Information System (INIS)

Anon.

Determination of carbon in plutonium oxides and uranium plutonium mixed oxides, suitable for a carbon content between 20 to 3000 ppm. The sample is roasted in oxygen at 1200 0 C, the carbon dioxide produced by combustion is neutralized by barium hydroxide generated automatically by coulometry [fr

Determination of ATP as a fluorescence probe with europium(III)-doxycycline.

Science.gov (United States)

Hou, Faju; Wang, Xiaolei; Jiang, Chongqiu

2005-03-01

A new spectrofluorimetric method has been developed for the determination of adenosine disodium triphosphate (ATP). We studied the interactions between the doxycycline (DC)-Eu3+ complex and adenosine disodium triphosphate (ATP) by using UV-visible absorption and fluorescence spectra. Using doxycycline (DC)-Eu3+ as a fluorescence probe, under the optimum conditions, ATP could remarkably enhance the fluorescence intensity of the DC-Eu3+ complex at lambda = 612 nm. The enhanced fluorescence intensity of the Eu3+ ion was in proportion to the concentration of ATP. The optimum conditions for the determination of ATP were also investigated. The linear ranges for ATP were 1.00 x 10(-7) - 2.00 x 10(-6) mol L(-1) with detection limits of 4.07 x 10(-8) mol L(-1). This method is simple, practical and relatively free of interference from coexisting substances, and can be successfully applied to the determination of ATP in samples. The mechanism of fluorescence enhancement between the doxycycline (DC)-Eu3+ complex and ATP was also studied.

Determination of thorium and uranium isotopes in the mining lixiviation liquor samples

International Nuclear Information System (INIS)

Reis Júnior, Aluísio de Souza; Monteiro, Roberto Pellacani Guedes

2017-01-01

The alpha spectrometric analysis refers to determination of thorium and uranium isotopes in the mining lixiviation liquor samples. The analytical procedure involves sample preparation steps for rare earth elements, thorium and uranium separation using selective etching with hydrofluoric acid and further radiochemical separation of these using TRU chromatographic resins (Eichrom Industries Inc. USA) besides electroplating of the isolated radionuclides. An isotopic tracer is used to determine the overall chemical yield and to ensure traceability to a national standard. The results are compared to results obtained for the same samples by Becquerel laboratory. We improved the method looking for reproducibility and isotopes isolation as required by alpha spectrometry and the method showing effective in analysis of mining liquor. (author)

Determination of thorium and uranium isotopes in the mining lixiviation liquor samples

Energy Technology Data Exchange (ETDEWEB)

Reis Júnior, Aluísio de Souza; Monteiro, Roberto Pellacani Guedes, E-mail: reisas@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

The alpha spectrometric analysis refers to determination of thorium and uranium isotopes in the mining lixiviation liquor samples. The analytical procedure involves sample preparation steps for rare earth elements, thorium and uranium separation using selective etching with hydrofluoric acid and further radiochemical separation of these using TRU chromatographic resins (Eichrom Industries Inc. USA) besides electroplating of the isolated radionuclides. An isotopic tracer is used to determine the overall chemical yield and to ensure traceability to a national standard. The results are compared to results obtained for the same samples by Becquerel laboratory. We improved the method looking for reproducibility and isotopes isolation as required by alpha spectrometry and the method showing effective in analysis of mining liquor. (author)

Constant current coulometric method for the determination of uranium in active process solutions

International Nuclear Information System (INIS)

Chitnis, R.T.; Talnikar, S.G.; Paranjape, A.H.

1980-01-01

The determination of uranium in the range of 2.5-5 mg by constant current coulometry is described. The procedure is based on the modified version of the DAVIES - GRAY method, wherein uranium, after the reduction step, is oxidized by adding a known amount of potassium dichromate, and the excess of dichromate is determined by titration with Fe 2+ solution. Fe 2+ ions needed for the titration are generated in situ with 100% current efficiency by electrolytic reduction of Fe 3+ . The method is found to be accurate with a coefficient of variation better than 0.2%. (author)

Analytical methods associated with the recovery of uranium

International Nuclear Information System (INIS)

Dixon, K.

1983-01-01

This report summarizes various approaches made to the analysis of materials arising from the processing of Karoo deposits for uranium. These materials include head and residue samples, aqueous solutions and organic solvents and, finally, the precipitated cakes of the elements recovered, i.e. uranium, molybdenum, and arsenic. Analysis was required for these elements and also vanadium, carbon, sulphur, and carbonate in the head and residue samples. The concentration of uranium, molybdenum, and arsenic, other than in the precipitated cakes, ranges from 1 to 2000μg/g, and that of carbon, sulphur, and carbonate from 0,1 to 5 per cent. The analysis of cakes necessitates the determination of silver, arsenic, iron, copper, calcium, magnesium, manganese, molybdenum, lead, tin, titanium, and vanadium within the range 1 to 1000μg/g, and of sodium and silica within the range 10 to 20 000μg/g. The methods used include combustion methods for carbon, sulphur, and carbonate, and atomic-absorption, X-ray-fluorescence, and emission methods for the other analytes. The accuracy of the analysis is within 10 per cent

Procedure for Uranium-Molybdenum Density Measurements and Porosity Determination

Energy Technology Data Exchange (ETDEWEB)

Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-08-13

The purpose of this document is to provide guidelines for preparing uranium-molybdenum (U-Mo) specimens, performing density measurements, and computing sample porosity. Typical specimens (solids) will be sheared to small rectangular foils, disks, or pieces of metal. A mass balance, solid density determination kit, and a liquid of known density will be used to determine the density of U-Mo specimens using the Archimedes principle. A standard test weight of known density would be used to verify proper operation of the system. By measuring the density of a U-Mo sample, it is possible to determine its porosity.

Fluorimetric determination of uranium in certain refractory minerals, environmental samples and industrial waste materials

International Nuclear Information System (INIS)

Premadas, A.; Saravanakumar, G.

2005-01-01

A simple sample decomposition and laser fluorimetric determination of uranium at trace level is reported in certain refractory minerals, like ilmenite, rutile, zircon and monazite; environmental samples viz. soil and sediments; industrial waste materials, such as, coal fly ash and red mud. Ilmenite sample is decomposed by heating with ammonium fluoride. Rutile, zircon and monazite minerals are decomposed by fusion using a mixture of potassium bifluoride and sodium fluoride. Environmental and industrial waste materials are brought into solution by treating with a mixture of hydrofluoric and nitric acids. The laser induced fluorimetric determination of uranium is carried out directly in rutile, zircon and in monazite minerals and after separation in other samples. The determination limit was 1 μg x g -1 for ilmenite, soil, sediment, coal fly ash and red mud samples, and it is 5 μg x g -1 for rutile, zircon and monazite. The method is also developed for the optical fluorimetric determination of uranium (determination limit 10 μg x g -1 ) in ilmenite, rutile, zircon and monazite minerals. The methods are simple, accurate, and precise and they require small quantity of sample and can be applied for the routine analysis. (author)

Standard test method for determination of impurities in nuclear grade uranium compounds by inductively coupled plasma mass spectrometry

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This test method covers the determination of 67 elements in uranium dioxide samples and nuclear grade uranium compounds and solutions without matrix separation by inductively coupled plasma mass spectrometry (ICP-MS). The elements are listed in Table 1. These elements can also be determined in uranyl nitrate hexahydrate (UNH), uranium hexafluoride (UF6), triuranium octoxide (U3O8) and uranium trioxide (UO3) if these compounds are treated and converted to the same uranium concentration solution. 1.2 The elements boron, sodium, silicon, phosphorus, potassium, calcium and iron can be determined using different techniques. The analyst's instrumentation will determine which procedure is chosen for the analysis. 1.3 The test method for technetium-99 is given in Annex A1. 1.4 The values stated in SI units are to be regarded as standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish ...

Developing a rapid method for the determination of uranium in pure phosphoric acid and D2 EHPA

International Nuclear Information System (INIS)

Koudsi, Y.; Stas, J.; Al-Merey, R.; shaddoud, G.

1996-02-01

Arsenazo (III) used in titrate uranium spectrophotometrically in phosphoric acid after its extraction into organic phase. In this work we used arsenazo(III) to complex uranyl ion in pure phosphoric acid and in the aqueous phase. The spectrum of the complex shows that λ max is at 650 nm. The linearity of the method is corelated with acid molarity, it is (1 -4, 10 - 30, 10 - 40) ppm uranium for (0.2, 1, 2) M of phosphoric acid respectively. Uranium in D 2 EHPA stripped by phosphoric acid and then determined by this method. Also it has been applied to determine uranium in pure perchloric acid. The method is direct, rapid, very cheap and relatively accurate. (author)

A new approach for the high-precision determination of the elemental uranium concentration in uranium ore by gamma-ray spectrometry

International Nuclear Information System (INIS)

Nagel, W.; Quik, F.

1993-01-01

A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution gamma-ray spectrometry, was applied. Using a variant of the enrichment meter technique an agreement of better than 1% has been obtained between gamma-ray measurement results and the certified value obtained by other analytical methods. For the calibration of the gamma-ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window a uniform degree of infinite thickness of about 95%. The measurement results can be taken as an example for the applicability of gamma-ray spectrometry when high accuracy is required and under conditions where homogeneous distributed elemental uranium is embedded in a larger amount of matrix material. (author). 8 refs., 10 figs., 2 tabs., 2 appendices

Nitrogen content determinations in different stages of thermal treatment involved in conversion of ammonium diuranate to uranium metal

International Nuclear Information System (INIS)

Shrivastava, K.C.; Shelke, G.P.

2017-01-01

Determination of nitrogen content in the uranium metal and uranium oxide based reactor fuels is important to meet the requirement of specifications given by fuel designer. Therefore, a systematic study was carried out to determine the variations in nitrogen content during the conversion of ammonium diuranate (ADU) to uranium oxides (UO 3 and UO 2 ), and finally to uranium metal by inert gas fusion-thermal conductivity detection (IGF-TCD) technique. To understand the measured nitrogen content variations, the thermal decomposition study of ADU was carried out using thermogravimetry (TG)/differential thermogravimetry (DTG) and differential thermal analysis (DTA) in the temperature range of 25-1073 K. Powder X-ray diffraction (XRD) technique was used to confirm the formation of uranium oxide precursors at different temperature. (author)

Determination of gas residues in uranium dioxide pellets

International Nuclear Information System (INIS)

Riella, H.G.

1978-01-01

The measurement of low amounts of residual gases, excluding water, in ceramic grade uranium dioxide pellets, using high temperature vacuum extraction technique, is dealt with. The high temperature extraction gas analysis apparatus was designed and assembled for sequential analysis of up to eight uranium dioxide pellets by run. The system consists of three major units, namely outgassing unit, transfer unit and analytical unit. The whole system is evacuated to a final pressure of less then 10 -5 torr. A weighed pellet is transfered into the outgassing unit for subsequent dropping into a Platinum-Rhodium crucible which is heated inductively up to 1600 0 C during 30 minutes. The released gases are imediately transfered from the outgassing to analytical unit passing through a cold trap at -95 0 C to remove water vapor. The gases are transfered to previously calibrated volumetric bulb where the total pressure and temperature are determined. An estimate of the gas content in the pellets at STP condition is obtained from the measured volume, pressure and temperature of the gas mixture by applying ideal gases equation. Analysis to two lots (fourteen samples) of uranium dioxide pellets by the method described here indicated a mean gas content of 0,060cm 3 /g UO 2 . The lower limit of this technique is 0,03cm 3 /g UO 2 (STP). The time required for the analysis of eight pellets is about 9 hours [pt

Uranium leaching analysis (IAEA method) and total uranium determination in caldasite by the fluorometric method

International Nuclear Information System (INIS)

Sardela, I.A.; Fujimori, K.

1980-10-01

Caldasite is a radioactive mineral known mostly for its high radioactive content (U and Th). It is found only at the Pocos de Caldas Alkaline Complex, States of Minas Gerais. Samples colected at Campos do Serrote, Taquari and Brigrada located in the alkaline complex were submitted to the fluorometric method of uranium analysis. The results show a good precision and close agreement with those obtained with gamma ray spectroscopy. IAEA uranium leaching analysis has also been applied to this mineral, but only 0,4% of the total content was dissolved. The uranium leaching was more intense on the samples that have smaller equivalent uranium than total uranium and it may be attributed to a higher range Rn gas escape from this mineral. (Author) [pt

Determination of tracer quantities of chromium in uranium

International Nuclear Information System (INIS)

Huart, A.

1959-01-01

A method is described for the photometric determination of chromium in uranium by absorbency at 540 mμ of the Cr(VI) diphenylcarbazide combination. After attack by nitric acid, the solution is made perchloric, and the chromium oxidised at the boiling point by permanganate. Excess oxidant is removed by hydrochloric acid. Study of operating conditions resulted in a method with an accuracy of ± 0,5 ppm for 0,5 to 15 ppm chromium in the metal. (author) [fr

Determination of uranium and thorium isotopes by solid phase extraction and alpha spectrometry

International Nuclear Information System (INIS)

Kuruc, J.; Kovacova, M.; Strisovska, J.; Galanda, D.

2013-01-01

The aim of this work was to test the modified method suitable for the separation of isotopes of uranium and thorium samples of rocks, including gold ore and gold concentrate using of extraction chromatography method, after digestion of the sample, concentrating, separate the isotopes of uranium and thorium isotopes to prepare sources for the measurement of alpha spectra. Samples of rocks, gold ore and gold concentrate were digered in microwave decomposition in the environment of hydrogen peroxide and concentrated nitric acid. For the separation of uranium and thorium the vacuum box with cartridges DGA Resin and Resin(R) UTEVA (Triskem International, France) was used. Both sorbents allow separation of uranium from thorium. The results confirmed that the both sorbents give the same results within expanded uncertainty. The mass activity of monitored uranium and thorium radioisotopes was determined by alpha spectrometry method. The yields of separation were determined using uranium-232 as a tracer radionuclide; the activity of 232 U was 0.1438 Bq. Alpha spectra were measured on the Alpha spectrometer EG and G ORTEC 576A with the software MAESTRO, MCA Emulator and Gamma Vision-32 for Windows, USA. Mass activities of radionuclides were converted to mass concentration of isotopes 238 U, 234 U, 232 Th, 230 Th and 228 Th. The highest concentration of 238 U was sampled in granodiorite (Tunnel S-XIV-2, southwards, mining of Cu ore, not working there since 1990), where m( 238 U) = (0.81 ± 0.09) mg kg -1 (DGA Resin) and m( 238 U) = (0.90 ± 0.09) mg kg -1 (UTEVA(R) Resin), as well as m( 232 Th) = (18.8 ± 1.7) mg kg -1 (DGA Resin) and m( 232 Th) = (17.8 ± 1.5) mg kg -1 (UTEVA(R) Resin). In other samples of rocks, gold ore and gold concentrates have specific masses of isotopes of uranium and thorium two-to ten-folds lower. It can be concluded that the rocks, gold ores and concentrates of gold from the 'Rozalia' mine contain lower concentrations of uranium several times against

Spectrographic determination of impurities in enriched uranium solutions

International Nuclear Information System (INIS)

Capdevila, C.; Roca, M.

1980-01-01

A spectrographic procedure for the determination of trace amounts of Al, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, L i , Hg, Mn, Mo, Na, Nb, Ni, P, Pb, Ru, Sb, Sn, Sr, Ti, V, Zn, and Zr in enriched uranyl nitrate solutions from the reprocessing of spent nuclear fuels is described. After removal of uranium by either TBP or TNOA solvent extraction, the aqueous phase Is analysed by the graphite spark technique. TBP is adequate for all impurities, excepting boron and phosphorus; both of these elements can sat is factory be determined by using TNOA after the addition of mannitol to avoid boron losses. (Author) 4 refs

High-temperature thermal conductivity of uranium chromite and uranium niobate

International Nuclear Information System (INIS)

Fedoseev, D.V.; Varshavskaya, I.G.; Lavrent'ev, A.V.; Oziraner, S.N.; Kuznetsova, D.G.

1979-01-01

The technique of determining thermal conductivity coefficient of uranium niobate and uranium chromite on heating with laser radiation is described. Determined is the coefficient of free-convective heat transfer (with provision for a conduction component) by means of a standard specimen. The thermal conductivity coefficients of uranium chromite and niobate were measured in the 1300-1700 K temperature range. The results are presented in a diagram form. It has been calculated, that the thermal conductivity coefficient for uranium niobate specimens is greater in comparison with uranium chromite specimens. The thermal conductivity coefficients of the materials mentioned depend on temperature very slightly. Thermal conductivity of the materials considerably depends on their porosity. The specimens under investigation were fabricated by the pressing method and had the following porosity: uranium chromite - 30 %, uranium niobate - 10 %. Calculation results show, that thermal conductivity of dense uranium chromite is higher than thermal conductivity of dense uranium niobate. The experimental error equals approximately 20 %, that is mainly due to the error of measuring the temperature equal to +-25 deg, with a micropyrometer

Determination of uranium and polonium in Spa rus aura ta by alpha spectrometry

Energy Technology Data Exchange (ETDEWEB)

Luna P, M.; Renteria, M.; Montero C, M. E. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes No. 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico); Manjon C, G.; Diaz, I., E-mail: elena.montero@cimav.edu.mx [Universidad de Sevilla, Escuela Tecnica Superior de Arquitectura, Departamento de Fisica Aplicada II, San Fernando No. 4, 41004 Sevilla (Spain)

2012-06-15

The aim of this study was optimizing conditions for the specific activities determination of some uranium-series radionuclides present in Spa rus aura ta by alpha spectrometry. Determinations of specific activities were conducted varying the type of digestion: acid attack on hot plate, controlled microwave digestion and acid attack after calcination of the sample. The latter procedure was applied only to the case of uranium isotopes determination. The variation in the isotope extraction method consisted of applying the techniques of liquid-liquid extracting using Tributyl phosphate or chromatographic UTEVA resin. Results depending on the type of treatment given to the samples were compared based on obtained chemical yields. The results reveal a higher bioaccumulation of polonium in the liver sample, with activities of 0.809, 2.495 and 2.439 Bq kg{sup -1} fresh wt compared with the fillet. The best chemical yields of polonium were close to 60% for samples that were digested by microwave. In the case of uranium the best chemical yields, close to 80% for fillet, were obtained with a previous calcination of the sample and using the UTEVA resin. (Author)

Determination of Uranium and Thorium in Brazilian coals by epithermal neutron activation analysis

International Nuclear Information System (INIS)

Bernedo, L.F.B.

1981-08-01

An experimental technique for the determination of uranium and thorium in coal by epithermal neutron activation was developed and systemized. Seventeen different coal samples, six copper monitors for neutron flux corrections and three NBS standard coal samples were irradiated together in a cadmium cylinder. Uranium and thorium were determined by measuring the 239 N sub(p) and 233 P sub(a) activities respectively, being both produced in (n,γ) reactions and subsequent β - decay. The 239 N sub(p) was measured by counting the 106.4 KeV γ-ray in a LEPS detector and the 233 P sub(a) by counting the 311.8 KeV γ-ray, but in a Ge(Li) detector. A 4096 multichannel analizer and a PDP-11 computer complemented the basic measuring equipment. An average precision of 3% was obtained in the analysis of seventeen coal samples coming from different strata and heights of Charqueadas and Morungava mines in Rio Grande do Sul State. The sensitivity of the method is around 100 ppb. This technique will allow determinations of up to twenty elements, besides uranium and thorium, and it can be applied in routine analysis. (Author) [pt

Determination of uranium and polonium in Spa rus aura ta by alpha spectrometry

International Nuclear Information System (INIS)

Luna P, M.; Renteria, M.; Montero C, M. E.; Manjon C, G.; Diaz, I.

2012-01-01

The aim of this study was optimizing conditions for the specific activities determination of some uranium-series radionuclides present in Spa rus aura ta by alpha spectrometry. Determinations of specific activities were conducted varying the type of digestion: acid attack on hot plate, controlled microwave digestion and acid attack after calcination of the sample. The latter procedure was applied only to the case of uranium isotopes determination. The variation in the isotope extraction method consisted of applying the techniques of liquid-liquid extracting using Tributyl phosphate or chromatographic UTEVA resin. Results depending on the type of treatment given to the samples were compared based on obtained chemical yields. The results reveal a higher bioaccumulation of polonium in the liver sample, with activities of 0.809, 2.495 and 2.439 Bq kg -1 fresh wt compared with the fillet. The best chemical yields of polonium were close to 60% for samples that were digested by microwave. In the case of uranium the best chemical yields, close to 80% for fillet, were obtained with a previous calcination of the sample and using the UTEVA resin. (Author)

The Comparison Study of Neutron Activation Analysis and Fission Track Technique for Uranium Determination

International Nuclear Information System (INIS)

Sirinuntavid, Alice; Rodthongkom, Chouvana

2007-08-01

Full text: Comparison between Neutron Activation Analysis (NAA) and fission track technique for uranium determination in solid samples was studied by use of standard reference materials, i.e., ore, coal fly ash, soil. For NAA, the epithermal neutron was applied for activated irradiation. Then, the 74.5 keV gamma from U-239 or 277.7 keV gamma from Np-239 was measured. For high Uranium content samples, NAA method with 74.5 keV gamma measurement, gave higher precision result than the 277.7 keV gamma measurement method. NAA method with 277.7 keV gamma measurement, gave higher sensitivity and precision result for low Uranium content samples and the uranium contained less than 10 ppm samples. Nevertheless, the latter procedure needed longer time for neutron irradiation and analysis procedure. In comparison the results of Uranium analysis between NAA and fission track, it was found that no significant difference within 95 % of confidence level

Determination of 17 impurity elements in nuclear quality uranium compounds by atomic absorption spectroscopy

International Nuclear Information System (INIS)

Andonie, O.; Smith, L.A.; Cornejo, S.

1985-01-01

A method is described for the determination of 17 elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, V and Zn) in the ppm level, in nuclearly pure uranium compounds by flame atomic absorption spectroscopy. The analysis is performed by first dissolving the uranium sample in nitric acid and then extracting the uranium with tributyl phosphate solution. The aqueous phase, free of uranium, which contains the elements to analyze is inspirated into the flame of an atomic absorption spectrophotometer using air-acetylene or nitrous oxide-acetylene flame according to the element in study. This method allows to extract the uranium selectively in more than 99.0% and the recovery of the elements sudied was larger 90% (for K) to 100% (for Cr). The sensitivity of the method vary from 0.096 μg/g U (for Cd) to 5.5 μg/g U (for Na). (Author)

Statistical evaluation of an interlaboratory comparison for the determination of uranium by potentiometric titration

International Nuclear Information System (INIS)

Ketema, D.J.; Harry, R.J.S.; Zijp, W.L.

1990-09-01

Upon request of the ESARDA working group 'Low enriched uranium conversion - and fuel fabrication plants' an interlaboratory comparison was organized, to assess the precision and accuracy concerning the determination of uranium by the potentiometric titration method. This report presents the results of a statistical evaluation on the data of the first phase of this exercise. (author). 9 refs.; 5 figs.; 24 tabs

Gamma spectrometric determination of depleted Uranium in Yugoslavia

International Nuclear Information System (INIS)

Pantelic, G.; Eremic Savkovic, M.; Javorina, L.; Tanaskovic, I.; Vuletic, V.; Milacic, S.

2002-01-01

The radiation protection is very important interdisciplinary research field due to the presence of the radiation in daily life. The systematic examination of radioactive contamination of various environmental samples was established forty years ago in the Institute of Occupational and Radiological Health Dr Dragomir Karajovic for the sake of preventive protection of population and environment from the harmful effect of ionizing radiation. The global sources of radionuclide contamination in our country are the fallout due to previous nuclear testing and the deposition of radionuclides from the region of Chernobyl accident. The contents of radionuclides were determined in aerosol, soil, fallout (wet and dry deposition), rivers, lakes, drinking water, human and animal food. The samples were collected in several locations of the Republic of Serbia and in regular time intervals, according to methods determined by the regulation. The regulations and the monitoring programs were updated after the Chernobyl accident. In the recent time, after the NATO aggression, we analyzed depleted uranium content in the environmental samples. We used high-resolution gamma spectrometry measurements, because of their simplicity and accuracy. Aims of the control were to asses the increase of radioactivity above the natural levels in the immediate and near vicinity of the bomb craters, to asses the corresponding effect of changed natural radioactivity on the health of the population living in these places and finding unexploded depleted uranium bullets

Semiempirical method to determine the uranium isotopic compositions

International Nuclear Information System (INIS)

Tegas Sutondo

2008-01-01

In a nuclear reactor design calculation, some variations of U 235 enrichment are commonly needed. This will affect the isotopic compositions of the 3 main uranium isotopes i.e. U 234 , U 235 and U 238 for the respective enrichment. Due to the limited compositions data available, it is urgent to make an approximate way that can be used to determine the compositions of the 3 isotopes, for the desired enrichments. This paper presents the theoretical background used for constructing a semi empirical formula to estimate the composition of the 3 uranium isotopes as a function of U 235 enrichment, obtained based on the measurement data available. Based on the available data, and the lack of compositions data within the enrichment range between 3.5 % and around 12 %, it is concluded that 2 separate linear equations i.e. for ≤ 3.5 % and ≥ 3.5 % might be needed for U 235 isotope. For the U 234 isotope, a polynomial equation of 4 th order is well suited to be used for the whole range of enrichment between 0.711 % and 20 %, whilst for higher enrichment (> 20 %), a power function seems to give a better approach. The composition of U 238 can then be determined from the U 235 and U 234 composition at the desired enrichment of U 235 . (author)

Spectrophotometric determination of uranium using 2-(2- Thiazolylazo-p-Cresol (TAC in the presence of surfactants

Directory of Open Access Journals (Sweden)

Teixeira Leonardo Sena Gomes

1999-01-01

Full Text Available A sensitive and selective spectrophotometric method is proposed for the rapid determination of uranium using 2-(2- Thiazolylazo-p-Cresol (TAC. The reaction between TAC and uranium (VI is instantaneous at pH 6.5 and the absorbance remains stable for over 3 h. N-cetyl-N,N,N-trimethylamonium bromide (CTAB and triton X-100 are used for increasing the sensitivity and solubility of the system respectively. The method allows the determination of uranium in the range from 0.30 to 12.0 mug mL-1 with a molar absorptivity of 1.31 x 10(4 L mol-1 cm-1 and features a detection limit of 26 ng mL-1 at 588 nm. The selectivity of the reagent was improved by the use of (1,2-cyclohexylenedinitrilo tetraacetic acid (CyDTA as masking agent. The proposed method has been successfully applied to the determination of uranium in mine drainage waters. The precision (R.S.D. < 2% and the accuracy obtained were satisfactory.

Quantitative determination of uranium distribution homogeneity in MTR fuel type plates

International Nuclear Information System (INIS)

Ferrufino, Felipe Bonito Jaldin

2011-01-01

IPEN/CNEN-SP produces the fuel to supply its nuclear research reactor IEA-R1. The fuel is assembled with fuel plates containing an U 3 Si 2 -Al composite meat. A good homogeneity in the uranium distribution inside the fuel plate meat is important from the standpoint of irradiation performance. Considering the lower power of reactor IEA-R1, the uranium distribution in the fuel plate has been evaluated only by visual inspection of radiographs. However, with the possibility of IPEN to manufacture the fuel for the new Brazilian Multipurpose Reactor (RMB), with higher power, it urges to develop a methodology to determine quantitatively the uranium distribution into the fuel. This paper presents a methodology based on X-ray attenuation, in order to quantify the uranium concentration distribution in the meat of the fuel plate by using optical densities in radiographs and comparison with standards. The results demonstrated the inapplicability of the method, considering the current specification for the fuel plates due to the high intrinsic error to the method. However, the study of the errors involved in the methodology, seeking to increase their accuracy and precision, can enable the application of the method to qualify the final product. (author)

Separation of thulium, ytterbium and lutetium from uranium

International Nuclear Information System (INIS)

Lopez, G.H.

1987-01-01

The behaviour at different temperatures, shaking times and hydrochloric acid concentrations on the solvent extraction system UO 2 2+ - (Tm 3+ , Yb 3+ , Lu 3+ ) - H 2 O - HCl - TBP was studied. Quantitative determinations of the elements were performed by visible spectrophotometry and X-ray fluorescence. The uranyl ion was efficiently extracted by TBP from an aqueous hydrochloric acid solution (4-7M) shaken during 10 minutes at room temperature. On these conditions the separation factors for uranium from thulium and ytterbium were found to be 3000 and from lutetium 140. (author)

Studies on O/M ratio determination in uranium oxide, plutonium oxide and uranium-plutonium mixed oxide

International Nuclear Information System (INIS)

Sampath, S.; Chawla, K.L.

1975-01-01

Thermogravimetric studies were carried out in unsintered and sintered samples of uranium oxide, plutonium oxide and uranium-plutonium mixed oxide under different atmospheric conditions (air, argon and moist argon/hydrogen). Moisture loss was found to occur below 200 0 C for uranium dioxide samples, upto 700 0 C for sintered plutonium dioxide and negligible for sintered samples. The O/M ratios for non-stoichiometric uranium dioxide (sintered and unsintered), plutonium dioxide and mixed uranium and plutonium oxides (sintered) could be obtained with a precision of +- 0.002. Two reference states UOsub(2.000) and UOsub(2.656) were obtained for uranium dioxide and the reference state MOsub(2.000) was used for other cases. For unsintered plutonium dioxide samples, accurate O/M ratios could not be obtained of overlap of moisture loss with oxygen loss/gain. (author)

Comparison of neutron activation analysis techniques for the determination of uranium concentrations in geological and environmental materials

International Nuclear Information System (INIS)

Landsberger, S.; Kapsimalis, R.

2013-01-01

We have described the determination of uranium in environmental, geological, and agricultural specimens by three different non-destructive nuclear methods. The effectiveness, as defined as the lower limits of detection in this work, of quantifying trace levels of bulk uranium in geological samples was evaluated for several common NAA techniques. These techniques include short-lived and medium-lived neutron activation analysis using thermal and epithermal neutrons; these results were compared with an assessment of Compton suppressed gamma-ray counting. A careful evaluation of three major (n,γ) reactions with chlorine, manganese and sodium that could impede determining low levels of uranium due to high Compton continuums was done. The evaluation of Compton suppressed passive gamma counting revealed that uranium concentrations below 50 mg kg −1 were not adequate to achieve good counting statistics using the 234m Pa the second daughter product of 238 U. -- Highlights: ► Determination of uranium concentrations in geological, environmental, and agricultural specimens. ► Use of several NAA and passive counting methods. ► Identified several key interferences. ► Use of Compton suppression to minimize effects of interferences

Preliminary Results of Nuclear Fluorescence Imaging of Alpha and Beta Emitting Sources

International Nuclear Information System (INIS)

Feener, Jessica S.; Charlton, William S.

2013-06-01

The preliminary results from a series of nuclear fluorescence imaging experiments using a variety of radioactive sources and shielding are given. These experiments were done as part of a proof of concept to determine if nuclear fluorescence imaging could be used as a safeguards measurements tool or for nuclear warhead verification for nuclear arms control treaties such as the New Strategic Arms Reduction Treaty and the Fissile Material Cut-Off Treaty. An off-the-shelf Princeton Instruments charged coupled device camera system was used to image the emission of fluorescence photons from the de-excitation of nitrogen molecules in air that have been excited by ionizing radiation. The fluorescence emissions are primarily in the near ultraviolet range; between the wavelengths of 300 and 400 nm. Fluorescent imaging techniques are currently being investigated in a number of applications. A French research team has successfully demonstrated this concept for remote imaging of alpha contamination. It has also been shown that the phenomenon can be seen through translucent materials and that alpha radiation can be seen in the presence of large gamma backgrounds. Additionally, fluorescence telescopes and satellites utilize the de-excitation of nitrogen molecules to observe cosmic ray showers in the atmosphere. In cosmic ray shower detection, electrons are the main contributor to the excitation of the of nitrogen molecules in air. The experiments presented in this paper were designed to determine if the imaging system could observe beta emitting sources, differentiate between beta emitters and alpha emitting materials such as uranium oxide and uranium metal, and to further investigate the phenomenon through translucent and non-translucent materials. The initial results show that differentiation can be made between beta and alpha emitting sources and that the device can observe the phenomenon through very thin non-transparent material. Additionally, information is given on the

Extraction and determination of hydrogen in uranium and zirconium

International Nuclear Information System (INIS)

Champeix, L.; Coblence, G.; Darras, R.

1959-01-01

The method of desorption under vacuum at high temperatures in the solid phase, which gives good results in the case of steels, has been applied to uranium and zirconium. In these two metals hydrogen is found mainly in the form of hydride. It is chiefly a question of determining the most suitable temperature and the heating time necessary to obtain an almost total extraction of hydrogen. Two considerations must be taken into account in the choice of temperature. It should be such that on the one hand the hydride decomposes rapidly and completely at the reduced pressure applied, and on the other hand the diffusion of hydrogen through the metal takes place fairly quickly. The apparatus and the method used are described; systematic tests have led to the adoption of temperatures of 650 deg. C for uranium and 1050 deg. C for zirconium. (author) [fr

Determination of uranium in aqueous solutions by HPLC post column UV/VIS detection

International Nuclear Information System (INIS)

Abbasi, W.A.; Street, M.

1995-01-01

Analysis of uranium in different nitric acid concentration solutions is interest in nuclear industry where it is present in various process and waste streams. A method for the determination of uranium(VI) in nitric acid solution in described using ion chromatography and post-column derivatization with 4-(2-pyridylazo) resorcinol (PAR). The method does not require any sample treatment for acid removal or neutralization and can be used for routine laboratory analysis. The effluent used was ammonium sulphate / sulphuric acid and PAR was present in ammonium hydroxide/acetic acid buffer. The column effluents is reacted with PAR in a reaction coil and U(VI)-PAR complex is detector at 528 nm. The lowest uranium concentration detected was 100 ppb (0.1 mg/sup -1/) and linearity of up to 8 mgl -1 concentration was verified. The standard deviation in reproducibility at uranium concentration of 0.1 mgl/sup -1/ was 0.82%. (author)

Nuclear fuel technology - Determination of uranium in uranyl nitrate solutions of nuclear grade quality - Gravimetric method

International Nuclear Information System (INIS)

2003-01-01

This International Standard specifies a precise and accurate gravimetric method for determining the mass fraction of uranium in uranyl nitrate solutions of nuclear grade quality containing more than 100 g/kg of uranium. Non-volatile impurities influence the accuracy of the method

Report on the feasibility of the in situ radiometric determination of uranium grade in Witwatersrand gold and uranium mines

International Nuclear Information System (INIS)

Smit, C.J.B.; Wesolinski, E.S.; Corner, B.

1982-08-01

The chip-sampling technique currently employed by the South African gold and uranium-mining industry, for the prediction of face grade, has several drawbacks, namely: 1) it is labour-intensive; 2) sample volumes are often unrepresentative and prone to human error; and 3) the uranium mineralisation may be very erratic along the reef. In situ radiometric assaying for uranium along the reef, on the other hand, is a rapid, essentially one-man operation, enabling a much larger and hence a more representative sample volume to be measured. The high radiometric background inherent in any uranium mine necessitates some form of high-density shielding in order to facilitate quantitative in situ assaying. This report, therefore, briefly outlines the origin, nature, detection and shielding of gamma rays. Results obtained with a frontally shielded total-count instrument showed that radiometric estimates of uranium grade are comparable to those obtained by batch mining and can be used for the prediction of face grades, provided that the ore is in radiometric equilibrium and that thorium and potassium are either not present, or vary sympathetically with the uranium grade. Spectral analysis showed, however, that these circumstances will also permit the use of a collimated (side-shielded) detector of acceptable weight, provided that only the low-energy portion of the spectrum is measured. The advantages of a collimated detector over a frontally shielded detector are also noteworthy, viz.: 1) only one reading is taken per sample point rather than two, as is the case with the frontally shielded system, thus improving counting statistics; and 2) the shielding is permanently fixed to the detector. Comprehensive design considerations for a compact, portable instrument are suggested and methods for determining background radiation as applicable to a collimated detector are described

Determination of uranium in urine samples for workers in the phosphoric acid purification using fluorimetry technique

International Nuclear Information System (INIS)

Kharita, M. H.; Sakhita, Kh.; Aldalal, Z.

2003-10-01

There is probability of exposure to uranium for workers in the phosphoric acid purification (internal exposure) by inhalation, and the deposition of this uranium in organs and tissues, and the consequence excreation out of the body by perspiration or urine. This study focuses on the determination of uranium in urine samples of workers. All results seem to be under the detection limit of the method, therefore no routine monitoring is required. (author)

On the use of hydrogen peroxide as a masking agent for the determination of yttrium in uranium oxide - yttrium oxide mixture

International Nuclear Information System (INIS)

Rastogi, R.K.; Chaudhuri, N.K.; Rizvi, G.H.; Subramanian, M.S.

1985-01-01

The use of peroxide as a masking agent for uranium during the EDTA titration of yttrium in an yttrium-uranium mixture containing large amounts of uranium was investigated. High acetate ion concentration was necessary to keep the peroxy complex of uranium in solution during the titration. It was observed that uranium could be tolerated up to 500 mg in the determination of yttrium with 0.5 ml of 30% hydrogen peroxide in approx. 1M acetate medium. The precision and accuracy of the method based on 16 determinations of yttrium at 6-16 mg level in the presence of 300 mg uranium was found to be +-0.2%. (author)

Determination of uranium in environmental samples from the Nile delta and the adjacent regions of Egypt using laser fluorimetry

Energy Technology Data Exchange (ETDEWEB)

Shawky, S; Ibrahim, N; Farouk, A [National research Center for Nuclear safety and radiation Control, Atomic Energy Authority, cairo (Egypt); Ghods, A [IAEA Laboratories, Chemistry Unit., A 244 Seibersdorf, (Austria)

1995-10-01

Total uranium content was determined in soil and plant samples taken from various areas in the Nile delta. Samples from east and west of the delta, the suez canal` cities and from alexandria region were analyzed using laser fluorimetry (LF). Uranium was extracted from digested ashed samples with methyl-isobutyl ketone (MIBK) and measured using laser fluorimeter. The radium content of the same soil samples was determined using gamma spectrometry (GS). The uranium content of plant samples was determined using (LF), since it has a detection limit lower than of (GS). The uranium content varied between 0.6-4.4{mu}g/g and 0.032-0.17 {mu}g/g for soil and plant samples respectively. 1 fig., 3 tabs.

Determination of uranium in environmental samples from the Nile delta and the adjacent regions of Egypt using laser fluorimetry

International Nuclear Information System (INIS)

Shawky, S.; Ibrahim, N.; Farouk, A.; Ghods, A.

1995-01-01

Total uranium content was determined in soil and plant samples taken from various areas in the Nile delta. Samples from east and west of the delta, the suez canal' cities and from alexandria region were analyzed using laser fluorimetry (LF). Uranium was extracted from digested ashed samples with methyl-isobutyl ketone (MIBK) and measured using laser fluorimeter. The radium content of the same soil samples was determined using gamma spectrometry (GS). The uranium content of plant samples was determined using (LF), since it has a detection limit lower than of (GS). The uranium content varied between 0.6-4.4μg/g and 0.032-0.17 μg/g for soil and plant samples respectively. 1 fig., 3 tabs

The measurement of natural uranium in urine by fluorometry

International Nuclear Information System (INIS)

Kramer, G.H.; Johnson, J.R.; Green, W.

1984-02-01

The fluorometric method of measuring natural uranium in urine that is currently used by the Bioassay Laboratory at Chalk River Nuclear Laboratories has been tested, optimized and documented. The method, which measures the fluorescence of uranium in a fused sodium fluoride pellet, has been shown to be quench independent and is routinely used to measure uranium concentrations in the range of 1 μg/L to 90 μg/L. The fluorimeter has a dynamic range of 0.2 μg/L to 200 μg/L

Uranium (Vi) sorption onto zirconium diphosphate chemically modified

International Nuclear Information System (INIS)

Garcia G, N.; Ordonez R, E.

2010-10-01

This work deals with the uranium (Vi) speciation after sorption onto zirconium diphosphate (ZrP 2 O 7 ) surface, hydrated and in a surface modified with organic acids. Oxalic and citric acids were chosen to modify the ZrP 2 O 7 surface because they have poly carboxylic groups and they mimic the organic matter in nature. Thus the interest of this work is to evaluate the uranium (Vi) sorption edge at different s ph values in natural and modified surfaces. The luminescence technique (fluorescence and phosphorescence, respectively) was used for the quantification and speciation of uranyl sorbed at the zirconium diphosphate interface. The fluorescence experiment, showed that adsorption of uranyl on surface of zirconium diphosphate tends to 100%. The speciation shows that there are different complexes in surface which were formed between zirconium diphosphate and uranyl, since it is produced a displacement of wavelength in fluorescence spectra of each system. (Author)

Estimation of ultratrace level of uranium in sea water by laser fluorimeter

International Nuclear Information System (INIS)

Sahoo, S.K.; Tripathi, R.M.; Mohapatra, S.; Patra, A.C.; Lenka, P.; Puranik, V.D.

2010-01-01

Full text: Uranium, a naturally occurring primordial radionuclide, is imperative in the present Indian Nuclear Power Programme. Seawater may be an alternate source of uranium to meet the future demand. The total estimated quantity of uranium in seawater is around four and a half billion tonnes. Estimation of uranium in sea water is cumbersome and tedious because of ultra-trace concentration of uranium with high salt content and other interfering elements of sea water. Mainly chloride interferes in sea water analysis for estimation of nanogram level uranium because the ion at high concentration in sea water depresses uranyl complex fluorescence. At 500 ppm of chloride, the fluorescence response from a given uranium level is reduced by nearly 50%. Dilution method may be used in order to minimize the interference effect but it can't be implemented in this case as sea water contains 19000 ppm chloride but only 2-3 ppb of uranium. Thus, the separation of the interfering elements is necessary to analyze nanogram level of uranium in sea water. In the present study, an attempt has been made to analyze uranium in sea water by laser fluorimeter. Sample was treated with potassium persulphate to remove chloride ion and subsequent measurement was carried out after pH adjustment. The method was used for analysis of uranium content in 23 seawater samples ranged from 0.2 ± 0.1 μg/l to 2.2 ± 0.4 μg/l with a mean value of 1.01 ± 0.11 μg/l

Determination of Uranium, Thorium and Radium 226 in Zircon containig sands by alpha spectrometry

International Nuclear Information System (INIS)

Spezzano, P.

1985-01-01

The industrial utilization of Zircon sands for the production of refractories presents radiological problems owing to the risk of inhalation of Uranium, Thorium and their decay products, present in high concentrations in such materials. A method of analysis was realized for the determination of Uranium, Thorium and Radium-226 in Zircon sands, including the total dissolution of the sample, radiochemical separation and final measurement by alpha spectrometry with surface barrier detector. The concentrations of the main alpha-emitting radionuclides presents in two samples of Zircon sands have been determined and the possibility of disequilibrium along the decay series has been pointed out

Device for the determination of concentrations of fissile and/or fertile materials by means of x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Von Baeckmann, A.; Neuber, J.

1975-01-01

In analyzing fissile and/or fertile materials in the thorium, uranium, neptunium, plutonium, americium and curium group, time and accuracy are significant factors. An automated system for rapidly analyzing these materials includes: sample preparation device in which aliquots of sample are weighed and mixed with known amounts of solution; x-ray fluorescence spectrometer; and, a central control system for controlling the operation and analyzing the data. (auth)

Effect of solution composition on determination of uranium (6) microquantities by laser-induced luminescence method

International Nuclear Information System (INIS)

Romanovskaya, G.I.; Zakharova, G.V.; Chibisova, A.K.

1984-01-01

The effect of cation and anion composition of natural waters (sea water, ground water, etc.) on the uranium (6) determination in the form of uranyl complexes with Na 2 O3SiO 2 using the laser-induced luminescence method with the determination limit 2x10 -11 g/ml, has been studied. The dependence of the luminescence intensity of uranyl polysilicate complexes on the inorganic ion concentration has been measured. The measurement results permitted to determine the maximum permissible concentrations (MAC) of ions, the values of which are presented. The results reproducibility is characterized by a relative standard deveation within 0.01-0.05. It follows from the data analysis that the MPC of impurities vary from 10 -8 to 10 -2 g/ml. The MPCs of uranium as determined in the form of polysilicate complexes, are shown to be close to the values obtained during uranium determination in the form of complexes with fluoran for the CO 3 2- , Ni, Cu ions and they are by an order higher for the Na, K, Cl - , SO 4 2- , HPO 4 2- , Mn ions

Energetics and dynamics of atomic uranium levels

International Nuclear Information System (INIS)

Miron, E.

1978-01-01

New methods for discovering and identifying new electronic levels of atomic uranium and measuring parameters, such as radiative lifetimes and absorption cross-sections, are described. The uranium atoms are produced within an especially designed induction-heated oven. The uranium vapor is irradiated by nitrogen laser pumped, pulsed dye lasers. The various measurements are accomplished by detection of laser induced fluorescence from selectively excited levels. 138 atomic-uranium odd levels in the region 32260-34900 cm -1 and 16 even levels in the region 49500-49900 cm -1 are reported. Unique J values are presented for 64 levels and partial assignment (two possibilities) for 42 levels. Radiative lifetimes are presented for 134 levels. Absorption cross sections were measured for 12 transitions. Isotope shifts of 17 levels are given. Cross-sections for internal excitation transfer in uranium which are induced by collisions with argon atoms, are presented for 11 levels. (author)

Determination of paraquat in water samples using a sensitive fluorescent probe titration method.

Science.gov (United States)

Yao, Feihu; Liu, Hailong; Wang, Guangquan; Du, Liming; Yin, Xiaofen; Fu, Yunlong

2013-06-01

Paraquat (PQ), a nonselective herbicide, is non-fluorescent in aqueous solutions. Thus, its determination through direct fluorescent methods is not feasible. The supramolecular inclusion interaction of PQ with cucurbit[7]uril was studied by a fluorescent probe titration method. Significant quenching of the fluorescence intensity of the cucurbit[7]uril-coptisine fluorescent probe was observed with the addition of PQ. A new fluorescent probe titration method with high selectivity and sensitivity at the ng/mL level was developed to determine PQ in aqueous solutions with good precision and accuracy based on the significant quenching of the supramolecular complex fluorescence intensity. The proposed method was successfully used in the determination of PQ in lake water, tap water, well water, and ditch water in an agricultural area, with recoveries of 96.73% to 105.77%. The fluorescence quenching values (deltaF) showed a good linear relationship with PQ concentrations from 1.0 x 10(-8) to 1.2 x 10(-5) mol/L with a detection limit of 3.35 x 10(-9) mol/L. In addition, the interaction models of the supramolecular complexes formed between the host and the guest were established using theoretical calculations. The interaction mechanism between the cucurbit[7]uril and PQ was confirmed by 1H NMR spectroscopy.

Method and apparatus for determining uranium concentration in a moving stream

International Nuclear Information System (INIS)

Bartko, J.; Wonn, J.W.

1977-01-01

The concentration of uranium in a moving stream is determined by agglomerating background microbubbles out of the 6 to 10 micron size range, counting microbubbles in the stream which are about 6 to about 10 microns in size, exposing the stream to a radiation source to cause uranium fission fragments to produce microbubbles, counting microbubbles which are about 6 to about 10 microns in size, and subtracting one count from the other and multiplying by a calibration constant. The subtraction can be performed on an earlier first count so that both counts are made on the same volume. The radiation exposure can be automatically increased when the difference between the first and second counts is low

Determination of microquantities of zirconium and thorium in uranium dioxide

International Nuclear Information System (INIS)

Weber de D'Alessio, Ana; Zucal, Raquel.

1975-07-01

A method for the determination of 10 to 50 ppm of zirconium and thorium in uranium IV oxide of nuclear purity is established. Zirconium and thorium are retained in a strong cation-exchange resin Dowex 50 WX8 in 1 M HCl. Zirconium is eluted with 0,5% oxalic acid solution and thorium with 4% ammonium oxalate. The colorimetric determination of zirconium with xilenol orange is done in perchloric acid after destructtion of oxalic acid and thorium is determined with arsenazo III in 5 M HCl. 10 μg of each element were determined with a standard deviation of 2,1% for thorium and 3,4% for zirconium. (author) [es

Determination of the uranium concentration in apatite by the fission - track registration technique

International Nuclear Information System (INIS)

D'Oliveira Cardoso, D.

1983-01-01

The feasibility of using the fission-track registration technique to determine the uranium content in the phosphate rock beneficiation steps carried on by CompanhiA Arafertil, Araxa, Minas Gerais, Brazil is studied. This determination is of considerable interest to the environmental control of the Arafertil installations as well as of its surroundings or of the areas where these products will be used. The so called wet method was adopted and a 10 μm polycarbonate foil, fabricated by Bayer under the trade name Makrofol KG was used as detector. From the calibration curve obtained, it was possible to determine uranium contents in sample solutions ranging from 21 to 212 μg U/1 with an accuracy of 8 to 14.7%, respectively. The results obtained demonstrated that the technique used is appropriate to the purposes previously aimed at. (Author) [pt

Synchronous fluorescence based biosensor for albumin determination by cooperative binding of fluorescence probe in a supra-biomolecular host-protein assembly.

Science.gov (United States)

Patra, Digambara

2010-01-15

A synchronous fluorescence probe based biosensor for estimation of albumin with high sensitivity and selectivity was developed. Unlike conventional fluorescence emission or excitation spectral measurements, synchronous fluorescence measurement offered exclusively a new synchronous fluorescence peak in the shorter wavelength range upon binding of chrysene with protein making it an easy identification tool for albumin determination. The cooperative binding of a fluorescence probe, chrysene, in a supramolecular host-protein assembly during various albumin assessments was investigated. The presence of supramolecular host molecules such as beta-cyclodextrin, curucurbit[6]uril or curucurbit[7]uril have little influence on sensitivity or limit of detection during albumin determination but reduced dramatically interference from various coexisting metal ion quenchers/enhancers. Using the present method the limit of detection for BSA and gamma-Globulin was found to be 0.005 microM which is more sensitive than reported values. Copyright 2009 Elsevier B.V. All rights reserved.

Standard guide for the determination of iodine-129 In uranium oxide

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 This method covers the determination of iodine-129 (129I) in uranium oxide by gamma-ray spectrometry. The method could also be applicable to the determination of 129I in aqueous matrices. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.

Sensitive determination of nucleic acids using organic nanoparticle fluorescence probes

Science.gov (United States)

Zhou, Yunyou; Bian, Guirong; Wang, Leyu; Dong, Ling; Wang, Lun; Kan, Jian

2005-06-01

This paper describes the preparation of organic nanoparticles by reprecipitation method under sonication and vigorous stirring. Transmission electron microscopy (TEM) was used to characterize the size and size distribution of the luminescent nanoparticles. Their average diameter was about 25 nm with a size variation of ±18%. The fluorescence decay lifetime of the nanoparticles also was determined on a self-equipped fluorospectrometer with laser light source. The lifetime (˜0.09 μs) of nanoparticles is about three times long as that of the monomer. The nanoparticles were in abundant of hydrophilic groups, which increased their miscibility in aqueous solution. These organic nanoparticles have high photochemical stability, excellent resistance to chemical degradation and photodegradation, and a good fluorescence quantum yield (25%). The fluorescence can be efficiently quenched by nucleic acids. Based on the fluorescence quenching of nanoparticles, a fluorescence quenching method was developed for determination of microamounts of nucleic acids by using the nanoparticles as a new fluorescent probe. Under optimal conditions, maximum fluorescence quenching is produced, with maximum excitation and emission wavelengths of 345 and 402 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0.4-19.0 μg ml -1 for calf thymus DNA (ct-DNA) and 0.3-19.0 μg ml -1 for fish sperm DNA (fs-DNA). The corresponding detection limits are 0.25 μg ml -1 for ct-DNA and 0.17 μg ml -1 for fs-DNA. The relative standard deviation of six replicate measurements is 1.3-2.1%. The method is simple, rapid and sensitive with wide linear range. The recovery and relative standard deviation are very satisfactory.

Spectrographic determination of niobium in uranium - niobium alloys

International Nuclear Information System (INIS)

Charbel, M.Y.; Lordello, A.R.

1984-01-01

A method for the spectrographic determination of niobium in uranium-niobium alloys in the concentration range 1-10% has been developed. The metallic sample is converted to oxide by calcination in a muffle furnace at 800 0 C for two hours. The standards are prepared synthetically by dry-mixing. One part of the sample or standard is added to nineteen parts of graphite powder and the mixture is excited in a DC arc. Hafnium has been used as internal standard. The precision of the method is + - 4.8%. (Author) [pt

A sensitive fluorescence quenching method for determination of bismuth with tiron

Energy Technology Data Exchange (ETDEWEB)

Taher, Mohammad Ali; Rahimi, Mina [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Fazelirad, Hamid, E-mail: hamidfazelirad@gmail.com [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Department of Chemistry, Science and Research Branch, Islamic Azad University, Yazd (Iran, Islamic Republic of); Young Researchers Society, Shahid Bahonar University of Kerman, P.O. Box 76175-133, Kerman (Iran, Islamic Republic of)

2014-01-15

We describe a fluorescence quenching method for determination of bismuth with tiron. The method is based on the reaction of tiron by bismuth(III) in acidic media. The influence of variables such as the pH, type of buffer, tiron concentration, reaction time and temperature were investigated. Under optimized conditions, the fluorescence quenching extent is proportional to the concentration of bismuth for Bi–tiron system at the range 0.13–2.09 μg mL{sup −1} and the detection limit is 0.05 μg mL{sup −1}. The proposed sensor presented good repeatability, evaluated in terms of relative standard deviation (R.S.D.=±0.498%) for 11 replicates. This sensitive, rapid and accurate method has been successfully applied to the determination of trace bismuth(III) in water and hair samples and certified reference materials. -- Highlights: • No previous paper report on use of fluorescence quenching for determination of Bi. • Fluorescence quenching of trion is a sensitive method for determination of Bi(III). • Under the optimum conditions the detection limit is very low (0.05 μg mL{sup −1}). • The procedure is simple and safe and has high tolerance limit to interferences.

Determining uranium speciation in contaminated soils by molecular spectroscopic methods: Examples from the Uranium in Soils Integrated Demonstration

International Nuclear Information System (INIS)

Allen, P.G.; Berg, J.M.; Chisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.

1994-01-01

The US Department of Energy's former uranium production facility located at Fernald, OH (18 mi NW of Cincinnati) is the host site for an Integrated Demonstration for remediation of uranium-contaminated soils. A wide variety of source terms for uranium contamination have been identified reflecting the diversity of operations at the facility. Most of the uranium contamination is contained in the top ∼1/2 m of soil, but uranium has been found in perched waters indicating substantial migration. In support of the development of remediation technologies and risk assessment, we are conducting uranium speciation studies on untreated and treated soils using molecular spectroscopies. Untreated soils from five discrete sites have been analyzed. We have found that ∼80--90% of the uranium exists as hexavalent UO 2 2+ species even though many source terms consisted of tetravalent uranium species such as UO 2 . Much of the uranium exists as microcrystalline precipitates (secondary minerals). There is also clear evidence for variations in uranium species from the microscopic to the macroscopic scale. However, similarities in speciation at sites having different source terms suggest that soil and groundwater chemistry may be as important as source term in defining the uranium speciation in these soils. Characterization of treated soils has focused on materials from two sites that have undergone leaching using conventional extractants (e.g., carbonate, citrate) or novel chelators such as Tiron. Redox reagents have also been used to facilitate the leaching process. Three different classes of treated soils have been identified based on the speciation of uranium remaining in the soils. In general, the effective treatments decrease the total uranium while increasing the ratio of U(IV) to U(VI) species

Determination in soils of soluble uranium fraction in acid medium by fission tracks registration techniques

International Nuclear Information System (INIS)

Fernandes, G.P.

1980-01-01

The fission tracks registration technique was used to determine the concentration of uranium in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. The method was applied to a few samples of soils from Pocos de Caldas, Minas Gerais in Brazil. The concentrations of uranium in the samples and residues were also determined by other methods to compare the results obtained; only one sample showed deviation among the results obtained by the fission tracks method. (author)

Uranium conversion

International Nuclear Information System (INIS)

Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina

2006-03-01

FOI, has performed a study on uranium conversion processes that are of importance in the production of different uranium compounds in the nuclear industry. The same conversion processes are of interest both when production of nuclear fuel and production of fissile material for nuclear weapons are considered. Countries that have nuclear weapons ambitions, with the intention to produce highly enriched uranium for weapons purposes, need some degree of uranium conversion capability depending on the uranium feed material available. This report describes the processes that are needed from uranium mining and milling to the different conversion processes for converting uranium ore concentrate to uranium hexafluoride. Uranium hexafluoride is the uranium compound used in most enrichment facilities. The processes needed to produce uranium dioxide for use in nuclear fuel and the processes needed to convert different uranium compounds to uranium metal - the form of uranium that is used in a nuclear weapon - are also presented. The production of uranium ore concentrate from uranium ore is included since uranium ore concentrate is the feed material required for a uranium conversion facility. Both the chemistry and principles or the different uranium conversion processes and the equipment needed in the processes are described. Since most of the equipment that is used in a uranium conversion facility is similar to that used in conventional chemical industry, it is difficult to determine if certain equipment is considered for uranium conversion or not. However, the chemical conversion processes where UF 6 and UF 4 are present require equipment that is made of corrosion resistant material

Spectrophotometric and spectrofluorometric determination of uranium using a flotation process with benzoate and rivanol

Energy Technology Data Exchange (ETDEWEB)

Lopez Herroz, C.; Hernandez, M.; Sanchez-Pedreno, C.

1988-01-01

Tribenzouranyl anion forms with rivnol an ion-association compound which is floated with isopropyl ether and dissolved in ethanol. As a consequence, new spectrophotometric and spectrofluorimetric methods for the determination of trace amounts of uranium are developed. At 373 nm Beer's law is obeyed over the range 10-150 /mu/g of uranium. When the spectrofluorimetric technique is used, calibration graph is linear in the 2-25 /mu/g range.

Some factors affecting the accuracy of uranium content determined by DNC measurement

International Nuclear Information System (INIS)

Song Quanxun

1988-01-01

Some factors affecting the accuracy of uranium contents determined by delayed neutron counting and methods solving these problems are described. One of the factors is deterioration of the BF 3 proportional counters. This problem is discussed in more detail

Description of x-ray-fluorescence (XRF) system for the Wet Scrap Development Laboratory (WSDL)

International Nuclear Information System (INIS)

Jedlovec, D.R.

1981-06-01

In support of the process control and accountability needs of the Wet Scrap Design Laboratory (WSDL), a technique utilizing X-ray Fluorescence (XRF) to determine actinide concentrations was developed and tested in FY 80, FY 81 at the General Electric Vallecitos Nuclear Center (GE-VNC). XRF analysis of uranium and plutonium solutions representative of those expected from the wet chemical processes of the WSDL was performed. This contract was to develop, test, and demonstrate control system concepts to provide a basis for an Integrated Control System (ICS) for a COPRECAL Conversion Plant. Financial support to the ICS was withdrawn before any x-ray fluorescence plutonium testing and development work could be accomplished. The following XRF testing and operation were performed at GE-VNC in FY 80, FY 81: uranium, plutonium, U/Pu testing completed September 1980; in-line testing completed October 1980; high concentration testing completed October 1980; shipment of XRF system components to W-HEDL accomplished January 1981

Interaction of uranium with Pleurotus sp

International Nuclear Information System (INIS)

Ohnuki, Toshihiko; Sakamoto, Fuminori; Kozaki, Naofumi; Ozaki, Takuro; Samadfam, Mohammad

2002-01-01

Uptake of uranium by higher fungi, such as mushroom is little elucidated. We have studied the interaction of uranium with Pleurotus sp. (a mushroom) in pure culture over a wide range of U concentration (50-3000 mg/L). The Pleurotus sp. was cultured in two different media. One was rice bran medium, and the other was agar (yeast extract, peptone and dextrose) medium. The uptake of uranium in Pleurotus sp. was examined by alpha ray autoradiography (A,A), X-ray fluorescence spectroscopy (XRF) and scanning microcopy (SEM) equipped with EDS. In the agar medium, the higher uranium concentration gave lower growth of mycelia, and no fruiting body was observed. In the rice bran medium, the fruiting body was grown at U concentrations up to 1000 mg/L. The AA and XRF analysis showed that uranium taken up in the fruiting body was below the detection limit. The SEM-EDS analysis indicated that U was distributed in the limited region and was not transported to the mycelia far from U containing medium. It is concluded that uranium affects the growth of Pleurotus sp., and little uranium is taken up by Pleurotus sp. during the growth of both mycelia and fruiting body. (author)

Determination of internal exposure doses of the personnel of uranium-mining company due to radon isotopes decay products

International Nuclear Information System (INIS)

Sevostyanov, V.N.

2004-01-01

This work carries out a determination of individual doses of internal exposure of the staff of the uranium-mining company in Kazakhstan due to radon decay products. The company extracts uranium by in-situ leaching. After leaching, uranium is sorbed from a solution in facilities where the staff is located. The state of three uranium mines was analyzed. The dose determination was conducted in tune with the proposed method by using integral alpha-tracking detectors to identify the content of 222 Rn and express appliances to identify the content of radio-active aerosols in air of the working area for determination the equilibrium coefficient. The measurements were performed within one year. The work produced the results in average annual values of radon and thoron decay products activity concentration and variation, equilibrium coefficient variation, and so-called expressive-to-integral value conversion factor. The obtained personnel's individual radiation doses due to radon exposure for this period lie within the range of < 1 mSv/year. (author)

Determination of U (Ⅵ) content in uranium molybdenum ores

International Nuclear Information System (INIS)

Wang Haisheng; Ding Hongfang

2014-01-01

Potentionmetric titration is established to determine U (Ⅵ) in uranium molybdenum ores. In the closed condition, U (Ⅵ) is leached by carbonate solution. U (Ⅵ) is reduced to U (Ⅳ) by ferrous sulfate in phosphoric acid. The exess ferrous sulfate is oxidized by sodium nitrite. urea decompose the exess sodium nitrite. U (Ⅳ) is titrated by ammonium metavanadate standard solution with potentionmetric titration. The precision is better than 5%, The recovery rate is 97.2%∼101.9%. (authors)

Determination of 226Ra and natural uranium concentration in Botafogo river

International Nuclear Information System (INIS)

Nascimento, M.B. do; Amaral, R.S.; Khoury, H.J.; Andrade Lima, R. de

1990-01-01

In the Brazilian Northeast region at the coastal area from Pernambuco to Paraiba there is a 4 km wide strip deposit of phosphate rock. This phosphate is used to produce fertilizes by a factory located at the border of the Botafogo river, which cross this area. The phosphate is associated with uranium and no research has been conducted on the river radioactive contamination due the natural processes and to the fertizer factory the present investigation was undertaken to determine 226 Ra and natural uranium concentration in the river water, near the factory. Results show that the radionuclide concentration increases sharply in front of the place of the factory discharge and then decreases rapidly to the same levels found before the factory, 0,01 Bq/1. (author) [pt