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Sample records for perrhenates

  1. Structure and Thermochemistry of Perrhenate Sodalite and Mixed Guest Perrhenate/Pertechnetate Sodalite.

    PubMed

    Pierce, Eric M; Lilova, Kristina; Missimer, David M; Lukens, Wayne W; Wu, Lili; Fitts, Jeffrey; Rawn, Claudia; Huq, Ashfia; Leonard, Donovan N; Eskelsen, Jeremy R; F Woodfield, Brian; Jantzen, Carol M; Navrotsky, Alexandra

    2017-01-17

    Treatment and immobilization of technetium-99 ((99)Tc) contained in reprocessed nuclear waste and present in contaminated subsurface systems represents a major environmental challenge. One potential approach to managing this highly mobile and long-lived radionuclide is immobilization into micro- and meso-porous crystalline solids, specifically sodalite. We synthesized and characterized the structure of perrhenate sodalite, Na8[AlSiO4]6(ReO4)2, and the structure of a mixed guest perrhenate/pertechnetate sodalite, Na8[AlSiO4]6(ReO4)2-x(TcO4)x. Perrhenate was used as a chemical analogue for pertechnetate. Bulk analyses of each solid confirm a cubic sodalite-type structure (P4̅3n, No. 218 space group) with rhenium and technetium in the 7+ oxidation state. High-resolution nanometer scale characterization measurements provide first-of-a-kind evidence that the ReO4(-) anions are distributed in a periodic array in the sample, nanoscale clustering is not observed, and the ReO4(-) anion occupies the center of the sodalite β-cage in Na8[AlSiO4]6(ReO4)2. We also demonstrate, for the first time, that the TcO4(-) anion can be incorporated into the sodalite structure. Lastly, thermochemistry measurements for the perrhenate sodalite were used to estimate the thermochemistry of pertechnetate sodalite based on a relationship between ionic potential and the enthalpy and Gibbs free energy of formation for previously measured oxyanion-bearing feldspathoid phases. The results collected in this study suggest that micro- and mesoporous crystalline solids maybe viable candidates for the treatment and immobilization of (99)Tc present in reprocessed nuclear waste streams and contaminated subsurface environments.

  2. Structure and Thermochemistry of Perrhenate Sodalite and Mixed Guest Perrhenate/Pertechnetate Sodalite

    DOE PAGES

    Pierce, Eric M.; Lilova, Kristina; Missimer, David M.; ...

    2016-12-05

    Development of a sustainable fuel cycle, which must include closing the back-end by reprocessing and/or disposing of used nuclear fuel, is a key component of the nuclear energy renaissance. Technetium-99 ( = 293.7 keV, t1/2 = 2.1 105 years), a byproduct of 235U and 239Pu fission, comprises a significant component of radioactive waste (~5% fission yield), and its worldwide inventory has increased steadily. Treatment and immobilization of 99Tc contained in reprocessed nuclear waste represents a major challenge. One potential approach to managing this highly mobile and long-lived radionuclide is immobilization into micro- and mesoporous crystalline solids, specifically sodalite. We synthesizedmore » and characterized the structure of perrhenate sodalite, Na8[AlSiO4]6(ReO4)2, and the structure of a guest-guest perrhenate/pertechnetate sodalite, Na8[AlSiO4]6(ReO4)2-x(TcO4)x. Perrhenate was used as a chemical analogue for pertechnetate. Bulk analyses of each solid confirm a cubic sodalite-type structure ( 43 , No. 218 space group) with rhenium and technetium in the 7+ oxidation state. High-resolution nanometer scale characterization measurements provide first-of-a-kind evidence that the ReO4- anions are distributed in a periodic array in the sample, nanoscale clustering is not observed, and the ReO4- anion occupies the center of the sodalite -cage in Na8[AlSiO4]6(ReO4)2. We also demonstrate, for the first time, that the TcO4- anion can be incorporated into the sodalite structure. Lastly, thermochemistry measurements for the perrhenate sodalite were used to estimate the thermochemistry of pertechnetate sodalite based on a relationship between ionic potential and the enthalpy and Gibbs free energy of formation for previously measured oxyanion-bearing feldspathoid phases. These results not only provide the data required to evaluate the long-term chemical stability of pertechnetate sodalities, but also an approach to estimate thermodynamic constants for a range of micro

  3. Structure and Thermochemistry of Perrhenate Sodalite and Mixed Guest Perrhenate/Pertechnetate Sodalite

    SciTech Connect

    Pierce, Eric M.; Lilova, Kristina; Missimer, David M.; Lukens, Wayne W.; Wu, Lili; Fitts, Jeffrey P.; Rawn, Claudia; Huq, Ashfia; Leonard, Donovan N.; Eskelsen, Jeremy R.; Jantzen, Carol M.; Navrotsky, Alexandra

    2016-12-05

    Development of a sustainable fuel cycle, which must include closing the back-end by reprocessing and/or disposing of used nuclear fuel, is a key component of the nuclear energy renaissance. Technetium-99 ( = 293.7 keV, t1/2 = 2.1 105 years), a byproduct of 235U and 239Pu fission, comprises a significant component of radioactive waste (~5% fission yield), and its worldwide inventory has increased steadily. Treatment and immobilization of 99Tc contained in reprocessed nuclear waste represents a major challenge. One potential approach to managing this highly mobile and long-lived radionuclide is immobilization into micro- and mesoporous crystalline solids, specifically sodalite. We synthesized and characterized the structure of perrhenate sodalite, Na8[AlSiO4]6(ReO4)2, and the structure of a guest-guest perrhenate/pertechnetate sodalite, Na8[AlSiO4]6(ReO4)2-x(TcO4)x. Perrhenate was used as a chemical analogue for pertechnetate. Bulk analyses of each solid confirm a cubic sodalite-type structure ( 43 , No. 218 space group) with rhenium and technetium in the 7+ oxidation state. High-resolution nanometer scale characterization measurements provide first-of-a-kind evidence that the ReO4- anions are distributed in a periodic array in the sample, nanoscale clustering is not observed, and the ReO4- anion occupies the center of the sodalite -cage in Na8[AlSiO4]6(ReO4)2. We also demonstrate, for the first time, that the TcO4- anion can be incorporated into the sodalite structure. Lastly, thermochemistry measurements for the perrhenate sodalite were used to estimate the thermochemistry of pertechnetate sodalite based on a relationship between ionic potential and the enthalpy and Gibbs free energy of formation for previously measured oxyanion-bearing feldspathoid phases. These results not only provide the data required to evaluate the long-term chemical stability of pertechnetate sodalities, but also an approach to estimate thermodynamic constants for a range of micro- and

  4. Competitive incorporation of perrhenate and nitrate into sodalite.

    PubMed

    Dickson, Johnbull O; Harsh, James B; Flury, Markus; Lukens, Wayne W; Pierce, Eric M

    2014-11-04

    Nuclear waste storage tanks at the Hanford site in southeastern Washington have released highly alkaline solutions, containing radioactive and other contaminants, into subsurface sediments. When this waste reacts with subsurface sediments, feldspathoid minerals (sodalite, cancrinite) can form, sequestering pertechnetate (99TcO4-) and other ions. This study investigates the potential for incorporation of perrhenate (ReO4-), a chemical surrogate for 99TcO4-, into mixed perrhenate/nitrate (ReO4-/NO3-) sodalite. Mixed-anion sodalites were hydrothermally synthesized in the laboratory from zeolite A in sodium hydroxide, nitrate, and perrhenate solutions at 90 °C for 24 h. The resulting solids were characterized by bulk chemical analysis, X-ray diffraction, scanning electron microscopy, and X-ray absorption near edge structure spectroscopy (XANES) to determine the products' chemical composition, structure, morphology, and Re oxidation state. The XANES data indicated that nearly all rhenium (Re) was incorporated as Re(VII)O4-. The nonlinear increase of the unit cell parameter with ReO4-/NO3- ratios suggests formation of two separate sodalite phases in lieu of a mixed-anion sodalite. The results reveal that the sodalite cage is highly selective toward NO3- over ReO4-. Calculated enthalpy and Gibbs free energy of formation at 298 K for NO3- and ReO4-sodalite suggest that NO3- incorporation into the cage is favored over the incorporation of the larger ReO4-, due to the smaller ionic radius of NO3-. Based on these results, it is expected that NO3-, which is present at significantly higher concentrations in alkaline waste solutions than 99TcO4-, will be strongly preferred for incorporation into the sodalite cage.

  5. Hydrolysis of cellulose catalyzed by quaternary ammonium perrhenates in 1-allyl-3-methylimidazolium chloride.

    PubMed

    Wang, Jingyun; Zhou, Mingdong; Yuan, Yuguo; Zhang, Quan; Fang, Xiangchen; Zang, Shuliang

    2015-12-01

    Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5mol% of tetramethyl ammonium perrhenate as catalyst, 70μL of water, ca. 0.6mmol of microcrystalline cellulose (MCC) and 2.0g of [Amim]Cl as solvent under microwave irradiation for 30min at 150°C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose.

  6. Evaluation of Perrhenate Spectrophotometric Methods in Bicarbonate and Nitrate Media.

    PubMed

    Lenell, Brian A; Arai, Yuji

    2016-04-01

    2-pyridyl thiourea and methyl-2-pyridyl ketoxime based perrhenate, Re(VII), UV-vis spectrophotometric methods were evaluated in nitrate and bicarbonate solutions ranging from 0.001 M to 0.5 M. Standard curves at [Re]=2.5-50 mg L(-1) for the Re(IV)-thiourea and the Re ketoxime complexes were constructed at 405 nm and 490 nm, respectively. Detection of limits for N-(2-pyridyl) thiourea and methyl-2-pyridyl ketoxime methods in ultrapure water are 3.06 mg/L and 4.03 mg/L, respectively. Influences of NaHCO3 and NaNO3 concentration on absorbance spectra, absorptivity, and linearity were documented. For both methods, samples in ultrapure water and NaHCO3 have an R(2) value>0.99, indicating strong linear relationships. Statistical analysis supports that NaHCO3 does not affect linearity between standards for either method. NaNO3 causes major interference with the ketoxime method above 0.001 M NaNO3. Data provides information for practical use of Re spectrophotometric methods in environmental media that is high in bicarbonate and nitrate.

  7. Influence of substituents on cation-anion contacts in imidazolium perrhenates.

    PubMed

    Reich, Robert M; Cokoja, Mirza; Markovits, Iulius I E; Münchmeyer, Christian J; Kaposi, Marlene; Pöthig, Alexander; Herrmann, Wolfgang A; Kühn, Fritz E

    2015-05-14

    A series of imidazolium perrhenates with different substituents at the imidazolium ring were synthesised and characterised, including single crystal X-ray diffraction. The effect of the substitution pattern on the state of aggregation of the compounds, the charge delocalisation and the ion pairing interaction via hydrogen bonds was studied. Particularly the substitution at the C2 position of the imidazolium ring was shown to be crucial to fine-tune the ion contacts. Fluorinated substituents appear to exhibit enhanced interionic interactions. The ability to tune the degree of contacts of the perrhenate anion allows for adjusting the nucleophilicity of this anion.

  8. Perrhenate extraction studies by Cyphos 101-IL; screening for implementation in technetium removal

    SciTech Connect

    Mark D Ogden; Sarah E. Pepper

    2013-10-01

    The solvent extraction of rhenium (VII) from chloride solutions by Cyphos 101-IL in toluene has been studied. Distribution values for the extraction of perrhenate are extremely high leading to almost quantitative extraction. From slope analysis, an anion exchange extraction mechanism is proposed, with formation of a ReO4 association with one Cyphos IL-101 cation. The extraction kinetics are fast, with complete equilibration occurring within 60 s. Under identical conditions, distribution coefficients for Cyphos 101-IL are greater than for Aliquat-336. Extraction of the perrhenate anion does not seem to be negatively impacted by common environmental contaminants including iron, sulphate and nitrate at the pH values tested.

  9. Bamboo (Acidosasa edulis) shoot shell biochar: Its potential isolation and mechanism to perrhenate as a chemical surrogate for pertechnetate.

    PubMed

    Hu, Hui; Jiang, Bangqiang; Wu, Huixiong; Zhang, Jubin; Chen, Xiaohui

    2016-12-01

    In this work, a biochar was prepared from bamboo (Acidosasa edulis) shoot shell through slow pyrolysis (under 300-700 °C). Characterization with various tools showed that the biochar surface was highly hydrophobic and also had more basic functional groups. Batch sorption experiments showed that the biochar had strong sorption ability to perrhenate (a chemical surrogate for pertechnetate) with maximum sorption capacity of 46.46 mg/g, which was significantly higher than commercial coconut shell activated carbon and some adsorbents reported previously. Desorption experiments showed that more than 94% of total perrhenate adsorbed could be recovered using 0.1 mol/L KOH as a desorption medium. Pearson correlation analysis showed that the recovery of perrhenate by the biochars was mainly through surface adsorption mechanisms involving both high hydrophobicity and high basic sites of biochar surface.

  10. Selective perrhenate recognition in pure water by halogen bonding and hydrogen bonding alpha-cyclodextrin based receptors.

    PubMed

    Cornes, Stuart P; Sambrook, Mark R; Beer, Paul D

    2017-03-20

    Alpha-cyclodextrin based anion receptors functionalised with pendant arms containing halogen and hydrogen bond donor motifs display selective association of perrhenate in aqueous media at neutral pH. NMR and ITC anion binding investigations reveal the halogen bonding receptor to be the superior host.

  11. Raman Analysis of Perrhenate and Pertechnetate in Alkali Salts and Borosilicate Glasses

    SciTech Connect

    Gassman, Paul L.; McCloy, John S.; Soderquist, Chuck Z.; Schweiger, Michael J.

    2014-01-03

    Sodium borosilicate glasses containing various concentrations of rhenium or technetium were fabricated, and their vibrational spectra studied using a Raman microscope. Spectra were interpreted with reference to new high resolution measurements of alkali pertechnetates and perrhenates NaReO4, KReO4, NaTcO4, and KTcO4. At low concentrations of ReO4- or TcO4-, glass spectra show weak peaks superimposed on a dominant spectrum of glass characteristic of silicate and borate network vibrations. At high concentrations, sharp peaks characteristic of crystal field splitting and C4h symmetry dominate the spectra of glasses, indicating alkali nearby tetrahedral Re or Tc. Often peaks indicative of both the K and Na pertechnetates/ perrhenates are evident in the Raman spectrum, with the latter being favored at high additions of the source chemical, since Na is more prevalent in the glass and ion exchange takes place. These results have significance to immobilization of nuclear waste containing radioactive 99Tc in glass for ultimate disposal.

  12. Rhenium volatilisation as caesium perrhenate from simulated vitrified high level waste from a melter crucible

    SciTech Connect

    Taylor, T.A.; Short, R.J.; Gribble, N.R.; Roe, J.I.; Steele, C.J.

    2013-07-01

    The Waste Vitrification Plant (WVP) converts Highly Active Liquor (HAL) from spent nuclear fuel reprocessing into a stable vitrified product. Recently WVP have been experiencing accumulation of solids in their primary off gas (POG) system leading to potential blockages. Chemical analysis of the blockage material via Laser Induced Breakdown Spectroscopy (LIBS) has shown it to exclusively consist of caesium, technetium and oxygen. The solids are understood to be caesium pertechnetate (CsTcO{sub 4}), resulting from the volatilisation of caesium and technetium from the high level waste glass melt. Using rhenium as a chemical surrogate for technetium, a series of full scale experiments have been performed in order to understand the mechanism of rhenium volatilisation as caesium perrhenate (CsReO{sub 4}), and therefore technetium volatilisation as CsTcO{sub 4}. These experiments explored the factors governing volatilisation rates from the melt, potential methods of minimising the amount of volatilisation, and various strategies for mitigating the deleterious effects of the volatile material on the POG. This paper presents the results from those experiments, and discusses potential methods to minimise blockages that can be implemented on WVP, so that the frequency of the CsTcO{sub 4} blockages can be reduced or even eradicated altogether. (authors)

  13. Perrhenate and Pertechnetate Behavior on Iron and Sulfur-Bearing Compounds.

    SciTech Connect

    B.E. Anderson; U. Becker; K.B. Helean; R.C. Ewing

    2006-09-15

    Investigations on the behavior of the radioactive element technetium frequently use a stable isotope of rhenium as an analogue. This is justified by citing the elements similar radii and major oxidation states of +7 and +4. However, at least one study [1] has shown this analogy to be imperfect. Therefore, one goal of our study is to compare the adsorption behavior of perrhenate and pertechnetate (the major forms of Re and Tc in natural waters) on a number of different mineral surfaces. Quantum mechanical calculations were performed on the adsorption of these two anions on a series of iron oxides and sulfides. With these calculations, we gain insight into any differences between the anions adsorption behavior, including geometry, adsorption energies, and electronic structure such as density of states and orbital shapes and energies at the adsorption site. Differences between interactions on terraces and step edges, the effects of co-adsorbates such as Na{sup +} or H{sup +}, and possible reduction mechanisms are also explored. The influence of water was calculated using homogeneous dielectric fluids and explicit water molecules. As a complement to the calculations, batch sorption tests are in progress involving ReO{sub 4}{sup -}/TcO{sub 4}{sup -} solution in contact with Fe metal, 10% Fe-doped hydroxyapatite, goethite, hematite, magnetite, pyrite, galena, and sphalerite.

  14. Zirconium-Based Metal–Organic Framework for Removal of Perrhenate from Water

    SciTech Connect

    Banerjee, Debasis; Xu, Wenqian; Nie, Zimin; Johnson, Lewis E. V.; Coghlan, Campbell; Sushko, Maria L.; Kim, Dongsang; Schweiger, Michael J.; Kruger, Albert A.; Doonan, Christian J.; Thallapally, Praveen K.

    2016-09-06

    Efficient removal of pertechnetate (TcO4-) anions from liquid waste or melter off-gas solution for alternative treatment is one of the promising options to manage 99Tc in legacy nuclear waste. Safe immobilization of 99Tc is of major importance due to its long half-life (t1/2= 2.13 × 105 yrs) and environmental mobility. Different types of inorganic and solid state ion-exchange materials such as layered double hydroxides have been shown to absorb TcO4- anions from water. However, both high capacity and selectivity have yet to be achieved in a single material. Herein, we show that a protonated version of an ultra-stable zirconium based metal-organic framework can adsorb perrhenate (ReO4-) anions, a non-radioactive sur-rogate for TcO4-, from water even in the presence of other common anions. Synchrotron based powder X-ray diffraction and molecular simulations were used to identify the position of the adsorbed ReO4- (surrogate for TcO4-) molecule within the framework.

  15. Synthesis and structure determination of copper perrhenate, CuReO 4

    NASA Astrophysics Data System (ADS)

    Mikhailova, D.; Ehrenberg, H.; Fuess, H.

    2006-07-01

    Copper(I) perrhenate, CuReO 4, has been synthesized as a single-phase sample in sealed silica tubes at 500-800 °C, and its structure was determined for the first time by single-crystal X-ray diffraction. CuReO 4 forms a new structure type derived from the diamond-structure and crystallizes in space group I4 1cd with lattice parameters a=13.6965(5) Å and c=7.7729(5) Å, Z=16 (rotation method data acquisition using ω and ϕ scans, R1=0.0191, w R2=0.0403). Cu and Re atoms are tetrahedrally coordinated by O atoms, these tetrahedra are corner-shared, forming spirally twisted rings of 4-6-8-10- MeO 4 like Si xO y-rings in some silicon dioxide modifications or aluminosilicates. According to low-temperature powder X-ray diffraction and differential thermal analysis, CuReO 4 shows no phase transition down to 80 K and up to its melting point, 703 K.

  16. Synthesis of α,β-Unsaturated Acylsilanes via Perrhenate-Catalyzed Meyer-Schuster Rearrangement of 1-Silylalkyn-3-ols.

    PubMed

    Nikolaev, Andrei; Orellana, Arturo

    2015-12-04

    We report the synthesis of α,β-unsaturated acylsilanes via the perrhenate-catalyzed Meyer-Schuster rearrangement of 1-silylalkyn-3-ols. Propargylic alcohols derived from TES-acetylene and substituted benzaldehydes can be converted to acylsilanes using a combination of p-TSA·H(2)O and n-Bu(4)N·ReO(4), or Ph(3)SiOReO(3) in good yields. Some propargylic alcohols derived from ketones, as well as aliphatic and unsaturated aldehydes, can also be converted to acylsilanes; however, they were often prone to side reactions.

  17. Perrhenate incorporation into binary mixed sodalites: The role of anion size and implications for technetium-99 sequestration

    DOE PAGES

    Dickson, Johnbull O.; Harsh, James B.; Lukens, Wayne W.; ...

    2014-12-20

    Perrhenate (ReO4-), as a TcO4- analogue, was incorporated into mixed-anion sodalites from binary solutions containing ReO4- and a competing anion Xn- (Cl-, CO32-, SO42-, MnO4-, or WO42-). For this study, our objective was to determine the extent of solid solution formation and the dependence of competing ion selectivity on ion size. Using equivalent aqueous concentrations of the anions (ReO4-/Xn- molar ratio = 1:1), we synthesized mixed-anion sodalites from zeolite and NaOH at 90 °C for 96 h. The resulting solids were characterized by bulk chemical analysis, powder X-ray diffraction, scanning electron microscopy, and X-ray absorption near edge structure (XANES) spectroscopymore » to determine crystal structure, chemical composition, morphology, and rhenium (Re) oxidation state. Rhenium in the solid phase occurred predominately as Re(VII)O4- in the sodalites, which have a primitive cubic pattern in the space group P43n. The refined unit-cell parameters of the mixed sodalites ranged from 8.88 to 9.15 Å and showed a linear dependence on the size and mole fraction of the incorporated anion(s). The ReO4- selectivity, represented by its distribution coefficient (Kd), increased in the following order: Cl- < NO3- < MnO4- and CO32- < SO42- < WO42- for the monovalent and divalent anions, respectively. The relationship between the ReO4- distribution coefficient and competing anion size was nonlinear. When the difference in ionic radius (DIR) between ReO4- and Xn - (n = 1 or 2) was greater than ~ 12%, then ReO4- incorporation into sodalite was insignificant. The results imply that anion size is the major factor that determines sodalite anion compositions. Given the similarity in chemical behavior and anion size, ReO4- serves as a suitable analogue for TcO4- under oxidizing conditions where both elements are expected to remain as oxyanions in the + 7 oxidation state.« less

  18. Perrhenate incorporation into binary mixed sodalites: The role of anion size and implications for technetium-99 sequestration

    SciTech Connect

    Dickson, Johnbull O.; Harsh, James B.; Lukens, Wayne W.; Pierce, Eric M.

    2014-12-20

    Perrhenate (ReO4-), as a TcO4- analogue, was incorporated into mixed-anion sodalites from binary solutions containing ReO4- and a competing anion Xn- (Cl-, CO32-, SO42-, MnO4-, or WO42-). For this study, our objective was to determine the extent of solid solution formation and the dependence of competing ion selectivity on ion size. Using equivalent aqueous concentrations of the anions (ReO4-/Xn- molar ratio = 1:1), we synthesized mixed-anion sodalites from zeolite and NaOH at 90 °C for 96 h. The resulting solids were characterized by bulk chemical analysis, powder X-ray diffraction, scanning electron microscopy, and X-ray absorption near edge structure (XANES) spectroscopy to determine crystal structure, chemical composition, morphology, and rhenium (Re) oxidation state. Rhenium in the solid phase occurred predominately as Re(VII)O4- in the sodalites, which have a primitive cubic pattern in the space group P43n. The refined unit-cell parameters of the mixed sodalites ranged from 8.88 to 9.15 Å and showed a linear dependence on the size and mole fraction of the incorporated anion(s). The ReO4- selectivity, represented by its distribution coefficient (Kd), increased in the following order: Cl- < NO3- < MnO4- and CO32- < SO42- < WO42- for the monovalent and divalent anions, respectively. The relationship between the ReO4- distribution coefficient and competing anion size was nonlinear. When the difference in ionic radius (DIR) between ReO4- and Xn - (n = 1 or 2) was greater than ~ 12%, then ReO4- incorporation

  19. Experimental Determination of the Speciation, Partitioning, and Release of Perrhenate as a Chemical Surrogate for Pertechnetate from a Sodalite-Bearing Multiphase Ceramic Waste Form

    SciTech Connect

    Pierce, Eric M; Lukens, Wayne W; Fitts, Jeffrey P; Tang, Guoping; Jantzen, C M

    2013-01-01

    A key component to closing the nuclear fuel cycle is the storage and disposition of nuclear waste in geologic systems. Multiphase ceramic waste forms have been studied extensively as a potential host matrix for nuclear waste. Understanding the speciation, partitioning, and release behavior of radionuclides immobilized in multiphase ceramic waste forms is a critical aspect of developing the scientific and technical basis for nuclear waste management. In this study, we evaluated a sodalite-bearing multiphase ceramic waste form (i.e., fluidized-bed steam reform sodium aluminosilicate [FBSR NAS] product) as a potential host matrix for long-lived radionuclides, such as technetium (99Tc). The FBSR NAS material consists primarily of nepheline (ideally NaAlSiO4), anion-bearing sodalites (ideally M8[Al6Si6O24]X2, where M refers to alkali and alkaline earth cations and X refers to monovalent anions), and nosean (ideally Na8[AlSiO4]6SO4). Bulk x-ray absorption fine structure analysis of the multiphase ceramic waste form, suggest rhenium (Re) is in the Re(VII) oxidation state and has partitioned to a Re-bearing sodalite phase (most likely a perrhenate sodalite Na8[Al6Si6O24](ReO4)2). Rhenium was added as a chemical surrogate for 99Tc during the FBSR NAS synthesis process. The weathering behavior of the FBSR NAS material was evaluated under hydraulically unsaturated conditions with deionized water at 90 C. The steady-state Al, Na, and Si concentrations suggests the weathering mechanisms are consistent with what has been observed for other aluminosilicate minerals and include a combination of ion exchange, network hydrolysis, and the formation of an enriched-silica surface layer or phase. The steady-state S and Re concentrations are within an order of magnitude of the nosean and perrhenate sodalite solubility, respectively. The order of magnitude difference between the observed and predicted concentration for Re and S may be associated with the fact that the anion

  20. Experimental determination of the speciation, partitioning, and release of perrhenate as a chemical surrogate for pertechnetate from a sodalite-bearing multiphase ceramic waste form

    SciTech Connect

    Pierce, Eric M.; Lukens, Wayne W.; Fitts, Jeff. P.; Jantzen, Carol. M.; Tang, G.

    2013-12-01

    A key component to closing the nuclear fuel cycle is the storage and disposition of nuclear waste in geologic systems. Multiphase ceramic waste forms have been studied extensively as a potential host matrix for nuclear waste. Understanding the speciation, partitioning, and release behavior of radionuclides immobilized in multiphase ceramic waste forms is a critical aspect of developing the scientific and technical basis for nuclear waste management. In this study, we evaluated a sodalite-bearing multiphase ceramic waste form (i.e., fluidized-bed steam reform sodium aluminosilicate [FBSR NAS] product) as a potential host matrix for long-lived radionuclides, such as technetium (99Tc). The FBSR NAS material consists primarily of nepheline (ideally NaAlSiO4), anion-bearing sodalites (ideally M8[Al6Si6O24]X2, where M refers to alkali and alkaline earth cations and X refers to monovalent anions), and nosean (ideally Na8[AlSiO4]6SO4). Bulk X-ray absorption fine structure analysis of the multiphase ceramic waste form, suggest rhenium (Re) is in the Re(VII) oxidation state and has partitioned to a Re-bearing sodalite phase (most likely a perrhenate sodalite Na8[Al6Si6O24](ReO4)2). Rhenium was added as a chemical surrogate for 99Tc during the FBSR NAS synthesis process. The weathering behavior of the FBSR NAS material was evaluated under hydraulically unsaturated conditions with deionized water at 90 ?C. The steady-state Al, Na, and Si concentrations suggests the weathering mechanisms are consistent with what has been observed for other aluminosilicate minerals and include a combination of ion exchange, network hydrolysis, and the formation of an enriched-silica surface layer or phase. The steady-state S and Re concentrations are within an order of magnitude of the nosean and perrhenate sodalite solubility, respectively. The order of magnitude difference between the observed and predicted concentration for Re and S may be associated with the fact that the anion

  1. Synthesis and Structure of Perrhenate Sodalite

    SciTech Connect

    Mattigod, Shas V.; McGrail, B. PETER; McCready, David E.; Wang, Li Q.; Parker, Kent E.; Young, James S.

    2006-04-15

    Na8(AlSiO4)6(ReO4)2 sodalite was synthesized using a hydrothermal method, and its crystal structure was determined from Rietveld refinement of experimental X-ray powder diffraction data. The refinement showed that this compound adopts the cubic sodalite structure (Space Group, No.218) with a = 9.1528 (1) ?. Raman spectroscopic measurements confirm the presence of tetrahedral ReO4- groups. Broadening of the asymmetric stretching and bending vibrational modes suggests the tetrahedra are slightly distorted from ideal Td symmetry in the sodalite lattice. MAS NMR of 29Si and 27Al nuclei showed single intense peaks at ?iso = -92.4 ppm and ?iso = 57.5 ppm, respectively, confirming the alternating Si, Al tetrahedral ordering in sodalite deduced from the structural data. Chemical shifts for 29Si and 27Al calculated using correlative structural parameters (56.6 ? 0.8 ppm and -92.3 ? 0.9 ppm) showed good agreement with measured data indicating the validity of data derived from the Rietveld structural refinement.

  2. Concentration of perrhenate and pertechnetate solutions

    SciTech Connect

    Knapp, Furn F.; Beets, Arnold L.; Mirzadeh, Saed; Guhlke, Stefan

    1998-01-01

    A method of preparing a concentrated solution of a carrier-free radioisotope which includes the steps of: a. providing a generator column loaded with a composition containing a parent radioisotope; b. eluting the generator column with an eluent solution which includes a salt of a weak acid to elute a target daughter radioisotope from the generator column in a first eluate. c. eluting a cation-exchange column with the first eluate to exchange cations of the salt for hydrogen ions and to elute the target daughter radioisotope and a weak acid in a second eluate; d. eluting an anion-exchange column with the second eluate to trap and concentrate the target daughter radioisotope and to elute the weak acid solution therefrom; and e. eluting the concentrated target daughter radioisotope from the anion-exchange column with a saline solution.

  3. Concentration of perrhenate and pertechnetate solutions

    DOEpatents

    Knapp, F.F.; Beets, A.L.; Mirzadeh, S.; Guhlke, S.

    1998-03-17

    A method is described for preparing a concentrated solution of a carrier-free radioisotope which includes the steps of: (a) providing a generator column loaded with a composition containing a parent radioisotope; (b) eluting the generator column with an eluent solution which includes a salt of a weak acid to elute a target daughter radioisotope from the generator column in a first eluate; (c) eluting a cation-exchange column with the first eluate to exchange cations of the salt for hydrogen ions and to elute the target daughter radioisotope and a weak acid in a second eluate; (d) eluting an anion-exchange column with the second eluate to trap and concentrate the target daughter radioisotope and to elute the weak acid solution therefrom; and (e) eluting the concentrated target daughter radioisotope from the anion-exchange column with a saline solution. 1 fig.

  4. Tungsten-188/carrier-free rhenium-188 perrhenic acid generator system

    DOEpatents

    Knapp, F.F. Jr.; Lisic, E.C.; Mirzadeh, S.; Callahan, A.P.

    1994-01-04

    A generator system has been invented for providing a carrier-free radioisotope in the form of an acid comprises a chromatography column in tandem fluid connection with an ion exchange column, the chromatography column containing a charge of a radioactive parent isotope. The chromatography column, charged with a parent isotope, is eluted with an alkali metal salt solution to generate the radioisotope in the form of an intermediate solution, which is passed through the ion-exchange column to convert the radioisotope to a carrier-free acid form. 1 figure.

  5. Tungsten-188/carrier-free rhenium-188 perrhenic acid generator system

    DOEpatents

    Knapp, Jr., Furn F.; Lisic, Edward C.; Mirzadeh, Saed; Callahan, Alvin P.

    1993-01-01

    A generator system for providing a carrier-free radioisotope in the form of an acid comprises a chromatography column in tandem fluid connection with an ion exchange column, the chromatography column containing a charge of a radioactive parent isotope. The chromatography column, charged with a parent isotope, is eluted with an alkali metal salt solution to generate the radioisotope in the form of an intermediate solution, which is passed through the ion-exchange column to convert the radioisotope to a carrier-free acid form.

  6. Tungsten-188/carrier-free rhenium-188 perrhenic acid generator system

    DOEpatents

    Knapp, F.F. Jr.; Lisic, E.C.; Mirzadeh, S.; Callahan, A.P.

    1993-02-16

    A generator system for providing a carrier-free radioisotope in the form of an acid comprises a chromatography column in tandem fluid connection with an ion exchange column, the chromatography column containing a charge of a radioactive parent isotope. The chromatography column, charged with a parent isotope, is eluted with an alkali metal salt solution to generate the radioisotope in the form of an intermediate solution, which is passed through the ion-exchange column to convert the radioisotope to a carrier-free acid form.

  7. Tungsten-188/carrier-free rhenium-188 perrhenic acid generator system

    DOEpatents

    Knapp, Jr., Furn F.; Lisic, Edward C.; Mirzadeh, Saed; Callahan, Alvin P.

    1994-01-01

    A generator system for providing a carrier-free radioisotope in the form of an acid comprises a chromatography column in tandem fluid connection with an ion exchange column, the chromatography column containing a charge of a radioactive parent isotope. The chromatography column, charged with a parent isotope, is eluted with an alkali metal salt solution to generate the radioisotope in the form of an intermediate solution, which is passed through the ion-exchange column to convert the radioisotope to a carrier-free acid form.

  8. Copper(II) perrhenate Cu(C3H7OH)2(ReO4)2: Synthesis from isopropanol and CuReO4, structure and properties

    NASA Astrophysics Data System (ADS)

    Mikhailova, D.; Engel, J. M.; Schmidt, M.; Tsirlin, A. A.; Ehrenberg, H.

    2015-12-01

    The crystal structure of Cu+Re7+O4 is capable of a quasi-reversible incorporation of C3H7OH molecules. A room-temperature reaction between CuReO4 and C3H7OH under oxidizing conditions leads to the formation of a novel metal-organic hybrid compound Cu2+(C3H7OH)2(ReO4)2. Upon heating under reducing conditions, this compound transforms back into CuReO4, albeit with ReO2 and metallic Cu as by-products. The crystal structure of Cu(C3H7OH)2(ReO4)2 solved from single-crystal X-ray diffraction (Pbca, a=10.005(3) Å, b=7.833(2) Å, and c=19.180(5) Å) reveals layers of corner-sharing CuO6-octahedra and ReO4-tetrahedra, whereas isopropyl groups are attached to both sides of these layers, thus providing additional connections within the layers through hydrogen bonds. Cu(C3H7OH)2(ReO4)2 is paramagnetic down to 4 K because the spatial arrangement of the Cu2+ half-filled orbitals prevents magnetic superexchange. The paramagnetic effective moment of 2.0(1) μB is slightly above the spin-only value and typical for Cu2+ ions.

  9. Copper(II) perrhenate Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}: Synthesis from isopropanol and CuReO{sub 4}, structure and properties

    SciTech Connect

    Mikhailova, D.; Engel, J.M.; Schmidt, M.; Tsirlin, A.A.; Ehrenberg, H.

    2015-12-15

    The crystal structure of Cu{sup +}Re{sup 7+}O{sub 4} is capable of a quasi-reversible incorporation of C{sub 3}H{sub 7}OH molecules. A room-temperature reaction between CuReO{sub 4} and C{sub 3}H{sub 7}OH under oxidizing conditions leads to the formation of a novel metal-organic hybrid compound Cu{sup 2+}(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}. Upon heating under reducing conditions, this compound transforms back into CuReO{sub 4}, albeit with ReO{sub 2} and metallic Cu as by-products. The crystal structure of Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} solved from single-crystal X-ray diffraction (Pbca, a=10.005(3) Å, b=7.833(2) Å, and c=19.180(5) Å) reveals layers of corner-sharing CuO{sub 6}-octahedra and ReO{sub 4}-tetrahedra, whereas isopropyl groups are attached to both sides of these layers, thus providing additional connections within the layers through hydrogen bonds. Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} is paramagnetic down to 4 K because the spatial arrangement of the Cu{sup 2+} half-filled orbitals prevents magnetic superexchange. The paramagnetic effective moment of 2.0(1) μ{sub B} is slightly above the spin-only value and typical for Cu{sup 2+} ions. - Highlights: • Novel Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} compound has a sequence of inorganic and organic layers. • Hydrogen bonds provide an additional bonding Isopropanol molecules serve as a reducing agent during decomposition. • No direct Cu-O-Re-O-Cu connections via d{sub x2-y2} orbital of Cu{sup 2+} explain paramagnetism. • Hydrogen bonds provide an additional bonding. • Isopropanol molecules serve as a reducing agent during decomposition.

  10. Experimental Ion Exchange Column With SuperLig 639 And Simulant Formulation

    SciTech Connect

    Morse, Megan; Nash, C.

    2013-08-26

    SuperLig®639 ion exchange resin was tested as a retrieval mechanism for pertechnetate, through decontamination of a perrhenate spiked 5M Simple Average Na{sup +} Mass Based Simulant. Testing included batch contacts and a three-column ion exchange campaign. A decontamination of perrhenate exceeding 99% from the liquid feed was demonstrated. Analysis of the first formulation of a SBS/WESP simulant found unexpectedly low concentrations of soluble aluminum. Follow-on work will complete the formulation.

  11. Binding of ReO[subscript 4];#8722; with an engineered MoO[subscript 4 superscript 2];#8722;-binding protein: towards a new approach in radiopharmaceutical applications

    SciTech Connect

    Aryal, Baikuntha P.; Brugarolas, Pedro; He, Chuan

    2012-05-25

    Radiolabeled biomolecules are routinely used for clinical diagnostics. {sup 99m}Tc is the most commonly used radioactive tracer in radiopharmaceuticals. {sup 188}Re and {sup 186}Re are also commonly used as radioactive tracers in medicine. However, currently available methods for radiolabeling are lengthy and involve several steps in bioconjugation processes. In this work we present a strategy to engineer proteins that may selectively recognize the perrhenate (ReO{sub 4}{sup -}) ion as a new way to label proteins. We found that a molybdate (MoO{sub 4}{sup 2-})-binding protein (ModA) from Escherichia coli can bind perrhenate with high affinity. Using fluorescence and isothermal titration calorimetry measurements, we determined the dissociation constant of ModA for ReO{sub 4}{sup -} to be 541 nM and we solved a crystal structure of ModA with a bound ReO{sub 4}{sup -}. On the basis of the structure we created a mutant protein containing a disulfide linkage, which exhibited increased affinity for perrhenate (K{sub d} = 104 nM). High-resolution crystal structures of ModA (1.7 {angstrom}) and A11C/R153C mutant (2.0 {angstrom}) were solved with bound perrhenate. Both structures show that a perrhenate ion occupies the molybdate binding site using the same amino acid residues that are involved in molybdate binding. The overall structure of the perrhenate-bound ModA is unchanged compared with that of the molybdate-bound form. In the mutant protein, the bound perrhenate is further stabilized by the engineered disulfide bond.

  12. Binding of ReO4(-) with an engineered MoO4(2-)-binding protein: towards a new approach in radiopharmaceutical applications.

    PubMed

    Aryal, Baikuntha P; Brugarolas, Pedro; He, Chuan

    2012-01-01

    Radiolabeled biomolecules are routinely used for clinical diagnostics. (99m)Tc is the most commonly used radioactive tracer in radiopharmaceuticals. (188)Re and (186)Re are also commonly used as radioactive tracers in medicine. However, currently available methods for radiolabeling are lengthy and involve several steps in bioconjugation processes. In this work we present a strategy to engineer proteins that may selectively recognize the perrhenate (ReO(4)(-)) ion as a new way to label proteins. We found that a molybdate (MoO(4)(2-))-binding protein (ModA) from Escherichia coli can bind perrhenate with high affinity. Using fluorescence and isothermal titration calorimetry measurements, we determined the dissociation constant of ModA for ReO(4)(-) to be 541 nM and we solved a crystal structure of ModA with a bound ReO(4)(-). On the basis of the structure we created a mutant protein containing a disulfide linkage, which exhibited increased affinity for perrhenate (K(d) = 104 nM). High-resolution crystal structures of ModA (1.7 Å) and A11C/R153C mutant (2.0 Å) were solved with bound perrhenate. Both structures show that a perrhenate ion occupies the molybdate binding site using the same amino acid residues that are involved in molybdate binding. The overall structure of the perrhenate-bound ModA is unchanged compared with that of the molybdate-bound form. In the mutant protein, the bound perrhenate is further stabilized by the engineered disulfide bond.

  13. Removal of Pertechnetate-Related Oxyanions from Solution Using Functionalized Hierarchical Porous Frameworks

    SciTech Connect

    Banerjee, Debasis; Elsaidi, Sameh K.; Aguila, Briana; Li, Baiyan; Kim, Dongsang; Schweiger, Michael J.; Kruger, Albert A.; Doonan, Christian J.; Ma, Shengqian; Thallapally, Praveen K.

    2016-10-20

    Efficient and cost-effective removal of radioactive pertechnetate anions from nuclear waste is a key challenge to mitigate long-term nuclear waste storage issues. Traditional materials such as resins and layered double hydroxides (LDHs) were evaluated for their pertechnetate or perrhenate (the non-radioactive surrogate) removal capacity, but there is room for improvement in terms of capacity, selectivity and kinetics. A series of functionalized hierarchical porous frameworks were evaluated for their perrhenate removal capacity in the presence of other competing anions.

  14. Elution of Re-188 from W-188/Re-188 generators with salts of weak acids permits efficient concentration to low volumes using a new tandem cation/anion exchange system

    SciTech Connect

    Guhlke, S. |; Beets, A.L.; Knapp, F.F. Jr.

    1997-05-01

    Re-188, available from a W-188/Re-188 generator, is an important therapeutic radioisotope for bone pain palliation, cancer therapy and intravascular brachytherapy, etc. Because of the relatively low specific activity of reactor-produced W-188 (ORNL HFIR, 296-370 MBq mCi/mg W-186 for 2 cycles), methods of concentrating the Re-188 bolus (10-12 mL) from clinical scale (18.5-37 BGq W-188) generators (5-6 gm alumina) are thus very important. We demonstrate for the first time a new strategy of generator elution with salts of weak acids and specific perrhenate anion {open_quotes}trapping{close_quotes} with QMA anion columns. Re-188 perrhenate is efficiently eluted (65-75%) from the alumina-based generator with 0.15-0.3 M ammonium acetate. An acetic acid solution of Re-188 perrhenic acid is obtained by subsequent on-line passage of the generator eluant through a DOWEX AG 50Wx8 (200-400 mesh, H{sup +} form) column. Since acetic acid is not ionized (< 0.001%) at this pH (< pK{sub a} = 4.76) the perrhenate anion is then specifically trapped on a QMA {open_quotes}Light{close_quotes} anion extraction column. QMA elution with 0.9% NaCl, provides Re-188 perrhenate solution in <1 mL. Concentration of 10-20 mL of Re-188 solution (> 15 BGq) in <1 mL has been demonstrated using this simple new approach, which is also effective for concentration of Tc-99m from low specific activity Mo-99 (n,y) generators. The cation/anion tandem system is inexpensive and disposable and use can be easily automated. The availability of this very simple, efficient system is important for broad use of rhenium-188.

  15. Ion Exchange Column Tests Supporting Technetium Removal Resin Maturation

    SciTech Connect

    Nash, C.; McCabe, D.; Hamm, L.; Smith, F.; Morse, M.

    2013-12-20

    The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant, currently under construction. The baseline plan for this facility is to treat the waste, splitting it into High Level Waste (HLW) and Low Activity Waste (LAW). Both waste streams are then separately vitrified as glass and sealed in canisters. The LAW glass will be disposed on site. There are currently no plans to treat the waste to remove technetium, so its disposition path is the LAW glass. Due to the soluble properties of pertechnetate and long half-life of 99Tc, effective management of 99Tc is important. Options are being explored to immobilize the supplemental LAW portion of the tank waste, as well as to examine the volatility of 99Tc during the vitrification process. Removal of 99Tc, followed by off-site disposal has potential to reduce treatment and disposal costs. A conceptual flow sheets for supplemental LAW treatment and disposal that could benefit from technetium removal will specifically examine removing 99Tc from the LAW feed stream to supplemental immobilization. SuperLig® 639 is an elutable ion exchange resin. In the tank waste, 99Tc is predominantly found in the tank supernate as pertechnetate (TcO4-). Perrhenate (ReO4-) has been shown to be a good non-radioactive surrogate for pertechnetate in laboratory testing for this ion exchange resin. This report contains results of experimental ion exchange distribution coefficient and column resin maturation kinetics testing using the resin SuperLig® 639a to selectively remove perrhenate from simulated LAW. This revision includes results from testing to determine effective resin operating temperature range. Loading tests were performed at 45°C, and the computer modeling was updated to include the temperature effects. Equilibrium contact testing indicated that this batch of

  16. New Gel-Like Polymers as Selective Weak-Base Anion Exchangers

    PubMed Central

    Gierczyk, Błażej; Cegłowski, Michał; Zalas, Maciej

    2015-01-01

    A group of new anion exchangers, based on polyamine podands and of excellent ion-binding capacity, were synthesized. The materials were obtained in reactions between various poly(ethyleneamines) with glycidyl derivatives of cyclotetrasiloxane. The final polymeric, strongly cross-linked materials form gel-like solids. Their structures and interactions with anions adsorbed were studied by spectroscopic methods (CP-MAS NMR, FR-IR, UV-Vis). The sorption isotherms and kinetic parameters were determined for 29 anions. Materials studied show high ion capacity and selectivity towards some important anions, e.g., selenate(VI) or perrhenate. PMID:25946220

  17. Bolometric Bounds on the Antineutrino Mass

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Brofferio, C.; Cremonesi, O.; Fiorini, E.; Lo Bianco, C.; Martensson, L.; Nucciotti, A.; Pavan, M.; Pessina, G.; Pirro, S.; Previtali, E.; Sisti, M.; Giuliani, A.; Margesin, B.; Zen, M.

    2003-10-01

    High statistics calorimetric measurements of the β spectrum of 187Re are being performed with arrays of silver perrhenate crystals operated at low temperature. After a substantial modification of the experimental setup, a new measurement with ten silver perrhenate microbolometers has been running since July 2002. The crystals have masses around 300 μg and their average FWHM energy resolution is of 28.3eV at the β end point. The Kurie plot collected during 4485 h×mg effective running time has an end-point energy of 2466.1±0.8stat±1.5syst eV, while the half lifetime of the decay is found to be 43.2±0.2stat±0.1syst Gy. These values are the most precise obtained so far for 187Re. The best fit value for m2ν¯e is 147±237stat±90syst eV2, which corresponds to an upper limit for the electron antineutrino mass mν¯e≤21.7 eV at 90%C.L.

  18. Purification of alkaline solutions and wastes from actinides and technetium by coprecipitation with some carriers using the method of appearing reagents: Final Report

    SciTech Connect

    Peretrukhin, V.F.; Silin, V.I.; Kareta, A.V.; Gelis, A.V.; Shilov, V.P.; German, K.E.; Firsova, E.V.; Maslennikov, A.G.; Trushina, V.E.

    1998-09-01

    The coprecipitation of transuranium elements (TRU) and technetium from alkaline solutions and from simulants of Hanford Site tank wastes has been studied in reducing and oxidizing conditions on uranium(IV,VI) hydroxocompounds, tetraalkylammonium perrhenate and perchlorate, and on hydroxides of Fe(III), Co(III), Mn(II), and Cr(III) using the method of appearing reagents (MAR). Coprecipitations in alkaline solution have been shown to give high decontamination factors (DF) at low content of carrier and in the presence of high salt concentrations. Uranium(IV) hydroxide in concentrations higher than 3 {times} 10{sup {minus}3} M coprecipitates Pu and Cm in any oxidation state from 0.2 to 4 M NaOH with DFs of 110 to 1000 and Np and Tc with DFs of 51 to 176. Technetium (VII) coprecipitates with (5 to 8) {times} 10{sup {minus}4} M tetrabutylammonium (TBA) perrhenate in 0.01 to 0.02 M TBA hydroxide from 0.5 to 1.5 M NaOH to give DFs of 150 to 200. Coprecipitations of Np and Pu with Co(OH){sub 3}, Fe(OH){sub 3}, Cr(OH){sub 3}, and Mn(OH){sub 2} obtained by the MAR from precursors in the range from pH 10.5 to 0.4 M NaOH give DFs from 80 to 400.

  19. Vibrational spectroscopy of the double complex salt Pd(NH3)4(ReO4)2, a bimetallic catalyst precursor

    NASA Astrophysics Data System (ADS)

    Thompson, Simon T.; Lamb, H. Henry; Delley, Bernard; Franzen, Stefan

    2017-02-01

    Tetraamminepalladium(II) perrhenate, a double complex salt, has significant utility in PdRe catalyst preparation; however, the vibrational spectra of this readily prepared compound have not been described in the literature. Herein, we present the infrared (IR) and Raman spectra of tetraamminepalladium(II) perrhenate and several related compounds. The experimental spectra are complemented by an analysis of normal vibrational modes that compares the experimentally obtained spectra with spectra calculated using DFT (DMol3). The spectra are dominated by features due to the ammine groups and the Resbnd O stretch in Td ReO4-; lattice vibrations due to the D4h Pd(NH3)42+ are also observed in the Raman spectrum. Generally, we observe good agreement between ab initio calculations and experimental spectra. The calculated IR spectrum closely matches experimental results for peak positions and their relative intensities. The methods for calculating resonance Raman intensities are implemented using the time correlator formalism using two methods to obtain the excited state displacements and electron-vibration coupling constants, which are the needed inputs in addition to the normal mode wave numbers. Calculated excited state energy surfaces of Raman-active modes correctly predict relative intensities of the peaks and Franck-Condon activity; however, the position of Raman bands are predicted at lower frequencies than observed. Factor group splitting of Raman peaks observed in spectra of pure compounds is not predicted by DFT.

  20. Vibrational spectroscopy of the double complex salt Pd(NH3)4(ReO4)2, a bimetallic catalyst precursor.

    PubMed

    Thompson, Simon T; Lamb, H Henry; Delley, Bernard; Franzen, Stefan

    2017-02-15

    Tetraamminepalladium(II) perrhenate, a double complex salt, has significant utility in PdRe catalyst preparation; however, the vibrational spectra of this readily prepared compound have not been described in the literature. Herein, we present the infrared (IR) and Raman spectra of tetraamminepalladium(II) perrhenate and several related compounds. The experimental spectra are complemented by an analysis of normal vibrational modes that compares the experimentally obtained spectra with spectra calculated using DFT (DMol(3)). The spectra are dominated by features due to the ammine groups and the ReO stretch in Td ReO4(-); lattice vibrations due to the D4h Pd(NH3)4(2+) are also observed in the Raman spectrum. Generally, we observe good agreement between ab initio calculations and experimental spectra. The calculated IR spectrum closely matches experimental results for peak positions and their relative intensities. The methods for calculating resonance Raman intensities are implemented using the time correlator formalism using two methods to obtain the excited state displacements and electron-vibration coupling constants, which are the needed inputs in addition to the normal mode wave numbers. Calculated excited state energy surfaces of Raman-active modes correctly predict relative intensities of the peaks and Franck-Condon activity; however, the position of Raman bands are predicted at lower frequencies than observed. Factor group splitting of Raman peaks observed in spectra of pure compounds is not predicted by DFT.

  1. Intraarterial irradiation with rhenium-188 for inhibition of restenosis after PTCA - strategy and evaluation of Re-188-species for rapid urinary excretion

    SciTech Connect

    Knapp, F.F. Jr.; Guhlke, S.; Beets, A.L.

    1997-05-01

    Estimated costs for coronary restenosis therapy after PTCA are > $ 1 billion (U.S.). Radiation is a simple and effective tool for inhibition of neointimal proliferation an important component of restenosis. We propose use of Re-188 (t{sub {1/2}} 16.9 h, 2.1 MeV {beta}), obtained from decay of W-188 (T{sub {1/2}} 69 d). Our alumina-based W-188/Re-188 generator has a shelf-life of several months and we have developed an on-line tandem cation/anion exchange column system to concentrate to > 18.5 BGq/mL. Estimates for targeted regional dose of 8.4 rad/37 MBq/min/mL, which is > 1,400 cGy for about 370 MBq Re-188 for 5 min. Balloon inflation with Re-188 solutions is a new approach for more uniform vascular dose distribution as an alternative to use of radioactive wires or other linear sources. Rapid urinary excretion kinetics are important in the unlikely event of balloon rupture (<0.1%). We have therefore evaluated relative excretion kinetics of Re-188-perrhenate and -MAG3 in rats; Re-188-perrhenate was obtained from generator elution with 0.9% NaCl and re-188-MAG3 was prepared be reaction of the ligand with Sn(II)-reduced perrhenate. Fischer rats (n=4-5/group) were injected i.v. and urine and feces collected every 2 h for 12 h and then daily for 5 d. Both agents excreted > 90% in urine; biodistribution studies showed low organ uptake with intestines as the major site. Rhenium-188-MAG3 excreted more rapidly (2 h = 59.6{+-}18.5%) then Re-188-MAG3 excreted more rapidly (2 h = 68.3{+-}13.5%) in same model. Both Re-188 species are thus good candidates for balloon inflation. Studies are in progress in a swine model to evaluate the effectiveness of Re-188 for inhibition of restenosis.

  2. Pyrazole complexes as anion receptors: effects of changing the metal, the pyrazole substitution pattern, and the number of pyrazole ligands.

    PubMed

    Nieto, Sonia; Pérez, Julio; Riera, Lucía; Riera, Víctor; Miguel, Daniel; Golen, James A; Rheingold, Arnold L

    2007-04-16

    Compound cis,fac-[Mo(eta3-allyl)(CO)2(Hdmpz)3]BAr'4 (1) (Hdmpz = 3,5-dimethylpyrazole, Ar' = 3,5-bis(trifluoromethyl)phenyl) undergoes rapid substitution of one of the pyrazole ligands by anions, including the low nucleophilic ReO4-, a reaction that afforded [Mo(OReO3)(eta3-allyl)(CO)2(Hdmpz)2] (2), structurally characterized by X-ray diffraction. The new compounds fac-[Mn(CO)3(Hdmpz)3]BAr'4 (4a) and fac-[Mn(CO)3(HtBupz)3]BAr'4 (4b) (HtBupz = 3(5)-tert-butylpyrazole) also undergo pyrazole substitution with most anions, and the product from the reaction with nitrate was crystallographically characterized. Compounds 4a,b were found to be substitutionally stable toward perrhenate, and the adducts [Mn(CO)3(Hdmpz)3].[ReO4] (7a) and [Mn(CO)3(HtBupz)3].[ReO4].[Bu4N].[BAr'4] (7b), crystallographically characterized, display hydrogen bonds between one of the perrhenate oxygens and the N-H groups of two of the pyrazole ligands. The structurally similar adduct [Re(CO)3(Hdmpz)3].[ReO4] (8) was found to result from the interaction of [Re(CO)3(Hdmpz)3]BAr'4 with perrhenate. The reaction of [Re(OTf)(CO)5] with 3,5-dimethylpyrazole (Hdmpz) afforded [Re(CO)5(Hdmpz)]OTf (9). The reaction of 9 with Hdmpz and NaBAr'4 yielded [Re(CO)4(Hdmpz)2]BAr'4 (10), which was found to be unstable toward chloride anion. In contrast, the new compound fac,cis-[Re(CO)3(CNtBu)(Hdmpz)2]BAr'4 (11) is stable in solution in the presence of different anions. Binding constants for 11 with chloride, bromide, and nitrate are 1-2 orders of magnitude lower than those found for these anions and rhenium tris(pyrazole) hosts, indicating that the presence of the third pyrazole ligand is crucial. Compounds fac-[Re(CO)3(HPhpz)3]BAr'4 (14) (HPhpz = 3(5)-phenylpyrazole) and fac-[Re(CO)3(HIndz)3]BAr'4 (15) (HIndz = indazole) are, in terms of anion binding strength and selectivity, inferior to those with dimethylpyrazole or tert-butylpyrazole ligands.

  3. Sodalite as a vehicle to increase Re retention in waste glass simulant during vitrification

    SciTech Connect

    Luksic, Steven A.; Riley, Brian J.; Parker, Kent E.; Hrma, Pavel

    2016-10-01

    Technetium retention during Hanford waste vitrification can be increased by inhibiting technetium volatility from the waste glass melter. Incorporating technetium into a mineral phase, such as sodalite, is one way to achieve this. Rhenium-bearing sodalite was tested as a vehicle to transport perrhenate (ReO4-), a nonradioactive surrogate for pertechnetate (TcO4-), into high-level (HLW) and low-activity waste (LAW) glasses. After melting feeds of these two glasses, the retention of rhenium was measured and compared with the rhenium retention in glass prepared from a feed containing Re2O7 as a standard. The rhenium retention was 21% higher for HLW glass and 85% higher for LAW glass when added to samples in the form of sodalite as opposed to when it was added as Re2O7, demonstrating the efficacy of this type of an approach.

  4. Crystallization and rhenium MAD phasing of the acyl-homoserinelactone synthase EsaI

    SciTech Connect

    Watson, W.T.; Murphy IV, Frank V.; Gould, Ty A.; Jambeck, Per; Val, Dale L.; Cronan, Jr., John E.; Beck von Bodman, Susan; Churchill, Mair E.A.

    2009-04-22

    Acyl-homoserine-L-lactones (AHLs) are diffusible chemical signals that are required for virulence of many Gram-negative bacteria. AHLs are produced by AHL synthases from two substrates, S-adenosyl-L-methionine and acyl-acyl carrier protein. The AHL synthase EsaI, which is homologous to the AHL synthases from other pathogenic bacterial species, has been crystallized in the primitive tetragonal space group P4{sub 3}, with unit-cell parameters a = b = 66.40, c = 47.33 {angstrom}. The structure was solved by multiple-wavelength anomalous diffraction with a novel use of the rhenium anomalous signal. The rhenium-containing structure has been refined to a resolution of 2.5 {angstrom} and the perrhenate ion binding sites and liganding residues have been identified.

  5. Methods for the separation of rhenium, osmium and molybdenum applicable to isotope geochemistry

    USGS Publications Warehouse

    Morgan, J.W.; Golightly, D.W.; Dorrzapf, A.F.

    1991-01-01

    Effective methods are described for the chemical separation of rhenium, osmium and molybdenum. The methods are based on distillation and anion-exchange chromatography, and have been the basis for rhenium-osmium isotope studies of ore deposits and meteorites. Successful anion-exchange separation of osmium requires both recognition and careful control of the osmium species in solution; thus, distillation of osmium tetroxide from a mixture of sulfuric acid and hydrogen peroxide is preferred to anion-exchange. Distribution coefficients measured for perrhenate in sulfuric acid media are sufficiently high (Kd > 500) for rhenium to be directly loaded onto an ion-exchange column from a distillation residue and subsequently eluted with nitric acid. Polymerization of molybdenum species during elution is prevented by use of a solution that is 1M in hydrochloric acid and 1M in sodium chloride. ?? 1991.

  6. Aqueous biphasic systems for metal separations : a microcalorimetric analysis of polymer/salt interactions.

    SciTech Connect

    Chaiko, D. J.; Hatton, T. A.; Zaslavsky, B.

    1999-05-03

    Certain radionuclide ions (e.g., TcO{sub 4}{sup 16}) exhibit unusually strong Affinities toward the polymer-rich phase in aqueous biphase systems generated by combinations of salt solutions with polymers such as poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG). Thus, aqueous polymer phases could potentially be used to selectively extract these ions during pretreatment of radioactive tank wastes at Hanford. To help develop a fundamental understanding of the interactions between various ions and polymers in aqueous solution, interaction enthalpies between sodium perrhenate and a random copolymer of PEG and PPG (UCON-50) were measured by microcalorimetric titration. An entropy compensation effect was observed in this system in which changes in enthalpic interactions were balanced by entropy changes such that the interaction free energy remained constant and approximately equal to zero.

  7. Development of in situ forming thermosensitive hydrogel for radiotherapy combined with chemotherapy in a mouse model of hepatocellular carcinoma.

    PubMed

    Peng, Cheng-Liang; Shih, Ying-Hsia; Liang, Kuo-Sheng; Chiang, Ping-Fang; Yeh, Chung-Hsin; Tang, I-Chang; Yao, Cheng-Jung; Lee, Shin-Yi; Luo, Tsai-Yueh; Shieh, Ming-Jium

    2013-05-06

    This study evaluated a system for local cancer radiotherapy combined with chemotherapy. The delivery system is a thermosensitive hydrogel containing a therapeutic radionuclide ((188)Re-Tin colloid) and a chemotherapeutic drug (liposomal doxorubicin). The thermosensitive PCL-PEG-PCL copolymer was designed to spontaneously undergo a sol-gel phase transition in response to temperature, remaining liquid at room temperature and rapidly forming a gel at body temperature. A scanning electron microscope was used to observe the microstructure of the fully loaded hydrogel. Release of radionuclide and doxorubicin from the hydrogel was slow, and the system tended to remain stable for at least 10 days. After the intratumoral administration of Lipo-Dox/(188)Re-Tin hydrogel in mice with hepatocellular carcinoma (HCC), its retention by the tumor, spatiotemporal distribution, and therapeutic effect were evaluated. The residence time in the tumor was significantly longer for (188)Re-Tin loaded hydrogel than for Na (188)Re perrhenate (Na (188)ReO4). The hydrogel after thermal transition kept the radionuclide inside the tumor, whereas free (188)Re perrhenate ((188)ReO4) diffused quickly from the tumor. The tumor growth was more profoundly inhibited by treatment with Lipo-Dox/(188)Re-Tin hydrogel (with up to 80% regression of well-established tumors on day 32) than treatment with either (188)Re-Tin hydrogel or Lipo-Dox hydrogel. Therefore, this injectable and biodegradable hydrogel may offer the advantage of focusing radiotherapy and chemotherapy locally to maximize their effects on hepatocellular carcinoma.

  8. Use of the Oak Ridge National Laboratory tungsten-188/rhenium-188 generator for preparation of the rhenium-188 HDD/lipiodol complex for trans-arterial liver cancer therapy

    SciTech Connect

    Jeong, J M; Knapp Jr, Russ F

    2008-01-01

    This work describes the installation, use, and quality control (QC) of the alumina-based tungsten-188 ({sup 188}W)/rhenium-188 ({sup 188}Re) generators provided by the Oak Ridge National Laboratory (ORNL). In addition, methods used for concentration of the {sup 188}Re-perrhenate bolus and preparation of {sup 188}Re-labeled HDD (4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol) for trans-arterial administration for therapy of nonresectable liver cancer also are described. The {sup 188}W/{sup 188}Re generator has a long useful shelf-life of several months and is a convenient on-site {sup 188}Re production system. {sup 188}Re has excellent therapeutic and imaging properties (T{sub 1/2} 16.9 hours; E{sub {beta}max} 2.12 MeV; 155-keV gamma ray, 15%) and is cost effectively obtained on demand by saline elution of the generator. The clinical efficacy of a variety of {sup 188}Re-labeled agents has been demonstrated for several therapeutic applications. Because of the favorable physical properties of {sup 188}Re, several {sup 188}Re-labeled agents are being developed and evaluated for the treatment of nonresectable/refractory liver cancer. {sup 188}Re-labeled HDD has been the most widely studied of these agents for this application and has been introduced into clinical trials at a number of institutions. The trans-arterial administration of {sup 188}Re-labeled agents for treatment of inoperable liver cancer requires use of high-level (1-2 Ci) {sup 188}W/{sup 188}Re generators. The handling of such high levels of {sup 188}Re imposes radiological precautions normally not encountered in a radiopharmacy and adequate care and ALARA (i.e., 'As Low As Reasonably Achievable') principles must be followed. The ORNL generator provides consistently high {sup 188}Re yields (>75%) and low {sup 188}W parent breakthrough (<10{sup -3}%) over an extended shelf-life of several months. However, the high elution volumes (20-40 mL for 1-2 Ci generators) can require concentration of the

  9. Use of the ORNL Tungsten-188/Rhenium-188 Generator for Preparation of the Rhenium-188 HDD/Lipiodol Complex for Transarterial Liver Cancer Therapy

    SciTech Connect

    Knapp Jr, Russ F; Jeong, J M

    2008-01-01

    This work describes the installation, use, and quality control (QC) of the alumina-based tungsten-188 ({sup 188}W)/rhenium-188 ({sup 188}Re) generators provided by the Oak Ridge National Laboratory (ORNL). In addition, methods used for concentration of the {sup 188}Re-perrhenate bolus and preparation of {sup 188}Re-labeled HDD (4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol) for trans-arterial administration for therapy of nonresectable liver cancer also are described. The {sup 188}W/{sup 188}Re generator has a long useful shelf-life of several months and is a convenient on-site {sup 188}Re production system. {sup 188}Re has excellent therapeutic and imaging properties (T{sub 1/2} 16.9 hours; E{beta}{sub max} 2.12 MeV; 155-keV gamma ray, 15%) and is cost effectively obtained on demand by saline elution of the generator. The clinical efficacy of a variety of {sup 188}Re-labeled agents has been demonstrated for several therapeutic applications. Because of the favorable physical properties of {sup 188}Re, several {sup 188}Re-labeled agents are being developed and evaluated for the treatment of nonresectable/refractory liver cancer. {sup 188}Re-labeled HDD has been the most widely studied of these agents for this application and has been introduced into clinical trials at a number of institutions. The trans-arterial administration of {sup 188}Re-labeled agents for treatment of inoperable liver cancer requires use of high-level (1-2 Ci) {sup 188}W/{sup 188}Re generators. The handling of such high levels of {sup 188}Re imposes radiological precautions normally not encountered in a radiopharmacy and adequate care and ALARA (ie, 'As Low As Reasonably Achievable') principles must be followed. The ORNL generator provides consistently high {sup 188}Re yields (>75%) and low {sup 188}W parent breakthrough (<10{sup -3}%) over an extended shelf-life of several months. However, the high elution volumes (20-40 mL for 1-2 Ci generators) can require concentration of the

  10. Ion Exchange Distribution Coefficient Tests and Computer Modeling at High Ionic Strength Supporting Technetium Removal Resin Maturation

    SciTech Connect

    Nash, Charles A.; Hamm, L. Larry; Smith, Frank G.; McCabe, Daniel J.

    2014-12-19

    The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant (WTP) that is currently under construction. The baseline plan for this facility is to treat the waste, splitting it into High Level Waste (HLW) and Low Activity Waste (LAW). Both waste streams are then separately vitrified as glass and poured into canisters for disposition. The LAW glass will be disposed onsite in the Integrated Disposal Facility (IDF). There are currently no plans to treat the waste to remove technetium, so its disposition path is the LAW glass. Due to the water solubility properties of pertechnetate and long half-life of 99Tc, effective management of 99Tc is important to the overall success of the Hanford River Protection Project mission. To achieve the full target WTP throughput, additional LAW immobilization capacity is needed, and options are being explored to immobilize the supplemental LAW portion of the tank waste. Removal of 99Tc, followed by off-site disposal, would eliminate a key risk contributor for the IDF Performance Assessment (PA) for supplemental waste forms, and has potential to reduce treatment and disposal costs. Washington River Protection Solutions (WRPS) is developing some conceptual flow sheets for supplemental LAW treatment and disposal that could benefit from technetium removal. One of these flowsheets will specifically examine removing 99Tc from the LAW feed stream to supplemental immobilization. To enable an informed decision regarding the viability of technetium removal, further maturation of available technologies is being performed. This report contains results of experimental ion exchange distribution coefficient testing and computer modeling using the resin SuperLig® 639a to selectively remove perrhenate from high ionic strength simulated LAW. It is advantageous to operate at higher concentration in order to treat the waste

  11. Use of the Oak Ridge National Laboratory tungsten-188/rhenium-188 generator for preparation of the rhenium-188 HDD/lipiodol complex for trans-arterial liver cancer therapy.

    PubMed

    Jeong, Jae Min; Knapp, F F Russ

    2008-03-01

    This work describes the installation, use, and quality control (QC) of the alumina-based tungsten-188 ((188)W)/rhenium-188 ((188)Re) generators provided by the Oak Ridge National Laboratory (ORNL). In addition, methods used for concentration of the (188)Re-perrhenate bolus and preparation of (188)Re-labeled HDD (4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol) for trans-arterial administration for therapy of nonresectable liver cancer also are described. The (188)W/(188)Re generator has a long useful shelf-life of several months and is a convenient on-site (188)Re production system. (188)Re has excellent therapeutic and imaging properties (T(1/2) 16.9 hours; E(betamax) 2.12 MeV; 155-keV gamma ray, 15%) and is cost effectively obtained on demand by saline elution of the generator. The clinical efficacy of a variety of (188)Re-labeled agents has been demonstrated for several therapeutic applications. Because of the favorable physical properties of (188)Re, several (188)Re-labeled agents are being developed and evaluated for the treatment of nonresectable/refractory liver cancer. (188)Re-labeled HDD has been the most widely studied of these agents for this application and has been introduced into clinical trials at a number of institutions. The trans-arterial administration of (188)Re-labeled agents for treatment of inoperable liver cancer requires use of high-level (1-2 Ci) (188)W/(188)Re generators. The handling of such high levels of (188)Re imposes radiological precautions normally not encountered in a radiopharmacy and adequate care and ALARA (ie, "As Low As Reasonably Achievable") principles must be followed. The ORNL generator provides consistently high (188)Re yields (>75%) and low (188)W parent breakthrough (<10(-3)%) over an extended shelf-life of several months. However, the high elution volumes (20-40 mL for 1-2 Ci generators) can require concentration of the (188)Re bolus by postelution passage through silver cation chloride trapping columns

  12. Sodalite as a vehicle to increase Re retention in waste glass simulant during vitrification

    NASA Astrophysics Data System (ADS)

    Luksic, Steven A.; Riley, Brian J.; Parker, Kent E.; Hrma, Pavel

    2016-10-01

    Technetium (Tc) retention during Hanford waste vitrification can be increased if the volatility can be controlled. Incorporating Tc into a thermally stable mineral phase, such as sodalite, is one way to achieve increased retention. Here, rhenium (Re)-bearing sodalite was tested as a vehicle to transport perrhenate (ReO4-), a nonradioactive surrogate for pertechnetate (TcO4-), into high-level (HLW) and low-activity waste (LAW) glass simulants. After melting HLW and LAW simulant feeds, the retention of Re in the glass was measured and compared with the Re retention in glass prepared from a feed containing Re2O7. Phase analysis of sodalite in both these glasses across a profile of temperatures describes the durability of Re-sodalite during the feed-to-glass transition. The use of Re sodalite improved the Re retention by 21% for HLW glass and 85% for LAW glass, demonstrating the potential improvement in Tc-retention if TcO4- were to be encapsulated in a Tc-sodalite prior to vitrification.

  13. Crystallization of rhenium salts in a simulated low-activity waste borosilicate glass

    SciTech Connect

    Riley, Brian J.; McCloy, John S.; Goel, Ashutosh; Liezers, Martin; Schweiger, Michael J.; Liu, Juan; Rodriguez, Carmen P.; Kim, Dong-Sang

    2013-04-01

    This study presents a new method for looking at the solubility of volatile species in simulated low-activity waste glass. The present study looking at rhenium salts is also applicable to real applications involving radioactive technetium salts. In this synthesis method, oxide glass powder is mixed with the volatiles species, vacuum-sealed in a fused quartz ampoule, and then heat-treated under vacuum in a furnace. This technique restricts the volatile species to the headspace above the melt but still within the sealed ampoule, thus maximizing the volatile concentration in contact with the glass. Various techniques were used to measure the solubility of rhenium in glass and include energy dispersive spectroscopy, wavelength dispersive spectroscopy, laser ablation inductively-coupled plasma mass spectroscopy, and inductively-coupled plasma optical emission spectroscopy. The Re-solubility in this glass was determined to be ~3004 parts per million Re atoms. Above this concentration, the salts separated out of the melt as inclusions and as a low viscosity molten salt phase on top of the melt observed during and after cooling. This salt phase was analyzed with X-ray diffraction, scanning electron microscopy as well as some of the other aforementioned techniques and identified to be composed of alkali perrhenate and alkali sulfate.

  14. Use of a new tandem cation/anion exchange system with clinical-scale generators provides high specific volume solutions of technetium-99m and rhenium-188

    SciTech Connect

    Knapp, F.R. Jr.; Beets, A.L.; Mirzadeh, S.; Guhlke, S. |

    1998-03-01

    In this paper the authors describe the first application of a simple and inexpensive post elution tandem cation-anion exchange column system which is based on generator elution with salts of weak acids such as ammonium acetate instead of saline solution to provide very high specific volume solutions of technetium-99m and rhenium-188 from clinical scale molybdenum-99/technetium-99m generator prepared from low specific activity (n,y) molybdenum-99, and tungsten-188/rhenium-188 generators, respectively. Initial passage of the bolus through a strong cation exchange cartridge converts the ammonium acetate to acetic acid which is essentially not ionized at the acidic pH, allowing specific subsequent amine type (QMA SepPak{trademark}) anion exchange cartridge column trapping of the microscopic levels of the pertechnetate or perrhenate. Subsequent elution of the anion cartridge with a small volume (< 1 mL) of saline then provides high specific volume solutions of technetium-99m by concentration of the high eluant volumes obtained by elution of clinical-scale (1 Ci) generators. This new approach also works very effectively to obtain high specific volume solutions of rhenium-188 (> 500 mCi/mL) from the alumina-based tungsten-188/rhenium-188 generator.

  15. Rhenium Radioisotopes for Therapeutic Radiopharmaceutical Development

    SciTech Connect

    Beets, A.L.; Knapp, F.F., Jr.; Kropp, J.; Lin, W.-Y.; Pinkert, J.; Wang, S.-Y.

    1999-01-18

    The availability of therapeutic radioisotopes at reasonable costs is important for applications in nuclear medicine, oncology and interventional cardiology, Rhenium-186 (Re-186) and rhenium-1 88 (Re-188) are two reactor-produced radioisotope which are attractive for a variety of therapeutic applications, Rhenium-186 has a half-life of 90 hours and decays with emission of a &particle with a maximum energy of 1.08 MeV and a 135 keV (9Yo) gamma which permits imaging. In contrast, Re- 188 has a much shorter half-life of 16.9 hours and emits a p-particle with a much higher energy of 2.12 MeV (Em=) and a 155 keV gamma photon (15Yo) for imaging. While Re-186 is unavailable from a generator system and must be directly produced in a nuclear reactor, Re-188 can also be directly produced in a reactor with high specific activity, but is more conveniently and cost-effectively available as carrier-free sodium perrhenate by saline elution of the alumina-based tungsten-188 (W1 88)/Re-l 88 generator system [1-2]. Since a comprehensive overviewofRe-186 and Re-188 therapeutic agents is beyond the scope of this &tended Abstrac4 the goal is to provide key examples of various agents currently in clinical use and those which are being developed for important clinical applications.

  16. Pyrazole complexes as anion receptors.

    PubMed

    Nieto, Sonia; Pérez, Julio; Riera, Lucía; Riera, Víctor; Miguel, Daniel

    2006-03-01

    The behavior of the receptors [Re(CO)3(Hdmpz)3]BAr'4 (Hdmpz = 3,5-dimethylpyrazole) (1) and [Re(CO)3(HtBupz)3]BAr'4 (HtBupz = 3(5)-tert-butylpyrazole) (2; Ar' = 3,5-bis(trifluoromethyl)phenyl) toward the anions fluoride, chloride, bromide, iodide, hydrogensulfate, dihydrogenphosphate, nitrate, and perrhenate was studied in CD3CN solution. In most cases, the receptors were stable. Anion exchange was fast, and binding constants were calculated from the NMR titration profiles. The structure of the adduct [Re(CO)3(HtBupz)3] x NO3 (3) was determined by X-ray diffraction. Two pyrazole moieties are hydrogen-bonded to one nitrate oxygen atom, and the third pyrazole moiety is hydrogen-bonded to an oxygen atom of an adjacent nitrate, leading to infinite chains. The structure of the adduct [Re(CO)3(Hdmpz)3]BAr'4acetone (4), also determined by X-ray diffraction, showed a similar interaction of two pyrazole N-H groups with the acetone oxygen atom. F- and H2PO4(-) deprotonate the receptors, and HSO4(-) decomposed 1. The structure of one of the decomposition products (5), determined by X-ray diffraction, is consistent with pyrazole protonation and substitution by sulfate.

  17. Non-Complexing Anions for Quantitative Speciation Studies Using Raman Spectroscopy in Fused Silica High-Pressure Optical Cells Under Hydrothermal Conditions.

    PubMed

    Applegarth, Lucas M S G A; Alcorn, Christopher; Bissonette, Katherine; Noël, John; Tremaine, Peter R

    2015-08-01

    This paper reports methods for obtaining time-dependent reduced isotropic Raman spectra of aqueous species in quartz capillary high-pressure optical cells under hydrothermal conditions, as a means of determining quantitative speciation in hydrothermal fluids. The methods have been used to determine relative Raman scattering coefficients and to examine the thermal decomposition kinetics of the non-complexing anions bisulfate (HSO4(-)), perchlorate (CIO4(-)), perrhenate (ReO4(-)), and trifluoromethanesulfonate, or "triflate" (CF3SO3(-)) in acidic and neutral solutions at temperatures up to 400°C and 30 MPa. Arrhenius expressions for calculating the thermal decomposition rate constants are also reported. Thermal stabilities in the acidic solutions followed the order HSO4(-) (stable) > ReO4(-) > CIO4(-) > CF3SO3(-), with half-lives (t1/2) > 7 h at 300°C. In neutral solutions, the order was HSO4(-) (stable) > CF3SO3(-) > ReO4(-) > CIO4(-), with t1/2 > 8 h at 350°C. CF3SO3(-) was extremely stable in neutral solutions, with t1/2 > 11 h at 400°C.

  18. SIMS analysis: Development and evaluation 1995 summary report

    SciTech Connect

    Groenewold, G.S.; Appelhans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

    1995-10-01

    Secondary ion mass spectrometry (SIMS) was evaluated for characterizing Hg salts. It was found that sulfate and chloride species could be identified directly without sample preparation. Mercuric oxide could be identified by complexation with formic acid. Hg nitrates could be identified by complexation with cyclohexylamine (CHA). Laser desorption ion trap MS was evaluated for characterizing EDTA on environmental samples. No intact EDTA ions were observed, but a series of EDTA fragment ions were visible, particularly on basalt and soil. An ion trap SIMS was developed: a perrhenate ion gun was interfaced to a Teledyne ion trap spectrometer, and the entire device was mounted on a cart. The technology was demonstrated using a prototype ion trap SIMS instrument for detecting Hg{center_dot}CHA complexes formed from nitrate salts. Intensity of the ion gun was improved, and the surface damage of the particle was small, and ion gun technology transfer to Phi-Evans, Inc. is being considered. Two technology end users are at INEL`s Central Facilities Area 674 pond and acid pit of the Radioactive Waste Management Complex; target problem at both sites is the need for Hg speciation on soil samples.

  19. Rhenium solubility in borosilicate nuclear waste glass: implications for the processing and immobilization of technetium-99.

    PubMed

    McCloy, John S; Riley, Brian J; Goel, Ashutosh; Liezers, Martin; Schweiger, Michael J; Rodriguez, Carmen P; Hrma, Pavel; Kim, Dong-Sang; Lukens, Wayne W; Kruger, Albert A

    2012-11-20

    The immobilization of technetium-99 ((99)Tc) in a suitable host matrix has proven to be a challenging task for researchers in the nuclear waste community around the world. In this context, the present work reports on the solubility and retention of rhenium, a nonradioactive surrogate for (99)Tc, in a sodium borosilicate glass. Glasses containing target Re concentrations from 0 to 10,000 ppm [by mass, added as KReO(4) (Re(7+))] were synthesized in vacuum-sealed quartz ampules to minimize the loss of Re from volatilization during melting at 1000 °C. The rhenium was found as Re(7+) in all of the glasses as observed by X-ray absorption near-edge structure. The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) using inductively coupled plasma optical emission spectroscopy. At higher rhenium concentrations, additional rhenium was retained in the glasses as crystalline inclusions of alkali perrhenates detected with X-ray diffraction. Since (99)Tc concentrations in a glass waste form are predicted to be <10 ppm (by mass), these Re results implied that the solubility should not be a limiting factor in processing radioactive wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

  20. Lipid Nanocapsules Loaded with Rhenium-188 Reduce Tumor Progression in a Rat Hepatocellular Carcinoma Model

    PubMed Central

    Vanpouille-Box, Claire; Lacoeuille, Franck; Roux, Jérôme; Aubé, Christophe; Garcion, Emmanuel; Lepareur, Nicolas; Oberti, Frédéric; Bouchet, Francis; Noiret, Nicolas; Garin, Etienne; Benoît, Jean-Pierre; Couturier, Olivier; Hindré, François

    2011-01-01

    Background Due to their nanometric scale (50 nm) along with their biomimetic properties, lipid nanocapsules loaded with Rhenium-188 (LNC188Re-SSS) constitute a promising radiopharmaceutical carrier for hepatocellular carcinoma treatment as its size may improve tumor penetration in comparison with microspheres devices. This study was conducted to confirm the feasibility and to assess the efficacy of internal radiation with LNC188Re-SSS in a chemically induced hepatocellular carcinoma rat model. Methodology/Principal Findings Animals were treated with an injection of LNC188Re-SSS (80 MBq or 120 MBq). The treated animals (80 MBq, n = 12; 120 MBq, n = 11) were compared with sham (n = 12), blank LNC (n = 7) and 188Re-perrhenate (n = 4) animals. The evaluation criteria included rat survival, tumor volume assessment, and vascular endothelial growth factor quantification. Following treatment with LNC188Re-SSS (80 MBq) therapeutic efficiency was demonstrated by an increase in the median survival from 54 to 107% compared with control groups with up to 7 long-term survivors in the LNC188Re-SSS group. Decreased vascular endothelial growth factor expression in the treated rats could indicate alterations in the angiogenesis process. Conclusions/Significance Overall, these results demonstrate that internal radiation with LNC188Re-SSS is a promising new strategy for hepatocellular carcinoma treatment. PMID:21408224

  1. Separation of technetium from nuclear waste stream simulants. Final report

    SciTech Connect

    Strauss, S.H.

    1995-09-11

    The author studied liquid anion exchangers, such as Aliquat-336 nitrate, various pyridinium nitrates, and related salts, so that they may be applied toward a specific process for extracting (partitioning) and recovering {sup 99}TcO{sub 4}{sup {minus}} from nuclear waste streams. Many of the waste streams are caustic and contain a variety of other ions. For this reason, the author studied waste stream simulants that are caustic and contain appropriate concentrations of selected, relevant ions. Methods of measuring the performance of the exchangers and extractant systems included contact experiments. Batch contact experiments were used to determine the forward and reverse extraction parameters as a function of temperature, contact time, phase ratio, concentration, solvent (diluent), and other physical properties. They were also used for stability and competition studies. Specifically, the author investigated the solvent extraction behavior of salts of perrhenate (ReO{sub 4}{sup {minus}}), a stable (non-radioactive) chemical surrogate for {sup 99}TcO{sub 4}{sup {minus}}. Results are discussed for alternate organic solvents; metalloporphyrins, ferrocenes, and N-cetyl pyridium nitrate as alternate extractant salts; electroactive polymers; and recovery of ReO{sub 4}{sup {minus}} and TcO{sub 4}{sup {minus}}.

  2. Upgrade to Ion Exchange Modeling for Removal of Technetium from Hanford Waste Using SuperLig® 639 Resin

    SciTech Connect

    Hamm, L.; Smith, F.; Aleman, S.; McCabe, D.

    2013-05-16

    This report documents the development and application of computer models to describe the sorption of pertechnetate [TcO₄⁻], and its surrogate perrhenate [ReO₄⁻], on SuperLig® 639 resin. Two models have been developed: 1) A thermodynamic isotherm model, based on experimental data, that predicts [TcO₄⁻] and [ReO₄⁻] sorption as a function of solution composition and temperature and 2) A column model that uses the isotherm calculated by the first model to simulate the performance of a full-scale sorption process. The isotherm model provides a synthesis of experimental data collected from many different sources to give a best estimate prediction of the behavior of the pertechnetate-SuperLig® 639 system and an estimate of the uncertainty in this prediction. The column model provides a prediction of the expected performance of the plant process by determining the volume of waste solution that can be processed based on process design parameters such as column size, flow rate and resin physical properties.

  3. Root Absorption and Transport Behavior of Technetium in Soybean 1

    PubMed Central

    Cataldo, Dominic A.; Wildung, Raymond E.; Garland, Thomas R.

    1983-01-01

    The absorption characteristics and mechanisms of pertechnetate (TcO4−) uptake by hydroponically grown soybean seedlings (Glycine max cv Williams) were determined. Absorption from 10 micromolar solutions was linear for at least 6 hours, with 30% of the absorbed TcO4− being transferred to the shoot. Evaluation of concentration-dependent absorption rates from solutions containing 0.02 to 10 micromolar TcO4− shows the presence of multiphasic absorption isotherms with calculated Ks values of 0.09, 8.9, and 54 micromolar for intact seedlings. The uptake of TcO4− was inhibited by a 4-fold concentration excess of sulfate, phosphate, selenate, molybdate, and permanganate; no reduction was noted with borate, nitrate, tungstate, perrhenate, iodate, or vanadate. Analyses of the kinetics of interaction between TcO4− and inhibiting anions show permanganate to be a noncompetitive inhibitor, while sulfate, phosphate, and selenate, and molybdate exhibit characteristics of competitive inhibitors of TcO4− transport suggesting involvement of a common transport process. PMID:16663311

  4. Root absorption and transport behavior of technetium in soybean.

    PubMed

    Cataldo, D A; Wildung, R E; Garland, T R

    1983-11-01

    The absorption characteristics and mechanisms of pertechnetate (TcO(4) (-)) uptake by hydroponically grown soybean seedlings (Glycine max cv Williams) were determined. Absorption from 10 micromolar solutions was linear for at least 6 hours, with 30% of the absorbed TcO(4) (-) being transferred to the shoot. Evaluation of concentration-dependent absorption rates from solutions containing 0.02 to 10 micromolar TcO(4) (-) shows the presence of multiphasic absorption isotherms with calculated K(s) values of 0.09, 8.9, and 54 micromolar for intact seedlings. The uptake of TcO(4) (-) was inhibited by a 4-fold concentration excess of sulfate, phosphate, selenate, molybdate, and permanganate; no reduction was noted with borate, nitrate, tungstate, perrhenate, iodate, or vanadate. Analyses of the kinetics of interaction between TcO(4) (-) and inhibiting anions show permanganate to be a noncompetitive inhibitor, while sulfate, phosphate, and selenate, and molybdate exhibit characteristics of competitive inhibitors of TcO(4) (-) transport suggesting involvement of a common transport process.

  5. MARE-l in Milan: Status and Perspectives

    NASA Technical Reports Server (NTRS)

    Ferri, E.; Arnaboldi, C.; Ceruti, G.; Faverzani, M.; Gatti, C.; Giachero, A.; Gotti, C.; Kilbourne, C.; Kraft-Bermuth, S.; Nucciotti, A.; Pessini, G.; Schaeffer, D.; Sisti, M.

    2012-01-01

    The international project MARE (Microcalorimeter Array for a Rhenium Experiment) aims at the direct and calorimetric measurement of the electron neutrino mass with sub-eV sensitivity. Although the baseline of the MARE project consists in a large array of rhenium based thermal detectors, a different option for the isotope is also being considered. The different option is Ho-163. The potential of using Re-187 for a calorimetric neutrino mass experiment has been already demonstrated. On the contrary, no calorimetric spectrum of Ho-163 has been so far measured with the precision required to set a useful limit on the neutrino mass. The first phase of the project (MARE-1) is a collection of activities with the aim of sorting out both the best isotope and the most suited detector technology to be used for the final experiment. One of the MARE-1 activities is carried out in Milan by the group of Milano-Bicocca in collaboration with NASA/GSFC and Wisconsin groups. The Milan MARE-l arrays are based on semiconductor thermistors, provided by the NASA/GSFC group, with dielectric silver perrhenate absorbers, AgReO4. The experiment, which is presently being assembled, is designed to host up to 8 arrays.

  6. Characterization of rhenium oxide films and their application to liquid crystal cells

    NASA Astrophysics Data System (ADS)

    Cazzanelli, E.; Castriota, M.; Marino, S.; Scaramuzza, N.; Purans, J.; Kuzmin, A.; Kalendarev, R.; Mariotto, G.; Das, G.

    2009-06-01

    Rhenium trioxide exhibits high electronic conductivity, while its open cubic crystal structure allows an appreciable hydrogen intercalation, generating disordered solid phases, with protonic conductivity. Rhenium oxide thin films have been obtained by thermal evaporation of ReO3 powders on different substrates, maintained at different temperatures, and also by reactive magnetron sputtering of a Re metallic target. A comparative investigation has been carried out on these films, by using micro-Raman spectroscopy and x-ray diffraction. Two basic types of solid phases appear to grow in the films: a red metallic HxReO3 compound, with distorted perovskite structures, like in the bulk material, and ordered HReO4 crystals based on tetrahedral perrhenate ions. Because of its conduction properties, the electrical and electro-optical behaviors of ReO3 films deposited on standard indium tin oxide/glass substrate have been tested inside asymmetric nematic liquid crystal cells, showing an appreciable capability of rectification of their electro-optical response, in similar way to tungsten trioxide.

  7. 188Rhenium-induced cell death and apoptosis in a panel of tumor cell lines

    NASA Astrophysics Data System (ADS)

    Antoccia, Antonio; Banzato, Alessandra; Bello, Michele; Bollini, Dante; De Notaristefani, Francesco; Giron, Cecilia; Mazzi, Ulderico; Alafort, Laura Melendez; Moschini, Giuliano; Nadali, Anna; Navarria, Francesco; Perrotta, Andrea; Rosato, Antonio; Tanzarella, Caterina; Uzunov, Nikolay

    2007-02-01

    Assessment of "in vitro" tumor growth inhibition and radiobiological effects, such as apoptosis, have been evaluated in human neoplastic cells of different histotypes (H460 lung cancer cells, U87 glioblastoma, LnCaP prostate tumor cells) treated using solutions of 188Rhenium-perrhenate. The MTT assay, which measures mitochondrial metabolism in the entire cell culture is a recognized test for cytotoxicity and was used in cells exposed 48-72 h to specific activities ranged from 37 to 148 GBq/l. Whereas H460 and LnCaP were particularly sensitive to treatment, U87 glioblastoma cells behaved as radioresistant ones. However, evaluation of 188Re-induced apoptosis indicated that this kind of cell death contributed only marginally to the reduction in cell viability of H460 and LNCaP lines, suggesting the existence of protective mechanisms against apoptosis. In this respect, the membrane receptor, CD44, whose expression is dysregulated in most malignant cell types has proven to alter the response of cancer cells to apoptotic stimuli, including ionizing radiation. Cell samples decorated with a FITC-labelled CD44 antibody indicated, that in H460 and U87 cells the CD44(+) correlated well with an apoptosis-resistant response. Conversely, LnCap cells proven as CD44(-) did not display however sensitivity to radio-induced apoptosis.

  8. Radiant{trademark} Liquid Radioisotope Intravascular Radiation Therapy System

    SciTech Connect

    Eigler, N.; Whiting, J.; Chernomorsky, A.; Jackson, J.; Knapp, F.F., Jr.; Litvack, F.

    1998-01-16

    RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery catheters are modified Champion{trademark} over-the-wire, and TNT{trademark} rapid exchange stent delivery balloons. These balloons have thickened polyethylene walls to augment puncture resistance; dual radio-opaque markers and specially configured connectors.

  9. Ambient aging of rhenium filaments used in thermal ionization mass spectrometry: Growth of oxo-rhenium crystallites and anti-aging strategies.

    PubMed

    Mannion, Joseph M; Wellons, Matthew S; Shick, Charles R; Fugate, Glenn A; Powell, Brian A; Husson, Scott M

    2017-01-01

    Degassing is a common preparation technique for rhenium filaments used for thermal ionization mass spectrometric analysis of actinides, including plutonium. Although optimization studies regarding degassing conditions have been reported, little work has been done to characterize filament aging after degassing. In this study, the effects of filament aging after degassing were explored to determine a "shelf-life" for degassed rhenium filaments, and methods to limit filament aging were investigated. Zone-refined rhenium filaments were degassed by resistance heating under high vacuum before exposure to ambient atmosphere for up to 2 months. After degassing the nucleation and preferential growth of oxo-rhenium crystallites on the surface of polycrystalline rhenium filaments was observed by atomic force microscopy and scanning electron microscopy (SEM). Compositional analysis of the crystallites was conducted using SEM-Raman spectroscopy and SEM energy dispersive X-ray spectroscopy, and grain orientation at the metal surface was investigated by electron back-scatter diffraction mapping. Spectra collected by SEM-Raman suggest crystallites are composed primarily of perrhenic acid. The relative extent of growth and crystallite morphology were found to be grain dependent and affected by the dissolution of carbon into filaments during annealing (often referred to as carbonization or carburization). Crystallites were observed to nucleate in region specific modes and grow over time through transfer of material from the surface. Factors most likely to affect the rates of crystallite growth include rhenium substrate properties such as grain size, orientation, levels of dissolved carbon, and relative abundance of defect sites; as well as environmental factors such as length of exposure to oxygen and relative humidity. Thin (∼180 nm) hydrophobic films of poly(vinylbenzyl chloride) were found to slow the growth of oxo-rhenium crystallites on the filament surfaces and may serve as

  10. RHENIUM SOLUBILITY IN BOROSILICATE NUCLEAR WASTE GLASS IMPLICATIONS FOR THE PROCESSING AND IMMOBILIZATION OF TECHNETIUM-99 (AND SUPPORTING INFORMATION WITH GRAPHICAL ABSTRACT)

    SciTech Connect

    AA KRUGER; A GOEL; CP RODRIGUEZ; JS MCCLOY; MJ SCHWEIGER; WW LUKENS; JR, BJ RILEY; D KIM; M LIEZERS; P HRMA

    2012-08-13

    The immobilization of 99Tc in a suitable host matrix has proved a challenging task for researchers in the nuclear waste community around the world. At the Hanford site in Washington State in the U.S., the total amount of 99Tc in low-activity waste (LAW) is {approx} 1,300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility and retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW sodium borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant because of previously established similarities in ionic radii and other chemical aspects. The glasses containing target Re concentrations varying from 0 to10,000 ppm by mass were synthesized in vacuum-sealed quartz ampoules to minimize the loss of Re by volatilization during melting at 1000 DC. The rhenium was found to be present predominantly as Re7 + in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be {approx}3,000 ppm (by mass) using inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of alkali perrhenate crystalline inclusions detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). Assuming justifiably substantial similarities between Re7 + and Tc 7+ behavior in this glass system, these results implied that the processing and immobilization of 99Tc from radioactive wastes should not be limited by the solubility of 99Tc in borosilicate LAW glasses.

  11. DOE FG02-03ER63557: Final Technical Report: Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks

    SciTech Connect

    Kathryn L. Nagy

    2009-05-04

    The purpose of the project was to investigate rates and mechanisms of reactions between primary sediment minerals and key components of waste tank solutions that leaked into the subsurface at the Hanford Site. Results were expected to enhance understanding of processes that cause (1) changes in porosity and permeability of the sediment and resultant changes in flow paths of the contaminant plumes, (2) formation of secondary precipitates that can take up contaminants in their structures, and (3) release of mineral components that can drive redox reactions affecting dissolved contaminant mobility. Measured rates can also be used directly in reactive transport models. Project tasks included (1) measurement of the dissolution rates of biotite mica from low to high pH and over a range of temperature relevant to the Hanford subsurface, (2) measurement of dissolution rates of quartz at high pH and in the presence of dissolved alumina, (3) measurement of the dissolution rates of plagioclase feldspar in high pH, high nitrate, high Al-bearing solutions characteristic of the BX tank farms, (4) incorporation of perrhenate in iron-oxide minerals as a function of pH, and (5) initiation of experiments to measure the formation of uranium(VI)-silicate phases under ambient conditions. Task 2 was started under a previous grant from the Environmental Management Science Program and Task 4 was partially supported by a grant to the PI from the Geosciences Program, Office of Basic Energy Sciences. Task 5 was continued under a subsequent grant from the Environmental Remediation Sciences Program, Office of Biological and Environmental Research.

  12. Ultra-small rhenium nanoparticles immobilized on DNA scaffolds: An excellent material for surface enhanced Raman scattering and catalysis studies.

    PubMed

    Anantharaj, S; Sakthikumar, K; Elangovan, Ayyapan; Ravi, G; Karthik, T; Kundu, Subrata

    2016-12-01

    Highly Sensitive and ultra-small Rhenium (Re) metal nanoparticles (NPs) were successfully stabilized in water by the staging and fencing action of the versatile biomolecule DNA that resulted in two distinct aggregated chain-like morphologies with average grain sizes of 1.1±0.1nm and 0.7±0.1nm for the very first time within a minute of reaction time. Re NPs are formed by the borohydride reduction of ammonium perrhenate (NH4ReO4) in the presence of DNA at room temperature (RT) under stirring. The morphologies were controlled by carefully monitoring the molar ratio of NH4ReO4 and DNA. The synthesized material was employed in two potential applications: as a substrate for surface enhanced Raman scattering (SERS) studies and as a catalyst for the reduction of aromatic nitro compounds. SERS study was carried out by taking methylene blue (MB) as the probe and the highest SERS enhancement factor (EF) of 2.07×10(7) was found for the aggregated chain-like having average grain size of 0.7±0.1nm. Catalytic reduction of 4-nitro phenol (4-NP), 2-nitro phenol (2-NP) and 4-nitroaniline (4-NA) with a rate constant value of 6×10(-2)min(-1), 33.83×10(-2)min(-1) and 37.4×10(-2)min(-1) have testified the excellent catalytic performance of our Re NPs immobilized on DNA. The overall study have revealed the capability of DNA in stabilizing the highly reactive Re metal at nanoscale and made them applicable in practice. The present route can also be extended to prepare one dimensional (1-D), self-assembled NPs of other reactive metals, mixed metals or even metal oxides for specific applications in water based solutions.

  13. Palliation and Survival After Repeated Re-188-HEDP Therapy of Hormone-Refractory Bone Metastases of Prostate Cancer: A Retrospsective Analysis

    SciTech Connect

    Knapp Jr, Russ F

    2011-01-01

    This retrospective study compared the effects of single and multiple administrations of {sup 186}Re-hydroxyethylidenediphosphonate (186Re-HEDP) on palliation and survival of prostate cancer patients presenting with more than 5 skeletal metastases. Methods: A total of 60 patients were divided into 3 groups. Group A (n = 19) consisted of patients who had received a single injection; group B (n = 19), patients who had 2 injections; and group C (n = 22), patients who had 3 or more successive injections. The {sup 188}Re-HEDP was prepared using non-carrier-added {sup 188}Re obtained from an in-house {sup 188}W/{sup 188}Re generator after dilution with carrier perrhenate. Patients data available from the referring physicians - including prostate-specific antigen levels - were entered into a Windows-based matrix and analyzed using a statistical program. The Gleason scores were similar for all 3 groups. Results: Mean survival from the start of treatment was 4.50 {+-} 0.81 mo (95% confidence interval [CI], 2.92-6.08) for group A, 9.98 {+-} 2.21 mo (95% CI, 5.65-14.31) for group B, and 15.66 {+-} 3.23 (95% CI, 9.33-22.0) for group C. Although the 3 groups did not differ in Gleason score, the number of lost life-years was significantly lower in group C than in groups A and B. Pain palliation was achieved in 89.5% of group A, 94.7% of group B, and 90.9% of group C. Conclusion: Posttreatment overall survival could be improved from 4.50 to 15.66 mo by multiple-injection bone-targeted therapy with {sup 188}Re-HEDP, when compared with a single injection. Significant pain palliation was common and independent of administration frequency.

  14. Preparation and initial characterization of fluidized bed steam reforming pure-phase standards

    SciTech Connect

    Missimer, D. M.; Rutherford, R. L.

    2013-03-21

    Hanford is investigating the Fluidized Bed Steam Reforming (FBSR) process for their Low Activity Waste. The FBSR process offers a low-temperature continuous method by which liquid waste can be processed with the addition of clay into a sodium aluminosilicate (NAS) waste form. The NAS waste form is mainly comprised of nepheline (NaAlSiO{sub 4}), sodalite (Na{sub 8}[AlSiO{sub 4}]{sub 6}Cl{sub 2}), and nosean (Na{sub 8}[AlSiO{sub 4}]{sub 6}SO{sub 4}). Anions such as perrhenate (ReO{sub 4}{sup -}), pertechnetate (TcO{sub 4}{sup -}), and iodine (I{sup -}) are expected to replace sulfate in the nosean structure and/or chloride in the sodalite mineral structure (atomically bonded inside the aluminosilicate cages that these mineral structures possess). In the FBSR waste form, each of these phases can exist in a variety of solid solutions that differ from the idealized forms observed in single crystals in nature. The lack of understanding of the durability of these stoichiometric or idealized mineral phases complicates the ability to deconvolute the durability of the mixed phase FBSR product since it is a combination of different NAS phases. To better understand the behavior, fabrication and testing of the individual phases of the FBSR product is required. Analytical Development (AD) of the Science and Technology directorate of the Savannah River National Laboratory (SRNL) was requested to prepare the series of phase-pure standards, consisting of nepheline, nosean, and Cl, Re, and I sodalite. Once prepared, X-ray Diffraction (XRD) analyses were used to confirm the products were phase pure. These standards are being used for subsequent characterization studies consisting of the following: single-pass flow-through (SPFT) testing, development of thermodynamic data, and x-ray diffraction (XRD) calibration curves. In addition to the above mentioned phase-pure standards, AD was tasked with fabricating a mixed Tc-Re sodalite.

  15. Technetium (VII) Co-precipitation with Framework Aluminosilicates

    SciTech Connect

    Harsh, James B.; Dickson, Johnbull Otah; Pierce, Eric M.; Bargar, John

    2015-07-13

    Technetium-99 (99Tc), a long-lived radionuclide, is one of the most widespread contaminants within the Hanford subsurface. At some depths, it is only extractable with strong acids, suggesting incorporation into a solid phase. We hypothesized that Tc may have coprecipitated with feldspathoid aluminosilicates under waste tanks that had leaked caustic solutions into the vadose zone. Our objectives were to determine if Tc could be incorporated into the feldspathoids cancrinite and sodalite and under what conditions coprecipitation could occur. Our hypothesis was that sodalite was more likely to incorporate and retain Tc. Our approach was to use known methods of feldspathoid formation in solutions resembling those in Hanford waste tanks contacting sediments in terms of major ion (Na, NO3, OH, Al(OH)4, and Si(OH)4 concentrations. In some cases, Al and Si were supplied from zeolite. We used perrhenate (ReO4) as a surrogate for pertechnetate (TcO4) to avoid the radioactivity. The major findings of this study were 1) ReO4 could be incorporated into either sodalite or cancrinite but the concentration in the solid was < 1% of the competing ion Cl, NO3, or NO2. 2) The small amount of ReO4 incorporated was not exchangeable with NO3 or NO2. 3) In sodalite, NO3 was highly preferred over ReO4 but significant Re-sodalite was formed when the mole fraction in solution (Re/Re+N) exceeded 0.8. 4) A nonlinear relation between the unit cell parameter and amount of Re incorporated suggested that a separate Re-sodalite phase was formed rather than a solid solution. 5) We determined that sodalite preference for sodalite in the presence of different anions increased with the ionic size of the competing anion: Cl < CO3 < NO3 < SO4 < MnO4 < WO4 and significant incorporation did not occur unless the difference in anion radii was less than 12%. 6) Re(VII) was not significantly reduced to Re(IV) under the conditions of this experiment and Re appeared to be a good surrogate for Tc under oxidizing

  16. Interaction between anions and cationic metal complexes containing tridentate ligands with exo-C-H groups: complex stability and hydrogen bonding.

    PubMed

    Martínez-García, Héctor; Morales, Dolores; Pérez, Julio; Puerto, Marcos; del Río, Ignacio

    2014-05-05

    [Re(CO)3 ([9]aneS3 )][BAr'4 ] (1), prepared by reaction of ReBr(CO)5 , 1,4,7-trithiacyclononane ([9]aneS3 ) and NaBAr'4 , forms stable, soluble supramolecular adducts with chloride (2), bromide, methanosulfonate (3) and fluoride (4) anions. These new species were characterized by IR, NMR spectroscopy and, for 2 and 3, also by X-ray diffraction. The results of the solid state structure determinations indicate the formation of CH⋅⋅⋅X hydrogen bonds between the anion (X) and the exo-CH groups of the [9]aneS3 ligand, in accord with the relatively large shifts found by (1) H NMR spectroscopy in dichloromethane solution for those hydrogens. The stability of the chloride adduct contrasts with the lability of the [9]aneS3 ligand in allyldicarbonyl molybdenum complexes recently studied by us. With fluoride, in dichloromethane solution, a second, minor neutral dimeric species 5 is formed in addition to 4. In 4, the deprotonation of a CH group of the [9]aneS3 ligand, accompanied by CS bond cleavage and dimerization, afforded 5, featuring bridging thiolates. Compounds [Mo(η(3) -methallyl)(CO)2 (TpyN)][BAr'4 ] (6) and [Mo(η(3) -methallyl)(CO)2 (TpyCH)][BAr'4 ] (7) were synthesized by the reactions of [MoCl(η(3) -methallyl)(CO)2 (NCMe)2 ], NaBAr'4 and tris(2-pyridyl)amine (TpyN) or tris(2-pyridyl)methane (TpyCH) respectively, and characterized by IR and (1) H and (13) C NMR spectroscopy in solution, and by X-ray diffraction in the solid state. Compound 6 undergoes facile substitution of one of the 2-pyridyl groups by chloride, bromide, and methanosulfonate anions. Stable supramolecular adducts were formed between 7 and chloride, bromide, iodide, nitrate, and perrhenate anions. The solid state structures of these adducts (12-16) were determined by X-ray diffraction. Binding constants in dichloromethane were calculated from (1) H NMR titration data for all the new supramolecular adducts. The signal of the bridgehead CH group is the one that undergoes a