WorldWideScience

Sample records for borosilicate glass tailored

  1. The borosilicate glass for 'PAMELA'

    International Nuclear Information System (INIS)

    Schiewer, E.

    1986-01-01

    The low enriched waste concentrate (LEWC) stored at Mol, Belgium, will be solidified in the vitrification plant 'PAMELA'. An alkali-borosilicate glass was developed by the Hahn-Meitner-Institut, Berlin, which dissolves (11 +- 3)wt% waste oxides while providing sufficient flexibility for changes in the process parameters. The development of the glass labelled SM513LW11 is described. Important properties of the glass melt (viscosity, resistivity, formation of yellow phase) and of the glass (corrosion in aqueous solutions, crystallization) are reported. The corrosion data of this glass are similar to those of other HLW-glasses. Less than five wt% of crystalline material are produced upon cooling of large glass blocks. Crystallization does not affect the chemical durability. (Auth.)

  2. Borosilicate glass for gamma irradiation fields

    Science.gov (United States)

    Baydogan, N.; Tugrul, A. B.

    2012-11-01

    Four different types of silicate glass specimens were irradiated with gamma radiation using a Co-60 radioisotope. Glass specimens, with four different chemical compositions, were exposed to neutron and mixed neutron/gamma doses in the central thimble and tangential beam tube of the nuclear research reactor. Optical variations were determined in accordance with standardisation concept. Changes in the direct solar absorbance (αe) of borosilicate glass were examined using the increase in gamma absorbed dose, and results were compared with the changes in the direct solar absorbance of the three different type silicate glass specimens. Solar absorption decreased due to decrease of penetration with absorbed dose. αe of borosilicate increased considerably when compared with other glass types. Changes in optical density were evaluated as an approach to create dose estimation. Mixed/thermal neutron irradiation on glass caused to increse αe.

  3. Topological Principles of Borosilicate Glass Chemistry

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, J. C.; Youngman, R. E.

    2011-01-01

    and laboratory glassware to high-tech applications such as liquid crystal displays. In this paper, we investigate the topological principles of borosilicate glass chemistry covering the extremes from pure borate to pure silicate end members. Based on NMR measurements, we present a two-state statistical...

  4. Investigation on neptunium in a borosilicate glass

    International Nuclear Information System (INIS)

    Poirot, I.

    1988-03-01

    The oxidization state and coordination of neptunium, introduced as dopant in borosilicate glasses were studied through optical, Mossbauer spectroscopies and magnetic measurements. The neptunium oxide, introduced previously as NpO 2 is reduced during the melting process of the glass. This leads to an equilibrium in which the ratio of Np 4+ to Np 3+ valences depends on experimental conditions. Spectroscopic analysises conduct to postulate the presence of different sites for each of the oxydation states of neptunium [fr

  5. Safety assessment of borosilicate glasses as used in cosmetics.

    Science.gov (United States)

    Becker, Lillian C; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2013-01-01

    The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of calcium sodium borosilicate, calcium aluminum borosilicate, calcium titanium borosilicate, silver borosilicate, and zinc borosilicate as used in cosmetics. These borosilicate glasses function mostly as bulking agents. Available animal and human data were considered along with data from a previous safety assessment of magnesium silicates. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. Data submitted on calcium borosilicate, which is not a cosmetic ingredient, are also included as additional support for the safety of borosilicate glass ingredients. The Panel concluded that borosilicate glasses are safe as cosmetic ingredients in the practices of use and concentration as given in this safety assessment.

  6. 57Fe Moessbauer effect in borosilicate glasses

    International Nuclear Information System (INIS)

    Music, S.

    1989-01-01

    The present study was carried out to elucidate the valence state of iron and its co-ordination in borosilicate glasses, which are being investigated as possible solidification matrices for the immobilization of a simulated nuclear waste. 57 Fe Mossbauer spectroscopy was used as the experimental technique. The chemical compositions of glass samples and the experimental conditions for the preparation of these samples are given. Iron in the form of haematite (α-Fe 2 O 3 ) was used as doping material. Details of the experimental procedure have previously been described. Isomer shifts are calculated relative to α-iron. The results indicate a strong dependence of the valency of the iron and its coordination on the chemical composition of the glass and the Fe 2 O 3 content. The method of preparing the glasses also influences the state of the iron in oxide glasses. (Author)

  7. Topological Principles of Borosilicate Glass Chemistry - An Invited Talk

    DEFF Research Database (Denmark)

    Mauro, J.C.; Smedskjær, Morten Mattrup; Youngman, R. E.

    Borosilicate glasses display a rich complexity of chemical behavior depending on the details of their composition and thermal history. We investigate the topological principles of borosilicate glass chemistry covering the extremes from pure borate to pure silicate end members. Based on NMR...... topological representation of alkali-alkaline earth-borosilicate glasses that enables the accurate prediction of properties such as glass transition temperature, liquid fragility, hardness, and configurational heat capacity. The implications of the glass topology are discussed in terms of both the temperature...

  8. The structure of leached sodium borosilicate glass

    International Nuclear Information System (INIS)

    Bunker, B.C.; Tallant, D.R.; Headley, T.J.; Turner, G.L.; Kirkpatrick, R.J.

    1988-01-01

    Raman spectroscopy, solid state 29 Si, 11 B, 17 O, and 23 Na nuclear magnetic resonance spectroscopy, and transmission electron microscopy have been used to investigate how the structures of sodium borosilicate glasses change during leaching in water at pH 1, 9, and 12. Results show that the random network structure present prior to leaching is transformed into a network of small condensed ring structures and/or colloidal silica particles. The restructuring of leached glass can be rationalised on the basis of simple hydrolysis (depolymerisation) and condensation (repolymerisation) reactions involving Si-O-Si and Si-O-B bonds. The structural changes that occur during leaching influence the properties of the leached layer, including leaching kinetics, crazing and spalling, and slow crack growth. (author)

  9. Plutonium alteration phases from lanthanide borosilicate glass

    International Nuclear Information System (INIS)

    Fortner, J.A.; Mertz, C.J.; Chamberlain, D.C.; Bates, J.K.

    1997-01-01

    A prototype lanthanide borosilicate (LaBS) glass containing 10 mass % plutonium was reacted with water vapor at 200 C for periods of 14 to 56 days. These tests, while not designed to replicate specific conditions that may be found in a potential geologic repository (e.g., Yucca Mountain), have been shown to accelerate alteration phase formation. The surfaces of the glass samples, along with alteration phases, were examined with a transmission electron microscope (TEM). Tests of 14 days produced macroscopic (∼ 20 microm) crystallites of a plutonium-lanthanide silicate. An extensive alteration layer was found on the glass surface containing amorphous aluminosilicate layered with bands of a cryptocrystalline plutonium silicate. After 56 days of testing, additional alteration phases were formed, including a strontium lanthanide oxide phase. One of the options for disposal of surplus plutonium, particularly for impure residues that may be unfit for production of MOX fuel, is vitrification followed by geologic disposal. Since geologic disposal requires a passive system to isolate the radiotoxic elements from the biosphere, it is important to understand the possible corrosion mechanisms of the waste form

  10. WAXS investigation of lanthanide borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Bouty, O. [DEN/DTEC/SEPE, CEA Marcoule, BP 17171, Bagnols-sur-Ceze cedex, 30207 (France); Delaye, J.M.; DeBonfils, J.; Peuget, S. [DEN/DTCD/SECM, CEA Marcoule, BP 17171, Bagnols-sur-Ceze cedex, 30207 (France)

    2008-07-01

    Structural characterization of nuclear glasses requires the combination of several experimental and simulation techniques. Experimental ones probe the electronic environment at short distances (EXAFS, NMR) or at medium range distances (WAXS, AWAXS) or the nuclear environment (neutron scattering). We have built a new competence in X Ray Wide Angle Scattering (WAXS) by mounting two based-lab diffractometers with Mo X ray tubes, one of them being located in a shielded glove box, and by writing a new software to easily extract structure factors and radial distribution functions from the experiment. We present here a preliminary study of a simplified borosilicate glass doped with Eu (europium), which is a fission product, and which is often used as a stimulant of trivalent actinides. The WAXS technique has been successfully applied, the structure factor being in good agreement with the one obtained by molecular dynamics simulation. Thus, knowledge of the Eu local environment has been deduced and results compared with data from EXAFS and NMR analysis. (authors)

  11. Understanding the structural drivers governing glass-water interactions in borosilicate based model bioactive glasses.

    Science.gov (United States)

    Stone-Weiss, Nicholas; Pierce, Eric M; Youngman, Randall E; Gulbiten, Ozgur; Smith, Nicholas J; Du, Jincheng; Goel, Ashutosh

    2018-01-01

    The past decade has witnessed a significant upsurge in the development of borate and borosilicate based resorbable bioactive glasses owing to their faster degradation rate in comparison to their silicate counterparts. However, due to our lack of understanding about the fundamental science governing the aqueous corrosion of these glasses, most of the borate/borosilicate based bioactive glasses reported in the literature have been designed by "trial-and-error" approach. With an ever-increasing demand for their application in treating a broad spectrum of non-skeletal health problems, it is becoming increasingly difficult to design advanced glass formulations using the same conventional approach. Therefore, a paradigm shift from the "trial-and-error" approach to "materials-by-design" approach is required to develop new-generations of bioactive glasses with controlled release of functional ions tailored for specific patients and disease states, whereby material functions and properties can be predicted from first principles. Realizing this goal, however, requires a thorough understanding of the complex sequence of reactions that control the dissolution kinetics of bioactive glasses and the structural drivers that govern them. While there is a considerable amount of literature published on chemical dissolution behavior and apatite-forming ability of potentially bioactive glasses, the majority of this literature has been produced on silicate glass chemistries using different experimental and measurement protocols. It follows that inter-comparison of different datasets reveals inconsistencies between experimental groups. There are also some major experimental challenges or choices that need to be carefully navigated to unearth the mechanisms governing the chemical degradation behavior and kinetics of boron-containing bioactive glasses, and to accurately determine the composition-structure-property relationships. In order to address these challenges, a simplified

  12. Composition-Structure-Property Relations of Compressed Borosilicate Glasses

    Science.gov (United States)

    Svenson, Mouritz N.; Bechgaard, Tobias K.; Fuglsang, Søren D.; Pedersen, Rune H.; Tjell, Anders Ø.; Østergaard, Martin B.; Youngman, Randall E.; Mauro, John C.; Rzoska, Sylwester J.; Bockowski, Michal; Smedskjaer, Morten M.

    2014-08-01

    Hot isostatic compression is an interesting method for modifying the structure and properties of bulk inorganic glasses. However, the structural and topological origins of the pressure-induced changes in macroscopic properties are not yet well understood. In this study, we report on the pressure and composition dependences of density and micromechanical properties (hardness, crack resistance, and brittleness) of five soda-lime borosilicate glasses with constant modifier content, covering the extremes from Na-Ca borate to Na-Ca silicate end members. Compression experiments are performed at pressures ≤1.0 GPa at the glass transition temperature in order to allow processing of large samples with relevance for industrial applications. In line with previous reports, we find an increasing fraction of tetrahedral boron, density, and hardness but a decreasing crack resistance and brittleness upon isostatic compression. Interestingly, a strong linear correlation between plastic (irreversible) compressibility and initial trigonal boron content is demonstrated, as the trigonal boron units are the ones most disposed for structural and topological rearrangements upon network compaction. A linear correlation is also found between plastic compressibility and the relative change in hardness with pressure, which could indicate that the overall network densification is responsible for the increase in hardness. Finally, we find that the micromechanical properties exhibit significantly different composition dependences before and after pressurization. The findings have important implications for tailoring microscopic and macroscopic structures of glassy materials and thus their properties through the hot isostatic compression method.

  13. Chemical durability of zinc borosilicate nuclear waste glass

    International Nuclear Information System (INIS)

    Westsik, J.H. Jr.; Mendel, J.E.

    1977-03-01

    Chemical durability is of primary concern when evaluating the safety of waste glass. For this reason, testing the leachability of waste glasses is a fundamental part of their development and characterization. The leachability is also very much a function of glass composition as previously discussed. This discussion is limited to a representative waste glass composition, a high-zinc borosilicate formulation which has been studied in detail by Battelle Pacific Northwest Laboratories

  14. Assessment of Savannah River borosilicate glass in the repository environment

    International Nuclear Information System (INIS)

    Plodinec, M.J.; Wicks, G.G.; Bibler, N.E.

    1982-04-01

    Since 1973, borosilicate glass has been studied as a matrix for the immobilization of high-level radioactive waste generated at the Savannah River Plant (SRP). In 1977, efforts began to develop and test the large-scale equipment necessary to convert the alkaline waste slurries at SRP into a durable borosilicate glass. A process has now been developed for the proposed Defense Waste Processing Facility (DWPF) which will annually produce approximately 500 canisters of SRP waste glass which will be stored on an interim basis on the Savannah River site. Current national policy calls for the permanent disposal of high-level waste in deep geologic repositories. In the repository environment, SRP waste glass will eventually be exposed to such stresses as lithostatic or hydrostatic pressures, radiation fields, and self-heating due to radioactive decay. In addition, producing and handling each canister of glass will also expose the glass to thermal and mechanical stresses. An important objective of the extensive glass characterization and testing programs of the Savannah River Laboratory (SRL) has been to determine how these stresses affect the performance of SRP waste glass. The results of these programs indicate that: these stresses will not significantly affect the performance of borosilicate glass containing SRP waste; and SRP waste glass will effectively immobilize hazardous radionuclides in the repository environment

  15. Utilization of borosilicate glass for transuranic waste immobilization

    International Nuclear Information System (INIS)

    Ledford, J.A.; Williams, P.M.

    1979-01-01

    Incinerated transuranic waste and other low-level residues have been successfully vitrified by mixing with boric acid and sodium carbonate and heating to 1050 0 C in a bench-scale continuous melter. The resulting borosilicate glass demonstrates excellent mechanical durability and chemical stability

  16. IR study of Pb–Sr titanate borosilicate glasses

    Indian Academy of Sciences (India)

    Administrator

    IR study of Pb–Sr titanate borosilicate glasses. C R GAUTAM*, DEVENDRA KUMAR. † and OM PARKASH. †. Department of Physics, University of Lucknow, Lucknow 226 007, India. †. Department of Ceramic Engineering, Institute of Technology, Banaras Hindu University, Varanasi 221 005, India. MS received 3 January ...

  17. Low Velocity Sphere Impact of a Borosilicate Glass

    Energy Technology Data Exchange (ETDEWEB)

    Morrissey, Timothy G [ORNL; Ferber, Mattison K [ORNL; Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL

    2012-05-01

    This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Borofloat borosilicate glass, and is a follow-up to a similar study completed by the authors on Starphire soda-lime silicate glass last year. The response of the borosilicate glass to impact testing at different angles was also studied. The Borofloat glass was supplied by the US Army Research Laboratory and its tin-side was impacted or indented. The intent was to better understand low velocity impact response in the Borofloat. Seven sphere materials were used whose densities bracket that of rock: borosilicate glass, soda-lime silicate glass, silicon nitride, aluminum oxide, zirconium oxide, carbon steel, and a chrome steel. A gas gun or a ball-drop test setup was used to produce controlled velocity delivery of the spheres against the glass tile targets. Minimum impact velocities to initiate fracture in the Borofloat were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the seven sphere-Borofloat-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) BS glass responded similarly to soda-lime silicate glass when spherically indented but quite differently under sphere impact conditions; (2) Frictional effects contributed to fracture initiation in BS glass when it spherically indented. This effect was also observed with soda-lime silicate glass; (3) The force necessary to initiate fracture in BS glass under spherical impact decreases with increasing elastic modulus of the sphere material. This trend is opposite to what was observed with soda-lime silicate glass. Friction cannot explain this trend and the authors do not have a legitimate explanation for it yet; (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than under quasi-static conditions. That

  18. X-ray tomography of feed-to-glass transition of simulated borosilicate waste glasses

    Czech Academy of Sciences Publication Activity Database

    Harris, W.H.; Guillen, D.P.; Kloužek, Jaroslav; Pokorný, P.; Yano, T.; Lee, S.; Schweiger, M. J.; Hrma, P.

    2017-01-01

    Roč. 100, č. 9 (2017), s. 3883-3894 ISSN 0002-7820 Institutional support: RVO:67985891 Keywords : borosilicate glass * computed tomography * glass melting * morphology * nuclear waste * X-ray Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 2.841, year: 2016

  19. INTERFACE DEFEAT OF LONG RODS IMPACTING BOROSILICATE GLASS EXPERIMENTAL RESULTS

    Science.gov (United States)

    2009-02-01

    impact velocity vc consumption velocity vF failure front velocity tCu time to penetrate the Cu buffer or cover plate tdwell time interval that rod...dwelled on glass surface = tpen – tCu tpen time to begin penetration after impact vhydro hydrodynamic penetration velocity, Eqn. (4) ρt target...impact velocity for bare borosilicate glass. Table 4. Further Analyses of Experimental Data oc dCu h vp tCu tpen tdwell Exp. [mm] [mm] [mm] [m/s

  20. Sulphate Incorporation in Borosilicate Glasses and Melts: a Kinetic Approach

    Energy Technology Data Exchange (ETDEWEB)

    Lenoir, M. [CEA, DEN, Laboratoire d' etude et de Developpement de Matrices de Conditionnement, Centre de Marcoule, 30207 Bagnols-sur-Ceze (France); Physique des Mineraux et Magmas, UMR 7047, CNRS- Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris 05 (France); Grandjean, A. [Institut de Chimie Separative de Marcoule, UMR 5257, Laboratoire des Nanomateriaux Autoreparants, Marcoule, 30207 Bagnols-sur-Ceze (France); Dussossoy, J.L. [CEA, DEN, Laboratoire d' etude et de Developpement de Matrices de Conditionnement, Centre de Marcoule, 30207 Bagnols-sur-Ceze (France); Neuville, D.R. [Physique des Mineraux et Magmas, UMR 7047, CNRS- Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris 05 (France)

    2008-07-01

    The kinetics of sulphate departure in a sodium borosilicate melt were studied using in situ Raman spectroscopy. This technique allows the quantification of the amount of sulphate dissolved in a borosilicate glass as a function of heating time by comparison with measurements obtained by microprobe wavelength dispersive spectrometry. To quantify the sulphate content obtained with Raman spectroscopy, the integrated intensity of the sulphate band at 990 cm{sup -1} was scaled to the sum of the integrated bands between 800 and 1200 cm{sup -1}, bands that are assigned to Qn silica units on the basis of previous literature. Calibration curves were then determined for two different samples. An evaluation of the kinetics of departure of sulphate could thus be made as a function of the viscosity of the borosilicate glass, showing that the kinetics were controlled by the diffusion of sulphate and its volatilization from the melt. This experimental method allows in situ measurements of sulphate content at high temperature which cannot be obtained by any other simple technique. (authors)

  1. Alpha self irradiation effects in nuclear borosilicate glass

    International Nuclear Information System (INIS)

    Peuget, S.; Roudil, D.; Deschanels, X.; Jegou, C.; Broudic, V.; Bart, J.M.

    2004-01-01

    The properties of actinide glasses are studied in the context of high-level waste management programs. Reprocessing high burnup fuels in particular will increase the minor actinide content in the glass package, resulting in higher cumulative alpha decay doses in the glass, and raising the question of the glass matrix behavior and especially its containment properties. The effect of alpha self-irradiation on the glass behavior is evaluated by doping the glass with a short-lived actinide ( 244 Cm) to reach in several years the alpha dose received by the future glass packages over several thousand years. 'R7T7' borosilicate glasses were doped with 3 different curium contents (0.04, 0.4 and 1.2 wt% 244 CmO 2 ). The density and mechanical properties of the curium-doped glasses were characterized up to 2. 10 18 α/g, revealing only a slight evolution of the macroscopic behavior of R7T7 glass in this range. The leaching behavior of curium-doped glass was also studied by Soxhlet tests. The results do not show any significant evolution of the initial alteration rate with the alpha dose. (authors)

  2. Phase separation of borosilicate glass with molybdenum oxide addition and pore structure of porous glass

    International Nuclear Information System (INIS)

    Tanaka, Hiroshi; Yazawa, Tetsuo; Eguchi, Kiyohisa

    1985-01-01

    Porous glass prepared by acid leaching of phase-separated soda borosilicate glass usually contains colloidal silica which originates from the silica component in the borate phase. Molybdenum trioxide was added to the starting borosilicate glass to prevent the formation of colloidal silica. It promoted the opacification of the starting glass. Opaque glasses in as-cast state showed a spherical phase-separated structure and were amorphous by X-ray doffraction. The phase separation was related to the solubility of molybdenum oxide in the glass. The phase separation occurs at a high temperature and proceeds rapidly in the cooling process of the cast glass. Another type of phase separation, which was assigned to the phase separation in the ternary soda borosilicate glass, took place during the heat treatment of the opaque glasses. When the phase-separated structure of the heat-treated glasses is interconnected, the porous glasses composed of silica skeleton are obtained by the acid leaching of the phase-separated glasses. The colloidal silica in the porous glass increased with increasing silica content of the starting glass and at the same time the volume of the pores of skeleton decreased markedly. (author)

  3. Determination of the free enthalpies of formation of borosilicate glasses

    International Nuclear Information System (INIS)

    Linard, Y.

    2000-01-01

    This work contributes to the study of the thermochemical properties of nuclear waste glasses. Results are used to discuss mechanisms and parameters integrated in alteration models of conditioning materials. Glass is a disordered material defined thermodynamically as a non-equilibrium state. Taking into account one order parameter to characterise its configurational state, the metastable equilibrium for the glass was considered and the main thermochemical properties were determined. Calorimetric techniques were used to measure heat capacities and formation enthalpies of borosilicate glasses (from 3 to 8 constitutive oxides). Formation Entropies were measured too, using the entropy theory of relaxation processes proposed by Adam and Gibbs (1965). The configurational entropy contribution were determined from viscosity measurements. This set of data has allowed the calculation of Gibb's free energies of dissolution of glasses in pure water. By comparison with leaching experiments, it has been demonstrated that the decreasing of the dissolution rate at high reaction progress cannot be associated to the approach of an equilibrium between the sound glass and the aqueous solution. The composition changes of the reaction area at the glass surface need to be considered too. To achieve a complete description of the thermodynamic stability, the equilibrium between hydrated de-alkalinized glass and/or the gel layer with the aqueous solution should also be evaluated. (author)

  4. Antagonist effects of calcium on borosilicate glass alteration

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Depierre, S. [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France); Angeli, F., E-mail: frederic.angeli@cea.fr [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France); Frizon, F. [CEA Marcoule, DTCD SECM LP2C, 30207 Bagnols sur Cèze (France); Gin, S. [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France)

    2013-10-15

    Graphical abstract: Display Omitted -- Highlights: •Kinetic study of glass alteration is investigated in calcium-enriched solutions. •New insights into silicon–calcium interactions in glass/cement systems are proposed. •Glass alteration is controlled by pH, Ca concentration and reaction progress. •Evidence of antagonist effects according to the importance of these parameters. -- Abstract: Numerous studies have been conducted on glass and cement durability in contact with water, but very little work to date has focused directly on interactions between the two materials. These interactions are mostly controlled by silicon–calcium reactivity. However, the physical and chemical processes involved remain insufficiently understood to predict the evolution of coupled glass–cement systems used in several industrial applications. Results are reported from borosilicate glass alteration in calcium-rich solutions. Our data show that four distinct behaviors can be expected according to the relative importance of three key parameters: the pH, the reaction progress (short- or long-term alteration) and the calcium concentration. Glass alteration is thus controlled by specific mechanisms depending on the solution chemistry: calcium complexation at the glass surface, precipitation of calcium silicate hydrates (C–S–H) or calcium incorporation in the altered layer. These findings highlight the impact of silicon–calcium interactions on glass durability and open the way for a better understanding of glass–cement mixing in civil engineering applications as well as in nuclear waste storage.

  5. Antagonist effects of calcium on borosilicate glass alteration

    Science.gov (United States)

    Mercado-Depierre, S.; Angeli, F.; Frizon, F.; Gin, S.

    2013-10-01

    Numerous studies have been conducted on glass and cement durability in contact with water, but very little work to date has focused directly on interactions between the two materials. These interactions are mostly controlled by silicon-calcium reactivity. However, the physical and chemical processes involved remain insufficiently understood to predict the evolution of coupled glass-cement systems used in several industrial applications. Results are reported from borosilicate glass alteration in calcium-rich solutions. Our data show that four distinct behaviors can be expected according to the relative importance of three key parameters: the pH, the reaction progress (short- or long-term alteration) and the calcium concentration. Glass alteration is thus controlled by specific mechanisms depending on the solution chemistry: calcium complexation at the glass surface, precipitation of calcium silicate hydrates (C-S-H) or calcium incorporation in the altered layer. These findings highlight the impact of silicon-calcium interactions on glass durability and open the way for a better understanding of glass-cement mixing in civil engineering applications as well as in nuclear waste storage.

  6. Crystallization characteristics of lithium calcium gallium aluminium borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, H.; Salama, S.N.; Salman, S.M. [National Research Centre, Cairo (Egypt). Glass Research Dept.

    2002-07-01

    The crystallization processes of lithium calcium gallium borosilicate glass containing Al{sub 2}O{sub 3} have been followed by X-ray diffractometry (XRD), differential thermal analysis (DTA) and scanning electron microscope (SEM). Lithium gallium silicate - LiGaSiO{sub 4} phase was formed as a major constituent during the crystallization of the base glass. Solid solutions of lithium aluminosilicate and lithium aluminium gallium silicate - LiAl{sub 0.5}Ga{sub 0.5}SiO{sub 4} phases were mostly formed as a function of Al{sub 2}O{sub 3}/Ga{sub 2}O{sub 3} ratios in the glasses. Varieties of lithium borate phases including Li{sub 2}B{sub 4}O{sub 7}, {alpha}-Li{sub 4}B{sub 2}O{sub 5}, Li{sub 3}BO{sub 3}, {beta}-LiBO{sub 2} and LiB{sub 3}O{sub 5} phases were detected together with lithium metasilicate and lithium disilicate. Different calcium bearing phases including wollastonite-CaSiO{sub 3}, calcium borosilicate -Ca{sub 2}B{sub 2}SiO{sub 7}, larnite -Ca{sub 2}SiO{sub 4}, rankinite -Ca{sub 3}Si{sub 2}O{sub 7}, and calcium borate -CaB{sub 2}O{sub 4} were mainly detected as a function of heat-treatment in the CaO-containing samples. The role played by the glass oxide constituents in determining the crystallization characteristics and the nature of the crystal phases formed in the glasses are discussed. (orig.)

  7. Porous vycor glass tube joined to borosilicate glass

    Science.gov (United States)

    Abe, Shinichi; Kikuchi, Takemitsu; Onodera, Shinji

    1992-09-01

    Porous glass can absorb various size of molecules with large surface area even in high temperature. However, it is difficult to use porous glass tubes at high-temperature, for example as a separation membrane for hydrogen condensation, because adhesives at joining sites could be damaged. In this study, welding of a porous glass tube and a glass tube was attempted to develop a gas separation membrane used at 500 C. Since forms present in porous glass may cause crack at high temperature, it is necessary to remove such forms by heat processing. Such porous glass is called to be porous vycor glass, which contains quartz 6 percents, and can be joined with a quartz tube. As a result, a gas separator with porous glass membrane which is joined by this process could endure high temperature up to 600 C and could maintain high vacuum.

  8. Structural origin of hardness decrease in irradiated sodium borosilicate glass

    Science.gov (United States)

    Yuan, Wei; Peng, Haibo; Sun, Mengli; Du, Xin; Lv, Peng; Zhao, Yan; Liu, Fengfei; Zhang, Bingtao; Zhang, Xiaoyang; Chen, Liang; Wang, Tieshan

    2017-12-01

    Mechanical properties such as hardness and modulus of sodium borosilicate (NBS) glasses in irradiation conditions were studied extensively in recent years. With irradiation of heavy ions, a trend that the hardness of NBS glasses decreased and then stabilized with increase of dose has been reported. Variations in network structures were suggested for the decrease of hardness after irradiation. However, details of these variations in a network of glass are not clear yet. In this paper, molecular dynamics was applied to simulate the network variations in a type of NBS glass and the changes in hardness after xenon irradiation. The simulation results indicated that hardness variation decreased with fluence in an exponential law, which was consistent with experimental results. The origin of hardness decrease after irradiation might be attributed to the break of Biv-O links that could be derived from the (1) decrease of average coordinate number of boron, (2) decrease of Si-O-Biv bonds, and (3) increase of non-bridging oxygen.

  9. Magnetic Glass Ceramics by Sintering of Borosilicate Glass and Inorganic Waste

    Directory of Open Access Journals (Sweden)

    Inès M. M. M. Ponsot

    2014-07-01

    Full Text Available Ceramics and glass ceramics based on industrial waste have been widely recognized as competitive products for building applications; however, there is a great potential for such materials with novel functionalities. In this paper, we discuss the development of magnetic sintered glass ceramics based on two iron-rich slags, coming from non-ferrous metallurgy and recycled borosilicate glass. The substantial viscous flow of the glass led to dense products for rapid treatments at relatively low temperatures (900–1000 °C, whereas glass/slag interactions resulted in the formation of magnetite crystals, providing ferrimagnetism. Such behavior could be exploited for applying the obtained glass ceramics as induction heating plates, according to preliminary tests (showing the rapid heating of selected samples, even above 200 °C. The chemical durability and safety of the obtained glass ceramics were assessed by both leaching tests and cytotoxicity tests.

  10. Dynamic fracture and fragmentation patterns of borosilicate laminate glasses

    Directory of Open Access Journals (Sweden)

    Gómez del Río, T.

    2009-10-01

    Full Text Available The dynamic behaviour of laminate borosilicate glasses (BSG with polyvinylbutiral (PVB interfaces (0,38 mm located at different distances from the impact point have been studied and compared with monolithic glass. The mechanical behaviour under impact loads have been studied using a compression split Hopkinson pressure bar (SHPB. In these experiments, the stress-strain curves of the materials at high loading rates and the capability of transmitting and reflecting the impact energy have been determined. The influence of the position of the interface on the fragmentation statistics of the SHPB recovered fragments has also been considered and analysed according to the published theoretical models.

    En este trabajo se ha estudiado los comportamientos dinámicos de un vidrio monolítico de borosilicato y varios laminados de cristal de borosilicato (BSG con intercaras de polyvinylbutiral (PVB (0,38 mm situados a diferentes distancias respecto del punto de impacto. Los resultados de las diferentes configuraciones de laminados se han comparado con el vidrio monolítico. El comportamiento mecánico bajo cargas de impacto se han estudiado realizando ensayos de compresión con una barra Hopkinson (SHPB. A partir de estos experimentos se obtienen las curvas tensión-deformación de los materiales a altas velocidades de carga y su capacidad de transmitir y reflejar la energía del impacto. La influencia de la posición de la interfaz en las estadísticas de la fragmentación de los fragmentos recuperados también se ha considerado y analizado de acuerdo a los modelos teóricos publicados.

  11. Effect of heat treatment duration on phase separation of sodium borosilicate glass, containing copper

    International Nuclear Information System (INIS)

    Shejnina, T.G.; Gutner, S.Kh.; Anan'in, N.I.

    1989-01-01

    The effect of heat treatment duration on phase separation of sodium borosilicate (SBS) glass, containing copper is studied. It is stated that phase separation close to equilibrium one is attained under 12 hours of heat treatment of SBS glass containing copper

  12. Modelling the evaporation of boron species. Part 1: Alkali-free borosilicate glass melts

    NARCIS (Netherlands)

    Limpt, J.A.C. van; Beerkens, R.G.C.; Cook, S.; O'Connor, R.; Simon, J.

    2011-01-01

    A laboratory test facility has been used to measure the boron evaporation rates from borosilicate glass melts. The impact of furnace atmosphere composition and glass melt composition on the temperature dependent boron evaporation rates has been investigated experimentally. In Part 1 of this paper

  13. Atomic layer deposited borosilicate glass microchannel plates for large area event counting detectors

    International Nuclear Information System (INIS)

    Siegmund, O.H.W.; McPhate, J.B.; Tremsin, A.S.; Jelinsky, S.R.; Hemphill, R.; Frisch, H.J.; Elam, J.; Mane, A.

    2012-01-01

    Borosilicate glass micro-capillary array substrates with 20 μm and 40 μm pores have been deposited with resistive, and secondary electron emissive, layers by atomic layer deposition to produce functional microchannel plates. Device formats of 32.7 mm and 20 cm square have been fabricated and tested in analog and photon counting modes. The tests show amplification, imaging, background rate, pulse shape and lifetime characteristics that are comparable to standard glass microchannel plates. Large area microchannel plates of this type facilitate the construction of 20 cm format sealed tube sensors with strip-line readouts that are being developed for Cherenkov light detection. Complementary work has resulted in Na 2 KSb bialkali photocathodes with peak quantum efficiency of 25% being made on borosilicate glass. Additionally GaN (Mg) opaque photocathodes have been successfully made on borosilicate microchannel plates.

  14. Atomic layer deposited borosilicate glass microchannel plates for large area event counting detectors

    Science.gov (United States)

    Siegmund, O. H. W.; McPhate, J. B.; Tremsin, A. S.; Jelinsky, S. R.; Hemphill, R.; Frisch, H. J.; Elam, J.; Mane, A.; Lappd Collaboration

    2012-12-01

    Borosilicate glass micro-capillary array substrates with 20 μm and 40 μm pores have been deposited with resistive, and secondary electron emissive, layers by atomic layer deposition to produce functional microchannel plates. Device formats of 32.7 mm and 20 cm square have been fabricated and tested in analog and photon counting modes. The tests show amplification, imaging, background rate, pulse shape and lifetime characteristics that are comparable to standard glass microchannel plates. Large area microchannel plates of this type facilitate the construction of 20 cm format sealed tube sensors with strip-line readouts that are being developed for Cherenkov light detection. Complementary work has resulted in Na2KSb bialkali photocathodes with peak quantum efficiency of 25% being made on borosilicate glass. Additionally GaN (Mg) opaque photocathodes have been successfully made on borosilicate microchannel plates.

  15. Evaluation of the borosilicate glass matrix for the immobilization of actinide waste concentrates

    International Nuclear Information System (INIS)

    Scheffler, K.; Krause, H.

    1978-01-01

    During liquid storage of HLLW the formation of actinide enriched sludges is being expected due to the hydrolysis esp. of plutonium and other mechanisms. Also during melting of HLW glasses an increase of top-to-bottom actinide concentration can take place. Both effects will account for increased actinide concentrations in the glasses. The phenomena of these actinide enrichment processes are studied. Following the investigations on actinide compatibility with HLW glass a research program has been started aiming at the vitrification of special actinide waste concentrates. A hazards evaluation is established on the basis of experimental results for simulated disposal periods of millenia with respect to leaching of actinides and alpha irradiation damage. The chemical compatibility of borosilicate glass with actinides has been determined and basic considerations are drawn for the solidification of different types of alpha-bearing wastes in borosilicate glasses

  16. High-level waste glass compendium; what it tells us concerning the durability of borosilicate waste glass

    International Nuclear Information System (INIS)

    Cunnane, J.C.; Allison, J.

    1993-01-01

    Facilities for vitrification of high-level nuclear waste in the United States are scheduled for startup in the next few years. It is, therefore, appropriate to examine the current scientific basis for understanding the corrosion of high-level waste borosilicate glass for the range of service conditions to which the glass products from these facilities may be exposed. To this end, a document has been prepared which compiles worldwide information on borosilicate waste glass corrosion. Based on the content of this document, the acceptability of canistered waste glass for geological disposal is addressed. Waste glass corrosion in a geologic repository may be due to groundwater and/or water vapor contact. The important processes that determine the glass corrosion kinetics under these conditions are discussed based on experimental evidence from laboratory testing. Testing data together with understanding of the long-term corrosion kinetics are used to estimate radionuclide release rates. These rates are discussed in terms of regulatory performance standards

  17. High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 3

    International Nuclear Information System (INIS)

    Cunnane, J.C.

    1994-03-01

    The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II

  18. High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)] [and others

    1994-03-01

    The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II.

  19. Simulating the physicochemical properties of borosilicate and lanthanum borosilicate glasses using a polarizable force field

    International Nuclear Information System (INIS)

    Pacaud, Fabien

    2016-01-01

    as result of the nuclear waste vitrification, the knowledge and understanding of the dynamic and structural properties of glasses, including the behavior of radionuclides, is important (in liquid and solid phases). It can influence the glass waste properties, the lifetime of the vitrification process and the amount of radionuclides introduced in the glass matrix. Molecular dynamic simulations have been done to study the influence of the glass matrix composition into the structural and dynamic properties of the glass. a simplified glass, with 3 major oxides of the R7T7 glass such as SiO 2 , B 2 O 3 and Na 2 O, have been used to simulate the R7T7 industrial nuclear glass (a 30 oxides glass). The inclusion of La 2 O 3 allows us to simulate the impact of fission products and minor actinides into the properties of the glass matrix. Both systems, the SiO 2 -B 2 O 3 -Na 2 O and SiO 2 -B 2 O 3 -Na 2 O-La 2 O 3 , allow us to study the sodium and lanthanum effect on the properties of the glass. During this work, a polarizable force field has been developed to do these simulations. The results obtained at room temperature let us reproduce the experimental results of the structure, the distribution of BIII/BIV and the density. a study has been done on the viscosity and electrical conductivity of the liquid. The distribution BIV/BIII and the influence of the structural changes on the density along with the temperature have also been observed with thermal quenching. The current limits of this approach are also described. (author) [fr

  20. Quantification of the boron speciation in alkali borosilicate glasses by electron energy loss spectroscopy

    DEFF Research Database (Denmark)

    Cheng, D.S.; Yang, G.; Zhao, Y.Q.

    2015-01-01

    developed a method based on electron energy loss spectroscopy (EELS) data acquisition and analyses, which enables determination of the boron speciation in a series of ternary alkali borosilicate glasses with constant molar ratios. A script for the fast acquisition of EELS has been designed, from which...

  1. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds.

    Science.gov (United States)

    Wang, Hui; Zhao, Shichang; Xiao, Wei; Xue, Jingzhe; Shen, Youqu; Zhou, Jie; Huang, Wenhai; Rahaman, Mohamed N; Zhang, Changqing; Wang, Deping

    2016-01-01

    Copper doped borosilicate glasses (BG-Cu) were studied by means of FT-IR, Raman, UV-vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B-O bond of BO4 groups at 980 cm(-1), while they decrease that of BO2O(-) groups at 1440-1470 cm(-1) as shown by Raman spectra. A negative shift was observed from (11)B and (29)Si NMR spectra. The (11)B NMR spectra exhibited a clear transformation from BO3 into BO4 groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG-Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. High-level waste borosilicate glass a compendium of corrosion characteristics. Volume 1

    International Nuclear Information System (INIS)

    Cunnane, J.C.

    1994-03-01

    Current plans call for the United States Department of Energy (DOE) to start up facilities for vitrification of high-level radioactive waste (HLW) stored in tanks at the Savannah River Site, Aiken, South Carolina, in 1995; West Valley Demonstration Project, West Valley, New York, in 1996; and at the Hanford Site, Richland, Washington, after the year 2000. The product from these facilities will be canistered HLW borosilicate glass, which will be stored, transported, and eventually disposed of in a geologic repository. The behavior of this glass waste product, under the range of likely service conditions, is the subject of considerable scientific and public interest. Over the past few decades, a large body of scientific information on borosilicate waste glass has been generated worldwide. The intent of this document is to consolidate information pertaining to our current understanding of waste glass corrosion behavior and radionuclide release. The objective, scope, and organization of the document are discussed in Section 1.1, and an overview of borosilicate glass corrosion is provided in Section 1.2. The history of glass as a waste form and the international experience with waste glass are summarized in Sections 1.3 and 1.4, respectively

  3. High-level waste borosilicate glass a compendium of corrosion characteristics. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)

    1994-03-01

    Current plans call for the United States Department of Energy (DOE) to start up facilities for vitrification of high-level radioactive waste (HLW) stored in tanks at the Savannah River Site, Aiken, South Carolina, in 1995; West Valley Demonstration Project, West Valley, New York, in 1996; and at the Hanford Site, Richland, Washington, after the year 2000. The product from these facilities will be canistered HLW borosilicate glass, which will be stored, transported, and eventually disposed of in a geologic repository. The behavior of this glass waste product, under the range of likely service conditions, is the subject of considerable scientific and public interest. Over the past few decades, a large body of scientific information on borosilicate waste glass has been generated worldwide. The intent of this document is to consolidate information pertaining to our current understanding of waste glass corrosion behavior and radionuclide release. The objective, scope, and organization of the document are discussed in Section 1.1, and an overview of borosilicate glass corrosion is provided in Section 1.2. The history of glass as a waste form and the international experience with waste glass are summarized in Sections 1.3 and 1.4, respectively.

  4. Preliminary assessment of modified borosilicate glasses for chromium and ruthenium immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Farid, Osama M. [Reactors Department, Nuclear Research Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt); Centre of Nuclear Engineering (CNE), Department of Materials, Imperial College London, London, SW7 2BP (United Kingdom); Abdel Rahman, R.O., E-mail: alaarehab@yahoo.com [Hot Laboratory Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt)

    2017-01-15

    The feasibility of using modified alkali borosilicate glasses for ruthenium and chromium immobilization is preliminary assessed by investigating the immobilization system structure under normal conditions. Within this context, reference alkali borosilicate, and simulated Magnox-modified glasses were prepared and studied. The results indicate that ruthenium is immobilized in the vitreous structure as encapsulated RuO{sub 2} crystallites that act as seeds for heterogeneous nucleation of other crystalline phases. The presence of Zn, as modifier, has contributed to chromium immobilization in zincochromite spinel structure, whereas Ca is accommodated in the vitreous structure. Immobilization performance was evaluated by conducting conservative static leach test and studying the leached glass. Leached glass morphology was altered, where near surface reference glass is leached over 400 nm and simulated Magnox-modified sample is altered over 300 nm. Normalized release rates are within normal range for borosilicate material. For simulated Magnox-modified sample, Ca and alkali structural element, i.e. Na and Li, are leached via ion-exchange reaction. The ion-exchanged fraction equals 1.06 × 10{sup −8} mol/m{sup 2} s and chromium has slightly lower normalized release rate value than ruthenium. - Highlights: • The presence of modifiers and waste oxides led to localized de-vitrification. • Ruthenium is encapsulated within the vitreous glass network as RuO{sub 2} crystals. • Chromium is immobilized within the zincochromite spinel structure. • Pitting and cracks induced by leaching did not affect the immobilization performance.

  5. Comparison of hardness variation of ion irradiated borosilicate glasses with different projected ranges

    Science.gov (United States)

    Sun, M. L.; Peng, H. B.; Duan, B. H.; Liu, F. F.; Du, X.; Yuan, W.; Zhang, B. T.; Zhang, X. Y.; Wang, T. S.

    2018-03-01

    Borosilicate glass has potential application for vitrification of high-level radioactive waste, which attracts extensive interest in studying its radiation durability. In this study, sodium borosilicate glass samples were irradiated with 4 MeV Kr17+ ion, 5 MeV Xe26+ ion and 0.3 MeV P+ ion, respectively. The hardness of irradiated borosilicate glass samples was measured with nanoindentation in continuous stiffness mode and quasi continuous stiffness mode, separately. Extrapolation method, mean value method, squared extrapolation method and selected point method are used to obtain hardness of irradiated glass and a comparison among these four methods is conducted. The extrapolation method is suggested to analyze the hardness of ion irradiated glass. With increasing irradiation dose, the values of hardness for samples irradiated with Kr, Xe and P ions dropped and then saturated at 0.02 dpa. Besides, both the maximum variations and decay constants for three kinds of ions with different energies are similar indicates the similarity behind the hardness variation in glasses after irradiation. Furthermore, the hardness variation of low energy P ion irradiated samples whose range is much smaller than those of high energy Kr and Xe ions, has the same trend as that of Kr and Xe ions. It suggested that electronic energy loss did not play a significant role in hardness decrease for irradiation of low energy ions.

  6. 3 and 4 oxidation state element solubilities in borosilicate glasses. Implement to actinides in nuclear glasses

    International Nuclear Information System (INIS)

    Cachia, J.N.

    2005-12-01

    In order to ensure optimal radionuclides containment, the knowledge of the actinide loading limits in nuclear waste glasses and also the comprehension of the solubilization mechanisms of these elements are essential. A first part of this manuscript deals with the study of the differences in solubility of the tri and tetravalent elements (actinides and surrogates) particularly in function of the melting temperature. The results obtained indicate that trivalent elements (La, Gd, Nd, Am, Cm) exhibit a higher solubility than tetravalent elements (Hf, Th, Pu). Consequently, it was planned to reduce plutonium at the oxidation state (III), the later being essentially tetravalent in borosilicate glasses. An innovating reduction process of multi-valent elements (cerium, plutonium) using silicon nitride has been developed in a second part of this work. Reduced plutonium-bearing glasses synthesized by Si 3 N 4 addition made it possible to double the plutonium solubility from 2 to 4 wt% at 1200 deg C. A structural approach to investigate the differences between tri and tetravalent elements was finally undertaken. These investigations were carried out by X-rays Absorption Spectroscopy (EXAFS) and NMR. Trivalent rare earth and actinide elements seem to behave as network modifiers while tetravalent elements rather present true intermediaries' behaviour. (author)

  7. Fabrication of Low Noise Borosilicate Glass Nanopores for Single Molecule Sensing.

    Directory of Open Access Journals (Sweden)

    Jayesh A Bafna

    Full Text Available We show low-cost fabrication and characterization of borosilicate glass nanopores for single molecule sensing. Nanopores with diameters of ~100 nm were fabricated in borosilicate glass capillaries using laser assisted glass puller. We further achieve controlled reduction and nanometer-size control in pore diameter by sculpting them under constant electron beam exposure. We successfully fabricate pore diameters down to 6 nm. We next show electrical characterization and low-noise behavior of these borosilicate nanopores and compare their taper geometries. We show, for the first time, a comprehensive characterization of glass nanopore conductance across six-orders of magnitude (1M-1μM of salt conditions, highlighting the role of buffer conditions. Finally, we demonstrate single molecule sensing capabilities of these devices with real-time translocation experiments of individual λ-DNA molecules. We observe distinct current blockage signatures of linear as well as folded DNA molecules as they undergo voltage-driven translocation through the glass nanopores. We find increased signal to noise for single molecule detection for higher trans-nanopore driving voltages. We propose these nanopores will expand the realm of applications for nanopore platform.

  8. PLUTONIUM SOLUBILITY IN HIGH-LEVEL WASTE ALKALI BOROSILICATE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Marra, J.; Crawford, C.; Fox, K.; Bibler, N.

    2011-01-04

    The solubility of plutonium in a Sludge Batch 6 (SB6) reference glass and the effect of incorporation of Pu in the glass on specific glass properties were evaluated. A Pu loading of 1 wt % in glass was studied. Prior to actual plutonium glass testing, surrogate testing (using Hf as a surrogate for Pu) was conducted to evaluate the homogeneity of significant quantities of Hf (Pu) in the glass, determine the most appropriate methods to evaluate homogeneity for Pu glass testing, and to evaluate the impact of Hf loading in the glass on select glass properties. Surrogate testing was conducted using Hf to represent between 0 and 1 wt % Pu in glass on an equivalent molar basis. A Pu loading of 1 wt % in glass translated to {approx}18 kg Pu per Defense Waste Processing Facility (DWPF) canister, or about 10X the current allowed limit per the Waste Acceptance Product Specifications (2500 g/m{sup 3} of glass or about 1700 g/canister) and about 30X the current allowable concentration based on the fissile material concentration limit referenced in the Yucca Mountain Project License Application (897 g/m{sup 3}3 of glass or about 600 g Pu/canister). Based on historical process throughput data, this level was considered to represent a reasonable upper bound for Pu loading based on the ability to provide Pu containing feed to the DWPF. The task elements included evaluating the distribution of Pu in the glass (e.g. homogeneity), evaluating crystallization within the glass, evaluating select glass properties (with surrogates), and evaluating durability using the Product Consistency Test -- Method A (PCT-A). The behavior of Pu in the melter was evaluated using paper studies and corresponding analyses of DWPF melter pour samples.The results of the testing indicated that at 1 wt % Pu in the glass, the Pu was homogeneously distributed and did not result in any formation of plutonium-containing crystalline phases as long as the glass was prepared under 'well-mixed' conditions

  9. Plutonium Solubility In High-Level Waste Alkali Borosilicate Glass

    International Nuclear Information System (INIS)

    Marra, J.; Crawford, C.; Fox, K.; Bibler, N.

    2011-01-01

    The solubility of plutonium in a Sludge Batch 6 (SB6) reference glass and the effect of incorporation of Pu in the glass on specific glass properties were evaluated. A Pu loading of 1 wt % in glass was studied. Prior to actual plutonium glass testing, surrogate testing (using Hf as a surrogate for Pu) was conducted to evaluate the homogeneity of significant quantities of Hf (Pu) in the glass, determine the most appropriate methods to evaluate homogeneity for Pu glass testing, and to evaluate the impact of Hf loading in the glass on select glass properties. Surrogate testing was conducted using Hf to represent between 0 and 1 wt % Pu in glass on an equivalent molar basis. A Pu loading of 1 wt % in glass translated to ∼18 kg Pu per Defense Waste Processing Facility (DWPF) canister, or about 10X the current allowed limit per the Waste Acceptance Product Specifications (2500 g/m 3 of glass or about 1700 g/canister) and about 30X the current allowable concentration based on the fissile material concentration limit referenced in the Yucca Mountain Project License Application (897 g/m 3 3 of glass or about 600 g Pu/canister). Based on historical process throughput data, this level was considered to represent a reasonable upper bound for Pu loading based on the ability to provide Pu containing feed to the DWPF. The task elements included evaluating the distribution of Pu in the glass (e.g. homogeneity), evaluating crystallization within the glass, evaluating select glass properties (with surrogates), and evaluating durability using the Product Consistency Test -- Method A (PCT-A). The behavior of Pu in the melter was evaluated using paper studies and corresponding analyses of DWPF melter pour samples.The results of the testing indicated that at 1 wt % Pu in the glass, the Pu was homogeneously distributed and did not result in any formation of plutonium-containing crystalline phases as long as the glass was prepared under 'well-mixed' conditions. The incorporation of 1 wt

  10. A kinetic approach of sulphur behaviour in borosilicate glasses and melts: implications for sulphate incorporation in nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lenoir, Marion [Service de Confinement des Dechets et Vitrification - Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols sur Ceze (France); Physique des Mineraux et des Magmas, UMR 7047 - CNRS, Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris Cedex 05 (France); Grandjean, Agnes [Service de Confinement des Dechets et Vitrification - Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols sur Ceze (France); Neuville, Daniel R. [Physique des Mineraux et des Magmas, UMR 7047 - CNRS, Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris Cedex 05 (France)

    2008-07-01

    The kinetics of sulphate decomposition in a borosilicate melt were studied using in situ Raman spectroscopy. This technique permits the quantification of the amount of sulphate dissolved in a borosilicate glass as a function of heating time by comparison with measurements obtained by microprobe WDS (Wavelength Dispersive Spectrometry). In order to quantify the content of sulphate obtained by Raman spectroscopy, the integrated intensity of the sulphate band at 985 cm{sup -1} was scaled to the sum of the integrated bands between 800 and 1200 cm{sup -1}, bands that are assigned to Q{sup n} silica units on the basis of previous literature. Viscosities of some borosilicate glasses are also presented here in order to study the kinetics of sulphate decomposition as a function of the viscosity of the melt. This underlines the importance of variations in viscosity depending on the composition of the melt and thus shows that viscosity is an important parameter governing the kinetics of decomposition of sulphate in borosilicate glasses. (authors)

  11. Electrical characterization of strontium titanate borosilicate glass ceramics system with bismuth oxide addition using impedance spectroscopy

    International Nuclear Information System (INIS)

    Thakur, O.P.; Kumar, Devendra; Parkash, Om; Pandey, Lakshman

    2003-01-01

    The ac electrical data, measured in the frequency range 0.1 kHz-1 MHz, were used to study the electrical response of strontium titanate borosilicate glass ceramic system with bismuth oxide addition. Complex plane plots from these electrical data for various glass ceramic samples reveal contributions from simultaneously operating polarization mechanisms to overall dielectric behavior. The complex modulus (M * ) representation of electrical data for various glass ceramic samples were found to be more informative. Equivalent circuit models, which represent the electrical behavior of glass ceramic samples, were determined using complex non-linear least square (CNLS) fitting. An attempt has been made to understand the dielectric behavior of various glass ceramics in terms of contributions arising from different polarization processes occurring at glassy matrix, crystalline phases, glass to crystal interface region and blocking electrodes. Glass ceramics containing SrTiO 3 and TiO 2 (rutile) phases show thermally stable dielectric behavior

  12. X-ray absorption and Raman spectroscopy studies of molybdenum environments in borosilicate waste glasses

    Science.gov (United States)

    McKeown, David A.; Gan, Hao; Pegg, Ian L.

    2017-05-01

    Mo-containing high-level nuclear waste borosilicate glasses were investigated as part of an effort to improve Mo loading while avoiding yellow phase crystallization. Previous work showed that additions of vanadium decrease yellow phase formation and increases Mo solubility. X-ray absorption spectroscopy (XAS) and Raman spectroscopy were used to characterize Mo environments in HLW borosilicate glasses and to investigate possible structural relationships between Mo and V. Mo XAS spectra for the glasses indicate isolated tetrahedral Mo6+O4 with Mo-O distances near 1.75 Å. V XANES indicate tetrahedral V5+O4 as the dominant species. Raman spectra show composition dependent trends, where Mo-O symmetrical stretch mode frequencies (ν1) are sensitive to the mix of alkali and alkaline earth cations, decreasing by up to 10 cm-1 for glasses that change from Li+ to Na+ as the dominant network-modifying species. This indicates that MoO4 tetrahedra are isolated from the borosilicate network and are surrounded, at least partly, by Na+ and Li+. Secondary ν1 frequency effects, with changes up to 7 cm-1, were also observed with increasing V2O5 and MoO3 content. These secondary trends may indicate MoO4-MoO4 and MoO4-VO4 clustering, suggesting that V additions may stabilize Mo in the matrix with respect to yellow phase formation.

  13. New insight into nanoparticle precipitation by electron beams in borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sabri, M.M.; Moebus, G. [University of Sheffield, Department of Materials Science and Engineering (United Kingdom)

    2017-06-15

    Nanoprecipitation in different oxide glasses by means of electron irradiation in transmission electron microscopy (TEM) has been compared in this study. Upon irradiation, groups or patterns of nanoparticles with various morphologies and sizes were formed in borosilicate glasses, loaded with zinc, copper, and silver. The study successfully includes loading ranges for the target metal from doping level (1%) over medium level (20%) to majority phase (60%). It is found that particle patterning resolution is affected by parallel processes of amorphous phase separation, glass ablation, and delocalised precipitation. In addition, via an in-situ study, it is confirmed that by heating alone without irradiation, no precipitate nanoparticles form. (orig.)

  14. A review of phase separation in borosilicate glasses, with reference to nuclear fuel waste immobilization

    International Nuclear Information System (INIS)

    Taylor, P.

    1990-08-01

    This report reviews information on miscibility limits in borosilicate glass-forming systems. It includes both a literature survey and an account of experimental work performed within the Canadian Nuclear Fuel Waste Management Program. Emphasis is placed on the measurement and depiction of miscibility limits in multicomponent (mainly quaternary) systems, and the effects of individual components on the occurrence of phase separation. The behaviour of the multicomponent system is related to that of simpler (binary and ternary) glass systems. The possible occurrence of phase separation, as well as its avoidance, during processing of nuclear waste glasses is discussed

  15. New insight into nanoparticle precipitation by electron beams in borosilicate glasses

    International Nuclear Information System (INIS)

    Sabri, M.M.; Moebus, G.

    2017-01-01

    Nanoprecipitation in different oxide glasses by means of electron irradiation in transmission electron microscopy (TEM) has been compared in this study. Upon irradiation, groups or patterns of nanoparticles with various morphologies and sizes were formed in borosilicate glasses, loaded with zinc, copper, and silver. The study successfully includes loading ranges for the target metal from doping level (1%) over medium level (20%) to majority phase (60%). It is found that particle patterning resolution is affected by parallel processes of amorphous phase separation, glass ablation, and delocalised precipitation. In addition, via an in-situ study, it is confirmed that by heating alone without irradiation, no precipitate nanoparticles form. (orig.)

  16. New insight into nanoparticle precipitation by electron beams in borosilicate glasses

    Science.gov (United States)

    Sabri, M. M.; Möbus, G.

    2017-06-01

    Nanoprecipitation in different oxide glasses by means of electron irradiation in transmission electron microscopy (TEM) has been compared in this study. Upon irradiation, groups or patterns of nanoparticles with various morphologies and sizes were formed in borosilicate glasses, loaded with zinc, copper, and silver. The study successfully includes loading ranges for the target metal from doping level (1%) over medium level (20%) to majority phase (60%). It is found that particle patterning resolution is affected by parallel processes of amorphous phase separation, glass ablation, and delocalised precipitation. In addition, via an in-situ study, it is confirmed that by heating alone without irradiation, no precipitate nanoparticles form.

  17. Effect of Radiation on Silicon and Borosilicate Glass

    National Research Council Canada - National Science Library

    Allred, Clark

    2003-01-01

    .... These two glasses are commonly used as substrates for silicon microelectromechanical (MEMS) devices, and radiation-induced compaction in a substrate can have deleterious effects on device performance...

  18. On fluidization of borosilicate glasses in intense radiation fields - 16055

    International Nuclear Information System (INIS)

    Ojovan, Michael; Moebus, Guenter; Tsai, Jim; Cook, Stuart; Yang, Guang

    2009-01-01

    The viscosity is rate-limiting for many processes in glassy materials such as homogenisation and crystallisation. Changes in the viscous flow behaviour in conditions of long-term irradiation are of particular interest for glassy materials used in nuclear installations as well as for nuclear waste immobilising glasses. We analyse the viscous flow behaviour of oxide amorphous materials in conditions of electron-irradiation using the congruent bond lattice model of oxide materials accounting for the flow-mediating role of broken bonds termed configurons. An explicit equation of viscosity was obtained which is in agreement with experimental data for non-irradiated glasses and shows for irradiated glasses, first, a significant decrease of viscosity, and, second, a stepwise reduction of the activation energy of flow. An equation for glass-transition temperature was derived which shows that irradiated glasses have lower glass transition temperatures. Intensive electron irradiation of glasses causes their fluidization due to non-thermal bond breaking and can occur below the glass transition temperature. Due to surface tension forces fluidization of glasses at enough high electron flux densities can result in modification of nano-size volumes and particles such as those experimentally observed under TEM electron beams. (authors)

  19. Vanadium and Chromium Redox Behavior in borosilicate Nuclear Waste Glasses

    International Nuclear Information System (INIS)

    McKeown, D.; Muller, I.; Gan, H.; Feng, Z.; Viragh, C.; Pegg, I.

    2011-01-01

    X-ray absorption spectroscopy (XAS) was used to characterize vanadium (V) and chromium (Cr) environments in low activity nuclear waste (LAW) glasses synthesized under a variety of redox conditions. V 2 O 5 was added to the melt to improve sulfur incorporation from the waste; however, at sufficiently high concentrations, V increased melt foaming, which lowered melt processing rates. Foaming may be reduced by varying the redox conditions of the melt, while small amounts of Cr are added to reduce melter refractory corrosion. Three parent glasses were studied, where CO-CO 2 mixtures were bubbled through the corresponding melt for increasing time intervals so that a series of redox-adjusted-glasses was synthesized from each parent glass. XAS data indicated that V and Cr behaviors are significantly different in these glasses with respect to the cumulative gas bubbling times: V 4+ /V total ranges from 8 to 35%, while Cr 3+ /Cr total can range from 15 to 100% and even to population distributions including Cr 2+ . As Na-content decreased, V, and especially, Cr became more reduced, when comparing equivalent glasses within a series. The Na-poor glass series show possible redox coupling between V and Cr, where V 4+ populations increase after initial bubbling, but as bubbling time increases, V 4+ populations drop to near the level of the parent glass, while Cr becomes more reduced to the point of having increasing Cr 2+ populations.

  20. Electrical conductivity and viscosity of borosilicate glasses and melts

    DEFF Research Database (Denmark)

    Ehrt, Doris; Keding, Ralf

    2009-01-01

    , 0 to 62·5 mol% B2O3, and 25 to 85 mol% SiO2. The glass samples were characterised by different methods. Refractive indices, density and thermal expansion were measured. Phase separation effects were investigated by electron microscopy. The electrical conductivity of glasses and melts were determined...

  1. Chemical corrosion of highly radioactive borosilicate nuclear waste glass under simulated repository conditions

    International Nuclear Information System (INIS)

    Werme, L.; Bjoerner, I.K.; Bart, G.; Zwicky, H.U.; Grambow, B.; Lutze, W.; Ewing, R.C.; Magrabi, C.

    1990-01-01

    This review summarizes the results of the joint Japanese (Central Research Institute of Electric Power Industry, CRIEPI, Tokyo), Swiss (National Cooperative for the Storage of Radioactive Waste, NAGRA, Baden), Swedish (Swedish Nuclear Fuel and Waste Management Company, SKB, Stockholm) international 'JSS' project on the determination of the chemical durability of the French nuclear waste borosilicate glass, which was completed in 1988. Radioactive and non-radioactive glass specimens were investigated. A data base was created with results from glass corrosion tests performed with different water compositions, pH values, temperatures, sample surface areas (S), solution volumes (V), and flow rates. Glass corrosion tests were performed with and without bentonite and/or steel corrosion products present. Variation of the glass composition was taken into account by including the borosilicate glass 'MW' in the investigations, formulated by British Nuclear Fuels, plc. An understanding was achieved of the glass corrosion process in general, and of the performance of the French glass under various potential disposal conditions in particular. A special effort was made to establish a corrosion data base, using high S/V ratios in the experiments in order to understand the glass durability in the long term. A computer program, GLASSOL, was developed, based on a dissolution-precipitation model, to calculate the glass water reaction. Fair agreement between observations and the model calculations was achieved. Use of a constant (time-independent) long-term rate was justified by observations on naturally altered basaltic glasses of great age, which were compatible with what was inferred from experiments with nuclear waste glasses in the laboratory. A fractured glass block would not be altered within 10 000 years at 90 degree C (flow rate <100 L/year)

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

    Science.gov (United States)

    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 wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

  3. Optical and structural investigation on sodium borosilicate glasses doped with Cr2O3

    Science.gov (United States)

    Ebrahimi, E.; Rezvani, M.

    2018-02-01

    In this work, Sodium borosilicate glasses with chemical composition of 60% SiO2-20% B2O3-20%Na2O doped with different contents of Cr2O3 were prepared by melting-quenching method. Physical, structural and optical properties of glasses were investigated by studying density and molar volume, Fourier Transform Infrared (FT-IR) Spectra and UV-visible absorption spectroscopy. The results showed an increase in density of glasses with the increase of Cr2O3 that can be due to addition of oxide with high molar mass. The optical absorption spectra of un-doped glass reveals UV absorption due to trace iron impurities with no visible band however Cr2O3 doped glasses shows absorption in visible range that are characteristic. Increasing of Cr3 + ions in the glassy microstructure of samples provides a semiconducting character to Sodium borosilicate glass by reducing the direct and indirect optical band gaps of glass samples from 3.79 to 2.59 (ev) and 3.36 to 2.09 (ev), respectively. These changes could be attributed to the role of Cr3 + ions as the network former which asserts improvement of semiconducting behavior in presence of Cr2O3.

  4. Proving the role of boron in the structure of fly-ash/borosilicate glass based geopolymers

    Czech Academy of Sciences Publication Activity Database

    Taveri, Gianmarco; Toušek, J.; Bernardo, E.; Toniolo, N.; Boccaccini, A. R.; Dlouhý, Ivo

    2017-01-01

    Roč. 200, AUG (2017), s. 105-108 ISSN 0167-577X EU Projects: European Commission(XE) 642557 - CoACH Institutional support: RVO:68081723 Keywords : Fly-ash * Borosillicate * Geopolymerization * Spectroscopy * NMR * FTIR Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 2.572, year: 2016 http://www.sciencedirect.com/science/article/pii/S0167577X1730650X

  5. Effects of system size and cooling rate on the structure and properties of sodium borosilicate glasses from molecular dynamics simulations

    Science.gov (United States)

    Deng, Lu; Du, Jincheng

    2018-01-01

    Borosilicate glasses form an important glass forming system in both glass science and technologies. The structure and property changes of borosilicate glasses as a function of thermal history in terms of cooling rate during glass formation and simulation system sizes used in classical molecular dynamics (MD) simulation were investigated with recently developed composition dependent partial charge potentials. Short and medium range structural features such as boron coordination, Si and B Qn distributions, and ring size distributions were analyzed to elucidate the effects of cooling rate and simulation system size on these structure features and selected glass properties such as glass transition temperature, vibration density of states, and mechanical properties. Neutron structure factors, neutron broadened pair distribution functions, and vibrational density of states were calculated and compared with results from experiments as well as ab initio calculations to validate the structure models. The results clearly indicate that both cooling rate and system size play an important role on the structures of these glasses, mainly by affecting the 3B and 4B distributions and consequently properties of the glasses. It was also found that different structure features and properties converge at different sizes or cooling rates; thus convergence tests are needed in simulations of the borosilicate glasses depending on the targeted properties. The results also shed light on the complex thermal history dependence on structure and properties in borosilicate glasses and the protocols in MD simulations of these and other glass materials.

  6. Effects of optical dopants and laser wavelength on atom probe tomography analyses of borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiaonan; Schreiber, Daniel K.; Neeway, James J.; Ryan, Joseph V.; Du, Jincheng

    2017-06-07

    Atom probe tomography (APT) is a novel analytical microscopy method that provides three dimensional elemental mapping with sub-nanometer spatial resolution and has only recently been applied to insulating glass and ceramic samples. In this paper, we have studied the influence of the optical absorption in glass samples on APT characterization by introducing different transition metal optical dopants to a model borosilicate nuclear waste glass (international simple glass). A systematic comparison is presented of the glass optical properties and the resulting APT data quality in terms of compositional accuracy and the mass spectra quality for two APT systems: one with a green laser (532 nm, LEAP 3000X HR) and one with a UV laser (355 nm, LEAP 4000X HR). These data were also compared to the study of a more complex borosilicate glass (SON68). The results show that the analysis data quality such as compositional accuracy and total ions collected, was clearly linked to optical absorption when using a green laser, while for the UV laser optical doping aided in improving data yield but did not have a significant effect on compositional accuracy. Comparisons of data between the LEAP systems suggest that the smaller laser spot size of the LEAP 4000X HR played a more critical role for optimum performance than the optical dopants themselves. The smaller spot size resulted in more accurate composition measurements due to a reduced background level independent of the material’s optical properties.

  7. Advances in understanding the structure of borosilicate glasses: A Raman spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Manara, D.; Grandjean, A. [CEA Marcoule, Serv Confinement Deches and Vitrificat, DTCD, DEN - 30 (France); Neuville, D.R. [Institut Physique Globe, Physique des Mineraux et Magmas, CNRS, F-75252 Paris 05 (France)

    2009-05-15

    This study is focused on the behavior of ternary SiO{sub 2}-Na{sub 2}O-B{sub 2}O{sub 3} borosilicate glasses at temperatures between 298 and 1800 K. Unpolarized Raman spectra were measured up to high temperature. SiO{sub 2}-Na{sub 2}O-B{sub 2}O{sub 3} glass samples were prepared with different values of the ratio R [Na{sub 2}O]/[B{sub 2}O{sub 3}], while the ratio K = [SiO{sub 2}]/[B{sub 2}O{sub 3}] was kept constant and equal 2.12. Spectra were measured at room temperature in samples with 0.43 {<=} R {<=} 1.68, and the effect of the modifier content was clearly observed in these glasses, only in partial agreement with previous literature results. In particular, the formation in the glass of sodium-danburite units Na{sub 2}O-B{sub 2}O{sub 3}-2SiO{sub 2} was postulated. This feature led to a new assessment of R{sup *}, the critical value of R above which every new alkali atom added to the system breaks a Fo-O-Fo (Fo=glass former) bridge causing depolymerization of the glass. A revised formula is proposed to obtain the value of R{sup *} as a function of K. Raman spectra measured at high temperature yielded important information about the temperature-dependent evolution of the borosilicate system. In particular, borate and borosilicate units including tetra-coordinated boron seem to be unstable at high temperature, where the formation of metaborate chains or rings is fostered. Above 1500 degrees C, evaporation of borate compounds is clearly observed, stemming from the small sample size. (authors)

  8. Photoelastic examination of borosilicate glass discs used in the insulating legs for the NSF tandem

    International Nuclear Information System (INIS)

    Acton, W.J.; Cundy, D.

    1981-04-01

    The results are presented of a photoelastic stress analysis carried out to establish the effect of re-annealing borosilicate glass discs used in the insulating legs of the 30 MV tandem van de Graaff accelerator of the NSF. The results show that re-annealing of the glass discs has no measurable effect on reducing the high stress at inclusions and re-emphasise the need to exercise great care in selecting suitable discs for use in the insulating legs. (U.K.)

  9. Structural investigations of bismuth lead borosilicate glasses under the influence of gamma irradiation through ultrasonic studies

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Laopaiboon, Raewat

    2012-04-01

    The ultrasonic velocity measurements for different compositions of irradiated bismuth lead borosilicate glasses xBi2O3-(50-x)PbO-20B2O3-30SiO2 (x=2, 4, 6, 8, and 10 mol.%) were performed at room temperature using pulse-echo technique. Densities of glass samples were measured by Archimedes' principle using n-hexane as the immersion liquid. The results from the studies show that ultrasonic velocity, elastic moduli, Poisson's ratio, microhardness, and the Debye temperature increase with increasing bismuth oxide content and increasing gamma-radiation dose (3-12 Gy).

  10. Borosilicate glasses for the high activity waste vetrification

    International Nuclear Information System (INIS)

    Cantale, C.; Donato, A.; Guidi, G.

    1984-01-01

    Some results concerning the researches carried out on the high-level wastes vitrification at ENEA, Comb-Mepis-Rifiu laboratory are reported. A fission product solution referred to power plant nuclear fuel reprocessing has been selected and simulated with no radioactive chemicals. Some glass composition have been tested for the vitrification of this solution, the best of them being taken into consideration for real active tests at the hot bench scale plant ESTER in Ispra. The final glasses have been characterized from the chemical and physical point of view; moreover some microstructural investigations have been performed in order to identify few microsegregations and to test the degree of amorphousness of the products

  11. Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations

    International Nuclear Information System (INIS)

    Ledieu, A.

    2004-10-01

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  12. Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations

    International Nuclear Information System (INIS)

    Ledieu, A.

    2004-10-01

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  13. IR study of Pb–Sr titanate borosilicate glasses

    Indian Academy of Sciences (India)

    Administrator

    to study their structure systematically. IR spectrum of each glass composition shows a number of absorption bands. These bands are strongly influenced by the increasing substitution of SrO for PbO. Various bands shift with composition. Absorption peaks occur due to the vibrational mode of the borate network in these ...

  14. Ultrasonic and structural features of some borosilicate glasses ...

    Indian Academy of Sciences (India)

    Therefore, the glass structure becomes contractedand compacted, which decreases its molar volume and increases its rigidity. This concept was asserted from the increase in the ultrasonic velocity, Debye temperature and elastic moduli with the increase of SiO2 content. The present compositional dependence of the elastic ...

  15. Ultrasonic and structural features of some borosilicate glasses ...

    Indian Academy of Sciences (India)

    ... was prepared and studied by Fourier transform infrared spectroscopy, density and ultrasonic techniques to debate the issue of the role of SiO2 in the structureof lead alkali borate glasses. The results indicate that SiO2 generates an abundance of bridging oxygen atoms, [BO 4 ] and [SiO 4 ] structural units and changes the ...

  16. Thermokinetic model of borosilicate glass dissolution: contextual affinity

    International Nuclear Information System (INIS)

    Advocat, T.; Vernaz, E.; Crovisier, J.L.; Fritz, B.

    1989-01-01

    Short and long-term geochemical interactions of R7T7 nuclear glass with water at 100 0 C were simulated with the DISSOL thermokinetic computer code. Both the dissolved glass quantity and the resulting water composition, saturation states and mineral quantities produced were calculated as a function of time. The rate equation used in the simulation was first proposed by Aagaard and Helgeson. It simulates a gradually diminishing dissolution rate as the reaction affinity diminishes. The best agreement with 1-year experimental data was obtained with a reaction affinity calculated from silica activity (Grambow's hypothesis) rather than taking into account the activity of all the glass components as proposed by Jantzen and Plodinec. The concept of residual affinity was introduced by Grambow to express the fact that the glass dissolution rate does not cease. We prefer to replace the term residual affinity by contextual affinity, which expresses the influence on the dissolution rate of three factors: the solution chemistry, the metastability of SiO 2 (m), and the possible precipitation of certain aluminosilicates such as zeolites. 19 refs

  17. Ultrasonic and structural features of some borosilicate glasses ...

    Indian Academy of Sciences (India)

    2017-06-09

    - perature in the quaternary glass system Na1.4B2.8Six Pb0.3−x O5.2+x on the parameter x (the lines are drawn as a guide to the eye). Another important parameter that depends on both the mean ultrasonic velocity and the ...

  18. Physical and optical properties of lithium borosilicate glasses doped with Dy3+ ions

    Science.gov (United States)

    Ramteke, D. D.; Gedam, R. S.; Swart, H. C.

    2018-04-01

    The borosilicate glasses with Dy3+ ions were prepared by the melt quench technique with varying concentration of Dy2O3. The glasses were characterized by the density calculation, absorbance and photoluminescence (PL) spectroscopy measurements. Density and molar volume of the glasses increases with increase in Dy3+ ions in the glass matrix. This behavior is correlated with the higher molecular weight and larger ionic radius of Dy3+ ion compared to the other constituents of glass matrix. Emission of Dy3+ doped glasses showed three bands at 482, 573 and at 665 nm which correspond to 6H15/2 (blue), 6H13/2 (yellow) and 6H11/2 (red) transitions. The emission spectra of glasses with different concentration of Dy3+ ions shows that, glasses with 0.5 mol% of Dy2O3 shows highest emission and decreases with further doping. CIE 1931 chromaticity diagram showed that the emission of these glasses was in the white region. Photographs of these glasses under 349 nm Light emitting diode excitation also confirmed the white light emission from these glasses.

  19. Basaltic glasses from Iceland and the deep sea: Natural analogues to borosilicate nuclear waste-form glass

    International Nuclear Information System (INIS)

    Jercinovic, M.J.; Ewing, R.C.

    1987-12-01

    The report provides a detailed analysis of the alteration process and products for natural basaltic glasses. Information of specific applicability to the JSS project include: * The identification of typical alteration products which should be expected during the long-term corrosion process of low-silica glasses. The leached layers contain a relatively high proportion of crystalline phases, mostly in the form of smectite-type clays. Channels through the layer provide immediate access of solutions to the fresh glass/alteration layer interface. Thus, glasses are not 'protected' from further corrosion by the surface layer. * Corrosion proceeds with two rates - an initial rate in silica-undersaturated environments and a long-term rate in silica-saturated environments. This demonstrates that there is no unexpected change in corrosion rate over long periods of time. The long-term corrosion rate is consistent with that of borosilicate glasses. * Precipitation of silica-containing phases can result in increased alteration of the glass as manifested by greater alteration layer thicknesses. This emphasizes the importance of being able to predict which phases form during the reaction sequence. * For natural basaltic glasses the flow rate of water and surface area of exposed glass are critical parameters in minimizing glass alteration over long periods of time. The long-term stability of basalt glasses is enhanced when silica concentrations in solution are increased. In summary, there is considerable agreement between corrosion phenomena observed for borosilicate glasses in the laboratory and those observed for natural basalt glasses of great age. (With 121 refs.) (authors)

  20. Chemical compatibility of HLW borosilicate glasses with actinides

    International Nuclear Information System (INIS)

    Walker, C.T.; Scheffler, K.; Riege, U.

    1978-11-01

    During liquid storage of HLLW the formation of actinide enriched sludges is being expected. Also during melting of HLW glasses an increase of top-to-bottom actinide concentrations can take place. Both effects have been studied. Besides, the vitrification of plutonium enriched wastes from Pu fuel element fabrication plants has been investigated with respect to an isolated vitrification process or a combined one with the HLLW. It is shown that the solidification of actinides from HLLW and actinide waste concentrates will set no principal problems. The leaching of actinides has been measured in salt brine at 23 0 C and 115 0 C. (orig.) [de

  1. Investigations on LM6 Metal Matrix Composite with borosilicate Glass Reinforcement for Aerospace applications

    Science.gov (United States)

    Rathnaraj, J. David; Sathish, S.

    2017-10-01

    The recycling of glass wastes from the industries and society holds a threat to the environment and leads to the need for new applications. While producing a metal matrix composite production cost is an important factor which decides the suitable application. So, while developing a new material with this low - cost has great importance in this competitive world. In this study, an metal-matrix composite fabricated from an aluminum alloy (LM6) and Borosilicate glass powder particles with % addition of 2.5%, 5%, 7.5%, and 10% were produced by liquid Processing (stir casting) technique. The variations in the mechanical properties like toughness, compressive strength, hardness, and tensile were examined. The microstructures of the fabricated metal matrix composite have been obtained by using Metallographic microscope. The addition of the borosilicate glass indicated an improved behavior in the hardness and toughness properties. The Rockwell hardness value of fabricated metal matrix composite increases with the increase in % of reinforcement. The compressive and tensile strength of the fabricated MMC increases until reinforcement reaches a maximum of 7.5%. The microstructure of the fabricated MMC shows that the reinforcements were homogeneously distributed in the fabricated metal matrix composite.

  2. Influence of iron ions on the structural properties of Zn-borosilicate glasses

    International Nuclear Information System (INIS)

    Music, S.; Gotic, M.; Popovic, S.

    1989-01-01

    The objectives of this study were to determine the influence of iron ions on the appearance of crystalline phases in Zn-borosilicate glasses, and to obtain information about valence state and coordination of iron ions. The systems Na 2 O-ZnO-B 2 O 3 -SiO 2 and ZnO-B 2 O 3 -SiO 2 were doped with α-Fe 2 O 3 . X-ray diffraction, IR spectroscopy and 57 Fe Moessbauer spectroscopy were used as experimental techniques. (author) 32 refs.; 5 figs.; 5 tabs

  3. Investigation of gamma radiation induced changes in local structure of borosilicate glass by TDPAC and EXAFS

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ashwani, E-mail: kashwani@barc.gov.in [Bhabha Atomic Research Centre, Radioanalytical Chemistry Division (India); Nayak, C.; Rajput, P. [Bhabha Atomic Research Centre, Atomic and Molecular Physics Division (India); Mishra, R. K. [Bhabha Atomic Research Centre, Waste Management Division (India); Bhattacharyya, D. [Bhabha Atomic Research Centre, Atomic and Molecular Physics Division (India); Kaushik, C. P. [Bhabha Atomic Research Centre, Waste Management Division (India); Tomar, B. S. [Bhabha Atomic Research Centre, Radioanalytical Chemistry Division (India)

    2016-12-15

    Gamma radiation induced changes in local structure around the probe atom (Hafnium) were investigated in sodium barium borosilicate (NBS) glass, used for immobilization of high level liquid waste generated from the reprocessing plant at Trombay, Mumbai. The (NBS) glass was doped with {sup 181}Hf as a probe for time differential perturbed angular correlation (TDPAC) spectroscopy studies, while for studies using extended X-ray absorption fine structure (EXAFS) spectroscopy, the same was doped with 0.5 and 2 % (mole %) hafnium oxide. The irradiated as well as un-irradiated glass samples were studied by TDPAC and EXAFS techniques to obtain information about the changes (if any) around the probe atom due to gamma irradiation. TDPAC spectra of unirradiated and irradiated glasses were similar and reminescent of amorphous materials, indicating negligible effect of gamma radiation on the microstructure around Hafnium probe atom, though the quaqdrupole interaction frequency (ω{sub Q}) and asymmetry parameter (η) did show a marginal decrease in the irradiated glass compared to that in the unirradiated glass. EXAFS measurements showed a slight decrease in the Hf-O bond distance upon gamma irradiation of Hf doped NBS glass indicating densification of the glass matrix, while the cordination number around hafnium remains unchanged.

  4. Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest

    Energy Technology Data Exchange (ETDEWEB)

    Kilymis, D. A.; Delaye, J.-M., E-mail: jean-marc.delaye@cea.fr [CEA Marcoule, DEN/DTCD, Service d’Etude et Comportement des Matériaux de Conditionnement, BP17171 30207 Bagnols-sur-Cèze Cedex (France)

    2014-07-07

    In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO{sub 2} content of the glass, which promotes densification due to the open structure of SiO{sub 4} tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, as has been previously observed.

  5. Comparison of radiation and quenching rate effects on the structure of a sodium borosilicate glass

    International Nuclear Information System (INIS)

    Peuget, Sylvain; Maugeri, Emilio-Andrea; Mendoza, Clement; Fares, Toby; Bouty, Olivier; Jegou, Christophe; Charpentier, Thibault; Moskura, Melanie

    2013-01-01

    The effects of quenching rate and irradiation on the structure of a sodium borosilicate glass were compared using 29 Si, 11 B, and 23 Na nuclear magnetic resonance and Raman spectroscopy. Quenching rate ranging from 0.1 to 3 * 10 4 K min -1 was studied. Various irradiation conditions were performed, i.e. gold-ion irradiation in a multi-energy mode (from 1 to 6.75 MeV), and Kr and Xe ion irradiations with energy of 74 and 92 MeV, respectively. In pile irradiation with thermal neutron flux was performed as well, to study the effect of alpha radiation from the nuclear reaction 10 B(n,α) 7 Li. Both irradiation and high quenching rate induce similar local order modification of the glass structure, mainly a decrease of the mean boron coordination and an increase of Q 3 units. Nevertheless, the variations observed under irradiation are more pronounced than the ones induced by the quenching rate. Moreover, some important modifications of the glass medium range order, i.e. the emergence of the D2 band associated to three members silica rings and a modification of the Si-O-Si angle distribution were only noticed after irradiation. These results suggest that the irradiated structure is certainly not exactly the one obtained by a rapidly quenched equilibrated melt, but rather a more disordered structure that was weakly relaxed during the very rapid quenching phase following the energy deposition step. Raman spectroscopy showed a similar irradiated structure whereas the glass evolutions were controlled by the electronic energy loss in the ion track formation regime for Kr-ion irradiation or by the nuclear energy loss for Au and OSIRIS irradiation. The similar irradiated structure despite different irradiation routes, suggests that the final structural state of this sodium borosilicate glass is mainly controlled by the glass reconstruction after the energy deposition step. (authors)

  6. Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-15

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  7. Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte-Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-01

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  8. Smoothing of ultrasonically drilled holes in borosilicate glass by wet chemical etching

    Science.gov (United States)

    Diepold, T.; Obermeier, E.

    1996-03-01

    Besides silicon various types of glass play an important role in microsystem technology. One requirement of the glasses is that they have to be microstructurable. In many applications for microsensors and microstructures the glass must be suitable for anodic bonding. Usually borosilicate glass (e.g. Corning Pyrex code 7740 glass) is used, which has a thermal expansion coefficient that is almost equal to the thermal expansion coefficient of silicon and which has the necessary electrical conductivity at the temperature at which the bonding process occurs. For many applications, e.g., microfluidic systems, it is necessary to have fluids flown through ultrasonically drilled holes in the Pyrex glass to the silicon chip. The main objective of the investigation was to obtain smooth walls of ultrasonically drilled holes because every contamination influences the performance of the microsystem. In this paper the ultrasonic drilling method is compared with two other procedures for machining holes (sand blasting and laser machining). Other ways of structuring glass have been presented previously. A process was developed to smooth the walls of the drilled holes with different concentrations of hydrofluoric acid.

  9. High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 2

    International Nuclear Information System (INIS)

    Cunnane, J.C.

    1994-03-01

    The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion.This document is organized into three volumes. Volumes I and II represent a tiered set of information intended for somewhat different audiences. Volume I is intended to provide an overview of waste glass corrosion, and Volume 11 is intended to provide additional experimental details on experimental factors that influence waste glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II. Volume I is intended for managers, decision makers, and modelers, the combined set of Volumes I, II, and III is intended for scientists and engineers working in the field of high-level waste

  10. High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)] [and others

    1994-03-01

    The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion.This document is organized into three volumes. Volumes I and II represent a tiered set of information intended for somewhat different audiences. Volume I is intended to provide an overview of waste glass corrosion, and Volume 11 is intended to provide additional experimental details on experimental factors that influence waste glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II. Volume I is intended for managers, decision makers, and modelers, the combined set of Volumes I, II, and III is intended for scientists and engineers working in the field of high-level waste.

  11. Structural analysis of mixed alkali borosilicate glasses containing Cs+ and Na+ using strong magnetic field magic angle spinning nuclear magnetic resonance

    Directory of Open Access Journals (Sweden)

    S. Kaneko

    2017-03-01

    Full Text Available We have investigated the local structure of alkali atoms in mixed alkali silicate, borate, and borosilicate glasses, which contain Cs+ and Na+, using strong magnetic field magic angle spinning nuclear magnetic resonance (MAS NMR spectroscopy of 133Cs and 23Na. The spectral peaks of 133Cs in borosilicate (Si:B = 1:1 and Si-rich borosilicate (Si:B = 2:1 glasses shifted to upfield with increasing Cs+/(Na+ + Cs+ ratio, which implies that the coordination number of Cs+ decreased as in the case of silicate and borate glasses. However, this trend was not observed in the 23Na spectra of either borosilicate glass. This might be because the chemical shift of 23Na in borosilicate glass is strongly affected by nearby species such as Si or B, and not by the coordination number of Na+.

  12. Conversion of plutonium-containing materials into borosilicate glass using the glass material oxidation and dissolution system

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1996-01-01

    The end of the cold war has resulted in excess plutonium-containing materials (PCMs) in multiple chemical forms. Major problems are associated with the long-term management of these materials: safeguards and nonproliferation issues; health, environment, and safety concerns; waste management requirements; and high storage costs. These issues can be addressed by conversion of the PCMs to glass: however, conventional glass processes require oxide-like feed materials. Conversion of PCMs to oxide-like materials followed by vitrification is a complex and expensive process. A new vitrification process has been invented, the Glass Material Oxidation and Dissolution System (GMODS) to allow direct conversion of PCMs to glass. GMODS directly converts metals, ceramics, and amorphous solids to glass; oxidizes organics with the residue converted to glass; and converts chlorides to borosilicate glass and a secondary sodium chloride stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium (a plutonium surrogate), Zircaloy, stainless steel, multiple oxides, and other materials to glass. Equipment options have been identified for processing rates between 1 and 100,000 t/y. Significant work, including a pilot plant, is required to develop GMODS for applications at an industrial scale

  13. Contribution of germanium dioxide to the thermal expansion characteristics of some borosilicate glasses and their corresponding glass-ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, H.; Salama, S.N.; Salman, S.M. [National Research Centre, Cairo (Egypt). Glass Research Dept.

    2002-07-01

    The thermal expansion characteristics of some lithium aluminium germanium borosilicate glasses and their crystalline solids have been investigated. The base glass composition was modified by partial replacement of germanium dioxide instead of silica. In some cases, however, TiO{sub 2} was also added to some selected glasses as a nucleation catalyst. Slight increase in the thermal expansion coefficient ({alpha}) values of the glasses and corresponding slight decrease in both transition (Tg) and softening (Ts) temperatures are detected by GeO{sub 2}/SiO{sub 2} replacements, however, the reverse results were recorded by TiO{sub 2} addition. The obtained data were correlated to the local structure changes induced by GeO{sub 2} or TiO{sub 2} and their contributions to the thermal expansion property of the glasses. On the crystallization, the expansivity of the glasses was markedly changed. It was greatly affected by crystallization of GeO{sub 2}-containing phases and aluminosilicate solid solutions together with the TiO{sub 2}-containing phases formed. The results obtained were explained in relation to the nature, composition and concentration of all phases formed in the glass-ceramics including a residual glass matrix. (orig.)

  14. Influence of zeolite precipitation on borosilicate glass alteration under hyperalkaline conditions

    Science.gov (United States)

    Mercado-Depierre, S.; Fournier, M.; Gin, S.; Angeli, F.

    2017-08-01

    This study enables a better understanding of how nucleation-growth of zeolites affects glass dissolution kinetics in hyperalkaline solutions characteristic of cement waters. A 20-oxide borosilicate glass, an inactive surrogate of a typical intermediate level waste glass, was altered in static mode at 50 °C in a hyperalkaline solution rich in Na+, K+ and Ca2+ and at an initial pH50°C of 12.6. Experiments were performed at four glass-surface-area-to-solution-volume (S/V) ratios to investigate various reaction progresses. Two types of glass alteration kinetics were obtained: (i) at low S/V, a sharp alteration resumption occurred after a rate drop regime, (ii) at high S/V, a high dissolution rate was maintained throughout the test duration with a slight progressive slow-down. In all the experiments, zeolites precipitated but the time taken to form stable zeolite nuclei varied dramatically depending on the S/V. Resulting changes in pH affected zeolite composition, morphology, solubility and growth rate. A change in a critical parameter such as S/V affected all the processes controlling glass dissolution.

  15. Effect of annealing on the composition of PECVD borosilicate and borophosphosilicate glasses

    Science.gov (United States)

    Osório, S. P. A.; Montero, I.; Perrière, J.; Martinez-Duart, J. M.

    1993-06-01

    Borosilicate, B xSiO z (BSG), and borophosphosilicate, B xP ySiO z (BPSG) glasses, for applications as intermetal dielectrics in VLSI technology were deposited by plasma enhanced chemical vapor deposition on silicon substrates. Quantitative infrared spectroscopy (IR), Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA) and X-ray energy dispersion (EDX) were used to obtain the composition of the films. After annealing at temperatures in the range 200 to 900°C under a nitrogen ambient, the concentration of phosphorus and boron in the deposited films is analyzed. It is found that the phosphorus concentration is independent of the annealing temperature. However, the boron concentration decreases with the annealing temperature in both types of glasses. This effect can be attributed to the influence of the concentration of the P-O bonds in the phosphorus doped films, and also to the morphology and hygroscopicity of the films.

  16. Development of Composite Materials Under Ecological Aspects as Recycling Concept For Borosilicate Glass Containing Iron Slags

    International Nuclear Information System (INIS)

    Khalil, T.K.; Bossert, J.; Aly, H.F.; Bossert, J.

    1999-01-01

    Composite concept in materials science can be conveniently applied in the waste treatment technology to construct specific t ailor made c omposite materials, in which at least one of the phases is built by the waste material. In this work the applicability of this concept for the fixation and recycling of slags wastes is done, whereby different mixtures of blast furnace slags are mixed with two different borosilicate glasses, which serve as matrix material. Thermal behaviour of the produced compacts were studied. Both melting and powder technology are applied for the fabrication of dense products. The microstructure of sintered samples is investigated by electron microscopy. The mechanical properties such as hardness and fracture toughness are determined by a Vickers technique. An improvement of the fracture toughness of more than 50% over the value for the original glass VG 98 is achieved by slag addition

  17. Determination of iron redox ratio in borosilicate glasses and melts from Raman spectra

    Energy Technology Data Exchange (ETDEWEB)

    Cochain, B. [SCDV-Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols-sur-ceze (France); Physique des Mineraux et des Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris Cedex05 (France); Neuville, D.R.; Richet, P. [Physique des Mineraux et des Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris Cedex05 (France); Henderson, G.S. [Dept of Geology, University of Toronto, 22 Russell Street, Toronto (Canada); Pinet, O. [SCDV-Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols-sur-ceze (France)

    2008-07-01

    A method is presented to determine the redox ratio of iron in borosilicate glasses and melts relevant to nuclear waste storage from an analysis of Raman spectra recorded at room or high temperature. The basis of this method is the strong variation of the spectral feature observed between 800 and 1200 cm{sup -1}, in which it is possible to assign a band to vibrational modes involving ferric iron in tetrahedral coordination whose intensity increases with iron content and iron oxidation. After baseline correction and normalization, fits to the Raman spectra made with Gaussian bands enable us to determine the proportion of ferric iron provided the redox ratio is known independently for at least two redox states for a given glass composition. This method is particularly useful for in situ determinations of the kinetics and mechanisms of redox reactions. (authors)

  18. Barium borosilicate glass - a potential matrix for immobilization of sulfate bearing high-level radioactive liquid waste

    International Nuclear Information System (INIS)

    Kaushik, C.P.; Mishra, R.K.; Sengupta, P.; Kumar, Amar; Das, D.; Kale, G.B.; Raj, Kanwar

    2006-01-01

    Borosilicate glass formulations adopted worldwide for immobilization of high-level radioactive liquid waste (HLW) is not suitable for sulphate bearing HLW, because of its low solubility in such glass. A suitable glass matrix based on barium borosilicate has been developed for immobilization of sulphate bearing HLW. Various compositions based on different glass formulations were made to examine compatibility with waste oxide with around 10 wt% sulfate content. The vitrified waste product obtained from barium borosilicate glass matrix was extensively evaluated for its characteristic properties like homogeneity, chemical durability, glass transition temperature, thermal conductivity, impact strength, etc. using appropriate techniques. Process parameters like melt viscosity and pour temperature were also determined. It is found that SB-44 glass composition (SiO 2 : 30.5 wt%, B 2 O 3 : 20.0 wt%, Na 2 O: 9.5 wt% and BaO: 19.0 wt%) can be safely loaded with 21 wt% waste oxide without any phase separation. The other product qualities of SB-44 waste glass are also found to be on a par with internationally adopted waste glass matrices. This formulation has been successfully implemented in plant scale

  19. Comparison of SRP high-level waste disposal costs for borosilicate glass and crystalline ceramic waste forms

    International Nuclear Information System (INIS)

    McDonell, W.R.

    1982-04-01

    An evaluation of costs for the immobilization and repository disposal of SRP high-level wastes indicates that the borosilicate glass waste form is less costly than the crystalline ceramic waste form. The wastes were assumed immobilized as glass with 28% waste loading in 10,300 reference 24-in.-diameter canisters or as crystalline ceramic with 65% waste loading in either 3400 24-in.-diameter canisters or 5900 18-in.-diameter canisters. After an interim period of onsite storage, the canisters would be transported to the federal repository for burial. Total costs in undiscounted 1981 dollars of the waste disposal operations, excluding salt processing for which costs are not yet well defined, were about $2500 million for the borosilicate glass form in reference 24-in.-diameter canisters, compared to about $2900 million for the crystalline ceramic form in 24-in.-diameter canisters and about $3100 million for the crystalline ceramic form in 18-in.-diameter canisters. No large differences in salt processing costs for the borosilicate glass and crystalline ceramic forms are expected. Discounting to present values, because of a projected 2-year delay in startup of the DWPF for the crystalline ceramic form, preserved the overall cost advantage of the borosilicate glass form. The waste immobilization operations for the glass form were much less costly than for the crystalline ceramic form. The waste disposal operations, in contrast, were less costly for the crystalline ceramic form, due to fewer canisters requiring disposal; however, this advantage was not sufficient to offset the higher development and processing costs of the crystalline ceramic form. Changes in proposed Nuclear Regulatory Commission regulations to permit lower cost repository packages for defense high-level wastes would decrease the waste disposal costs of the more numerous borosilicate glass forms relative to the crystalline ceramic forms

  20. Processing and optical characterization of lead calcium titanate borosilicate glass doped with germanium

    Science.gov (United States)

    Gautam, C. R.; Das, Sangeeta; Gautam, S. S.; Madheshiya, Abhishek; Singh, Anod Kumar

    2018-04-01

    In this study, various compositions of lead calcium titanate borosilicate glass doped with a fixed amount of germanium were synthesized using the rapid melt quench technique. The amorphous nature of the synthesized glass was confirmed by X-ray diffraction and scanning electron microscopy analyses. The structural and optical properties were deduced using Raman, Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy. FTIR spectroscopy confirmed the presence of borate groups in triangular and tetrahedral coordination. Infrared and Raman analyses detected the vibrational bonds of Gesbnd Osbnd Ge, Bsbnd Osbnd Ge, Sisbnd Osbnd Ge, Sisbnd Osbnd Si, and Pbsbnd Osbnd Ge. The energy band gaps were evaluated for the prepared glass samples based on Tauc plots of the UV-Vis spectra. The calculated values of the optical band gap decreased from 2.91 to 2.85 eV as the PbO content increased from x = 0.0 to x = 0.7. Furthermore, the Urbach energy was studied based on the UV-Vis results to confirm the disordered structure of the glass. The calculated densities of the glass samples (1.5835 g/cm3 to 3.9184 g/cm3) increased as the concentration of PbO increased, whereas they decreased with the molar volume.

  1. There Is Still Room for Improvement: Presentation of a Neutral Borosilicate Glass with Improved Chemical Stability for Parenteral Packaging.

    Science.gov (United States)

    Boltres, Bettine; Tratzky, Stephan; Kass, Christof; Eichholz, Rainer; Naß, Peter

    2016-01-01

    For pharmaceutical parenteral packaging the glass compositions have always been either Type I borosilicate or Type III soda-lime glass. As both the compositions and certain chemical and physical properties are mandated by international standards, there has not been room for any changes. However, by applying only minor adjustments, a borosilicate glass was developed that showed improved chemical stability. The chemical composition is still in the range of currently used borosilicate glasses, which makes it a Type I glass according to all current pharmacopeia. A study was performed on glass vials comparing the new glass with the standard FIOLAX(®) and two other publicly available glasses. In an extraction study with water at 121 °C the new glass showed the highest chemical stability with the lowest amount of extractables. In an accelerated ageing study, which was done with water, phosphate, and carbonate buffer at 40 °C for 12 months, the new glass also proved to have the lowest amount of leachables. In this article the new glass and the results from the studies are presented, showing the reader how much of an effect can be attained with only minor adjustments if the scientific fundamentals are clear. The pharmaceutical market has been quite constant and risk-oriented due to the high impact on the safety of the patient. As any change necessitates a complicated change process, this has, in consequence, lead the industry to resist changing the parenteral primary packaging material for decades. The main glasses have either been Type I borosilicate or Type III soda-lime glass. On the other hand, a combination of improved inspection systems and the development of more sensitive biologically based drugs has elevated the standards for parental packaging materials. For example, the measurement of extractables and leachables from the packaging material steadily came into focus. In this article, a new glass is presented that still belongs to the group of Type I borosilicate

  2. Intrinsic dosimetry. Properties and mechanisms of thermoluminescence in commercial borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-10-01

    Intrinsic dosimetry is the method of measuring total absorbed dose received by the walls of a container holding radioactive material. By considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container, this method has the potential to provide enhanced pathway information regarding the history of the container and its radioactive contents. The latest in a series of experiments designed to validate and demonstrate this newly developed tool are reported. Thermoluminescence (TL) dosimetry was used to measure dose effects on raw stock borosilicate container glass up to 70 days after gamma ray, x-ray, beta particle or ultraviolet irradiations at doses from 0.15 to 20 Gy. The TL glow curve when irradiated with 60Co was separated into five peaks: two relatively unstable peaks centered near 120 and 165°C, and three relatively stable peaks centered near 225, 285, and 360°C. Depending on the borosilicate glass source, the minimum measurable dose using this technique is 0.15-0.5 Gy, which is roughly equivalent to a 24 hr irradiation at 1 cm from a 50-165 ng source of 60Co. Differences in TL glow curve shape and intensity were observed for the glasses from different geographical origins. These differences can be explained by changes in the intensities of the five peaks. Electron paramagnetic resonance (EPR) and multivariate statistical methods were used to relate the TL intensity and peaks to electron/hole traps and compositional variations.

  3. X-ray absorption studies of chlorine valence and local environments in borosilicate waste glasses

    International Nuclear Information System (INIS)

    McKeown, David A.; Gan, Hao; Pegg, Ian L.; Stolte, W.C.; Demchenko, I.N.

    2011-01-01

    Chlorine (Cl) is a constituent of certain types of nuclear wastes and its presence can affect the physical and chemical properties of silicate melts and glasses developed for the immobilization of such wastes. Cl K-edge X-ray absorption spectra (XAS) were collected and analyzed to characterize the unknown Cl environments in borosilicate waste glass formulations, ranging in Cl-content from 0.23 to 0.94 wt.%. Both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) data for the glasses show trends dependent on calcium (Ca) content. Near-edge data for the Ca-rich glasses are most similar to the Cl XANES of CaCl 2 , where Cl - is coordinated to three Ca atoms, while the XANES for the Ca-poor glasses are more similar to the mineral davyne, where Cl is most commonly coordinated to two Ca in one site, as well as Cl and oxygen nearest-neighbors in other sites. With increasing Ca content in the glass, Cl XANES for the glasses approach that for CaCl 2 , indicating more Ca nearest-neighbors around Cl. Reliable structural information obtained from the EXAFS data for the glasses is limited, however, to Cl-Cl, Cl-O, and Cl-Na distances; Cl-Ca contributions could not be fit to the glass data, due to the narrow k-space range available for analysis. Structural models that best fit the glass EXAFS data include Cl-Cl, Cl-O, and Cl-Na correlations, where Cl-O and Cl-Na distances decrease by approximately 0.16 A as glass Ca content increases. XAS for the glasses indicates Cl - is found in multiple sites where most Cl-sites have Ca neighbors, with oxygen, and possibly, Na second-nearest neighbors. EXAFS analyses suggest that Cl-Cl environments may also exist in the glasses in minor amounts. These results are generally consistent with earlier findings for silicate glasses, where Cl - was associated with Ca 2+ and Na + in network modifier sites.

  4. Entrapment of 137Cs vapour generated during vitrification and casting of cesium borosilicate glass by inorganic materials

    International Nuclear Information System (INIS)

    Ram, Ramu; Gandhi, Shyamala; Dash, A.; Varma, R.N.

    2003-01-01

    Efficiency of different inorganic materials like zirconium antimonate (ZrA), ammonium molybdophosphate (AMP), synthetic zeolites, activated charcoal, glass wool etc, towards the entrapment of 137 Cs vapour escaping during vitrification and casting of cesium borosilicate glass required for the preparation of 137 Cs sources for medical and industrial applications have been determined. The recovery of entrapped cesium using dilute acids for subsequent recycling has also been explored. (author)

  5. Optical properties of 3d transition metal ion-doped sodium borosilicate glass

    International Nuclear Information System (INIS)

    Wen, Hongli; Tanner, Peter A.

    2015-01-01

    Graphical abstract: Photographs of undoped (SiO 2 ) 50 (Na 2 O) 25 (B 2 O 3 ) 25 (SiNaB) glass and transition metal ion-doped (TM) 0.5 (SiO 2 ) 49.5 (Na 2 O) 25 (B 2 O 3 ) 25 glass samples. - Highlights: • 3d transition metal ion (from Ti to Zn) doped SiO 2 -Na 2 O-B 2 O 3 glasses. • Optical properties of doped glasses investigated. • V(IV,V); Cr(III, VI); Mn(II,III); Fe(II,III); Co(II); Ni(II); Cu(II) by XANES, DRS. • Strong visible absorption but only vanadium ion gives strong emission in glass. - Abstract: SiO 2 -Na 2 O-B 2 O 3 glasses doped with 3d-transition metal species from Ti to Zn were prepared by the melting-quenching technique and their optical properties were investigated. The X-ray absorption near edge spectra of V, Cr, and Mn-doped glasses indicate that the oxidation states of V(IV, V), Cr(III, VI) and Mn(II, III) exist in the studied glasses. The oxidation states revealed from the diffuse reflectance spectra of the glasses are V(IV, V), Cr(III, VI), Mn(III), Fe(II, III), Co(II), Ni(II), and Cu(II). Most of the 3d transition element ions exhibit strong absorption in the visible spectral region in the glass. Under ultraviolet excitation, the undoped sodium borosilicate glass produces weak and broad emission, while doping of vanadium introduces strong and broad emission due to the V(V) charge transfer transition. Only weak emission is observed from Ti(IV), Mn(II), Fe(III) and Cu(II), partly resulting from the strong electron–phonon coupling of the 3d-electrons and the relatively high phonon energy of the studied glass host, with the former leading to dominant nonradiative relaxation based on multiphonon processes for most of the 3d excited states

  6. GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSILICATE FRIT X COMPOSITION FOR PLUTONIUM DISPOSITION

    Energy Technology Data Exchange (ETDEWEB)

    Marra, J

    2006-11-15

    The Department of Energy Office of Environmental Management (DOE/EM) plans to conduct the Plutonium Disposition Project at the Savannah River Site (SRS) to disposition excess weapons-usable plutonium. A plutonium glass waste form is the preferred option for immobilization of the plutonium for subsequent disposition in a geologic repository. A reference glass composition (Lanthanide Borosilicate (LaBS) Frit B) was developed during the Plutonium Immobilization Program (PIP) to immobilize plutonium in the late 1990's. A limited amount of performance testing was performed on this baseline composition before efforts to further pursue Pu disposition via a glass waste form ceased. Recent FY05 studies have further investigated the LaBS Frit B formulation as well as development of a newer LaBS formulation denoted as LaBS Frit X. The objectives of this present task were to fabricate plutonium loaded LaBS Frit X glass and perform corrosion testing to provide near-term data that will increase confidence that LaBS glass product is suitable for disposal in the Yucca Mountain Repository. Specifically, testing was conducted in an effort to provide data to Yucca Mountain Project (YMP) personnel for use in performance assessment calculations. Plutonium containing LaBS glass with the Frit X composition with a 9.5 wt% PuO{sub 2} loading was prepared for testing. Glass was prepared to support Product Consistency Testing (PCT) at Savannah River National Laboratory (SRNL). The glass was thoroughly characterized using x-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) prior to performance testing. A series of PCTs were conducted at SRNL using quenched Pu Frit X glass with varying exposed surface areas. Effects of isothermal and can-in-canister heat treatments on the Pu Frit X glass were also investigated. Another series of PCTs were performed on these different heat-treated Pu Frit X glasses. Leachates from all these PCTs

  7. Investigation of local environment around rare earths (La and Eu) by fluorescence line narrowing during borosilicate glass alteration

    Energy Technology Data Exchange (ETDEWEB)

    Molières, Estelle [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Panczer, Gérard; Guyot, Yannick [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Jollivet, Patrick [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Majérus, Odile; Aschehoug, Patrick; Barboux, Philippe [Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, École Nationale Supérieure de Chimie de Paris (ENSCP Chimie-ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Gin, Stéphane [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Angeli, Frédéric, E-mail: frederic.angeli@cea.fr [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France)

    2014-01-15

    The local environment of europium in soda-lime borosilicate glasses with a range of La{sub 2}O{sub 3} content was probed by continuous luminescence and Fluorescence Line Narrowing (FLN) to investigate the local environment of rare earth elements in pristine and leached glass. After aqueous leaching at 90 °C at pH 7 and 9.5, rare earths were fully retained and homogeneously distributed in the amorphous alteration layer (commonly called gel). Two separate silicate environments were observed in pristine and leached glasses regardless of the lanthanum content and the leaching conditions. A borate environment surrounding europium was not observed in pristine and leached glasses. During glass alteration, OH groups were located around the europium environment, which became more organized (higher symmetry) in the first coordination shell. -- Highlights: • No borate environment surrounding europium was detected in pristine borosilicate glasses. • Up to 12 mol% of REE2O3 in glass, local environment of europium does not significantly change. • Europium environment becomes more ordered and symmetric in gels than in pristine glasses. • Two distinct silicate sites were observed, as well in pristine glass as in gels (leached glasses). • In altered glasses, OH groups were located around europium.

  8. Structural and crystallisation study of a rare earth alumino borosilicate glass designed for nuclear waste confinement

    International Nuclear Information System (INIS)

    Quintas, A.

    2007-09-01

    This work is devoted to the study of a rare earth alumino borosilicate glass, which molar composition is 61,81 SiO 2 - 3,05 Al 2 O 3 - 8,94 B 2 O 3 - 14,41 Na 2 O - 6,33 CaO - 1,90 ZrO 2 - 3,56 Nd 2 O 3 , and envisaged for the immobilization of nuclear wastes originating from the reprocessing of high discharge burn up spent fuel. From a structural viewpoint, we investigated the role of the modifier cations on the arrangement of the glass network through different modifications of the glass composition: variation of the Na/Ca ratio and modification of the nature of the alkali and alkaline earth cations. The NMR and Raman spectroscopic techniques were useful to determine the distribution of modifier cations among the glass network and also to cast light on the competition phenomena occurring between alkali and alkaline earth cations for charge compensation of [AlO 4 ] - and [BO 4 ] - species. The neodymium local environment could be probed by optical absorption and EXAFS spectroscopies which enabled to better understand the insertion mode of Nd 3+ ions among the silicate domains of the glass network. Concerning the crystallization behavior we were interested in how the glass composition may influence the crystallization processes and especially the formation of the apatite phase of composition Ca 2 Nd 8 (SiO 4 ) 6 O 2 . In particular, this work underlined the important role of both alkaline earth and rare earth cations on the crystallization of the apatite phase. (author)

  9. Borosilicate glass as a matrix for immobilization of SRP high-level waste

    International Nuclear Information System (INIS)

    Wicks, G.G.

    1980-01-01

    Approximately 22 million gallons of high-level radioactive defense waste are currently being stored in large underground tanks located on the Savannah River Plant (SRP) site in Aiken, South Carolina. One option now being considered for long-term management of this waste involves removing the waste from the tanks, chemically processing the waste, and immobilizing the potentially harmful radionuclides in the waste into a borosilicate glass matrix. The technology for producing waste glass forms is well developed and has been demonstrated on various scales using simulated as well as radioactive SRP waste. Recently, full-scale prototypical equipment has been made operational at SRP. This includes both a joule-heated ceramic melter and an in-can melter. These melters are a part of an integrated vitrification system which is under evaluation and includes a spray calciner, direct liquid feed apparatus, and various elements of an off-gas system. Two of the most important properties of the waste glass are mechanical integrity and leachability. Programs are in progress at SRL aimed at minimizing thermally induced cracking by carefully controlling cooling cycles and using ceramic liners or coatings. The leachability of SRP waste glass has been studied under many different conditions and consistently found to be low. For example, the leachability of actual SRP waste glass was found to be 10 -6 to 10 -5 g/(cm 2 )(day) initially and decreasing to 10 -9 to 10 -8 g/(cm 2 )(day) after 100 days. Waste glass is also being studied under anticipated storage conditions. In brine at 90 0 C, the leachability is about 5 x 10 -8 g/(cm 2 )(day) after 60 days. The effects of other geological media including granite, basalt, shale, and tuff are also being studied as part of the multibarrier isolation system

  10. A Raman spectroscopy study on the effects of intermolecular hydrogen bonding on water molecules absorbed by borosilicate glass surface

    Science.gov (United States)

    Li, Fabing; Li, Zhanlong; Wang, Ying; Wang, Shenghan; Wang, Xiaojun; Sun, Chenglin; Men, Zhiwei

    2018-05-01

    The structural forms of water/deuterated water molecules located on the surface of borosilicate capillaries have been first investigated in this study on the basis of the Raman spectral data obtained at different temperatures and under atmospheric pressure for molecules in bulk and also for molecules absorbed by borosilicate glass surface. The strongest two fundamental bands locating at 3063 cm-1 (2438 cm-1) in the recorded Raman spectra are assigned here to the Osbnd H (Osbnd D) bond stretching vibrations and they are compared with the corresponding bands observed at 3124 cm-1 (2325 cm-1) in the Raman spectrum of ice Ih. Our spectroscopic observations have indicated that the structure of water and deuterated water molecules on borosilicate surface is similar to that of ice Ih (hexagonal phase of ice). These observations have also indicated that water molecules locate on the borosilicate surface so as to construct a bilayer structure and that strong and weak intermolecular hydrogen bonds are formed between water/deuterated molecules and silanol groups on borosilicate surface. In accordance with these findings, water and deuterated water molecules at the interface of capillary have a higher melting temperature.

  11. A Raman spectroscopy study on the effects of intermolecular hydrogen bonding on water molecules absorbed by borosilicate glass surface.

    Science.gov (United States)

    Li, Fabing; Li, Zhanlong; Wang, Ying; Wang, Shenghan; Wang, Xiaojun; Sun, Chenglin; Men, Zhiwei

    2018-05-05

    The structural forms of water/deuterated water molecules located on the surface of borosilicate capillaries have been first investigated in this study on the basis of the Raman spectral data obtained at different temperatures and under atmospheric pressure for molecules in bulk and also for molecules absorbed by borosilicate glass surface. The strongest two fundamental bands locating at 3063cm -1 (2438cm -1 ) in the recorded Raman spectra are assigned here to the OH (OD) bond stretching vibrations and they are compared with the corresponding bands observed at 3124cm -1 (2325cm -1 ) in the Raman spectrum of ice Ih. Our spectroscopic observations have indicated that the structure of water and deuterated water molecules on borosilicate surface is similar to that of ice Ih (hexagonal phase of ice). These observations have also indicated that water molecules locate on the borosilicate surface so as to construct a bilayer structure and that strong and weak intermolecular hydrogen bonds are formed between water/deuterated molecules and silanol groups on borosilicate surface. In accordance with these findings, water and deuterated water molecules at the interface of capillary have a higher melting temperature. Copyright © 2018. Published by Elsevier B.V.

  12. Volatilization from borosilicate glass melts of simulated Savannah River Plant waste

    International Nuclear Information System (INIS)

    Wilds, G.W.

    1978-01-01

    Laboratory scale studies determined the rates at which the semivolatile components sodium, boron, lithium, cesium, and ruthenium volatilized from borosilicate glass melts that contained simulated Savannah River Plant waste sludge. Sodium and boric oxides volatilize as the thermally stable compound sodium metaborate, and accounted for approx. 90% of the semivolatiles that evolved. The amounts of semivolatiles that evolved increased linearly with the logarithm of the sodium content of the glass-forming mixture. Cesium volatility was slightly suppressed when titanium dioxide was added to the melt, but was unaffected when cesium was added to the melt as a cesium-loaded zeolite rather than as a cesium carbonate solution. Volatility of ruthenium was not suppressed when the glass melt was blanketed with a nonoxidizing atmosphere. Trace quantities of mercury were removed from vapor streams by adsorption onto a silver-exchanged zeolite. A bed containing silver in the ionic state removed more than 99.9% of the mercury and had a high chemisorption capacity. Beds of lead-, copper-, and copper sulfide-exchanged zeolite-X and also an unexchanged zeolite-X were tested. None of these latter beds had high removal efficiency and high chemisorption capacity

  13. Volatilization from borosilicate glass melts of simulated Savannah River Plant waste

    International Nuclear Information System (INIS)

    Wilds, G.W.

    1979-01-01

    Laboratory scale studies determined the rates at which the semivolatile components sodium, boron, lithium, cesium, and ruthenium volatilized from borosilicate glass melts that contained simulated Savannah River Plant waste sludge. Sodium and boric oxides volatilize as the thermally stable compound sodium metaborate, and accounted for approx. 90% of the semivolatiles that evolved. The amounts of semivolatiles that evolved increased linearly with the logarithm of the sodium content of the glass-forming mixture. Cesium volatility was slightly suppressed when titanium dioxide was added to the melt, but was unaffected when cesium was added to the melt as a cesium-loaded zeolite rather than as a cesium carbonate solution. Volatility of ruthenium was not suppressed when the glass melt was blanketed with a nonoxidizing atmosphere. Trace quantities of mercury were removed from vapor streams by adsorption onto a silver-exchanged zeolite. A bed containing silver in the ionic state removed more than 99.9% of the mercury and had a high chemisorption capacity. Beds of lead-, copper-, and copper sulfide-exchanged zeolite-X and also an unexchanged zeolite-X were tested. None of these latter beds had high removal efficiency and high chemisorption capacity

  14. Laser-assisted fabrication of gold nanoparticle-composed structures embedded in borosilicate glass

    Directory of Open Access Journals (Sweden)

    Nikolay Nedyalkov

    2017-11-01

    Full Text Available We present results on laser-assisted formation of two- and three-dimensional structures comprised of gold nanoparticles in glass. The sample material was gold-ion-doped borosilicate glass prepared by conventional melt quenching. The nanoparticle growth technique consisted of two steps – laser-induced defect formation and annealing. The first step was realized by irradiating the glass by nanosecond and femtosecond laser pulses over a wide range of fluences and number of applied pulses. The irradiation by nanosecond laser pulses (emitted by a Nd:YAG laser system induced defect formation, expressed by brown coloration of the glass sample, only at a wavelength of 266 nm. At 355, 532 and 1064 nm, no coloration of the sample was observed. The femtosecond laser irradiation at 800 nm also induced defects, again observed as brown coloration. The absorbance spectra indicated that this coloration was related to the formation of oxygen deficiency defects. After annealing, the color of the irradiated areas changed to pink, with a corresponding well-defined peak in the absorbance spectrum. We relate this effect to the formation of gold nanoparticles with optical properties defined by plasmon excitation. Their presence was confirmed by high-resolution TEM analysis. No nanoparticle formation was observed in the samples irradiated by nanosecond pulses at 355, 532 and 1064 nm. The optical properties of the irradiated areas were found to depend on the laser processing parameters; these properties were studied based on Mie theory, which was also used to correlate the experimental optical spectra and the characteristics of the nanoparticles formed. We also discuss the influence of the processing conditions on the characteristics of the particles formed and the mechanism of their formation and demonstrate the fabrication of structures composed of nanoparticles inside the glass sample. This technique can be used for the preparation of 3D nanoparticle systems

  15. Results of Vertical Scanning Interferometry (VSI) of Dissolved Borosilicate Glass: Evidence for Variable Surface Features and Global Surface Retreat

    Energy Technology Data Exchange (ETDEWEB)

    Icenhower, Jonathan P.; Luttge, Andreas; McGrail, B. Peter; Beig, Mikhala S.; Arvidson, Rolf S.; Cordova, Elsa A.; Steele, Jackie L.; Baum, Steven R.

    2003-10-29

    Two disparate reaction mechanisms have been invoked to explain the reactivity of glass in contact with aqueous solution. One model is based on arguments from Transition State Theory (TST), which postulates that glass dissolution rates are surface reaction controlled. Alternatively, the second model argues that release of elements from glass to solution is governed by diffusion through an altered layer that forms on the surface of glass. Vertical Scanning Interferometry (VSI) is a new technique that allows one to observe surface features of specimens exposed to solution and may, potentially, be used to distinguish between competing models. We performed a series of dissolution experiments with a suite of glass compositions from chemically simple (sodium borosilicate) to complex (sixteen component borosilicate). Dissolution rates were determined using single-pass flow-through (SPFT) apparatus at 90ºC and pH = 9 and over a solution saturation interval. Upon termination of the experiments, glass coupons were examined by VSI techniques. Effluent chemistry and VSI measurements indicate a nearly constant rate of 2.2 to 3.4 g m-2 d-1 over the solution interval; rates calculated from both methods are identical within experimental uncertainty. We argue that this glass is phase separated, and propose a model for dissolution based on the relative rates of dissolution of the two glass compositions. The data are consistent with a modified version of TST and indicate the potency of VSI methods to elucidate glass reaction mechanisms.

  16. Microwave Absorption of Barium Borosilicate, Zinc Borate, Fe-Doped Alumino-Phosphate Glasses and Its Raw Materials

    Directory of Open Access Journals (Sweden)

    Ashis Kumar Mandal

    2015-05-01

    Full Text Available This study presents microwave absorption of raw materials used in barium borosilicate, Fe-doped alumina phosphate and zinc borate glass. Microwave absorption was investigated for the raw materials SiO2, Na2CO3, BaCO3, BPO4, Al(PO33, Mg(PO32, Al(OH3, TiO2. The study shows that SiO2 could be heated directly above 1000 °C within 30 min at 1.5 kW microwave output (MW power and 0.8 kW MW power is necessary to initiate heating (from 260 °C. Microwave heating of material with low dielectric loss has been investigated by increasing MW power. Microwave absorption of above glass systems has also been investigated. Dielectric properties such as loss tangent of glass as a function of temperature are presented. Glass melting under direct microwave heating was demonstrated for the studied glass systems. Temperature-Microwave power-Time (T-P-t profiles for the three glasses indicate maximum MW output power ~1 kW, 0.65 kW and ~1 kW for barium borosilicate, zinc borate glass and alumino-phosphate glass for 60 g glass melting.

  17. Upconversion studies of Er3+/Yb3+ doped SrO.TiO2 borosilicate glass ceramic system

    International Nuclear Information System (INIS)

    Maheshwari, Aditya; Om Prakash; Kumar, Devendra; Rai, S.B.

    2011-01-01

    Upconversion behaviour has been studied in various matrices and fine powders of SrTiO 3 by previous workers. In present work, Er 3+ /Yb 3+ were doped in appropriate ratio in SrO.TiO 2 borosilicate glass ceramic system to study the upconversion phenomenon. Dielectric properties of this class of glass ceramic system have been extensively investigated by Thakur et al. It has been observed that both upconversion efficiency and dielectric constant increases with transformation of glass into glass ceramic. Therefore, present investigation is based upon the study of optical as well as the electrical properties of same glass ceramic system. In order to prepare different crystalline matrices, two different Er 3+ /Yb 3+ :SrO.TiO 2 borosilicate glasses with same amount of Er 2 O 3 and Yb 2 O 3 were prepared by melt quench method. Glasses were transparent with light-wine colour. Glass ceramics were prepared from the glasses by heat treatment based on DTA (Differential thermal analysis) results. Glass ceramics were fully opaque with brownish-cream colour. Powder X-ray diffraction (XRD) patterns confirmed that two different crystalline matrices, Sr 3 Ti 2 O 7 , Ti 10 O 19 and SrTiO 3 , TiO 2 were present in two glass ceramic samples respectively. Luminescence properties of glass and glass ceramic samples with 976nm laser irradiation showed that the intensities of the green and red emission increased multiple times in glass ceramic than that of the glass. Possible mechanisms responsible for upconversion eg. Energy Transfer (ET) and Excited State Absorption (ESA), were studied through laser pumping power log dependence

  18. Leaching of the simulated borosilicate waste glasses and spent nuclear fuel under a repository condition

    International Nuclear Information System (INIS)

    Kim, Seung Soo; Chun, Kwan Sik; Kang, Chul Hyung; Suh, Hang Suk

    2002-12-01

    Leaching behaviors of simulated waste glass and spent fuel, contacted on bentonite blocks, in synthetic granitic groundwater were investigated in this study. The leach rate of boron from borosilicate waste glass between the compacted bentonite blocks reached about 0.03 gm-2day-1 at 1500 days, like as that of molybdenum. However, the concentration of uranium in leachate pass through bentonite blocks was less than their detection limits of 2 μg/L and whose yellow amorphous compound was found on the surface of glass contacted with the bentonite blocks. The leaching mechanism of waste glasses differed with their composition. The release rate of cesium from PWR spent fuel in the simulated granitic water without bentonite was leas than $1.0x10 -5 fraction/day after 300 days. The retardation factor of cesium by a 10 -mm thickness of bentonite block was more than 100 for 4-years leaching time. The cumulative release fraction of uranium for 954 days was 0.016% (1.7x10 -7 fraction/day) in granitic water without bentonite. The gap inventory of cesium for spent fuel G23-J11 was 0.15∼0.2%. However, the release of cesium from C15-I08 was 0.9% until 60 days and has being continued after that. Gap inventories of strontium and iodine in G23-J11 were 0.033% and below 0.2%, respectively. The sum of fraction of cesium in gap and grain boundary of G23-J11 was suggested below 3% and less

  19. Luminescence properties of Dy3+ doped lithium zinc borosilicate glasses for photonic applications

    Directory of Open Access Journals (Sweden)

    N. Jaidass

    2018-03-01

    Full Text Available Different concentrations of Dy3+ ions doped lithium zinc borosilicate glasses of chemical composition (30-x B2O3 - 25 SiO2 -10 Al2O3 -30 LiF - 5 ZnO - x Dy2O3 (x = 0, 0.1, 0.5, 1.0 and 2.0 mol% were prepared by the melt quenching technique. The prepared glasses were investigated through X-ray diffraction, optical absorption, photoluminescence and decay measurements. Intensities of absorption bands expressed in terms of oscillator strengths (f were used to determine the Judd-Ofelt (J-O intensity parameters Ωλ (λ = 2, 4 and 6. The evaluated J-O parameters were used to determine the radiative parameters such as transition probabilities (AR, total transition probability rate (AT, radiative lifetime (τR and branching ratios (βR for the excited 4F9/2 level of Dy3+ ions. The chromaticity coordinates determined from the emission spectra were found to be located in the white light region of CIE chromaticity diagram. Keywords: Condensed matter physics, Engineering, Materials science

  20. Preparation and characterization of an improved borosilicate glass for the solidification of high level radioactive fission product solutions (HLW). Pt. 2

    International Nuclear Information System (INIS)

    Kahl, L.; Ruiz-Lopez, M.C.; Saidl, J.; Dippel, T.

    1982-04-01

    In the 'Institut fuer Nuklare Entsorgungstechnik' the borosilicate glass VG 98/12 has been developed for the solidification of the high level radioactive waste (HLW). This borosilicate glass can be used in a direct heated ceramic melter and forms together with the HLW the borosilicate glass product GP 98/12. This borosilicate glass product has been examined in detail both in liquid and solid state. The elements contained in the HLW can be incorporated without problems. Only in a few exceptions the concentration must be kept below certain limits to exclude the formation of a second phase ('yellow phase') by separation. No spontaneous crystallization and no crystallization over a long time could be observed as long as the temperature of the borosilicate glass product is kept below its transformation area. Simulating accidental conditions in the final storage, samples had been leached at temperatures up to 200 0 C and pressures up to 130 bar with saturated rock salt brine and saturated quinary salt brine. The leaching process seems to be stopped by the formed 'leached layer' on the surface of the borosilicate glass product after a limited leaching time. Detailed investigations have been started to explain this phenomenon. (orig.) [de

  1. Effect of the Callovian-Oxfordian clayey fraction on borosilicate glass alteration

    International Nuclear Information System (INIS)

    Debure, M.; Frugier, P.; GIN, S.; De Windt, L.; Michau, N.

    2012-01-01

    easily exchangeable Mg and to check whether remaining Mg, especially structural Mg could still feed the solution. The cation exchange capacity (CEC) and the exchangeable cation population after treatment were measured by the cobaltihexamine test, indicating an enrichment of Na (from 14% to 79% in equivalents) of the exchangeable population at the expense of Ca (from 50% to 4%), Mg (from 15% to 6%) and K (from 18% to 7%) compared to the pristine clay-stone. Synthetic borosilicate Mg-free glasses were used as simplified references of the French nuclear glass R7T7. Batch experiments were performed in closed system at 90 deg. C during 150 days. The clay/glass (C/G) weight ratio ranged from 0.01 to 100 for a liquid/solid (L/S) weight ratio of 20. The specific surface was estimated to be around 0.06 m 2 /g and 100 m 2 /g for the glass powder and the clayey fraction, respectively. Chemical analysis of the batch solutions were carried out with time, as well as XRD, SEM and TOF-SIMS analysis of the solids after completion of the batch experiments. Modeling was performed with the GRAAL kinetic model of glass dissolution that considers elements and water diffusion in the alteration layer (Frugier et al., 2008), implemented within the reactive transport code HYTEC (van der Lee et al., 2003). The experiments showed that the higher the clay/glass ratio, the lower the pH 90deg.C and the higher the glass alteration. As shown in Fig. 1, the pH 90deg.C varied from 8.9 for the lowest clay/glass proportion (C/G 1) to 5.4 for the highest one (C/G = 100). The corresponding mean glass dissolution rates are 15 nm/d and 300 nm/d, respectively. A batch test performed with the sole clayey fraction in pure water yielded a pH 90deg.C of 5.2, whereas the test made with the glass alone led to a pH 90deg.C around 9. The main effect of the clayey fraction in the batch tests seems to drop the pH down to more acidic values that concentrations of B (a tracer of the glass alteration) on the one hand, and of

  2. Formation and growth of semiconductor PbTe nanocrystals in a borosilicate glass matrix

    International Nuclear Information System (INIS)

    Craievich, A.F.; Alves, O.L.; Barbosa, L.C.

    1997-01-01

    Pb- and Te-doped borosilicate glasses are transformed by appropriate heat treatment into a composite material consisting of a vitreous matrix in which semiconductor PbTe nanocrystals are embedded. This composite exhibits interesting non-linear optical properties in the infrared region, in the range 10-20000 A. The shape and size distribution of the nanocrystals and the kinetics of their growth were studied by small-angle X-ray scattering (SAXS) during in situ isothermal treatment at 923 K. The experimental results indicate that nanocrystals are nearly spherical and have an average radius increasing from 16 to 33 A after 2 h at 923 K, the relative size dispersion being time-invariant and approximately equal to 8%. This investigation demonstrates that the kinetics of nanocrystal growth are governed by the classic mechanism of atomic diffusion. The radius of nanocrystals, deduced by applying the simple Efros and Efros (1982) model using the energy values corresponding to the exciton peaks of optical absorption spectra, does not agree with the average radius determined by SAXS. (orig.)

  3. Glass transition and crystallization kinetics of a barium borosilicate glass by a non-isothermal method

    International Nuclear Information System (INIS)

    Lopes, Andreia A. S.; Soares, Roque S.; Lima, Maria M. A.; Monteiro, Regina C. C.

    2014-01-01

    The glass transition and crystallization kinetics of a glass with a molar composition 60BaO-30B 2 O 3 -10SiO 2 were investigated by differential scanning calorimetry (DSC) under non-isothermal conditions. DSC curves exhibited an endothermic peak associated with the glass transition and two partially overlapped exothermic peaks associated with the crystallization of the glass. The dependence of the glass transition temperature (T g ) and of the maximum crystallization temperature (T p ) on the heating rate was used to determine the activation energy associated with the glass transition (E g ), the activation energy for crystallization (E c ), and the Avrami exponent (n). X-ray diffraction (XRD) revealed that barium borate (β-BaB 2 O 4 ) was the first crystalline phase to be formed followed by the formation of barium silicate (Ba 5 Si 8 O 21 ). The variations of activation energy for crystallization and of Avrami exponent with the fraction of crystallization (χ) were also examined. When the crystallization fraction (χ) increased from 0.1 to 0.9, the value of local activation energy (E c (χ)) decreased from 554 to 458 kJ/mol for the first exothermic peak and from 1104 to 831 kJ/mol for the second exothermic peak. The value determined for the Avrami exponent was near 2 indicating a similar one-dimensional crystallization mechanism for both crystalline phases. This was confirmed by the morphological studies performed by scanning electron microscopy (SEM) on glass samples heat-treated at the first and at the second crystallization temperatures

  4. Phase evolution and dielectric properties of MgTi2O5 ceramic sintered with lithium borosilicate glass

    International Nuclear Information System (INIS)

    Shin, Hyunho; Shin, Hee-Kyun; Jung, Hyun Suk; Cho, Seo-Yong; Hong, Kug Sun

    2005-01-01

    Phase evolution, densification, and dielectric properties of MgTi 2 O 5 dielectric ceramic, sintered with lithium borosilicate (LBS) glass, were studied. Reaction between LBS glass and MgTi 2 O 5 was significant in forming secondary phases such as TiO 2 and (Mg,Ti) 2 (BO 3 )O. The glass addition was not necessarily deleterious to the dielectric properties due to the formation of TiO 2 : permittivity increased and temperature coefficient of resonance frequency could be tuned to zero with the addition of LBS glass, although the inevitable glass-induced decrease of quality factor was not retarded by the formation of TiO 2 . The sintered specimen with 10 wt% LBS fired at 950 deg. C for 2 h showed permittivity of 19.3, quality factor of 6800 GHz, and τ f of -16 ppm/ deg. C

  5. Local structure near actinides and nucleating elements in borosilicate glass for nuclear industry: Results of X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Petit-Maire, D.

    1988-01-01

    Possibilities and limits of X-ray absorption spectroscopy for cation site description in silicate glasses and possible applications for complex glasses, like glass for fission product containment, are examined. In borosilicate glasses two types of sites are evidenced for actinides at the valence 4: Coordinance 6 sites with a narrow radial distribution for the distance An-0; higher coordination (7, 8 or more) with a wider and asymmetrical radial distribution. Proportion of low coordinance sites increases when cation size decreases (Th > Np). U and Np VI and V are characterized as actinyles with a chain 0-An-0 practically linear, coordinance in a plane perpendicular to this complex is probably 5. X-ray absorption spectroscopy allows an accurate description of actinide sites in fission product glasses [fr

  6. Preparation and nonlinear optical properties of indium nanocrystals in sodium borosilicate glass by the sol–gel route

    International Nuclear Information System (INIS)

    Zhong, Jiasong; Xiang, Weidong; Zhao, Haijun; Chen, Zhaoping; Liang, Xiaojuan; Zhao, Wenguang; Chen, Guoxin

    2012-01-01

    Graphical abstract: The sodium borosilicate glass doped with indium nanocrystals have been successfully prepared by sol–gel methods. And the indium nanocrystals in tetragonal crystal system have formed uniformly in the glass, and the average diameter of indium nanocrystals is about 30 nm. The third-order optical nonlinear refractive index γ, absorption coefficient β, and susceptibility χ (3) of the glass are determined to be −4.77 × 10 −16 m 2 /W, 2.67 × 10 −9 m/W, and 2.81 × 10 −10 esu, respectively. Highlights: ► Indium nanocrystals embedded in glass matrix have been prepared by sol–gel route. ► The crystal structure and composition are investigated by XRD and XPS. ► Size and distribution of indium nanocrystals is determined by TEM. ► The third-order optical nonlinearity is investigated by using Z-scan technique. -- Abstract: The sodium borosilicate glass doped with indium nanocrystals have been successfully prepared by sol–gel route. The thermal stability behavior of the stiff gel is investigated by thermogravimetric (TG) and differential thermal (DTA) analysis. The crystal structure of the glass is characterized by X-ray powder diffraction (XRD). Particle composition is determined by X-ray photoelectron spectroscopy (XPS). Size and distribution of the nanocrystals are characterized by transmission electron microscopy (TEM) as well as high-resolution transmission electron microscopy (HRTEM). Results show that the indium nanocrystals in tetragonal crystal structure have formed in glass, and the average diameter is about 30 nm. Further, the glass is measured by Z-scan technique to investigate the nonlinear optical (NLO) properties. The third-order NLO coefficient χ (3) of the glass is determined to be 2.81 × 10 −10 esu. The glass with large third-order NLO coefficient is promising materials for applications in optical devices.

  7. Investigating the effect of V{sub 2}O{sub 5} addition on sodium barium borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Halder, Rumu, E-mail: rumuhalder24feb@gmail.com; Sengupta, Pranesh; Dey, G. K. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai-700 085 (India); Sudarsan, V. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai-700 085 (India); Kaushik, C. P. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai-700 085 (India)

    2016-05-23

    V{sub 2}O{sub 5} doped sodium barium borosilicate glasses were characterized by photoluminescence spectroscopy and electron probe microanalyzer (EPMA). The glass remains homogeneous for lower concentration of V{sub 2}O{sub 5} but a phase separation is observed when V{sub 2}O{sub 5} doping is increased beyond 5 mol%. Detailed microanalysis reveals that the phase separated glass consists of a phase containing V, Ba and Si and a separate Si rich phase within the glass matrix. The luminescence study demonstrated that at low concentration the vanadium mainly interacts with the structural units of B/Si while at higher concentrations, V-O-V/ V-O{sup −} Na{sup +}/Ba{sup 2+} linkages are formed.

  8. Effects of magnesium minerals representative of the Callovian-Oxfordian clay-stone on borosilicate glass alteration

    International Nuclear Information System (INIS)

    Debure, M.

    2012-01-01

    Borosilicate glasses dissolution has been studied in presence of magnesium minerals. Those minerals (dolomite, illite, smectite...) belong to the Callovo-Oxfordian (COx) clay-stone layer, studied in France as a potential site for nuclear waste disposal. Such minerals contain magnesium, an element able to sustain glass alteration when it is available in solution. In the confined media of the wastes disposal, the solids reactivity controls the solution composition and can be the driving force of nuclear glass alteration. Experiments show that magnesium carbonates (hydro-magnesite and dolomite) increase in the glass alteration: the precipitation of magnesium silicates consumes silicon which slows down the formation of the glass passivating layer. The lower the magnesium mineral solubility, the lower the glass alteration. The purified clay phases (illite, smectite...) from the COx layer increase the glass alteration. Half the magnesium was replaced by sodium during the purification process. In such conditions, the effect of clay phases on glass alteration is in part due to the acidic pH-buffering effect of the clay fraction. The GRAAL model implemented in the geochemical transport code HYTEC has confirmed and quantified the mechanisms put in evidence in the experiments. Cells diffusion experiments where the two solids were separated by an inert diffusion barrier allow to valid reactive transport modelling. Such experiments are more representative of the glass package which will be separated from the COx by corrosion products. They show that glass alteration rate is reduced when solids are not close. (author) [fr

  9. Synthesis, electrical and magnetic properties of sodium borosilicate glasses containing Co-ferrites nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Othman, H.A. [Department of Physics, Faculty of Science, Menoufia University, Shibin El-Kom 32511, Menoufia (Egypt); Eltabey, M.M. [Department of Basic Engineering Science, Faculty of Engineering, Menoufia University, Shibin El-Kom, Menoufia (Egypt); Department of Physics, Faculty of Science, Jazan University (Saudi Arabia); Ibrahim, Samia E.; El-Deen, L.M. Sharaf; Elkholy, M.M. [Department of Physics, Faculty of Science, Menoufia University, Shibin El-Kom 32511, Menoufia (Egypt)

    2017-02-01

    Co-ferrites nanoparticles that have been prepared by the co-precipitation method were added to sodium borosilicate (Na{sub 2}O–B{sub 2}O{sub 3}–SiO{sub 2}) glass matrix by the solid solution method and they were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and magnetization measurements. (XRD) revealed the formation of the Co-ferrite magnetic crystalline phase embedded in an amorphous matrix in all the samples. The investigated samples by (TEM) showed the formation of the cobalt ferrite nanoparticles with a spherical shape and highly monodispersed with an average size about 13 nm. IR data revealed that the BO{sub 3} and BO{sub 4} are the main structural units of these samples network. IR spectra of the investigated samples showed the characteristic vibration bands of Co-ferrite. Composition and frequency dependent dielectric properties of the prepared samples were measured at room temperature in the frequency range 100–100 kHz. The conductivity was found to increase with increasing cobalt ferrite content. The variations of conductivity and dielectric properties with frequency and composition were discussed. Magnetic hysteresis loops were traced at room temperature using VSM and values of saturation magnetization M{sub S} and coercive field H{sub C} were determined. The obtained results revealed that a ferrimagnetic behavior were observed and as Co-ferrite concentration increases the values of M{sub S} and H{sub C} increase from 2.84 to 8.79 (emu/g) and from 88.4 to 736.3 Oe, respectively.

  10. Integrated Optic Surface Plasmon Resonance Measurements in a Borosilicate Glass Substrate

    Directory of Open Access Journals (Sweden)

    Antonino Parisi

    2008-11-01

    Full Text Available The surface plasmon resonance (SPR technique is a well-known optical method that can be used to measure the refractive index of organic nano-layers adsorbed on a thin metal film. Although there are many configurations for measuring biomolecular interactions, SPR-based techniques play a central role in many current biosensing experiments, since they are the most suited for sensitive and quantitative kinetic measurements. Here we give some results from the analysis and numerical elaboration of SPR data from integrated optics experiments in a particular borosilicate glass, chosen for its composition offering the rather low refractive index of 1.4701 at 633 nm wavelength. These data regard the flow over the sensing region (metal window of different solutions with refractive indexes in the range of interest (1.3÷1.5 for the detection of contaminants in aqueous solutions. After a discussion of the principles of SPR, of the metal window design optimization by means of optical interaction numerical modeling, and of waveguide fabrication techniques, we give a description of system setup and experimental results. Optimum gold film window thickness and width in this guided-wave configuration has been for the first time derived and implemented on an integrated optic prototype device. Its characterization is given by means of the real time waveguide output intensity measurements, which correspond to the interaction between the sensing gold thin film window and the flowing analyte. The SPR curve was subsequently inferred. Finally, a modified version of the device is reported, with channel waveguides arranged in a Y-junction optical circuit, so that laser source stability requirements are lowered by a factor of 85 dB, making possible the use of low cost sources in practical applications.

  11. Structure, thermal stability and resistance under external irradiation of rare earths and molybdenum-rich alumino-borosilicate glasses

    International Nuclear Information System (INIS)

    Chouard, N.

    2011-01-01

    In France, the highly radioactive nuclear liquid wastes arising from spent nuclear fuel reprocessing (fission products + minor actinides (FPA)) are currently immobilized in an alumino-borosilicate glass called 'R7T7'. In the future, the opportunity of using new alumino-borosilicate glass compositions (HTC glasses) is considered in order to increase the waste loading in glasses and thus significantly decrease the number of glass canisters. However, the increase of the concentration of FPA could lead to the crystallization of rare-earth-rich phases (Ca 2 RE 8 (SiO 4 ) 6 O 2 ) or molybdenum-rich phases (CaMoO 4 , Na 2 MoO 4 ) during melt cooling, which can modify the confinement properties of the glass (chemical durability, self-irradiation resistance..), particularly if they can incorporate radionuclides α or β in their structure. This thesis can be divided into two parts: The first part deals with studying the relationship that can occur between the composition, the structure and the crystallization tendency of simplified seven oxides glasses, belonging to the SiO 2 -B 2 O 3 -Al 2 O 3 -Na 2 O-CaO-MoO 3 -Nd 2 O 3 system and derived from the composition of the HTC glass at 22,5 wt. % in FPA. The impact of the presence of platinoid elements (RuO 2 in our case) on the crystallization of the different phases is also studied. The second part deals with the effect of actinides α decays and more particularly of nuclear interactions essentially coming from recoil nuclei (simulated here by heavy ions external irradiations) on the behaviour under irradiation of an alumino-borosilicate glass containing apatite Ca 2 Nd 8 (SiO 4 ) 6 O 2 crystals, that can incorporate actinides in their structure. Two samples containing apatite crystals with different size are studied, in order to understand the impact of microstructure on the irradiation resistance of this kind of material. (author) [fr

  12. Investigation of U3O8 immobilization in the GP-91 borosilicate glass by induction melter with a cold crucible (CCIM)

    International Nuclear Information System (INIS)

    Matyunin, Y.I.; Demin, A.V.; Smelova, T.V.; Yudintsev, S.V.; Lapina, M.I.

    1997-01-01

    One of the most promising and intensively developed methods for the solidification of high-level wastes is their vitrification with the use of a cold crucible induction melter (CCIM), which offers a number of advantages over ceramic melter. This work is concerned with comparison studies on the behavior of uranium in vitreous borosilicate materials synthesized by the traditional technique (melting in muffle furnaces) and CCIM method. The incorporation of uranium oxide U 3 O 8 into the GP-91 borosilicate glass with the use of CCIM technology is investigated. The limiting solubility of uranium in the GP-91 borosilicate glass is evaluated. The phase composition of precipitated dispersed particles based on uranium is determined. Some physicochemical properties of synthesized materials are explored. Investigations into the behavior of uranium in borosilicate glass prepared in the CCIM show a feasibility to synthesize the X-ray amorphous homogeneous borosilicate glasses incorporating as much as 25 - 28 wt% uranium, which is 4 - 5 times larger than that in glasses obtained by the traditional method. (author)

  13. X-ray tomography of feed-to-glass transition of simulated borosilicate waste glasses

    International Nuclear Information System (INIS)

    Harris, William H.; Guillen, Donna P.; Klouzek, Jaroslav; Pokorny, Richard; Yano, Tetsuji

    2017-01-01

    The feed composition of a high level nuclear waste (HLW) glass melter affects the overall melting rate by influencing the chemical, thermophysical, and morphological properties of a relatively insulating cold cap layer over the molten phase where the primary feed vitrification reactions occur. Data from X ray computed tomography imaging of melting pellets comprised of a simulated high-aluminum HLW feed heated at a rate of 10°C/min reveal the distribution and morphology of bubbles, collectively known as primary foam, within this layer for various SiO 2 /(Li 2 CO 3 +H 3 BO 3 +Na 2 CO 3 ) mass fractions at temperatures between 600°C and 1040°C. To track melting dynamics, cross-sections obtained through the central profile of the pellet were digitally segmented into primary foam and a condensed phase. Pellet dimensions were extracted using Photoshop CS6 tools while the DREAM.3D software package was used to calculate pellet profile area, average and maximum bubble areas, and two-dimensional void fraction. The measured linear increase in the pellet area expansion rates – and therefore the increase in batch gas evolution rates – with SiO 2 /(Li 2 CO 3 +H 3 BO 3 +Na 2 CO 3 ) mass fraction despite an exponential increase in viscosity of the final waste glass at 1050°C and a lower total amount of gas-evolving species suggest that the retention of primary foam with large average bubble size at higher temperatures results from faster reaction kinetics rather than increased viscosity. However, viscosity does affect the initial foam collapse temperature by supporting the growth of larger bubbles. Because the maximum bubble size is limited by the pellet dimensions, larger scale studies are needed to understand primary foam morphology at high temperatures. This temperature-dependent morphological data can be used in future investigations to synthetically generate cold cap structures for use in models of heat transfer within a HLW glass melter.

  14. Effect of 10B(n, α)7Li irradiation on the structure of a sodium borosilicate glass

    Science.gov (United States)

    Peuget, S.; Fares, T.; Maugeri, E. A.; Caraballo, R.; Charpentier, T.; Martel, L.; Somers, J.; Janssen, A.; Wiss, T.; Rozenblum, F.; Magnin, M.; Deschanels, X.; Jégou, C.

    2014-05-01

    The effects of the nuclear reaction 10B(n, α)7Li on the properties and structure of a sodium borosilicate glass were analysed by density, hardness and fracture toughness measurements, Raman and Nuclear Magnetic Resonance spectroscopy and Transmission Electronic Microscopy (TEM) characterization. The TEM observations showed a homogeneous irradiated glass structure up to the nanometer scale. Modifications of the local order around the main cations were noticed, mainly a slight decrease of the mean boron coordination number and an increase of non-bridging oxygen concentrations. At the glass medium range order, the appearance of the D2 Raman band and a modification of the Si-O-Si angle distribution were also observed after irradiation.

  15. In Vitro Degradation of Borosilicate Bioactive Glass and Poly(l-lactide-co-ε-caprolactone Composite Scaffolds

    Directory of Open Access Journals (Sweden)

    Jenna Tainio

    2017-11-01

    Full Text Available Composite scaffolds were obtained by mixing various amounts (10, 30 and 50 weight % [wt %] of borosilicate bioactive glass and poly(l-lactide-co-ε-caprolactone (PLCL copolymer. The composites were foamed using supercritical CO2. An increase in the glass content led to a decrease in the pore size and density. In vitro dissolution/reaction test was performed in simulated body fluid. As a function of immersion time, the solution pH increased due to the glass dissolution. This was further supported by the increasing amount of Ca in the immersing solution with increasing immersion time and glass content. Furthermore, the change in scaffold mass was significantly greater with increasing the glass content in the scaffold. However, only the scaffolds containing 30 and 50 wt % of glasses exhibited significant hydroxyapatite (HA formation at 72 h of immersion. The compression strength of the samples was also measured. The Young’s modulus was similar for the 10 and 30 wt % glass-containing scaffolds whereas it increased to 90 MPa for the 50 wt % glass containing scaffold. Upon immersion up to 72 h, the Young’s modulus increased and then remained constant for longer immersion times. The scaffold prepared could have great potential for bone and cartilage regeneration.

  16. Utilization of Cs137 to generate a radiation barrier for weapons grade plutonium immobilized in borosilicate glass canisters. Revision 1

    International Nuclear Information System (INIS)

    Jardine, L.J.; Armantrout, G.A.; Collins, L.F.

    1995-01-01

    One of the ways recommended by a recent National Academy of Sciences study to dispose of excess weapons-grade plutonium is to encapsulate the plutonium in a glass in combination with high-level radioactive wastes (HLW) to generate an intense radiation dose rate field. The objective is to render the plutonium as difficult to access as the plutonium contained in existing US commercial spent light-water reactor (LWR) fuel until it can be disposed of in a permanent geological repository. A radiation dose rate from a sealed canister of 1,000 rem/h (10 Sv/h) at 1 meter for at least 30 years after fabrication was assumed in this paper to be a radiation dose comparable to spent LWR fuel. This can be achieved by encapsulating the plutonium in a borosilicate glass with an adequate amount of a single fission product in the HLWS, namely radioactive Cs 137 . One hundred thousand curies of Cs 137 will generate a dose rate of 1,000 rem/h (10 Sv/h) at 1 meter for at least 30 years when imbedded into canisters of the size proposed for the Savannah River Site's vitrified high-level wastes. The United States has a current inventory of 54 MCi of CS 137 that has been separated from defense HLWs and is in sealed capsules. This single curie inventory is sufficient to spike 50 metric tons of excess weapons-grade plutonium if plutonium can be loaded at 5.5 wt% in glass, or 540 canisters. Additional CS 137 inventories exist in the United States' HLWs from past reprocessing operations, should additional curies be required. Using only one fission product, CS 137 , rather than the multiple chemical elements and compounds in HLWs to generate a high radiation dose rate from a glass canister greatly simplifies the processing engineering retirement for encapsulating plutonium in a borosilicate glass

  17. Linear thermal expansion coefficient (at temperatures from 130 to 800 K) of borosilicate glasses applicable for coupling with silicon in microelectronics

    OpenAIRE

    Sinev, Leonid S.; Petrov, Ivan D.

    2017-01-01

    Processing results of measurements of linear thermal expansion coefficients and linear thermal expansion of two brands of borosilicate glasses --- LK5 and Borofloat 33 --- are presented. The linear thermal expansion of glass samples have been determined in the temperature range 130 to 800 K (minus 143 to 526 $\\deg$C) using thermomechanical analyzer TMA7100. Relative imprecision of indirectly measured linear thermal expansion coefficients and linear thermal expansion of both glass brands is le...

  18. Enhanced mechanical properties of single walled carbon nanotube-borosilicate glass composite due to cushioning effect and localized plastic flow

    Directory of Open Access Journals (Sweden)

    Sujan Ghosh

    2011-12-01

    Full Text Available A borosilicate glass composite has been fabricated incorporating Single Wall Carbon Nanotubes (SWCNT in the glass matrix by melt-quench technique. Hardness and the fracture toughness of the composite, were found to increase moderately with respect to the base glass. Interestingly one can observe accumulation of SWCNT bundles around the crack zone though no such accumulation was observed in the crack free indentation zone. The enhanced hardness of the composite was discussed by correlating the cushioning as well as toughening behavior of the agglomerated SWCNT bundles. On the other hand enhanced plastic flow was proposed to be the prime reason for the accumulation of SWCNT bundles around the crack, which increases the toughness of the composite by reducing the crack length. Moreover to ascertain the enhanced plasticity of the composite than that of the glass we calculated the recovery resistance of glass and the composite where recovery resistance of composite was found to be higher than that of the glass.

  19. Effects of cobalt-60 gamma radiation on the strength-related internal structure of the borosilicate glass

    International Nuclear Information System (INIS)

    Cafe, Arven I.; Liamzon, Angelie J.

    2011-03-01

    Borosilicate glass in the form of glass slides (1.Omm in thickness and cut into 12.5mm x 55.Omm surface area) was examined to determine the reusability or recyclability and strength of glass apparatuses or compartments after exposing to gamma irradiation from Co-60 source. After knowing the initial parameters using EDXRF under six secondary targets, glass specimens prepared was subjected to gamma radiation for doses 3kGy, 6kGy, 15kGy, 25kGy, and 100kGy. Results of characterization under FTIR provides information about the occurred extension of B-O-Si and B-O-B linkages for lower doses (3-25kGy), while destruction of Si-O bonds for higher dose (100kGy). It shows direct relationship on the observed color change from clear ransparent to deep brown corresponding to the change in optical densities as irradiation dose increases. Ability to fade the induced deep brown color was also observed for a certain time interval which satisfies that this type of glass exhibits self healing property. Although, average energy of about 1.25MeV causes rearrangement of atoms within the glass, according to the XRD result, it remained to be an amorphous solid even in higher dose applied which satisfies that remanufacturing and recycling is possible. (author)

  20. Deep-UV Raman spectroscopic analysis of structure and dissolution rates of silica-rich sodium borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Eric M [ORNL; WindischJr., Charles F. [Pacific Northwest National Laboratory (PNNL); Burton, Sarah D. [Pacific Northwest National Laboratory (PNNL); Bovaird, Chase C. [Pacific Northwest National Laboratory (PNNL)

    2010-01-01

    As part of ongoing studies to evaluate relationships between structure and rates of dissolution of silicate glasses in aqueous media, sodium borosilicate glasses of composition Na2O xB2O3 (3 x)SiO2, with x 1 (Na2O/B2O3 ratio 1), were analyzed using deep-UV Raman spectroscopy. Results were quantified in terms of the fraction of SiO4 tetrahedra with one non-bridging oxygen (Q3) and then correlated with Na2O and B2O3 content. The Q3 fractionwas found to increase with increasing Na2O content, in agreement with studies on related glasses, and, as long as the value of x was not too high, this contributed to higher rates of dissolution in single pass flow-through testing. In contrast, dissolution rates were less strongly determined by the Q3 fraction when the value of x was near unity, and appeared to grow larger upon further reduction of the Q3 fraction. Results were interpreted to indicate the increasingly important role of network hydrolysis in the glass dissolution mechanism as the BO4 tetrahedron replaces the Q3 unit as the charge-compensating structure for Na+ ions. Finally, the use of deep-UV Raman spectroscopy was found to be advantageous in studying finely powdered glasses in cases where visible Raman spectroscopy suffered from weak Raman scattering and fluorescence interference.

  1. Deep-UV Raman spectroscopic analysis of structure and dissolution rates of silica-rich sodium borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Windisch, Charles F.; Pierce, Eric M.; Burton, Sarah D.; Bovaird, Chase C.

    2011-03-24

    As part of ongoing studies to evaluate the relationships between structural variations in silicate glasses and rates of glass dissolution in aqueous media, molecular structures present in sodium borosilicate glasses of composition Na2O.xB2O3.(3-x)SiO2, with x 1 (Na2O/B2O3 ratio 1), were analyzed using deep-UV Raman spectroscopy. The results were quantified in terms of the fraction of SiO4 tetrahedra with one non-bridging oxygen (Q3) and then correlated with Na2O and B2O3 content. Increasing Na2O was found to raise the fraction of Q3 units in the glasses systematically, in agreement with studies on related glasses, and, as long as the value of x was not too high, contribute to higher rates of dissolution in single pass flow-through testing. The finding was obtained across more than one series of silica-rich glasses prepared for independent dissolution studies. In contrast, dissolution rates were less strongly determined by the Q3 fraction when the value of x was near unity and appeared to grow larger upon further reduction of the Q3 fraction. The results were interpreted to indicate the increasingly important role of network hydrolysis in the glass dissolution mechanism as the BO4 tetrahedron replaces the Q3 unit as the charge-compensating structure for Na+ ions. Finally, the use of deep-UV Raman spectroscopy was found to be advantageous in studying finely powdered glasses in cases where visible Raman spectroscopy suffered from weak Raman scattering and fluorescence interference.

  2. Effects of adding barium-borosilicate glass to a simplified etch-and-rinse adhesive on radiopacity and selected properties.

    Science.gov (United States)

    Martins, Gislaine Cristine; Meier, Marcia Margarete; Loguercio, Alessandro Dourado; Reis, Alessandra; Gomes, João Carlos; Gomes, Osnara Maria

    2014-04-01

    To evaluate the radiopacity, ultimate tensile strength (UTS), microhardness (KHN), degree of conversion (DC), water sorption (WS) and solubility (SL) of experimental adhesives. Five experimental adhesives with different concentrations of barium-borosilicate oxide microfillers [0% (R0), 30% (R30), 40% (R40), 50% (R50), 60% (R60)] were formulated based on the adhesive system Ambar (FGM). The adhesive Adper Single Bond 2 (SB, 3M ESPE) was used as commercial reference. For the radiopacity (n = 5), KHN (n = 5), WS (n = 10), and SL (n = 10) tests, adhesive disks were constructed (5.0 mm in diameter and 1.0 mm thick), while for UTS (n = 5), hourglass-shaped specimens with a cross-sectional area of 0.8 mm2 were used. The FTIR spectra of unpolymerized and polymerized adhesives were used to determine the DC. Data were submitted to a one-way ANOVA and Tukey's test (α = 0.05). All experimental adhesives showed radiopacity similar to enamel, except those of R0 and SB. Filler addition did not jeopardize the UTS, KHN, or WS of the filled adhesives in comparison with the unfilled version. Except for R40, filler addition reduced the SL. The filled adhesives showed lower DC when compared with R0, but the DC was similar or higher when compared with SB. The addition of barium-borosilicate glass up to 50% did not jeopardize the mechanical properties of the adhesive layer and seems to reduce its solubility.

  3. Irradiations effects on the structure of boro-silicated glasses: long term behaviour of nuclear waste glassy matrices

    International Nuclear Information System (INIS)

    Bonfils, J. de

    2007-09-01

    This work deals with the long term behaviour of R7T7-type nuclear waste glasses and more particularly of non-active boro-silicated glasses made up of 3 or 5 oxides. Radioactivity of active glasses is simulated by multi energies ions implantations which reproduce the same defects. The damages due to the alpha particles are simulated by helium ions implantations and those corresponding to the recoil nucleus are obtained with gold ions ones. Minor actinides, stemming from the used fuel, is simulated by trivalent rare-earths (Eu 3+ and Nd 3+ ). In a first part, we have shown by macroscopic experiments (Vickers hardness - swelling) and optical spectroscopies (Raman - ATR-IR) that the structure of the glassy matrices is modified under implantations until a dose of 2,3.10 13 at.cm -2 , which corresponds to a R7T7 storage time estimated at 300 years. Beyond this dose, no additional modifications have been observed. The second part concerns the local environment of the rare-earth ions in glasses. Two different environments were found and identified as follows: one is a silicate rich one and the other is attributed to a borate rich one. (author)

  4. Silver diffusion and coloration of soda lime and borosilicate glasses, Part 1: Effect on the transmission and coloration of stained glasses

    Directory of Open Access Journals (Sweden)

    ABDELLAH CHORFA

    2012-03-01

    Full Text Available Using the conventional method of coloration, soda lime and borosilicate glasses have been painted. Once stained, these glasses were heat treated at temperatures close to their transition temperatures (Tg. A parametric study was carried out in order to determine at first the effect of the silver concentration in the stain spread on glass. In addition, it was studied the effect of the heat treatment duration and the chemical composition of the painted glasses on the formation and size of the silver nanoparticles, the silver diffusion depth and also the glasses coloration. The characterization was made using UV-Vis spectroscopy, Raman confocal spectroscopy, SEM, EDX Technique and Abbe Refractometer. The obtained results shows that the coloration intensity of both glass types painted by the conventional method differs and depends essentially on the proportion of alkali ions in the glass. Moreover, it was found that the effect of the silver concentration in the stain is primordial and the heat treatment duration has a limited effect.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. 3 and 4 oxidation state element solubilities in borosilicate glasses. Implement to actinides in nuclear glasses; Solubilite des elements aux degres d'oxydation (3) et (4) dans les verres de borosilicate. Application aux actinides dans les verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Cachia, J.N

    2005-12-15

    In order to ensure optimal radionuclides containment, the knowledge of the actinide loading limits in nuclear waste glasses and also the comprehension of the solubilization mechanisms of these elements are essential. A first part of this manuscript deals with the study of the differences in solubility of the tri and tetravalent elements (actinides and surrogates) particularly in function of the melting temperature. The results obtained indicate that trivalent elements (La, Gd, Nd, Am, Cm) exhibit a higher solubility than tetravalent elements (Hf, Th, Pu). Consequently, it was planned to reduce plutonium at the oxidation state (III), the later being essentially tetravalent in borosilicate glasses. An innovating reduction process of multi-valent elements (cerium, plutonium) using silicon nitride has been developed in a second part of this work. Reduced plutonium-bearing glasses synthesized by Si{sub 3}N{sub 4} addition made it possible to double the plutonium solubility from 2 to 4 wt% at 1200 deg C. A structural approach to investigate the differences between tri and tetravalent elements was finally undertaken. These investigations were carried out by X-rays Absorption Spectroscopy (EXAFS) and NMR. Trivalent rare earth and actinide elements seem to behave as network modifiers while tetravalent elements rather present true intermediaries' behaviour. (author)

  7. Physical and chemical characterization of borosilicate glasses containing Hanford high-level wastes

    International Nuclear Information System (INIS)

    Kupfer, M.J.; Palmer, R.A.

    1980-10-01

    Scouting studies are being performed to develop and evaluate silicate glass forms for immobilization of Hanford high-level wastes. Detailed knowledge of the physical and chemical properties of these glasses is required to assess their suitability for long-term storage or disposal. Some key properties to be considered in selecting a glass waste form include leach resistance, resistance to radiation, microstructure (includes devitrification behavior or crystallinity), homogeneity, viscosity, electrical resistivity, mechanical ruggedness, thermal expansion, thermal conductivity, density, softening point, annealing point, strain point, glass transformation temperature, and refractive index. Other properties that are important during processing of the glass include volatilization of glass and waste components, and corrosivity of the glass on melter components. Experimental procedures used to characterize silicate waste glass forms and typical properties of selected glass compositions containing simulated Hanford sludge and residual liquid wastes are presented. A discussion of the significance and use of each measured property is also presented

  8. Study of optical absorption and photoluminescence of quantum dots of CdS formed in borosilicate glass matrix

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Jitender; Verma, A; Pandey, P K; Bhatnagar, P K; Mathur, P C [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi-110021 (India); Liu, W; Tang, S H [Department of Physics, National University of Singapore, 119243 (Singapore)], E-mail: jitender_does@yahoo.co.in

    2009-06-15

    Optical absorption and photoluminescence (PL) measurements have been made on the quantum dots (QDs) of CdS grown in a borosilicate glass matrix using a two-step annealing technique. The absorption measurements, made in the energy range of 1.3-3.2 eV, indicate the presence of nonradiative trap centers located in the forbidden gap at an energy level near 1.5 eV. The origin of these traps is attributed to the impurities present in the glass matrix. The PL measurements have been made at an excitation energy of 2.75 eV and it is concluded that the origin of PL is not due to either direct recombination of electrons and holes or deep traps, but that it is the shallow traps which are responsible for the observed PL. The shallow traps are attributed to sulfur vacancies formed at the glass-QD interface. The reason for the observed decrease in PL peak intensity with the increase of annealing time is due to the decrease of surface to volume ratio for QDs of higher size.

  9. Determination of the free enthalpies of formation of borosilicate glasses; Determination des enthalpies libres de formation des verres borosilicates. Application a l'etude de l'alteration des verres de confinement de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Y

    2000-07-01

    This work contributes to the study of the thermochemical properties of nuclear waste glasses. Results are used to discuss mechanisms and parameters integrated in alteration models of conditioning materials. Glass is a disordered material defined thermodynamically as a non-equilibrium state. Taking into account one order parameter to characterise its configurational state, the metastable equilibrium for the glass was considered and the main thermochemical properties were determined. Calorimetric techniques were used to measure heat capacities and formation enthalpies of borosilicate glasses (from 3 to 8 constitutive oxides). Formation Entropies were measured too, using the entropy theory of relaxation processes proposed by Adam and Gibbs (1965). The configurational entropy contribution were determined from viscosity measurements. This set of data has allowed the calculation of Gibb's free energies of dissolution of glasses in pure water. By comparison with leaching experiments, it has been demonstrated that the decreasing of the dissolution rate at high reaction progress cannot be associated to the approach of an equilibrium between the sound glass and the aqueous solution. The composition changes of the reaction area at the glass surface need to be considered too. To achieve a complete description of the thermodynamic stability, the equilibrium between hydrated de-alkalinized glass and/or the gel layer with the aqueous solution should also be evaluated. (author)

  10. Phase formation during corrosion experiments with two simulated borosilicate nuclear waste glasses

    International Nuclear Information System (INIS)

    Haaker, R.F.

    1985-10-01

    Corrosion products resulting from the reaction of simulated high-level radioactive waste glasses with various solutions have been identified. At 200degC, in saturated NaCl, a degree of reaction of 10 g C31-3 glass or 2.6 g SON 68 glass per liter of solution was obtained. Analcime, vermiculite (a phyllosilicate) and a 2:1 zinc silicate are the major silica containing alteration products for the C31-3 glass. Analcime was the only silicate alteration product which could be identified for SON 68 glass. C31-3 glass appeared to be less reactive with a quinary brine containing Mg ++ than with NaCl. With the quinary brine, montmorillonite (a phyllosilicate) was the predominant silica containing alteration product. Hydrotalcite (a Mg-Al hydroxysulfate) and montmorillonite were the major Al-containing phases. A phyllosilicate, probably montmorillonite, was observed to form during the reaction of SON 68 glass with quinary brine. With either glass, modified NaCl brines which contained small amounts of MgCl 2 seem to have the effect of decreasing the amount of analcime and increasing the amount of phyllosilicate which is formed. In the case of C31-3 glass, there is approximately enough Mg, Al and Zn to precipitate most of the leached Si; measured Si concentrations remain well below that expected for amorphous silica. SON 68 glass has less Zn, Al and Mg than C31-3 glass and much higher Si concentrations of the leachates. (orig./RB)

  11. FTIR and optical assessment of zinc doped calcium phospho-borosilicate sol-gel glasses/glass-ceramics

    Science.gov (United States)

    Kumar, V.; Arora, N.; Pandey, O. P.; Kaur, G.

    2015-08-01

    CaO-P2O5-ZnO-SiO2-B2O3 glasses with varying compositions of calcium oxide and phosphorous oxide are synthesized using sol-gel technique. The glasses are heat-treated for a duration of 10 h at 500°C to obtain the glass-ceramics. The glass-ceramics and glasses are characterized using Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy. Extinction coefficients, attenuation coefficients and dielectric constant have been obtained for all the glasses as well as glass ceramics. The results are discussed in light of non-bridging oxygens (NBO) and heat-treatment of glasses. In addition to this, the effect of calcium and phosphorous on the infra-red spectra has been analysed thoroughly.

  12. Influence of gel morphology on the corrosion kinetics of borosilicate glass: calcium and zirconium effect

    International Nuclear Information System (INIS)

    Cailleteau, C.

    2008-12-01

    This study is related to the question of the long-term behaviour of the nuclear waste confinement glass. A glass alteration layer (known as the 'gel'), formed at the glass surface in contact with water, can limit the exchanges between the glass and the solution. We studied five oxide based glasses SiO 2 -B 2 O 3 -Na 2 O-CaO-ZrO 2 . Two series of glasses were synthesized by substituting CaO for Na 2 O and ZrO 2 for SiO 2 . The leaching showed that the presence of Ca improves the reticulation of the vitreous network, inducing a decrease in the final degree of corrosion and the presence of Zr prevents the hydrolysis of silicon, which leads to a decrease of the initial dissolution rate. However, the introduction of Zr delays the drop of the alteration rate and leads to an increase in the alteration degree. In order to explain this unexpected behaviour, the gel morphology was investigated by small angle X-ray scattering. These experiments showed that the restructuring of porous network during the glass alteration process is limited by the increase of the Zr-content. Then, the restructuring of gel is at the origin of the major drop in the alteration rate observed for the low Zr-content glasses. Besides, both time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) that provides an evaluation of extraneous element penetration into the gel pores and neutron scattering with index matching showed that the porosity closed during the corrosion in the glass without zirconia, but remained open in the high Zr-content glasses. These experiments, associated to simulations by a Monte Carlo method, establish a relationship between the morphologic transformations of gel and the alteration kinetics. (author)

  13. Calcium-borosilicate glass-ceramics wasteforms to immobilize rare-earth oxide wastes from pyro-processing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Miae [Department of Materials Science and Engineering and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Heo, Jong, E-mail: jheo@postech.ac.kr [Department of Materials Science and Engineering and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Department of Materials Engineering, Adama Science and Technology University (ASTU), PO Box 1888, Adama (Ethiopia)

    2015-12-15

    Glass-ceramics containing calcium neodymium(cerium) oxide silicate [Ca{sub 2}Nd{sub 8-x}Ce{sub x}(SiO{sub 4}){sub 6}O{sub 2}] crystals were fabricated for the immobilization of radioactive wastes that contain large portions of rare-earth ions. Controlled crystallization of alkali borosilicate glasses by heating at T ≥ 750 °C for 3 h formed hexagonal Ca–silicate crystals. Maximum lanthanide oxide waste loading was >26.8 wt.%. Ce and Nd ions were highly partitioned inside Ca–silicate crystals compared to the glass matrix; the rare-earth wastes are efficiently immobilized inside the crystalline phases. The concentrations of Ce and Nd ions released in a material characterization center-type 1 test were below the detection limit (0.1 ppb) of inductively coupled plasma mass spectroscopy. Normalized release values performed by a product consistency test were 2.64·10{sup −6} g m{sup −2} for Ce ion and 2.19·10{sup −6} g m{sup −2} for Nd ion. Results suggest that glass-ceramics containing calcium neodymium(cerium) silicate crystals are good candidate wasteforms for immobilization of lanthanide wastes generated by pyro-processing. - Highlights: • Glass-ceramic wasteforms containing Ca{sub 2}Nd{sub 8-x}Ce{sub x}(SiO{sub 4}){sub 6}O{sub 2} crystals were synthesized to immobilize lanthanide wastes. • Maximum lanthanide oxide waste loading was >26.8 wt.%. • Ce and Nd ions were highly partitioned inside Ca–Nd–silicate crystals compared to glass matrix. • Amounts of Ce and Nd ions released in the material characterization center-type 1 were below the detection limit (0.1 ppb). • Normalized release values performed by a PCT were 2.64• 10{sup −6} g m{sup −2} for Ce ions and 2.19• 10{sup −6} g m{sup −2} for Nd ions.

  14. The structure of phosphate and borosilicate glasses and their structural evolution at high temperatures as studied with solid state NMR spectroscopy: Phase separation, crystallisation and dynamic species exchange

    International Nuclear Information System (INIS)

    Wegner, S.; Van Wullen, L.; Tricot, G.; Tricot, G.

    2010-01-01

    In this contribution we present an in-depth study of the network structure of different phosphate based and borosilicate glasses and its evolution at high temperatures. Employing a range of advanced solid state NMR methodologies, complemented by the results of XPS, the structural motifs on short and intermediate length scales are identified. For the phosphate based glasses, at temperatures above the glass transition temperature Tg, structural relaxation processes and the devitrification of the glasses were monitored in situ employing MAS NMR spectroscopy and X-ray diffraction. Dynamic species exchange involving rapid P-O-P and P-O-Al bond breaking and reforming was observed employing in situ 27 Al and 31 P MAS NMR spectroscopy and could be linked to viscous flow. For the borosilicate glasses, an atomic scale investigation of the phase separation processes was possible in a combined effort of ex situ NMR studies on glass samples with different thermal histories and in situ NMR studies using high temperature MAS NMR spectroscopy including 11 B MAS, 29 Si MAS and in situ 29 Si{ 11 B} REAPDOR NMR spectroscopy. (authors)

  15. Coordination Environments of Highly Charged Cations (Ti, Cr, and Light REE's) in Borosilicate Glass/Melts to 1120C

    Energy Technology Data Exchange (ETDEWEB)

    Farges, Francois; /Museum Natl. Hist. Natur. /Stanford U., Geo. Environ. Sci.; Brown, Gordon E., Jr.; /Stanford U., Geo. Environ Sci. /SLAC, SSRL

    2007-01-02

    The local environments around Ti, Cr, and several light rare-earth elements (La, Ce, and Nd) were investigated by in-situ XANES spectroscopy in a number of complex borosilicate glasses and melts (to 1120 C) that are used for nuclear waste storage. Examination of the high-resolution XANES spectra at the Ti K-edge shows that the average coordination of Ti changes from {approx}5 to {approx}4.5. Cr is dominantly trivalent in the melts studied. However, its average coordination is probably lower in the melt (tetrahedral ?) as revealed by the more intense Cr-K pre-edge feature. Ce also changes its average valence from dominantly +4 to +3.5 upon glass melting. These changes are reversible at T{sub g}, the glass transition temperature ({approx}500-550 C for these glasses). In contrast, the local environments of Nd, Pr, and La are unaffected by melting. Therefore, structural reorganization of these borosilicate glass/melts above T{sub g} is variable, not only in terms of valence (as for Ce) but also speciation (Ti and Cr). Both the ability of B to adopt various coordination geometries (triangular and tetrahedral) and the chemical complexity of the glass/melts explain these changes.

  16. Issues related to volatilization, phase alteration, and presence of unreacted feed in the borosilicate glass wasteform

    International Nuclear Information System (INIS)

    Jain, V.

    1994-01-01

    The U.S. Department of Energy's Office of Civilian Radioactive Waste Management has outlined the requirements in the Waste Acceptance Product Specifications (WAPS) that must be met before they will accept West Valley canistered vitrified waste forms for shipment to a federal depository. In this study the glass volatilization was studied using a thermogravimetric analyzer (TGA) to evaluate the absence of free gases, free liquids, explosives, pyrophorics, combustibles, and organics in the waste form. The total carbon in the samples was analyzed using a carbon determinator, phase alteration by heat-treating samples for extended periods of time (45-day) at T g -10 degrees C and T g +10 degrees C (where T g is the glass transition temperature), and the presence of unreacted feed in glass by comparing x-ray diffraction (XRD) patterns for glass and dried feed. The results of this study indicate that the West Valley vitrification process completely transforms the feed into glass. Also the TGA, XRD, and scanning transmission electron microscopy data indicates that there is no significant volatilization, redox reactions, and phase alterations in the waste form up to more than 200 degrees C above the T g . 7 refs., 1 fig., 4 tabs

  17. High-level nuclear waste borosilicate glass: A compendium of characteristics

    International Nuclear Information System (INIS)

    Cunnane, J.C.; Bates, J.K.; Ebert, W.L.; Feng, X.; Mazer, J.J.; Wronkiewicz, D.J.; Sproull, J.; Bourcier, W.L.; McGrail, B.P.

    1992-01-01

    With the imminent startup, in the United States, of facilities for vitrification of high-level nuclear waste, a document has been prepared that compiles the scientific basis for understanding the alteration of the waste glass products under the range of service conditions to which they may be exposed during storage, transportation, and eventual geologic disposal. A summary of selected parts of the content of this document is provided. Waste glass alterations in a geologic repository may include corrosion of the glass network due to groundwater and/or water vapor contact. Experimental testing results are described and interpreted in terms of the underlying chemical reactions and physical processes involved. The status of mechanistic modeling, which can be used for long-term predictions, is described and the remaining uncertainties associated with long-term simulations are summarized

  18. Partial Molar Liquidus Temperatures of Multivalent Elements in Multicomponent Borosilicate Glass

    Czech Academy of Sciences Publication Activity Database

    Hrma, P.; Izák, Pavel; Vienna, J. D.; Thomas, M. L.; Irwin, G. M.

    2002-01-01

    Roč. 43, č. 2 (2002), s. 119-127 ISSN 0031-9090 Grant - others:DOE(US) DE/AC06/76RLO1830 Keywords : molar liquids * multivalent elements * glass Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.691, year: 2002

  19. Disposal costs for SRP high-level wastes in borosilicate glass and crystalline ceramic waste forms

    International Nuclear Information System (INIS)

    Rozsa, R.B.; Campbell, J.H.

    1982-01-01

    Purpose of this document is to compare and contrast the overall burial costs of the glass and ceramic waste forms, including processing, storage, transportation, packaging, and emplacement in a repository. Amount of waste will require approximately 10,300 standard (24 in. i.d. x 9-5/6 ft length) canisters of waste glass, each containing about 3260 lb of waste at 28% waste loading. The ceramic waste form requires about one-third the above number of standard canisters. Approximately $2.5 billion is required to process and dispose of this waste, and the total cost is independent of waste form (glass or ceramic). The major cost items (about 80% of the total cost) for all cases are capital and operating expenses. The capital and 20-year operating costs for the processing facility are the same order of magnitude, and their sum ranges from about one-half of the total for the reference glass case to two-thirds of the total for the ceramic cases

  20. Er –Al2O3 nanoparticles doping of borosilicate glass

    Indian Academy of Sciences (India)

    Administrator

    sponding to the telecommunication window (the 4I13/2–. 4I15/2 transition).1 In the development of optical devices based on rare-earth (RE) ions, the local environment around the RE was found to be of paramount importance for determining the optical properties.2 While in homoge- neous glasses, RE elements tend to ...

  1. Free volume of mixed cation borosilicate glass sealants elucidated by positron annihilation lifetime spectroscopy and its correlation with glass properties

    Science.gov (United States)

    Ojha, Prasanta K.; Rath, Sangram K.; Sharma, Sandeep K.; Sudarshan, Kathi; Pujari, Pradeep K.; Chongdar, Tapas K.; Gokhale, Nitin M.

    2015-01-01

    The role of La+3/Sr+2 ratios, which is varied from 0.08 to 5.09, on density, molar volume, packing fraction, free volume, thermal and electrical properties in strontium lanthanum aluminoborosilicate based glass sealants intended for solid oxide fuel cell (SOFC) applications is evaluated. The studies reveal expansion of the glass network evident from increasing molar volume and decreasing packing fraction of glasses with progressive La+3 substitutions. The molecular origin of these macroscopic structural features can be accounted for by the free volume parameters measured from positron annihilation lifetime spectroscopy (PALS). The La+3 induced expanded glass networks show increased number of subnanoscopic voids with larger sizes, as revealed from the ortho-positronium (o-Ps) lifetime and its intensity. A remarkably direct correspondence between the molar volume and fractional free volume trend is established with progressive La2O3 substitution in the glasses. The effect of these structural changes on the glass transition temperature, softening temperature, coefficient of thermal expansion, thermal stability as well as electrical conductivity has been studied.

  2. Spectroscopic Properties of Erbium Ions Doped in Bismuth Boro-Silicate Glasses

    Science.gov (United States)

    Bhardwaj, Sunil; Shukla, Rajni; Sanghi, Sujata; Agarwal, Ashish; Pal, Inder

    Glasses with composition 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) containing 0.5mol% of Er3+ ions were prepared by melt-quench technique. Optical absorption and fluorescence spectra were recorded at room temperature for all glass samples. Based on the Judd-Offelt theory, spectroscopic properties of Er3+ ions are discussed by changing the host glass compositions. The intensity parameters Ω2, Ω4, and Ω6 are determined by applying least square analysis method. The variation of Ω2 and Ω6 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross-section of various emission lines have been evaluated. An intense green luminescence bands with maximum around 516 nm and 536 nm are assigned to the 2H11/2→ 4I15/2 and 4S3/2→ 4I15/2 transitions respectively has been obtained.

  3. Simulation of Eu3+ luminescence spectra of borosilicate glasses by molecular dynamics calculations

    International Nuclear Information System (INIS)

    De Bonfils, J.; Panczer, G.; De Ligny, D.; Champagnon, B.; Peuget, S.; Delaye, J. M.; Chaussedent, S.; Monteil, A.

    2008-01-01

    Simplified inactive rare-earths doped nuclear waste glasses have been obtained by molecular dynamics (MD) simulation in order to investigate the local structure around the rare-earth by luminescence studies. MD calculations were performed with modified Born-Mayer-Huggins potentials and three body angular terms representing Coulomb and covalent interactions. Atomic positions within the glasses are then determined. Simulations of luminescence spectra were then obtained by calculation of the ligand field parameters affecting each luminescent ion. Considering the C 2v symmetry, it is possible to calculate the radiative transition probabilities between the emitter level, 5 D o , and the splitted receptor levels, 7 F J (J=0-3) for each Eu 3+ ion. The simulated emission spectra are obtained by convolution of all the Eu 3+ ions contributions. A comparison with the experimental data issue from fluorescence line narrowing and micro-luminescence spectroscopies allowed us not only to validate the simulation of luminescence spectra from simulated environments, but also to confirm the presence and the identification of two major Eu 3+ sites distribution in the nuclear glasses thanks to spectra-structure correlations. (authors)

  4. Lanthanide-activated Na5Gd9F32 nanocrystals precipitated from a borosilicate glass: Phase-separation-controlled crystallization and optical property

    International Nuclear Information System (INIS)

    Chen, Daqin; Wan, Zhongyi; Zhou, Yang; Chen, Yan; Yu, Hua; Lu, Hongwei; Ji, Zhenguo; Huang, Ping

    2015-01-01

    Highlights: • Na 5 Gd 9 F 32 nanocrystals embedded glass ceramics were fabricated for the first time. • Such glass ceramics were achieved by phase-separation-controlled crystallization. • Elemental mapping evidenced the segregation of activators into the Na 5 Gd 9 F 32 lattice. • Luminescent color could be tuned by controlling glass crystallization temperature. - Abstract: Lanthanide-activated cubic Na 5 Gd 9 F 32 nanocrystals were precipitated from a borosilicate glass with a specifically designed composition. The precursor glass is already phase-separated after melt-quenching, which is beneficial to the realization of the controllable glass crystallization for affording desirable size, morphology and activator partition. Elemental mapping in the scanning transmission electron microscopy evidenced that the segregation of lanthanide ions into the Na 5 Gd 9 F 32 lattice was in situ formed without the requirement of long-range ionic diffusion. Impressively, such fabricated glass ceramic co-doped with Yb 3+ /Er 3+ ions exhibited intense upconversion luminescence, which was about 500 times higher than that of the precursor glass, and its luminescent color could be easily tuned from red to green by controlling glass crystallization temperature. It is anticipated that such phase-separation synthesis strategy with precise control over nanostructure of glass ceramics offer a great opportunity to design other highly transparent nanocomposites with a wide range of tunable optical properties

  5. Impact of crystallization on the structure and chemical durability of borosilicate glass

    International Nuclear Information System (INIS)

    Nicoleau, Elodie

    2016-01-01

    This work describes a new approach to help understand the chemical durability of partially crystallized nuclear waste conditioning matrices. Among the studies carried out on nuclear waste deep geological disposal, long term behavior studies have so far been conducted on homogeneous glassy matrices. However, as the crystalline phases may generate modifications in the chemical composition and properties of such matrices, the description and a better understanding of their effects on the chemical durability of waste packages are of primary importance. A protocol to study the durability of heterogeneous model matrices of nuclear interest containing different types of crystalline phases was developed. It is based on a detailed description of the morphology, microstructure and structure of the glassy matrix and crystalline phases, and on the study of various alteration regimes. Three crystal phases that may form when higher concentrations of waste are immobilized in Uranium Oxide type conditioning glasses were studied: alkali and alkaline earth molybdates, rare earth silicates and ruthenium oxide. The results highlight the roles of the composition and the structure of the surrounding glassy matrix as the parameters piloting the alteration kinetics of the partially crystallized glassy matrices. This behavior is identical whatever the nature of the crystalline phases, as long as these phases do not lead to a composition gradient and do not percolate within the glassy matrix. Given these results, a methodology to study partially crystallized matrices with no composition gradient is then suggested. Its key development lies firstly in the evaluation of the behavior of partially crystallized matrices through the experimental study of the residual glassy matrix in various alteration regimes. This methodology may be adapted to the case of new glass formulations with more complex compositions (e.g. highly waste-loaded glass), which may contain crystals formed during cooling

  6. Effects of flow on corrosion and surface film formation on an alkali borosilicate glass

    International Nuclear Information System (INIS)

    Clark, D.E.; Christensen, H.; Hermansson, H.P.; Sundvall, S.B.; Werme, L.

    1984-01-01

    Samples of the Swedish KBS glass type ABS 39 have been leached in doubly distilled water for 28 days at 90 0 C under static and flow conditions. After leaching, pH, weight loss, and elemental mass loss were determined. Surface film formation was studied by using IRRS, SEM-EDS, and SIMS analyses. Increasing the flow rate resulted in a decreased attack on the glass surface. Na and B were depleted while Al, Fe, La, and U were enriched at the surfaces of all the samples. The depth of the extensively leached layer determined by SIMS was approximately 6 μm on the low-flow-rate sample and about 2 μm on the high-flow-rate sample. SEM analysis also showed some variations in the thickness of the leached layers, but in general, the thickness of the layer on the 0.5 mL/h samples was about 3 times greater than on the 90 mL/g samples. Small particles ( 2 for the static and 0.5 mL/h samples and 6 g/m 2 for the 90 mL/h samples. This factor of 3 difference in weight loss between the low and high flow rates correlates well with the factor of 3 difference in their leached depths. A model is proposed to explain the results based on the effectiveness of protective surface layers

  7. Mineralogical textural and compositional data on the alteration of basaltic glass from Kilauea, Hawaii to 300 degrees C: Insights to the corrosion of a borosilicate glass waste-form

    International Nuclear Information System (INIS)

    Smith, D.K.

    1990-01-01

    Mineralogical, textural and compositional data accompanying greenschist facies metamorphism (to 300 degrees C) of basalts of the East Rift Zone (ERZ), Kilauea, Hawaii may be evaluated relative to published and experimental results for the surface corrosion of borosilicate glass. The ERZ alteration sequence is dominated by intermittent palagonite, interlayered smectite-chlorite, chlorite, and actinolite-epidote-anhydrite. Alteration is best developed in fractures and vesicles where surface reaction layers root on the glass matrix forming rinds in excess of 100 microns thick. Fractures control fluid circulation and the alteration sequence. Proximal to the glass surface, palagonite, Fe-Ti oxides and clays replace fresh glass as the surface reaction layer migrates inwards; away from the surface, amphibole, anhydrite, quartz and calcite crystallize from hydrothermal fluids in contact with the glass. The texture and composition of basaltic glass surfaces are similar to those of a SRL-165 glass leached statically for sixty days at 150 degrees C. While the ERZ reservoir is a complex open system, conservative comparisons between the alteration of ERZ and synthetic borosilicate glass are warranted. 31 refs., 2 figs

  8. On the Morphology of the SDS Film on the Surface of Borosilicate Glass

    Directory of Open Access Journals (Sweden)

    Zih-Yao Shen

    2017-05-01

    Full Text Available Surfactant films on solid surfaces have attracted much attention because of their scientific interest and applications, such as surface treatment agent, or for micro- or nano-scale templates for microfluidic devices. In this study, anionic surfactant sodium dodecyl sulfate (SDS solutions with various charged inorganic salts was spread on a glass substrate and dried to form an SDS thin film. Atomic force microscopy (AFM was employed to observe the micro-structure of the SDS thin film. The effects of inorganic salts on the morphology of the SDS film were observed and discussed. The results of experiments demonstrated that pure SDS film formed patterns of long, parallel, highly-ordered stripes. The existence of the inorganic salt disturbed the structure of the SDS film due to the interaction between the cationic ion and the anionic head groups of SDS. The divalent ion has greater electrostatic interaction with anionic head groups than that of the monovalent ion, and causes a gross change in the morphology of the SDS film. The height of the SDS bilayer measured was consistent with the theoretical value, and the addition of the large-sized monovalent ion would lead to lowering the height of the adsorbed structures.

  9. Conceptual waste package interim product specifications and data requirements for disposal of borosilicate glass defense high-level waste forms in salt geologic repositories

    Energy Technology Data Exchange (ETDEWEB)

    1983-06-01

    The conceptual waste package interim product specifications and data requirements presented are applicable specifically to the normal borosilicate glass product of the Defense Waste Processing Facility (DWPF). They provide preliminary numerical values for the defense high-level waste form parameters and properties identified in the waste form performance specification for geologic isolation in salt repositories. Subject areas treated include containment and isolation, operational period safety, criticality control, waste form/production canister identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available.

  10. Conceptual waste package interim product specifications and data requirements for disposal of borosilicate glass defense high-level waste forms in salt geologic repositories

    International Nuclear Information System (INIS)

    1983-06-01

    The conceptual waste package interim product specifications and data requirements presented are applicable specifically to the normal borosilicate glass product of the Defense Waste Processing Facility (DWPF). They provide preliminary numerical values for the defense high-level waste form parameters and properties identified in the waste form performance specification for geologic isolation in salt repositories. Subject areas treated include containment and isolation, operational period safety, criticality control, waste form/production canister identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available

  11. A Comparison of Modifications Induced by Li3+ and Ag14+ Ion Beam in Spectroscopic Properties of Bismuth Alumino-Borosilicate Glass Thin Films

    Directory of Open Access Journals (Sweden)

    Ravneet Kaur

    2013-01-01

    Full Text Available Ion irradiation effects on the glass network and structural units have been studied by irradiating borosilicate glass thin film samples with 50 MeV Li3+ and 180 MeV Ag14+ swift heavy ions (SHI at different fluence rates ranging from 1012 ions/cm2 to 1014 ions/cm2. Glass of the composition (65-x Bi2O3-10Al2O3-(65-y B2O3-25SiO2 (x = 45, 40; y = 20, 25 has been prepared by melt quench technique. To study the effects of ionizing radiation, the glass thin films have been prepared from these glasses and characterized using XRD, FTIR, and UV-Vis spectroscopic techniques. IR spectra are used to study the structural arrangements in the glass before and after irradiation. The values of optical band gap, Urbach energy, and refractive index have been calculated from the UV-Vis measurements. The variation in optical parameters with increasing Bi2O3 content has been analyzed and discussed in terms of changes occurring in the glass network. A comparative study of the influence of Li3+ ion beam on structural and optical properties of the either glass system with Ag14+ ion is done. The results have been explained in the light of the interaction that SHI undergo on entering the material.

  12. Silicate, borosilicate, and borate bioactive glass scaffolds with controllable degradation rate for bone tissue engineering applications. II. In vitro and in vivo biological evaluation.

    Science.gov (United States)

    Fu, Qiang; Rahaman, Mohamed N; Bal, B Sonny; Bonewald, Lynda F; Kuroki, Keiichi; Brown, Roger F

    2010-10-01

    In Part I, the in vitro degradation of bioactivAR52115e glass scaffolds with a microstructure similar to that of human trabecular bone, but with three different compositions, was investigated as a function of immersion time in a simulated body fluid. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a borate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. This work is an extension of Part I, to investigate the effect of the glass composition on the in vitro response of osteogenic MLO-A5 cells to these scaffolds, and on the ability of the scaffolds to support tissue infiltration in a rat subcutaneous implantation model. The results of assays for cell viability and alkaline phosphatase activity showed that the slower degrading silicate 13-93 and borosilicate 13-93B1 scaffolds were far better than the borate 13-93B3 scaffolds in supporting cell proliferation and function. However, all three groups of scaffolds showed the ability to support tissue infiltration in vivo after implantation for 6 weeks. The results indicate that the required bioactivity and degradation rate may be achieved by substituting an appropriate amount of SiO2 in 13-93 glass with B2O3, and that these trabecular glass scaffolds could serve as substrates for the repair and regeneration of contained bone defects. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

  13. Effect of {sup 10}B(n, α){sup 7}Li irradiation on the structure of a sodium borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Peuget, S., E-mail: sylvain.peuget@cea.fr [CEA, DEN, Laboratoire d’Étude des Matériaux et Procédés Actif, 30207 Bagnols-sur-Cèze (France); Fares, T.; Maugeri, E.A.; Caraballo, R. [CEA, DEN, Laboratoire d’Étude des Matériaux et Procédés Actif, 30207 Bagnols-sur-Cèze (France); Charpentier, T. [CEA, IRAMIS, SIS2M, Laboratoire de Structure et Dynamique par Résonance Magnétique, UMR CEA/CNRS 3299, 91191 Gif-sur-Yvette (France); Martel, L.; Somers, J.; Janssen, A.; Wiss, T. [European Commission, JRC, Institute for Transuranium Elements (ITU), Hermann-von-Helmholtz Platz 1, PO Box 2340, DE-76125 Karlsruhe (Germany); Rozenblum, F. [CEA, DEN, DANS/DRSN/SIREN/LECSI, 91191 Gif-sur-Yvette (France); Magnin, M. [CEA, DEN, Laboratoire d’Étude des Matériaux et Procédés Actif, 30207 Bagnols-sur-Cèze (France); Deschanels, X. [Marcoule Institute of Separation Chemistry, LNAR, 30207 Bagnols-sur-Cèze Cedex (France); Jégou, C. [CEA, DEN, Laboratoire d’Étude des Matériaux et Procédés Actif, 30207 Bagnols-sur-Cèze (France)

    2014-05-01

    The effects of the nuclear reaction {sup 10}B(n, α){sup 7}Li on the properties and structure of a sodium borosilicate glass were analysed by density, hardness and fracture toughness measurements, Raman and Nuclear Magnetic Resonance spectroscopy and Transmission Electronic Microscopy (TEM) characterization. The TEM observations showed a homogeneous irradiated glass structure up to the nanometer scale. Modifications of the local order around the main cations were noticed, mainly a slight decrease of the mean boron coordination number and an increase of non-bridging oxygen concentrations. At the glass medium range order, the appearance of the D2 Raman band and a modification of the Si–O–Si angle distribution were also observed after irradiation. A comparison with other irradiation conditions with Swift Heavy Ions (Kr with 74 MeV) and Gold irradiation (with energies ranging from 1 to 7 MeV) is presented. Raman spectroscopy showed a similar final structure for irradiation conditions under which the glass evolutions are controlled by electronic energy loss in the ion tracks formation regime or nuclear energy loss. Despite important differences in energy deposition regimes, the similarities observed between the final glass structures suggest that structural evolutions are controlled by the glass relaxation mechanisms during the high quenching rate step that follows the energy deposition step.

  14. Thermodynamic properties of alkali borosilicate gasses and metaborates

    International Nuclear Information System (INIS)

    Asano, Mitsuru

    1992-01-01

    Borosilicate glasses are the proposed solidifying material for storing high level radioactive wastes in deep underground strata. Those have low melting point, and can contain relatively large amount of high level radioactive wastes. When borosilicate glasses are used for this purpose, they must be sufficiently stable and highly reliable in the vitrification process, engineered storage and the disposal in deep underground strata. The main vaporizing components from borosilicate glasses are alkali elements and boron. In this report, as for the vaporizing behavior of alkali borosilicate glasses, the research on thermodynamic standpoint carried out by the authors is explained, and the thermodynamic properties of alkali metaborates of monomer and dimer which are the main evaporation gases are reported. The evaporation and the activity of alkali borosilicate glasses, the thermodynamic properties of alkali borosilicate glasses, gaseous alkali metaborates and alkali metaborate system solid solution and so on are described. (K.I.)

  15. Silicate, borosilicate, and borate bioactive glass scaffolds with controllable degradation rate for bone tissue engineering applications. I. Preparation and in vitro degradation.

    Science.gov (United States)

    Fu, Qiang; Rahaman, Mohamed N; Fu, Hailuo; Liu, Xin

    2010-10-01

    Bioactive glass scaffolds with a microstructure similar to that of dry human trabecular bone but with three different compositions were evaluated for potential applications in bone repair. The preparation of the scaffolds and the effect of the glass composition on the degradation and conversion of the scaffolds to a hydroxyapatite (HA)-type material in a simulated body fluid (SBF) are reported here (Part I). The in vitro response of osteogenic cells to the scaffolds and the in vivo evaluation of the scaffolds in a rat subcutaneous implantation model are described in Part II. Scaffolds (porosity = 78-82%; pore size = 100-500 microm) were prepared using a polymer foam replication technique. The glasses consisted of a silicate (13-93) composition, a borosilicate composition (designated 13-93B1), and a borate composition (13-93B3), in which one-third or all of the SiO2 content of 13-93 was replaced by B2O3, respectively. The conversion rate of the scaffolds to HA in the SBF increased markedly with the B2O3 content of the glass. Concurrently, the pH of the SBF also increased with the B2O3 content of the scaffolds. The compressive strengths of the as-prepared scaffolds (5-11 MPa) were in the upper range of values reported for trabecular bone, but they decreased markedly with immersion time in the SBF and with increasing B2O3 content of the glass. The results show that scaffolds with a wide range of bioactivity and degradation rate can be achieved by replacing varying amounts of SiO(2) in silicate bioactive glass with B2O3. Copyright 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.

  16. Crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics for immobilization of simulated sulfate bearing high-level liquid waste

    Science.gov (United States)

    Wu, Lang; Xiao, Jizong; Wang, Xin; Teng, Yuancheng; Li, Yuxiang; Liao, Qilong

    2018-01-01

    The crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics with different content (0-30 wt %) of simulated sulfate bearing high-level liquid waste (HLLW) were evaluated. The sulfate phase segregation in vitrification process was also investigated. The results show that the glass-ceramics with 0-20 wt% of HLLW possess mainly zirconolite phase along with a small amount baddeleyite phase. The amount of perovskite crystals increases while the amount of zirconolite crystals decreases when the HLLW content increases from 20 to 30 wt%. For the samples with 20-30 wt% HLLW, yellow phase was observed during the vitrification process and it disappeared after melting at 1150 °C for 2 h. The viscosity of the sample with 16 wt% HLLW (HLLW-16) is about 27 dPa·s at 1150 °C. The addition of a certain amount (≤20 wt %) of HLLW has no significant change on the aqueous stability of glass-ceramic waste forms. After 28 days, the 90 °C PCT-type normalized leaching rates of Na, B, Si, and La of the sample HLLW-16 are 7.23 × 10-3, 1.57 × 10-3, 8.06 × 10-4, and 1.23 × 10-4 g·m-2·d-1, respectively.

  17. NMR study of a rare-earth alumino-borosilicate glass with varying CaO-to-Na{sub 2}O ratio

    Energy Technology Data Exchange (ETDEWEB)

    Quintas, A.; Majerus, O.; Caurant, D. [Ecole Natl Super Chim Paris, Lab Chim Mat Condensee Paris, F-75231 Paris 05 (France); Quintas, A.; Dussossoy, J.L. [Commissariat Energie Atom Marcoule, Lab Etudes Base Verres, Bagnols Sur Ceze (France); Charpentier, T. [Commissariat Energie Atom Saclay, Lab Struct and Dynam Responance Magnet, Gif Sur Yvette (France); Vermaut, P. [Ecole Natl Super Chim Paris, Lab Met Struct, F-75231 Paris, (France)

    2007-12-15

    The effect of substituting two Na{sup +} by one Ca{sup 2+} in a rare-earth alumino-borosilicate glass is investigated by multinuclear magic-angle spinning (MAS) and multiple-quantum (MQ)MAS nuclear magnetic resonance (NMR) spectroscopy. Quantitative analysis of the {sup 23}Na and {sup 27}Al MAS/MQMAS data along with the {sup 11}B MAS NMR data provides complementary information enabling to cast light on different structural key points. A strong decrease of the N{sub 4} = BO{sub 4}/(BO{sub 3} + BO{sub 4}) ratio is observed consecutively to this substitution, indicating that sodium is more favorable than calcium to the formation of BO{sub 4} units. The experimental N{sub 4} ratio is compared to the Dell and Bray model prediction and it is shown that several adjustments, due to the presence in our glass of Nd and Zr, are necessary to obtain acceptable agreement with experimental data. {sup 29}Si MAS NMR data also put in evidence an effect of the substitution on the polymerization degree. Glass in glass phase separation is clearly detected when the ratio of CaO to Na{sub 2}O is greater than 1 and a different evolution of NMR parameters is observed for the ratio of CaO to Na{sub 2}O being less than or equal to 1. Concerning aluminum charge compensation, it is demonstrated that, as long as no phase separation is detected, the negative charge of AlO{sub 4}{sup -} entities is almost exclusively balanced by sodium cations. Finally, changes of the sodium ions organization within the glass network are also evidenced by spin-lattice relaxation and spin echo decay measurements. (authors)

  18. Structure-composition trends in multicomponent borosilicate-based glasses deduced from molecular dynamics simulations with improved B-O and P-O force fields.

    Science.gov (United States)

    Stevensson, Baltzar; Yu, Yang; Edén, Mattias

    2018-03-28

    We present a comprehensive molecular dynamics (MD) simulation study of composition-structure trends in a set of 25 glasses of widely spanning compositions from the following four systems of increasing complexity: Na 2 O-B 2 O 3 , Na 2 O-B 2 O 3 -SiO 2 , Na 2 O-CaO-SiO 2 -P 2 O 5 , and Na 2 O-CaO-B 2 O 3 -SiO 2 -P 2 O 5 . The simulations involved new B-O and P-O potential parameters developed within the polarizable shell-model framework, thereby combining the beneficial features of an overall high accuracy and excellent transferability among different glass systems and compositions: this was confirmed by the good accordance with experimental data on the relative BO 3 /BO 4 populations in borate and boro(phospho)silicate networks, as well as with the orthophosphate fractions in bioactive (boro)phosphosilicate glasses, which is believed to strongly influence their bone-bonding properties. The bearing of the simulated melt-cooling rate on the borate/phosphate speciations is discussed. Each local {BO 3 , BO 4 , SiO 4 , PO 4 } coordination environment remained independent of the precise set of co-existing network formers, while all trends observed in bond-lengths/angles mainly reflected the glass-network polymerization, i.e., the relative amounts of bridging oxygen (BO) and non-bridging oxygen (NBO) species. The structural roles of the Na + /Ca 2+ cations were also probed, targeting their local coordination environments and their relative preferences to associate with the various borate, silicate, and phosphate moieties. We evaluate and discuss the common classification of alkali/alkaline-earth metal ions as charge-compensators of either BO 4 tetrahedra or NBO anions in borosilicate glasses, also encompassing the less explored NBO-rich regime: the Na + /Ca 2+ cations mainly associate with BO/NBO species of SiO 4 /BO 3 groups, with significant relative Na-BO 4 contacts only observed in B-rich glass networks devoid of NBO species, whereas NBO-rich glass networks also

  19. Tailoring properties of porous Poly (vinylidene fluoride) scaffold through nano-sized 58s bioactive glass.

    Science.gov (United States)

    Shuai, Cijun; Huang, Wei; Feng, Pei; Gao, Chengde; Shuai, Xiong; Xiao, Tao; Deng, Youwen; Peng, Shuping; Wu, Ping

    2016-01-01

    The biological properties of porous poly (vinylidene fluoride) (PVDF) scaffolds fabricated by selective laser sintering were tailored through nano-sized 58s bioactive glass. The results showed that 58s bioactive glass distributed evenly in the PVDF matrix. There were some exposed particles on the surface which provided attachment sites for biological response. It was confirmed that the scaffolds had highly bioactivity by the formation of bone-like apatite in simulated body fluid. And the bone-like apatite became dense with the increase in 58s bioactive glass and culture time. Moreover, the scaffolds were suitable for cell adhesion and proliferation compared with the PVDF scaffolds without 58s bioactive glass. The research showed that the PVDF/58s bioactive glass scaffolds had latent application in bone tissue engineering.

  20. Volatility mechanisms of borosilicate glasses and molten glasses of nuclear interest structural effects; Mecanismes de volatilite des verres et des fontes borosilicates d'interet nucleaire influence de la structure

    Energy Technology Data Exchange (ETDEWEB)

    Delorme, L

    1998-04-23

    This work is devoted to the study of the mechanisms which control the volatility of the reference glass used for the confinement of radioactive waste. It was conducted on simplified compositions, in the SiO{sub 2}-B{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-{alpha}Na{sub 2}O-(1-alpha)Li{sub 2}O-CaO system.The structural approach carried out by NMR, from room temperature up to 1500 deg.C, shows a strong increase in the mobility of alkalis above Tg. A rapid exchange between B{sup III} and B{sup IV} sites near 700 deg.C, and the change of coordination number B{sup IV-} B{sup III} near 1100 deg.C, also seem to take place. The analysis of the vapor phase, carried out by High Temperature Mass Spectrometry coupled to Knudsen cells, reveals the presence between 780 deg.C and 830 deg.C of NaBO{sub 2}(g), LiBO{sub 2}(g) and Na{sub 2}(BO{sub 2})2(g). The calculation of the partial pressure of each species shows that the total pressure of simplified glasses is dominated by the contribution of sodium. To study the volatility of glasses at higher temperature, equipment using the Transpiration method was used. The analysis of the deposits indicate the presence at 1060 deg.C of the species quoted previously. The vaporization rate and the vapor density were determined for each composition studied in a saturated state. Thus, we show that the volatility of the reference glass can be simulated by that of a simplified glass. For {alpha}=1, the kinetic of vaporization between 1060 deg.C and 1200 deg.C reveals an evaporation from the surface associated with a mechanism of diffusion in the molten glass. This is similar to the volatility of the reference glass at 1060 deg.C. To finally explain these mechanisms on a microscopic basis, we develop a model of molecular interactions. Between 780 deg.C and 830 deg.C, these mechanisms are controlled by a strong attraction between Na{sub 2}O and Li{sub 2}O, which maintains the total vapor pressure on a quasi-constant lever up to {alpha}=0.27. (author)

  1. Structural investigations of borosilicate glasses containing MoO{sub 3} by MAS NMR and Raman spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Caurant, D., E-mail: daniel-caurant@enscp.f [Laboratoire de Chimie de la Matiere Condensee de Paris, UMR-CNRS 7574, Ecole Nationale Superieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Majerus, O.; Fadel, E.; Quintas, A. [Laboratoire de Chimie de la Matiere Condensee de Paris, UMR-CNRS 7574, Ecole Nationale Superieure de Chimie de Paris (ENSCP, ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Gervais, C. [Laboratoire de Chimie de la Matiere Condensee de Paris, UMR-CNRS 7574, Universite Pierre et Marie Curie, 75252 Paris (France); Charpentier, T. [CEA, IRAMIS, Service Interdisciplinaire sur les Systemes Moleculaires et Materiaux, CEA Saclay, 91191 Gif-sur-Yvette (France); Neuville, D. [Physique des Mineraux et des Magmas, UMR-CNRS 7047, Institut de Physique du Globe, place Jussieu, 75252 Paris (France)

    2010-01-01

    High molybdenum concentration in glass compositions may lead to alkali and alkaline-earth molybdates crystallization during melt cooling that must be controlled particularly during the preparation of highly radioactive nuclear glassy waste forms. To understand the effect of molybdenum addition on the structure of a simplified nuclear glass and to know how composition changes can affect molybdates crystallization tendency, the structure of two glass series belonging to the SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O-CaO-MoO{sub 3} system was studied by {sup 29}Si, {sup 11}B, {sup 23}Na MAS NMR and Raman spectroscopies by increasing MoO{sub 3} or B{sub 2}O{sub 3} concentrations. Increasing MoO{sub 3} amount induced an increase of the silicate network reticulation but no significant effect was observed on the proportion of BO{sub 4}{sup -} units and on the distribution of Na{sup +} cations in glass structure. By increasing B{sub 2}O{sub 3} concentration, a strong evolution of the distribution of Na{sup +} cations was observed that could explain the evolution of the nature of molybdate crystals (CaMoO{sub 4} or Na{sub 2}MoO{sub 4}) formed during melt cooling.

  2. β-Irradiation Effects on the Formation and Stability of CaMoO4 in a Soda Lime Borosilicate Glass Ceramic for Nuclear Waste Storage.

    Science.gov (United States)

    Patel, Karishma B; Boizot, Bruno; Facq, Sébastien P; Lampronti, Giulio I; Peuget, Sylvain; Schuller, Sophie; Farnan, Ian

    2017-02-06

    Molybdenum solubility is a limiting factor to actinide loading in nuclear waste glasses, as it initiates the formation of water-soluble crystalline phases such as alkali molybdates. To increase waste loading efficiency, alternative glass ceramic structures are sought that prove resistant to internal radiation resulting from radioisotope decay. In this study, selective formation of water-durable CaMoO 4 in a soda lime borosilicate is achieved by introducing up to 10 mol % MoO 3 in a 1:1 ratio to CaO using a sintering process. The resulting homogeneously dispersed spherical CaMoO 4 nanocrystallites were analyzed using electron microscopy, X-ray diffraction (XRD), Raman and electron paramagnetic resonance (EPR) spectroscopies prior to and post irradiation, which replicated internal β-irradiation damage on an accelerated scale. Following 0.77 to 1.34 GGy of 2.5 MeV electron radiation CaMoO 4 does not exhibit amorphization or significant transformation. Nor does irradiation induce glass-in-glass phase separation in the surrounding amorphous matrix, or the precipitation of other molybdates, thus proving that excess molybdenum can be successfully incorporated into a structure that it is resistant to β-irradiation proportional to 1000 years of storage without water-soluble byproducts. The CaMoO 4 crystallites do however exhibit a nonlinear Scherrer crystallite size pattern with dose, as determined by a Rietveld refinement of XRD patterns and an alteration in crystal quality as deduced by anisotropic peak changes in both XRD and Raman spectroscopy. Radiation-induced modifications in the CaMoO 4 tetragonal unit cell occurred primarily along the c-axis indicating relaxation of stacked calcium polyhedra. Concurrently, a strong reduction of Mo 6+ to Mo 5+ during irradiation is observed by EPR, which is believed to enhance Ca mobility. These combined results are used to hypothesize a crystallite size alteration model based on a combination of relaxation and diffusion

  3. High temperature rheological study of borosilicate glasses containing platinum group metal particles by means of a mixer-type rheometer

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Jean; Hanotin, Caroline [CEA Marcoule, DEN/MAR/DTCD/SECM/LDMC, Bagnols-sur-Cèze, F-30207 (France); Neyret, Muriel, E-mail: muriel.neyret@cea.fr [CEA Marcoule, DEN/MAR/DTCD/SECM/LDMC, Bagnols-sur-Cèze, F-30207 (France); Marchal, Philippe [Laboratoire Réactions et Génie des Procédés (LRGP-GEMICO), Université de Lorraine-CNRS, UMR 7274, Nancy, F-54001 (France)

    2016-02-15

    In this paper, the rheological behavior of six simulated high level waste nuclear glasses containing 0 to 5.2 wt% platinum group metals (PGM) has been studied at a temperature of 1200 °C. By means of a stress imposed rheometer, the shear stress dependence of the viscosity, which was so far assessed only at high shear rates, has been investigated on a wider range. Experimental data have been well fitted by the Cross model and a critical stress corresponding to the rupture of PGM aggregates has been evidenced. At high shear rates, the dependence with the volume fraction in PGM particles is well accounted for by Quemada's law. At low shear rates, the first Newtonian plateau is shown to be strongly dependent on the PGM content, notably above 3 wt% and to follow an exponential dependence due to the existence of more complex structures at the origin of the critical stress. - Highlights: • Rheological behavior of nuclear glass melts is well accounted by the Cross model. • A first Newtonian plateau has been evidenced at low shear. • First Newtonian plateau and critical stress values depend on PGM (Platinum Group Metals) content. • At high shear, Quemada's law well represents the PGM content impact on viscosity.

  4. Effect of the nature of alkali and alkaline-earth oxides on the structure and crystallization of an alumino-borosilicate glass developed to immobilize highly concentrated nuclear waste solutions

    International Nuclear Information System (INIS)

    Quintas, A.; Caurant, D.; Majerus, O.; Charpentier, T.; Dussossoy, J.L.

    2008-01-01

    A complex rare-earth rich alumino-borosilicate glass has been proved to be a good candidate for the immobilization of new high level radioactive wastes. A simplified seven-oxides composition of this glass was selected for this study. In this system, sodium and calcium cations were supposed in other works to simulate respectively all the other alkali (R + = Li + , Rb + , Cs + ) and alkaline-earth (R 2+ = Sr 2+ , Ba 2+ ) cations present in the complex glass composition. Moreover, neodymium or lanthanum are used here to simulate all the rare-earths and actinides occurring in waste solutions. In order to study the impact of the nature of R + and R 2+ cations on both glass structure and melt crystallization tendency during cooling, two glass series were prepared by replacing either Na + or Ca 2+ cations in the simplified glass by respectively (Li + , K + , Rb + , Cs + ) or (Mg 2+ , Sr 2+ , Ba 2+ ) cations. From these substitutions, it was established that alkali ions are preferentially involved in the charge compensation of (AlO 4 ) - entities in the glass network comparatively to alkaline-earth ions. The glass compositions containing calcium give way to the crystallization of an apatite silicate phase bearing calcium and rare-earth ions. The melt crystallization tendency during cooling strongly varies with the nature of the alkaline-earth. (authors)

  5. Diffusion study in tailored gratings recorded in photopolymer glass with high refractive index species

    Science.gov (United States)

    Martínez-Matos, Óscar; Calvo, María L.; Rodrigo, José A.; Cheben, Pavel; del Monte, Francisco

    2007-10-01

    We report results on the temporal evolution of the diffraction efficiency of volume holographic gratings recorded in a photopolymer glass incorporating Zr-based high refractive index species (HRIS) at molecular level. We record high spatial frequency gratings in this material with diffraction efficiencies near 100%. A two-component diffusion model is introduced for the evolution of refractive index modulation in darkness. Diffusion parameters for the Zr-based HRIS and monomer components have been determined. Codirectional diffusion of both components is demonstrated. The results show the feasibility for tailoring in this photomaterial holographic gratings with high diffraction efficiency over a wide range of spatial frequencies.

  6. Irradiations effects on the structure of boro-silicated glasses: long term behaviour of nuclear waste glassy matrices; Effets d'irradiations sur la structure de verres borosilicates - comportement a long terme des matrices vitreuses de stockage des dechets nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Bonfils, J. de

    2007-09-15

    This work deals with the long term behaviour of R7T7-type nuclear waste glasses and more particularly of non-active boro-silicated glasses made up of 3 or 5 oxides. Radioactivity of active glasses is simulated by multi energies ions implantations which reproduce the same defects. The damages due to the alpha particles are simulated by helium ions implantations and those corresponding to the recoil nucleus are obtained with gold ions ones. Minor actinides, stemming from the used fuel, is simulated by trivalent rare-earths (Eu{sup 3+} and Nd{sup 3+}). In a first part, we have shown by macroscopic experiments (Vickers hardness - swelling) and optical spectroscopies (Raman - ATR-IR) that the structure of the glassy matrices is modified under implantations until a dose of 2,3.10{sup 13} at.cm{sup -2}, which corresponds to a R7T7 storage time estimated at 300 years. Beyond this dose, no additional modifications have been observed. The second part concerns the local environment of the rare-earth ions in glasses. Two different environments were found and identified as follows: one is a silicate rich one and the other is attributed to a borate rich one. (author)

  7. Influence of gel morphology on the corrosion kinetics of borosilicate glass: calcium and zirconium effect; Influence de la morphologie du gel sur la cinetique d'alteration des verres borosilicates: role du calcium et du zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Cailleteau, C

    2008-12-15

    This study is related to the question of the long-term behaviour of the nuclear waste confinement glass. A glass alteration layer (known as the 'gel'), formed at the glass surface in contact with water, can limit the exchanges between the glass and the solution. We studied five oxide based glasses SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O-CaO-ZrO{sub 2}. Two series of glasses were synthesized by substituting CaO for Na{sub 2}O and ZrO{sub 2} for SiO{sub 2}. The leaching showed that the presence of Ca improves the reticulation of the vitreous network, inducing a decrease in the final degree of corrosion and the presence of Zr prevents the hydrolysis of silicon, which leads to a decrease of the initial dissolution rate. However, the introduction of Zr delays the drop of the alteration rate and leads to an increase in the alteration degree. In order to explain this unexpected behaviour, the gel morphology was investigated by small angle X-ray scattering. These experiments showed that the restructuring of porous network during the glass alteration process is limited by the increase of the Zr-content. Then, the restructuring of gel is at the origin of the major drop in the alteration rate observed for the low Zr-content glasses. Besides, both time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) that provides an evaluation of extraneous element penetration into the gel pores and neutron scattering with index matching showed that the porosity closed during the corrosion in the glass without zirconia, but remained open in the high Zr-content glasses. These experiments, associated to simulations by a Monte Carlo method, establish a relationship between the morphologic transformations of gel and the alteration kinetics. (author)

  8. Effect of the nature of alkali and alkaline-earth oxides on the structure and crystallization of an alumino-borosilicate glass developed to immobilize highly concentrated nuclear waste solutions

    Energy Technology Data Exchange (ETDEWEB)

    Quintas, A.; Caurant, D.; Majerus, O. [Laboratoire de Chimie de la Matiere Condensee de Paris (UMR 7574), Ecole Nationale Superieure de Chimie de Paris - ENSCP, ParisTech, Paris, 75005 (France); Charpentier, T. [CEA Saclay, Laboratoire de Structure et Dynamique par Resonance Magnetique, DSM/DRECAM/SCM - CEA CNRS URA 331, Gif-sur-Yvette, 91191 (France); Dussossoy, J.L. [Laboratoire d' Etude de Base sur les Verres, CEA Valrho, DEN/DTCD/SCDV/LEBV, Bagnols-sur-Ceze, 30207 (France)

    2008-07-01

    A complex rare-earth rich alumino-borosilicate glass has been proved to be a good candidate for the immobilization of new high level radioactive wastes. A simplified seven-oxides composition of this glass was selected for this study. In this system, sodium and calcium cations were supposed in other works to simulate respectively all the other alkali (R{sup +} = Li{sup +}, Rb{sup +}, Cs{sup +}) and alkaline-earth (R{sup 2+} = Sr{sup 2+}, Ba{sup 2+}) cations present in the complex glass composition. Moreover, neodymium or lanthanum are used here to simulate all the rare-earths and actinides occurring in waste solutions. In order to study the impact of the nature of R{sup +} and R{sup 2+} cations on both glass structure and melt crystallization tendency during cooling, two glass series were prepared by replacing either Na{sup +} or Ca{sup 2+} cations in the simplified glass by respectively (Li{sup +}, K{sup +}, Rb{sup +}, Cs{sup +}) or (Mg{sup 2+}, Sr{sup 2+}, Ba{sup 2+}) cations. From these substitutions, it was established that alkali ions are preferentially involved in the charge compensation of (AlO{sub 4}){sup -} entities in the glass network comparatively to alkaline-earth ions. The glass compositions containing calcium give way to the crystallization of an apatite silicate phase bearing calcium and rare-earth ions. The melt crystallization tendency during cooling strongly varies with the nature of the alkaline-earth. (authors)

  9. Structural and crystallisation study of a rare earth alumino borosilicate glass designed for nuclear waste confinement; Etude de la structure et du comportement en cristallisation d'un verre nucleaire d'aluminoborosilicate de terre rare

    Energy Technology Data Exchange (ETDEWEB)

    Quintas, A

    2007-09-15

    This work is devoted to the study of a rare earth alumino borosilicate glass, which molar composition is 61,81 SiO{sub 2} - 3,05 Al{sub 2}O{sub 3} - 8,94 B{sub 2}O{sub 3} - 14,41 Na{sub 2}O - 6,33 CaO - 1,90 ZrO{sub 2} - 3,56 Nd{sub 2}O{sub 3}, and envisaged for the immobilization of nuclear wastes originating from the reprocessing of high discharge burn up spent fuel. From a structural viewpoint, we investigated the role of the modifier cations on the arrangement of the glass network through different modifications of the glass composition: variation of the Na/Ca ratio and modification of the nature of the alkali and alkaline earth cations. The NMR and Raman spectroscopic techniques were useful to determine the distribution of modifier cations among the glass network and also to cast light on the competition phenomena occurring between alkali and alkaline earth cations for charge compensation of [AlO{sub 4}]{sup -} and [BO{sub 4}]{sup -} species. The neodymium local environment could be probed by optical absorption and EXAFS spectroscopies which enabled to better understand the insertion mode of Nd{sup 3+} ions among the silicate domains of the glass network. Concerning the crystallization behavior we were interested in how the glass composition may influence the crystallization processes and especially the formation of the apatite phase of composition Ca{sub 2}Nd{sub 8}(SiO{sub 4}){sub 6}O{sub 2}. In particular, this work underlined the important role of both alkaline earth and rare earth cations on the crystallization of the apatite phase. (author)

  10. Influence of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} content on the structure of erbium-doped borosilicate glasses and on their physical, thermal, optical and luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Bourhis, Kevin, E-mail: k.bourhis@argolight.com [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Massera, Jonathan [Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); Petit, Laeticia; Ihalainen, Heikki [nLIGHT Corporation, Sorronrinne 9, FI-08500 Lohja (Finland); Fargues, Alexandre; Cardinal, Thierry [CNRS, Université de Bordeaux, ISM, 351Cours de la Libération, F-33405 Talence (France); Hupa, Leena; Hupa, Mikko [Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); Dussauze, Marc; Rodriguez, Vincent [CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr Schweitzer, F-33608 Pessac (France); Boussard-Plédel, Catherine; Bureau, Bruno; Roiland, Claire [Equipe Verres et Céramiques, UMR-CNRS 6226, Inst. des Sciences chimiques de Rennes, Université de Rennes 1, 35042 Rennes CEDEX (France); Ferraris, Monica [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)

    2015-03-15

    Highlights: • Reorganization of the glass structure induced by the addition of P{sub 2}O{sub 5} or Al{sub 2}O{sub 3}. • Emission properties related to the presence of P or Al in the Er{sup 3+} coordination shell. • Declustering observed upon addition of P{sub 2}O{sub 5}. • No declustering upon addition of Al{sub 2}O{sub 3}. - Abstract: The effect of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} addition in Er-doped borosilicate glasses on the physical, thermal, optical, and luminescence properties is investigated. The changes in these glass properties are related to the glass structure modifications induced by the addition of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3}, which were probed by FTIR, {sup 11}B MAS NMR and X-ray photoelectron spectroscopies. Variations of the polymerization degree of the silicate tetrahedra and modifications in the {sup [3]}B/{sup [4]}B ratio are explained by a charge compensation mechanism due to the formation of AlO{sub 4}, PO{sub 4} groups and the formation of Al-O-P linkages in the glass network. From the absorption and luminescence properties of the Er{sup 3+} ions at 980 nm and 1530 nm, declustering is suspected for the highest P{sub 2}O{sub 5} concentrations while for the highest Al{sub 2}O{sub 3} concentrations no declustering is observed.

  11. Tailoring the size and distribution of Ag nanoparticles in silica glass by defects

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yitao, E-mail: yangyt@impcas.ac.cn [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Chonghong; Song, Yin; Gou, Jie; Zhang, Liqing [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, Hengqing; Liu, Juan; Xian, Yongqiang [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Yizhun [Materials Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-02-15

    The composites embedded with metallic nanoparticles show large nonlinear optical susceptibility and strong surface plasmon resonance absorption, which enable potential application in opto-electronics. Ion implantation has been proven to be a powerful technique of synthesis of metallic nanoparticles due to its versatility and compatibility. However, the synthesis of nanoparticles by ion implantation inevitably leads to a broad size distribution due to Ostwald ripening process. The broad size distribution has a negative effect on improving the figure of merits for nonlinear optics. In this paper, we tried to introduce defects in silica glass to act as pre-nucleation centers to mediate the size and distribution of Ag nanoparticles. In experiment, the silica glass samples were pre-irradiated by 200 keV Ar ions to fluences of 0.8, 2.0 and 5.0 × 10{sup 16} ions/cm{sup 2}, and then 200 keV Ag ions were implanted into the pre-irradiated samples to fluence of 2.0 × 10{sup 16} ions/cm{sup 2}. UV–VIS results show that the absorbance intensity of Ag SPR peak initially increases and then decreases with pre-irradiation fluence, which implies the change in size and density of Ag nanoparticles in samples. TEM results verify that Ag nanoparticles in the sample pre-irradiated to the fluence of 0.8 × 10{sup 16} ions/cm{sup 2} grow bigger and distribute in a relatively narrow region comparing with that without pre-irradiation. With further increase of pre-irradiation fluence, the size of Ag nanoparticles shows a depth dependent distribution. A boundary can be clear seen at the depth of 110 nm, larger Ag nanoparticles disperse in region shallower than 110 nm, and smaller Ag nanoparticles disperse in the region deeper than 110 nm. The average size of Ag nanoparticles initially increases and then decreases with pre-irradiation fluence. Therefore, the introduction of defects by pre-irradiation could be an effective way to tailor the size and distribution of metallic nanoparticles in

  12. CsPbBr3:xEu3+ perovskite QD borosilicate glass: a new member of the luminescent material family.

    Science.gov (United States)

    Yuan, Rongrong; Shen, Lingli; Shen, Chenyang; Liu, Jianming; Zhou, Lei; Xiang, Weidong; Liang, Xiaojuan

    2018-03-29

    Eu3+ ions were introduced into the lattices of CsPbBr3 perovskite QDs and a tunable multicolour emission from CsPbBr3:xEu3+ perovskite QD glass was successfully obtained. Multicolour LEDs that were fabricated by combining the as-prepared CsPbBr3:xEu3+ QD glasses with a UV chip were also researched in this study.

  13. Recent progress to understand stress corrosion cracking in sodium borosilicate glasses: linking the chemical composition to structural, physical and fracture properties

    Science.gov (United States)

    Rountree, Cindy L.

    2017-08-01

    This topical review is dedicated to understanding stress corrosion cracking in oxide glasses and specifically the SiO_2{\\text-B_2O_3{\\text-}Na_2O} (SBN) ternary glass systems. Many review papers already exist on the topic of stress corrosion cracking in complex oxide glasses or overly simplified glasses (pure silica). These papers look at how systematically controlling environmental factors (pH, temperature...) alter stress corrosion cracking, while maintaining the same type of glass sample. Many questions still exist, including: What sets the environmental limit? What sets the velocity versus stress intensity factor in the slow stress corrosion regime (Region I)? Can researchers optimize these two effects to enhance a glass’ resistance to failure? To help answer these questions, this review takes a different approach. It looks at how systemically controlling the glass’ chemical composition alters the structure and physical properties. These changes are then compared and contrasted to the fracture toughness and the stress corrosion cracking properties. By taking this holistic approach, researchers can begin to understand the controlling factors in stress corrosion cracking and how to optimize glasses via the initial chemical composition.

  14. Phase Separation and Crystallization in soda-lime borosilicate glass enriched in MoO{sub 3} studied by in situ Raman spectroscopy at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Magnin, M.; Schuller, S.; Advocat, T. [CEA Valrho, DEN/DTCD/SCDV, Laboratoire d' Etude de Base sur les Verres, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Caurant, D.; Majerus, O. [Laboratoire de Chimie de la Matiere Condensee de Paris- LCMCP - UMR-CNRS 7574, Ecole Nationale Superieure de Chimie de Paris - ENSCP, Paristech, 75231 Paris (France); Ligny, D. de [Laboratoire de Physico-Chimie des Materiaux Luminescents- LPCML - UMR-CNRS 5620, Universite Claude Bernard Lyon1, 69622 Villeurbanne (France)

    2008-07-01

    Phase separation and crystallisation processes may arise in molten glass when the MoO{sub 3} content exceeds its solubility limit. Molybdenum combined with other elements such as alkali and alkaline-earth may form crystalline molybdates, known as 'yellow phases' in nuclear glasses. In order to establish the sequence of phase separation and crystallization processes occurring during the cooling of the melt, a non-radioactive simplified glass composition was chosen in the SiO{sub 2}-B{sub 2}O{sub 3}-Na{sub 2}O-CaO system, with 2 mol.% MoO{sub 3}. Various cooling scenarios were tested: cooling by air blowing, quenching between two copper plates and cooling on metallic plate. The resulting glass specimens were then characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy in temperature. These observations made it possible to determine the sequence and the appearance temperature of phenomena upon cooling: first, a phase separation occurs, (small droplets dispersed in the molten glass) followed by molybdates crystallization inside the droplets. (authors)

  15. TiO3 borosilicate glass–ceramics

    Indian Academy of Sciences (India)

    phase of the glass–ceramic sample with x ≤ 0·5 was found to have cubic structure similar to SrTiO3 ceramic. Scanning electron microscopy has been carried out to see the surface morphology of the crystallites dispersed in the glassy matrix. Keywords. (PbSr)TiO3 borosilicate glasses; infrared spectroscopy; DTA; XRD and ...

  16. Phosphate glass fibre scaffolds: Tailoring of the properties and enhancement of the bioactivity through mesoporous glass particles.

    Science.gov (United States)

    Novajra, G; Boetti, N G; Lousteau, J; Fiorilli, S; Milanese, D; Vitale-Brovarone, C

    2016-10-01

    Novel bone glass fibre scaffolds were developed by thermally bonding phosphate glass fibres belonging to the P2O5-CaO-Na2O-SiO2-MgO-K2O-TiO2 system (TiPS2.5 glass). Scaffolds with fibres of 85 or 110μm diameter were fabricated, showing compressive strength in the range of 2-3.5MPa, comparable to that of the trabecular bone. The effect of different thermal treatments and fibre diameters and length on the final scaffold structure was investigated by means of micro-CT analysis. The change of the sintering time from 30 to 60min led to a decrease in the scaffold overall porosity from 58 to 21vol.% for the 85μm fibre scaffold and from 50 to 40vol.% when increasing the sintering temperature from 490 to 500°C for the 110μm fibre scaffold. The 85μm fibres resulted in an increase of the scaffold overall porosity, increased pore size and lower trabecular thickness; the use of different fibre diameters allowed the fabrication of a scaffold showing a porosity gradient. In order to impart bioactive properties to the scaffold, for the first time in the literature the introduction in these fibre scaffolds of a bioactive phase, a melt-derived bioactive glass (CEL2) powder or spray-dried mesoporous bioactive glass particles (SD-MBG) was investigated. The scaffold bioactivity was assessed through soaking in simulated body fluid. CEL2/glass fibre scaffold did not show promising results due to particle detachment from the fibres during soaking in simulated body fluid. Instead the use of mesoporous bioactive powders showed to be an effective way to impart bioactivity to the scaffold and could be further exploited in the future through the ability of mesoporous particles to act as systems for the controlled release of drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Use of borosilicate-glass raschig rings as a neutron absorber in solutions of fissile material-ANSI/ANS-8.5-1996

    International Nuclear Information System (INIS)

    Rothe, R.E.; Ketzlach, N.; Finch, D.R.

    1996-01-01

    American National Standards Institute/American Nuclear Society (ANSI/ANS)-8.5 is one of several standards prepared by the ANS Standards Committee to provide guidance to enhance criticality safety in the handling, storage, and processing of fissionable materials. American National Standard ANSI/ANS-8.5-1996 provides this guidance for one type of boron-loaded glass in one type of geometry (cylindrical rings) for use with fissile solutions. Recorded use of such fixed neutron absorbers for criticality control of fissile solutions dates back to 1958, but some less-well-documented applications were recorded as early as the mid-1940's. The first solid efforts to collect recommendations derived from experience and technology were begun in 1965. Over the next 6 yr additional experiments were performed, and supporting data for the proposed standard were gathered. The first standard on this safety matter was issued in 1971. It was reaffirmed in 1979 with only minor changes and a slight expansion of the coverage. The standard was last revised in 1986

  18. Silicate glasses

    International Nuclear Information System (INIS)

    Lutze, W.

    1988-01-01

    Vitrification of liquid high-level radioactive wastes has received the greatest attention, world-wide, compared to any other HLW solidification process. The waste form is a borosilicate-based glass. The production of phosphate-based glass has been abandoned in the western world. Only in the Soviet Union are phosphate-based glasses still being developed. Vitrification techniques, equipment and processes and their remote operation have been developed and studied for almost thirty years and have reached a high degree of technical maturity. Industrial demonstration of the vitrification process has been in progress since 1978. This chapter is a survey of world-wide research and development efforts in nuclear waste glasses and its production technology. The principal glasses considered are silicate glasses which contain boron, i.e., borosilicate glasses

  19. Thermogravimetry analysis on fused borosilicate syntactic foams

    Science.gov (United States)

    Salleh, Zulzamri; Islam, Md Mainul; Epaarachchi, Jayantha Ananda

    2017-12-01

    Fused borosilicate/vinyl ester syntactic foams mostly used for thermal stability in many applications are considered to be characterised for their properties in higher temperature condition. Therefore, higher temperature characteristics need to be explored with respect to physical parameters such as porosity and void content. The filler, also known as glass microballoons, was incorporated in vinyl ester resin matrix in 2wt%, 4wt%, 6wt.%, 8wt.% and 10wt.%. These composites are characterised and degraded to examine the onset temperature, Tonset, peak temperature, Tpeak and end temperature, Tend using thermogravimetric analysis (TGA) method. The results for Tonset showed an increment while Tend and Tpeak showed decrement when glass microballoons were added in syntactic foams. Based on TGA data, they exhibited excellent thermal stability, showing 5% weight loss at 380-450 °C. Glass transition temperature (Tg) decreased when more glass microballoons were added, and also related to the effect on the physical properties of syntactic foams. Therefore, understanding of the relationship between thermal properties of syntactic foams and their physical properties such as porosity and void content will help in developing syntactic foams to optimise their thermal characteristics, which will be beneficial for engineering applications.

  20. Effect of Gd2O3 doping on structure and boron volatility of borosilicate glass sealants in solid oxide fuel cells-A study on the La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode

    Science.gov (United States)

    Zhang, Qi; Tan, Shengwei; Ren, Mengyuan; Yang, Hsiwen; Tang, Dian; Chen, Kongfa; Zhang, Teng; Jiang, San Ping

    2018-04-01

    Boron volatility is one of the most important properties of borosilicate-based glass sealants in solid oxide fuel cells (SOFCs), as boron contaminants react with lanthanum-containing cathodes, forming LaBO3 and degrading the activity of SOFCs. Here, we report that the reaction between the volatile boron and a La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode during polarization can be significantly reduced by doping aluminoborosilicate glass with Gd2O3. Specifically, the Gd cations in glass with 2 mol.% Gd2O3 dissolve preferentially in the borate-rich environment to form more Gd-metaborate structures and promote the formation of calcium metaborate (CaB2O4); they also condense the B-O network after heat treatment, which suppresses poisoning by boron contaminants on the LSCF cathode. The results provide insights into design and development of a reliable sealing glass for SOFC applications.

  1. A novel low cost polyvinyl alcohol-Nafion-borosilicate membrane separator for microbial fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, B.R. [Department of Civil Engineering, Indian Institute of Technology, Kharagpur, 721302 (India); Noori, Md.T. [Department of Agriculture and Food Engineering, Indian Institute of Technology, Kharagpur, 721302 (India); Ghangrekar, M.M., E-mail: ghangrekar@civil.iitkgp.ernet.in [Department of Civil Engineering, Indian Institute of Technology, Kharagpur, 721302 (India)

    2016-10-01

    Composite membranes were developed from PVA-borosilicate (MP) and PVA-Nafion-borosilicate (MPN) for application in microbial fuel cells (MFCs). The membranes were characterized in terms of water uptake, PBS uptake, oxygen diffusion and proton conductivity. Proton conductivity for MPN (0.07 Scm{sup −1}) was found to be higher as compared to that of MP (0.03 Scm{sup −1}). Oxygen diffusion coefficient for MPN was 1.47 fold lower than that for MP. As a result, MFC with PVA-Nafion-borosilicate membrane exhibited maximum power density of 6.8 Wm{sup −3}, which was 151% higher than the power produced by MFC having PVA-borosilicate membrane and it was comparable with MFC using Nafion 117 (7.1 Wm{sup −3}) membrane separator. This study demonstrates that borosilicate glass membrane incorporated with PVA-Nafion matrix can be a suitable alternative to costly polymeric membrane to increase power output of MFC. Using such membranes MFC can be fabricated at around 11 fold reduced cost as compared to Nafion 117. - Highlights: • Novel membranes using PVA and borosilicate composite were fabricated. • Proton diffusion for MPN was comparable with Nafion117. • MFC-PN produced power density comparable to MFC with Nafion 117 membrane. • MPN was fabricated at almost 11 times reduced cost than Nafion 117 membranes.

  2. Impact Strength of Glass and Glass Ceramic

    Science.gov (United States)

    Bless, S.; Tolman, J.

    2009-12-01

    Strength of glass and glass ceramic was measured with a bar impact technique. High-speed movies show regions of tensile and compressive failure. The borosilicate glass had a compressive strength of at least 2.2 GPa, and the glass ceramic at least 4 GPa. However, the BSG was much stronger in tension than GC. In ballistic tests, the BSG was the superior armor.

  3. A new glass option for parenteral packaging.

    Science.gov (United States)

    Schaut, Robert A; Peanasky, John S; DeMartino, Steven E; Schiefelbein, Susan L

    2014-01-01

    Glass is the ideal material for parenteral packaging because of its chemical durability, hermeticity, strength, cleanliness, and transparency. Alkali borosilicate glasses have been used successfully for a long time, but they do have some issues relating to breakage, delamination, and variation in hydrolytic performance. In this paper, alkali aluminosilicate glasses are introduced as a possible alternative to alkali borosilicate glasses. An example alkali aluminosilicate glass is shown to meet the compendial requirements, and to have similar thermal, optical, and mechanical attributes as the current alkali borosilicate glasses. In addition, the alkali aluminosilicate performed as well or better than the current alkali borosilicates in extractables tests and stability studies, which suggests that it would be suitable for use with the studied liquid product formulation. The physical, mechanical, and optical properties of glass make it an ideal material for packaging injectable drugs and biologics. Alkali borosilicate glasses have been used successfully for a long time for these applications, but there are some issues. In this paper, alkali aluminosilicate glasses are introduced as a possible alternative to alkali borosilicate glasses. An example alkali aluminosilicate glass is shown to meet the requirements for packaging injectable drugs and biologics, and to be suitable for use with a particular liquid drug. © PDA, Inc. 2014.

  4. Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

    International Nuclear Information System (INIS)

    Aytug, Tolga; Simpson, John T; Lupini, Andrew R; Trejo, Rosa M; Jellison, Gerald E; Ivanov, Ilia N; Pennycook, Stephen J; Hillesheim, Daniel A; Winter, Kyle O; Christen, David K; Hunter, Scott R; Allen Haynes, J

    2013-01-01

    We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie–Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military. (paper)

  5. Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films

    Science.gov (United States)

    Aytug, Tolga; Simpson, John T.; Lupini, Andrew R.; Trejo, Rosa M.; Jellison, Gerald E.; Ivanov, Ilia N.; Pennycook, Stephen J.; Hillesheim, Daniel A.; Winter, Kyle O.; Christen, David K.; Hunter, Scott R.; Haynes, J. Allen

    2013-08-01

    We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie-Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military.

  6. Deconstructing three-dimensional (3D) structure of absorptive glass mat (AGM) separator to tailor pore dimensions and amplify electrolyte uptake

    Science.gov (United States)

    Rawal, Amit; Rao, P. V. Kameswara; Kumar, Vijay

    2018-04-01

    Absorptive glass mat (AGM) separator is a vital technical component in valve regulated lead acid (VRLA) batteries that can be tailored for a desired application. To selectively design and tailor the AGM separator, the intricate three-dimensional (3D) structure needs to be unraveled. Herein, a toolkit of 3D analytical models of pore size distribution and electrolyte uptake expressed via wicking characteristics of AGM separators under unconfined and confined states is presented. 3D data of fiber orientation distributions obtained previously through X-ray micro-computed tomography (microCT) analysis are used as key set of input parameters. The predictive ability of pore size distribution model is assessed through the commonly used experimental set-up that usually apply high level of compressive stresses. Further, the existing analytical model of wicking characteristics of AGM separators has been extended to account for 3D characteristics, and subsequently, compared with the experimental results. A good agreement between the theory and experiments pave the way to simulate the realistic charge-discharge modes of the battery by applying cyclic loading condition. A threshold criterion describing the invariant behavior of pore size and wicking characteristics in terms of maximum permissible limit of key structural parameters during charge-discharge mode of the battery has also been proposed.

  7. Spectral characterization and excited-state interactions between rare earth ions doped in borosilicate and sol-gel glasses. Energy transfer up-conversion in the Pr-Sm system

    International Nuclear Information System (INIS)

    Assefa, Z.; Haire, R.G.; Stump, N.A.

    1996-01-01

    Spectroscopic properties of selected 4f-elements in a sol-gel and two high temperature silicate based glasses are reported. In particular, the spectral properties of the Eu[sup 3+] ion have been used to probe the local coordination environment of the f-elements in these glass matrices. Luminescence studies of the high temperature glasses indicated that the electric dipole allowed f-f transitions dominate the spectra which suggests that the local symmetry around the 4f-ions is low. Temperature-dependent spectroscopic studies of the sol-gel glasses indicated that the f-elements retain a 'solution-like' environment prior to thermal processing. After heat treatment, an increase in the emission intensities of the electric-dipole transitions is accompanied by a concomitant decrease in the magnetic- dipole allowed transitions. Moreover, excited state interactions has also been observed in the high temperature glasses that contain certain multiple f-elements. In Pr-Sm systems, exclusive excitation of the Sm[sup 3+] ion with a 514 nm argon ion laser line provides a higher- energy emission band ( ca. 490 mn ) from the PR[sup 3+] ion ([sup 3]P[sub 0] -> '[sup 3]H[sub 4]) transition. This energy up- conversion is attributed to energy transfer from the [sup 6]H[sub 13/2] level of the Se[sup 3+] ion to the [sup 3]H[sub 6] state of the PR[sup 3+] ion. Following a second photon absorption, the PR[sup 3+] ion is excited to the emitting [sup 3]P[sub O] level

  8. Glasses

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    2004-01-01

    The temperature dependence of the viscosity of most glassforming liquids is known to depart significantly from the classical Arrhenius behaviour of simple fluids. The discovery of an unexpected correlation between the extent of this departure and the Poisson ratio of the resulting glass could lead...... to new understanding of glass ageing and viscous liquid dynamics....

  9. glasses

    Indian Academy of Sciences (India)

    composed of VO5 pyramids. The vanadates-based glasses show semiconducting ..... the composition 1 mol% of CeO2. The AC conductivity obeys a power law. The glass samples exhibit typical inor- ganic semiconducting behaviour. The activation energy and conductivity at room temperature were found to be 0.09 eV ...

  10. Modelling the local atomic structure of molybdenum in nuclear waste glasses with ab initio molecular dynamics simulations.

    Science.gov (United States)

    Konstantinou, Konstantinos; Sushko, Peter V; Duffy, Dorothy M

    2016-09-21

    The nature of chemical bonding of molybdenum in high level nuclear waste glasses has been elucidated by ab initio molecular dynamics simulations. Two compositions, (SiO 2 ) 57.5 -(B 2 O 3 ) 10 -(Na 2 O) 15 -(CaO) 15 -(MoO 3 ) 2.5 and (SiO 2 ) 57.3 -(B 2 O 3 ) 20 -(Na 2 O) 6.8 -(Li 2 O) 13.4 -(MoO 3 ) 2.5 , were considered in order to investigate the effect of ionic and covalent components on the glass structure and the formation of the crystallisation precursors (Na 2 MoO 4 and CaMoO 4 ). The coordination environments of Mo cations and the corresponding bond lengths calculated from our model are in excellent agreement with experimental observations. The analysis of the first coordination shell reveals two different types of molybdenum host matrix bonds in the lithium sodium borosilicate glass. Based on the structural data and the bond valence model, we demonstrate that the Mo cation can be found in a redox state and the molybdate tetrahedron can be connected with the borosilicate network in a way that inhibits the formation of crystalline molybdates. These results significantly extend our understanding of bonding in Mo-containing nuclear waste glasses and demonstrate that tailoring the glass composition to specific heavy metal constituents can facilitate incorporation of heavy metals at high concentrations.

  11. Titanium impregnated borosilicate zeolites for epoxidation catalysis

    Czech Academy of Sciences Publication Activity Database

    Přech, Jan; Vitvarová, Dana; Lupínková, Lenka; Kubů, Martin; Čejka, Jiří

    2015-01-01

    Roč. 212, AUG 2015 (2015), s. 28-34 ISSN 1387-1811 R&D Projects: GA ČR GAP106/11/0819 Institutional support: RVO:61388955 Keywords : borosilicate * titanium impregnation * epoxidation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.349, year: 2015

  12. Solubility of actinides and surrogates in nuclear glasses

    International Nuclear Information System (INIS)

    Lopez, Ch.

    2003-01-01

    The nuclear wastes are currently incorporated in borosilicate glass matrices. The resulting glass must be perfectly homogeneous. The work discussed here is a study of actinide (thorium and plutonium) solubility in borosilicate glass, undertaken to assess the extent of actinide solubility in the glass and to understand the mechanisms controlling actinide solubilization. Glass specimens containing; actinide surrogates were used to prepare and optimize the fabrication of radioactive glass samples. These preliminary studies revealed that actinide Surrogates solubility in the glass was enhanced by controlling the processing temperature, the dissolution kinetic of the surrogate precursors, the glass composition and the oxidizing versus reducing conditions. The actinide solubility was investigated in the borosilicate glass. The evolution of thorium solubility in borosilicate glass was determined for temperatures ranging from 1200 deg C to 1400 deg C.Borosilicate glass specimens containing plutonium were fabricated. The experimental result showed that the plutonium solubility limit ranged from 1 to 2.5 wt% PuO 2 at 1200 deg C. A structural approach based on the determination of the local structure around actinides and their surrogates by EXAFS spectroscopy was used to determine their structural role in the glass and the nature of their bonding with the vitreous network. This approach revealed a correlation between the length of these bonds and the solubility of the actinides and their surrogates. (author)

  13. Ultra-Lightweight Borosilicate Gas-Fusion Mirror for Cryogenic Testing

    Science.gov (United States)

    Voevodsky, Michael

    2003-01-01

    Hextek Corporation fabricated a 250 mm diameter ultra-lightweight borosilicate mirror substrate for cryogenic testing at NASA MSFC XRCF facility in Huntsville AL under contract# H-34475D. The objectives of the program were to demonstrate that the Hextek Gas-Fusion technology is capable of meeting the 15kg/sq m areal density target required for future space missions, and to provide a demonstration substrate for NASA MSFC to finish and test at cryogenic temperature. This presentation reviews company background and capabilities, features and benefits of the Gas-Fusion technology, historical data on cryogenic performance of borosilicate glass showing near zero cte at 30-35 degrees Kelvin, design and fabrication results of the 250 mm 15kg/sq m areal density substrate, and finally, projected scaling, lightweighing and fabrication lead-times for meter class segments.

  14. glasses

    Indian Academy of Sciences (India)

    materials and electrochemical batteries.8 Rare earth metal ions when added to borate act as network modifiers and change the properties of glasses. In rare earth ... room temperature to 600◦C. For electrical measurements, samples were polished and conducting silver paste was deposited on both sides. The sample area ...

  15. Glass

    OpenAIRE

    Parker, K

    2010-01-01

    Audio recording of the sea from the breakwater in Plymouth Sound, by Stuart Moore. Presentations and exhibitions of the film Glass include: Finding Place exhibition, Plymouth (3 > 26 February 2010); University of the West of England's Radical British Screens symposium (3 September 2010); Plymouth University Festival of Research: Materiality and Technology film programme presented by the Centre for Media Art and Design Research (MADr), Jill Craigie Cinema, Plymouth University (14 March 2011); ...

  16. Continuous-wave laser-induced glass fiber generation

    Science.gov (United States)

    Nishioka, Nobuyasu; Hidai, Hirofumi; Matsusaka, Souta; Chiba, Akira; Morita, Noboru

    2017-09-01

    Pulsed-laser-induced glass fiber generation has been reported. We demonstrate a novel glass fiber generation technique by continuous-wave laser illumination and reveal the generation mechanism. In this technique, borosilicate glass, metal foil, and a heat insulator are stacked and clamped by a jig as the sample. Glass fibers are ejected from the side surface of the borosilicate glass by laser illumination of the sample from the borosilicate glass side. SEM observation shows that nanoparticles are attached on the glass fibers. High-speed imaging reveals that small bubbles are formed at the side surface of the borosilicate glass and the bursting of the bubble ejects the fibers. The temperature at the fiber ejection point is estimated to be 1220 K. The mechanism of the fiber ejection includes the following steps: the metal thin foil heated by the laser increases the temperature of the surrounding glass by heat conduction. Since the absorption coefficient of the glass is increased by increasing the temperature, the glass starts to absorb the laser irradiation. The heated glass softens and bubbles form. When the bubble bursts, molten glass and gas inside the bubble scatter into the air to generate the glass fibers.

  17. Immobilization of Uranium Silicides in Sintered Glass

    International Nuclear Information System (INIS)

    Mateos, P.; Russo, D.O.; Heredia, A.D.; Sanfilippo, M.

    2003-01-01

    High activity nuclear spent fuels vitrification by fusion is a well known technology which has industrial scale in France, England, Japan, EEUU. Borosilicates glasses are used in this process.Sintered glasses are an alternative to the immobilization task in which there is also a wide experience around the world.The available technics are: cold pressing and sintering , hot-pressing and hot isostatic pressing.This work compares Borosilicates and Iron silicates sintered glasses behaviour when different ammounts of nuclear simulated waste is added

  18. Glass Ceramic Formulation Data Package

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Rodriguez, Carmen P.; McCloy, John S.; Vienna, John D.; Chung, Chul-Woo

    2012-06-17

    A glass ceramic waste form is being developed for treatment of secondary waste streams generated by aqueous reprocessing of commercial used nuclear fuel (Crum et al. 2012b). The waste stream contains a mixture of transition metals, alkali, alkaline earths, and lanthanides, several of which exceed the solubility limits of a single phase borosilicate glass (Crum et al. 2009; Caurant et al. 2007). A multi-phase glass ceramic waste form allows incorporation of insoluble components of the waste by designed crystallization into durable heat tolerant phases. The glass ceramic formulation and processing targets the formation of the following three stable crystalline phases: (1) powellite (XMoO4) where X can be (Ca, Sr, Ba, and/or Ln), (2) oxyapatite Yx,Z(10-x)Si6O26 where Y is alkaline earth, Z is Ln, and (3) lanthanide borosilicate (Ln5BSi2O13). These three phases incorporate the waste components that are above the solubility limit of a single-phase borosilicate glass. The glass ceramic is designed to be a single phase melt, just like a borosilicate glass, and then crystallize upon slow cooling to form the targeted phases. The slow cooling schedule is based on the centerline cooling profile of a 2 foot diameter canister such as the Hanford High-Level Waste canister. Up to this point, crucible testing has been used for glass ceramic development, with cold crucible induction melter (CCIM) targeted as the ultimate processing technology for the waste form. Idaho National Laboratory (INL) will conduct a scaled CCIM test in FY2012 with a glass ceramic to demonstrate the processing behavior. This Data Package documents the laboratory studies of the glass ceramic composition to support the CCIM test. Pacific Northwest National Laboratory (PNNL) measured melt viscosity, electrical conductivity, and crystallization behavior upon cooling to identify a processing window (temperature range) for melter operation and cooling profiles necessary to crystallize the targeted phases in the

  19. Nuclear waste disposal: alternatives to solidification in glass proposed

    International Nuclear Information System (INIS)

    Kerr, R.A.

    1979-01-01

    More than a quarter-million cubic meters of liquid radioactive wastes are now being held at government installations awaiting final disposal. During the past 20 years, the disposal plan of choice has been to incorporate the 40 to 50 radioactive elements dissolved in liquid wastes into blocks of glass, seal the glass in metal canisters, and insert the canisters into deep, geologically stable salt beds. Over the last few years, some geologists and materials scientists have become concerned that perhaps not enough is known yet about the interaction of waste, container, and salt (or any rock) to have a reasonable assurance that the hazardous wastes will be contained successfully. The biggest advantage of glass at present is the demonstrated practicality of producing large, highly radioactive blocks of it. The frontrunner as a successor to glass is ceramics, which are nonmetallic crystalline materials formed at high temperature, such as chinaware or natural minerals. An apparent advantage of ceramics is that they already have an ordered atomic structure, whose properties can be tailored to a particular waste element and to conditions of a specific disposal site. A ceramic tailored for waste disposal called supercalcine-ceramic has been developed. It was emphasized that the best minerals for waste solidification may be those that have proved most stable under natural conditions over geologic time. Disadvantage to ceramics are radiation damage and transmutation. However, it is now obvious that some ceramics are more stable than glass under certain conditions. Metal-encapsulated ceramic, called cermet, is being developed as a waste form. Cermets are considerably more resistant at 100 0 C than a borosilicate waste glass. Researchers are now testing prospective waste forms under the most extreme conditions that might prevail in a waste disposal site

  20. Ultrasonic and structural features of some borosilicate glasses ...

    Indian Academy of Sciences (India)

    2017-06-09

    Jun 9, 2017 ... modified with heavy metals. YASSER B SADDEEK. Department of Physics, Faculty of .... acteristic broad humps of the amorphous materials. The FTIR absorption spectroscopy is a non-destructive .... and creates non-bridging oxygen (NBO) atoms on the [SiO4] silica tetrahedral [38]. Thus, the variation in the ...

  1. Oxide glass structure evolution under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Mendoza, C.; Peuget, S.; Charpentier, T.; Moskura, M.; Caraballo, R.; Bouty, O.; Mir, A.H.; Monnet, I.; Grygiel, C.; Jegou, C.

    2014-01-01

    Highlights: • Structure of SHI irradiated glass is similar to the one of a hyper quenched glass. • D2 Raman band associated to 3 members ring is only observed in irradiated glass. • Irradiated state seems slightly different to an equilibrated liquid quenched rapidly. - Abstract: The effects of ion tracks on the structure of oxide glasses were examined by irradiating a silica glass and two borosilicate glass specimens containing 3 and 6 oxides with krypton ions (74 MeV) and xenon ions (92 MeV). Structural changes in the glass were observed by Raman and nuclear magnetic resonance spectroscopy using a multinuclear approach ( 11 B, 23 Na, 27 Al and 29 Si). The structure of irradiated silica glass resembles a structure quenched at very high temperature. Both borosilicate glass specimens exhibited depolymerization of the borosilicate network, a lower boron coordination number, and a change in the role of a fraction of the sodium atoms after irradiation, suggesting that the final borosilicate glass structures were quenched from a high temperature state. In addition, a sharp increase in the concentration of three membered silica rings and the presence of large amounts of penta- and hexacoordinate aluminum in the irradiated 6-oxide glass suggest that the irradiated glass is different from a liquid quenched at equilibrium, but it is rather obtained from a nonequilibrium liquid that is partially relaxed by very rapid quenching within the ion tracks

  2. Study of the possibilities of using nuclear methods for characterizing the surface region of glasses

    International Nuclear Information System (INIS)

    Hsiung, P.

    1983-01-01

    Following a review of the different methods used for the analysis of surfaces, we give a detailed description of charged particle elastic backscattering and the experimental devices. We then apply this method to the study of the lixiviation of borosilicate glasses in aqueous media and to the characterization of two heavy elements, cerium and thorium and their possible interaction in simple borosilicates [fr

  3. Behaviour of rare earth elements, as natural analogues of transuranium elements, during weathering of basaltic glasses

    International Nuclear Information System (INIS)

    Daux, V.; Crovisier, J.L.; Petit, J.C.

    1991-01-01

    Subglacial basaltic glasses from Iceland have been studied in order to investigate REE behaviour low-temperature weathering. Just as actinides accumulate in the hydrated superficial corrosion layer of borosilicate glasses, REEs are found to be enriched in the natural corrosion layer of basaltic glasses (palagonite). However, this enrichment is only relative for basaltic glasses [fr

  4. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    International Nuclear Information System (INIS)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T; Padipatvuthikul, P

    2011-01-01

    Silicon nitride (Si 3 N 4 ) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si 3 N 4 ceramic as a dental core material. The white Si 3 N 4 was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si 3 N 4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si 3 N 4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder ( 2 O 3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si 3 N 4 specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10 -6 deg. C -1 , rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  5. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Science.gov (United States)

    Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

    2011-10-01

    Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y2O3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si3N4 specimens, the firing was performed in electric tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  6. The effect of surface roughness of glass on the leachability

    International Nuclear Information System (INIS)

    Yamanaka, Hiroshi; Terai, Ryohei; Hara, Shigeo

    1982-01-01

    The effect of surface roughness of glass samples on the leachability of simulated high-level nuclear waste containing borosilicate glasses has been investigated from view-point of safety evaluation, using the Soxhlet-type leaching apparatus. The quantity extracted from glasses had generally increased with increasing of the surface roughness of glass block samples. SEM photographs demonstrated that the surface abraded by coarse abrasive powder has had many unevennesses and cracks which brought about an accelerated attack on glass surface. It seems, therefore, that the surface roughness of specimens should be defined as a criterion of leachability. The reaction between glass and water brought about the formation of hydrated layer more easily on the borosilicate glass than on the soda-lime silicate glass. The resultant hydrated layer produces many cracks by drying, but the cracks can not be observed by naked eye. Therefore, the observation by SEM is necessary for precise evaluation on the corroded surface of glasses. (author)

  7. Preparation and characterization of special glasses for sealing and other applications

    Science.gov (United States)

    Shrikhande, V. K.

    2009-07-01

    Glasses find wide applications, among others, in process technologies, vacuum science and technology etc. because of their desired thermo-mechanical properties and chemical durability. In particular, hermetic glass-to-metal (GM) seals are required mainly as electrical feed through for various types of gas based and electron devices, chemical process industries, including for packaging of power devices. The physico-chemical properties of glasses play important role in forming hermetic sealing with metals/alloys. The properties like thermal expansion coefficient, glass transition temperature, micro hardness, chemical durability etc. can be tailored by varying the glass composition by adding multi alkali and alkaline earth metal oxides to the base glass and varying the process parameters. We have prepared different types of glasses for the fabrication of different types of hermetic seals. Some of these are i) Lead silicate (LS) glass having SiO2, Na2O, K2O, BaO and PbO for compression type GM seals with SS304/Inconel and AISI 446 alloy ii) Borosilicate (BS) glass containing SiO2.Na2O.K20. Al2O3.B2O3 for matched type GM seals with Mo/ Kovar alloy and for uptake of synthetic dyes like Rhodamine 6G, Methylene Blue, Uranyl ions in process industries and nuclear industry iii) Sodium alumino phosphate (NAP) glass with P2O5-Na2O-B2O3-BaO- PbO for matched type GM seals with low melting metals (Al,Cu)/alloys like Cu-Be.

  8. Immobilization of radioactive waste in glass matrices

    International Nuclear Information System (INIS)

    Wicks, G.G.

    1978-01-01

    A promising process for long-term management of high-level radioactive waste is to immobilize the waste in a borosilicate glass matrix. Among the most important criteria characterizing the integrity of the large-scale glass-waste forms are that they possess good chemical stability (including low leachability), thermal stability, mechanical integrity, and high radiation stability. Fulfillment of these criteria ensures the maximum margin of safety of glass-waste products, following solidification, handling, transportation, and long-term storage

  9. F/Yb-codoped sol-gel silica glasses: toward tailoring the refractive index for the achievement of high-power fiber lasers.

    Science.gov (United States)

    El Hamzaoui, Hicham; Bouwmans, Geraud; Cassez, Andy; Bigot, Laurent; Capoen, Bruno; Bouazaoui, Mohamed; Vanvincq, Olivier; Douay, Marc

    2017-04-01

    Accurate control of both the doping distribution inside the fiber core and the low refractive index contrast between the fiber core and cladding materials is essential for the development of high-power fiber lasers based on the use of single-mode large-mode-area (LMA) optical fibers. Herein, sol-gel monolithic F/Yb3+-codoped silica glasses were prepared from porous large silica xerogels doped with ytterbium salt solution, which had been subjected to fluorination with hexafluoroethane gas, before subsequent sintering. The fluorine content inside the doped glass has been varied by adjusting the fluorination duration. The space homogeneity of fluorine and ytterbium concentrations in the cylindrical preforms has been checked by chemical analysis and Raman spectroscopy. Moreover, the glass with the lowest fluorine content has been successfully integrated as a core material in a microstructured optical fiber made using the stack-and-draw method. This fiber was tested in an all-fiber cavity laser architecture to evaluate potential lasing performances of the F/Yb3+-codoped silica glass. It presents a maximum efficiency of 70.4%, achieved at 1031 nm from a 1.16 m length fiber. These results confirm the potentialities of the obtained F/Yb3+-codoped glasses for the fabrication of LMA optical fiber lasers.

  10. Corrosion of simulated nuclear waste glass

    International Nuclear Information System (INIS)

    Music, S.; Ristic, M.; Gotic, M.; Foric, J.

    1988-01-01

    In this study the preparation and characterization of borosilicate glasses of different chemical composition were investigated. Borosilicate glasses were doped with simulated nuclear waste oxides. The chemical corrosion in water of these glasses was followed by measuring the leach rates as a function of time. It was found that a simulated nuclear waste glass with the chemical composition (weight %), 15.61% Na 2 O, 10.39% B 2 O 3 , 45.31% SiO 2 , 13.42% ZnO, 6.61% TiO 2 and 8.66% waste oxides, is characterized by low melting temperature and with good corrosion resistance in water. Influence of passive layers on the leaching behaviour of nuclear waste glasses is discussed. (author) 20 refs.; 7 figs.; 4 tabs

  11. The Predictive Power of Electronic Polarizability for Tailoring the Refractivity of High Index Glasses Optical Basicity Versus the Single Oscillator Model

    Energy Technology Data Exchange (ETDEWEB)

    McCloy, John S.; Riley, Brian J.; Johnson, Bradley R.; Schweiger, Michael J.; Qiao, Hong (Amy); Carlie, Nathan

    2010-06-01

    Four compositions of high density (~8 g/cm3) heavy metal oxide glasses composed of PbO, Bi2O3, and Ga2O3 were produced and refractivity parameters (refractive index and density) were computed and measured. Optical basicity was computed using three different models – average electronegativity, ionic-covalent parameter, and energy gap – and the basicity results were used to compute oxygen polarizability and subsequently refractive index. Refractive indices were measured in the visible and infrared at 0.633 μm, 1.55 μm, 3.39 μm, 5.35 μm, 9.29 μm, and 10.59 μm using a unique prism coupler setup, and data were fitted to the Sellmeier expression to obtain an equation of the dispersion of refractive index with wavelength. Using this dispersion relation, single oscillator energy, dispersion energy, and lattice energy were determined. Oscillator parameters were also calculated for the various glasses from their oxide values as an additional means of predicting index. Calculated dispersion parameters from oxides underestimate the index by 3 to 4%. Predicted glass index from optical basicity, based on component oxide energy gaps, underpredicts the index at 0.633 μm by only 2%, while other basicity scales are less accurate. The predicted energy gap of the glasses based on this optical basicity overpredicts the Tauc optical gap as determined by transmission measurements by 6 to 10%. These results show that for this system, density, refractive index in the visible, and energy gap can be reasonably predicted using only composition, optical basicity values for the constituent oxides, and partial molar volume coefficients. Calculations such as these are useful for a priori prediction of optical properties of glasses.

  12. Boron nitride nanosheets reinforced glass matrix composites

    Czech Academy of Sciences Publication Activity Database

    Saggar, Richa; Porwal, H.; Tatarko, P.; Dlouhý, Ivo; Reece, M. J.

    2015-01-01

    Roč. 114, SEP (2015), S26-S32 ISSN 1743-6753 R&D Projects: GA MŠk(CZ) 7AMB14SK155 EU Projects: European Commission(XE) 264526 Institutional support: RVO:68081723 Keywords : Boron nitride nanosheets * Borosilicate glass * Mechanical properties Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.162, year: 2015

  13. Direct conversion of plutonium metal, scrap, residue, and transuranic waste to glass

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.; Malling, J.F.; Rudolph, J.

    1995-01-01

    A method for the direct conversion of metals, ceramics, organics, and amorphous solids to borosilicate glass has been invented. The process is called the Glass Material Oxidation and Dissolution System (GMODS). Traditional glass-making processes can convert only oxide materials to glass. However, many wastes contain complex mixtures of metals, ceramics, organics, and amorphous solids. Conversion of such mixtures to oxides followed by their conversion to glass is often impractical. GMODS may create a practical method to convert such mixtures to glass. Plutonium-containing materials (PCMS) exist in many forms, including metals, ceramics, organics, amorphous solids, and mixtures thereof. These PCMs vary from plutonium metal to filters made of metal, organic binders, and glass fibers. For storage and/or disposal of PCMS, it is desirable to convert PCMs to borosilicate glass. Borosilicate glass is the preferred repository waste form for high-level waste (HLW) because of its properties. PCMs converted to a transuranic borosilicate homogeneous glass would easily pass all waste acceptance and storage criteria. Conversion of PCMs to a glass would also simplify safeguards by conversion of heterogeneous PCMs to homogeneous glass. Thermodynamic calculations and proof-of-principle experiments on the GMODS process with cerium (plutonium surrogate), uranium, stainless steel, aluminum, Zircaloy-2, and carbon were successfully conducted. Initial analysis has identified potential flowsheets and equipment. Major unknowns remain, but the preliminary data suggests that GMODS may be a major new treatment option for PCMs

  14. Solubility of actinides and surrogates in nuclear glasses; Solubilite des actinides et de leurs simulants dans les verres nucleaires. Limites d'incorporation et comprehension des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Ch

    2003-07-01

    The nuclear wastes are currently incorporated in borosilicate glass matrices. The resulting glass must be perfectly homogeneous. The work discussed here is a study of actinide (thorium and plutonium) solubility in borosilicate glass, undertaken to assess the extent of actinide solubility in the glass and to understand the mechanisms controlling actinide solubilization. Glass specimens containing; actinide surrogates were used to prepare and optimize the fabrication of radioactive glass samples. These preliminary studies revealed that actinide Surrogates solubility in the glass was enhanced by controlling the processing temperature, the dissolution kinetic of the surrogate precursors, the glass composition and the oxidizing versus reducing conditions. The actinide solubility was investigated in the borosilicate glass. The evolution of thorium solubility in borosilicate glass was determined for temperatures ranging from 1200 deg C to 1400 deg C.Borosilicate glass specimens containing plutonium were fabricated. The experimental result showed that the plutonium solubility limit ranged from 1 to 2.5 wt% PuO{sub 2} at 1200 deg C. A structural approach based on the determination of the local structure around actinides and their surrogates by EXAFS spectroscopy was used to determine their structural role in the glass and the nature of their bonding with the vitreous network. This approach revealed a correlation between the length of these bonds and the solubility of the actinides and their surrogates. (author)

  15. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Energy Technology Data Exchange (ETDEWEB)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Padipatvuthikul, P, E-mail: raayaa_chula@hotmail.com [Faculty of Dentistry, Srinakharinwirot University, Bangkok (Thailand)

    2011-10-29

    Silicon nitride (Si{sub 3}N{sub 4}) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si{sub 3}N{sub 4} ceramic as a dental core material. The white Si{sub 3}N{sub 4} was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si{sub 3}N{sub 4} ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si{sub 3}N{sub 4} specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y{sub 2}O{sub 3} - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si{sub 3}N{sub 4} specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10{sup -6} deg. C{sup -1}, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  16. Development of a glass matrix for vitrification of sulphate bearing high level radioactive liquid waste

    International Nuclear Information System (INIS)

    Kaushik, C.P.; Mishra, R.K.; Thorat, Vidya; Ramchandran, M.; Amar Kumar; Ozarde, P.D.; Raj, Kanwar; Das, D.

    2004-07-01

    High level radioactive liquid waste (HLW) is generated during reprocessing of spent nuclear fuel. In the earlier reprocessing flow sheet ferrous sulphamate has been used for valancy adjustment of Pu from IV to III for effective separation. This has resulted in generation of HLW containing significance amount of sulphate. Internationally borosilicate glass matrix has been adopted for vitrification of HLW. The first Indian vitrification facility at Waste Immobilislition Plant (WIP), Tarapur a five component borosilicate matrix (SiO 2 :B 2 O 3 :Na 2 O : MnO : TiO 2 ) has been used for vitrification of waste. However at Trombay HLW contain significant amount of sulphate which is not compatible with standard borosilicate formulation. Extensive R and D efforts were made to develop a glass formulation which can accommodate sulphate and other constituents of HLW e.g., U, Al, Ca, etc. This report deals with development work of a glass formulations for immobilization of sulphate bearing waste. Different glass formulations were studied to evaluate the compatibility with respect to sulphate and other constituents as mentioned above. This includes sodium, lead and barium borosilicate glass matrices. Problems encountered in different glass matrices for containment of sulphate have also been addressed. A glass formulation based on barium borosilicate was found to be effective and compatible for sulphate bearing high level waste. (author)

  17. Taylor impact of glass rods

    International Nuclear Information System (INIS)

    Willmott, G.R.; Radford, D.D.

    2005-01-01

    The deformation and fracture behavior of soda-lime and borosilicate glass rods was examined during classic and symmetric Taylor impact experiments for impact pressures to 4 and 10 GPa, respectively. High-speed photography and piezoresistive gauges were used to measure the failure front velocities in both glasses, and for impact pressures below ∼2 GPa the failure front velocity increases rapidly with increasing pressure. As the pressure was increased above ∼3 GPa, the failure front velocities asymptotically approached maximum values between the longitudinal and shear wave velocities of each material; at ∼4 GPa, the average failure front velocities were 4.7±0.5 and 4.6±0.5 mm μs -1 for the soda-lime and borosilicate specimens, respectively. The observed mechanism of failure in these experiments involved continuous pressure-dependent nucleation and growth of microcracks behind the incident wave. As the impact pressure was increased, there was a decrease in the time to failure. The density of cracks within the failed region was material dependent, with the more open-structured borosilicate glass showing a larger fracture density

  18. Diffusion of actinides in glasses containing simulated radioactive wastes

    International Nuclear Information System (INIS)

    Ivanov, I.A.; Sedov, V.M.; Gulin, A.N.; Shatkov, V.M.; Shashukov, E.A.

    1991-01-01

    Diffusion coefficients of radionuclides 237 Pu, 239 Pu and 241 Am in simulated alumina phosphate and alumina borosilicate glasses at temperatures lower than their transformation temperatures were determined. Actinides are known to be the least mobile elements. It is shown that crystallization of glasses leads to increasing 237 Np diffusion mobility. It is also shown that a rather small quantity of water absorbed by a crystallized alumina phosphate glass intensifies low-temperature migration of 237 Np. (author) 6 refs.; 2 tabs

  19. Glasses and ceramics for immobilisation of radioactive wastes for disposal

    International Nuclear Information System (INIS)

    Johnson, K.D.B.; Marples, J.A.C.

    1979-05-01

    The U.K. Research Programme on Radioactive Waste Management includes the development of processes for the conversion of high level liquid reprocessing wastes from thermal and fast reactors to borosilicate glasses. The properties of these glasses and their behaviour under storage and disposal conditions have been examined. Methods for immobilising activity from other wastes by conversion to glass or ceramic forms is described. The U.K. philosophy of final solutions to waste management and disposal is presented. (author)

  20. Glasses and nuclear waste vitrification

    International Nuclear Information System (INIS)

    Ojovan, Michael I.

    2012-01-01

    Glass is an amorphous solid material which behaves like an isotropic crystal. Atomic structure of glass lacks long-range order but possesses short and most probably medium range order. Compared to crystalline materials of the same composition glasses are metastable materials however crystallisation processes are kinetically impeded within times which typically exceed the age of universe. The physical and chemical durability of glasses combined with their high tolerance to compositional changes makes glasses irreplaceable when hazardous waste needs immobilisation for safe long-term storage, transportation and consequent disposal. Immobilisation of radioactive waste in glassy materials using vitrification has been used successfully for several decades. Nuclear waste vitrification is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting wasteform. Vitrification involves melting of waste materials with glass-forming additives so that the final vitreous product incorporates the waste contaminants in its macro- and micro-structure. Hazardous waste constituents are immobilised either by direct incorporation into the glass structure or by encapsulation when the final glassy material can be in form of a glass composite material. Both borosilicate and phosphate glasses are currently used to immobilise nuclear wastes. In addition to relatively homogeneous glasses novel glass composite materials are used to immobilise problematic waste streams. (author)

  1. Structural role of molybdenum in nuclear glasses: an EXAFS study

    International Nuclear Information System (INIS)

    Calas, G.; Le Grand, M.; Galoisy, L.; Ghaleb, D.

    2003-01-01

    The Mo environment has been investigated in inactive nuclear glasses using extended X-ray absorption spectroscopy (XAS). Mo is present in a tetrahedron coordinated to oxygen in the form of molybdate groups [MoO 4 ] 2- (d(Mo-O)=1.78 A). This surrounding is not affected by the presence of noble metal phases in the nuclear glass. Relying on the XAS results, on the bond-valence model and on molecular dynamics simulations of a simplified borosilicate model glass, we show that these groups are not directly linked to the borosilicate network but rather located within alkali and alkaline-earth rich domains in the glass. This specific location in the glass network is a way to understand the low solubility of Mo in glasses melted under oxidizing conditions. It also explains the possible phase separation of a yellow phase enriched in alkali molybdates in molten nuclear glasses or the nucleation of calcium molybdates during thermal aging of these glasses. Boron coordination changes in the molten and the glassy states may explain the difference in the composition of the crystalline molybdates, as they exert a direct influence on the activity of alkalis in borosilicate glasses and melts

  2. Tailored ceramics

    International Nuclear Information System (INIS)

    Harker, A.B.

    1988-01-01

    In polyphase tailored ceramic forms two distinct modes of radionuclide immobilization occur. At high waste loadings the radionuclides are distributed through most of the ceramic phases in dilute solid solution, as indicated schematically in this paper. However, in the case of low waste loadings, or a high loading of a waste with low radionuclide content, the ceramic can be designed with only selected phases containing the radionuclides. The remaining material forms nonradioactive phases which provide a degree of physical microstructural isolation. The research and development work with polyphase ceramic nuclear waste forms over the past ten years is discussed. It has demonstrated the critical attributes which suggest them as a waste form for future HLW disposal. From a safety standpoint, the crystalline phases in the ceramic waste forms offer the potential for demonstrable chemical durability in immobilizing the long-lived radionuclides in a geologic environment. With continued experimental research on pure phases, analysis of mineral analogue behavior in geochemical environments, and the study of radiation effects, realistic predictive models for waste form behavior over geologic time scales are feasible. The ceramic forms extend the degree of freedom for the economic optimization of the waste disposal system

  3. Porous glass with high silica content for nuclear waste storage : preparation, characterization and leaching

    International Nuclear Information System (INIS)

    Aegerter, M.A.; Santos, D.I. dos; Ventura, P.C.S.

    1984-01-01

    Aqueous solutions simulating radioactive nuclear wastes (like Savanah River Laboratory) were incorporated in porous glass matrix with high silica content prepared by decomposition of borosilicate glass like Na 2 O - B 2 O 3 - SiO 2 . After sintering, the samples were submitted, during 28 days, to standard leaching tests MCC1, MCC5 (Soxhlet) and stagnating. The total weight loss, ph, as well as the integral and differential leaching rates and the accumulated concentrations in the leach of Si, Na, B, Ca, Mn, Al, Fe and Ni. The results are compared with the results from reference borosilicate glass, made by fusion, ceramic, synroc, concrets, etc... (E.G.) [pt

  4. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior

    International Nuclear Information System (INIS)

    Techer, I.

    1999-01-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol -1 . As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r 0 , The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  5. Radiation response of cubic mesoporous silicate and borosilicate thin films

    Science.gov (United States)

    Manzini, Ayelén; Alurralde, Martín; Luca, Vittorio

    2018-01-01

    The radiation response has been studied of cubic mesoporous silicate and borosilicate thin films having different boron contents prepared using the block copolymer template Brij 58 and the dip coating technique. The degree of pore ordering of the films was analysed using low-angle X-ray diffraction and film thickness measured by X-ray reflectivity. For films calcined at 350 °C, the incorporation of boron resulted in a reproducible oscillatory variation in the d-spacing and intensity of the primary reflection as a function of boron content. A clear peak was observed in the d-spacing at 5-10 mol% boron incorporation. For borosilicate films of a given composition an overall suppression of d-spacing was observed as a function of aging time relative to films that did not contain boron. This was ascribed to a slow condensation process. The films were irradiated in pile with neutrons and with iodine ions at energies of 180 keV and 70 MeV. Neutron irradiation of the silicate thin films for periods up to 30 days and aged for 400 days resulted in little reduction in either d-spacing or intensity of the primary low-angle X-ray reflection indicating that the films retained their mesopore ordering. In contrast borosilicate films for which the B (n, α) reaction was expected to result in enhanced displacement damage showed much larger variations in X-ray parameters. For these films short irradiation times resulted in a reduction of the d-spacing and intensity of the primary reflections considerably beyond that observed through aging. It is concluded that prolonged neutron irradiation and internal α irradiation have only a small, although measurable, impact on mesoporous borosilicate thin films increasing the degree of condensation and increasing unit cell contraction. When these borosilicate films were irradiated with iodine ions, more profound changes occurred. The pore ordering of the films was significantly degraded when low energy ions were used. In some cases the degree

  6. Volume changes in glass induced by an electron beam

    Czech Academy of Sciences Publication Activity Database

    Gavenda, T.; Gedeon, O.; Jurek, Karel

    2014-01-01

    Roč. 322, Mar (2014), s. 7-12 ISSN 0168-583X Institutional support: RVO:68378271 Keywords : borosilicate glass * electron irradiation * densification * alkali migration Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.124, year: 2014

  7. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D; Bradley Pickenheim, B

    2008-11-24

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  8. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    International Nuclear Information System (INIS)

    Adamson, D.; Pickenheim, Bradley

    2008-01-01

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  9. Structure and chemical durability of barium borosilicate glass–ceramics containing zirconolite and titanite crystalline phases

    International Nuclear Information System (INIS)

    Li, Huidong; Wu, Lang; Xu, Dong; Wang, Xin; Teng, Yuancheng; Li, Yuxiang

    2015-01-01

    In order to increase the solubility of actinides in the glass matrix, the effects of CaO, TiO 2 , and ZrSiO 4 addition (abbreviated as CTZ, in the mole ratio of 2:2:1) on crystalline phases, microstructure, and chemical durability of barium borosilicate glass–ceramics were investigated. The results show that the samples possess both zirconolite-2M and titanite phase when the CTZ content is greater than or equal to 45 wt.%. For the glass–ceramics with 45 wt.% CTZ (CTZ-45), only zirconolite-2M phase is observed after annealing at 680–740 °C for 2 h. The CTZ-45 possess zirconolite-2M and titanite phases after annealing at 700 °C first, and then annealing at 900–1050 °C for 2 h. Furthermore, the zirconolite-2M and titanite grains show a strip and brick shape, respectively. The CTZ-45 annealing at 950 °C shows the lower normalized leaching rates of B, Na and Nd when compared to that of CTZ-0 and CTZ-55. - Highlights: • CaO, TiO 2 , ZrSiO 4 (CTZ) as nucleating agents were added to barium borosilicate glass. • The samples with 45–55 wt% CTZ possess CaZrTi 2 O 7 -2M and CaTiSiO 5 crystalline phases. • CTZ-45 (45wt% CTZ) possesses only CaZrTi 2 O 7 -2M phase after annealing at 680–740 °C. • CTZ-45 possesses CaZrTi 2 O 7 -2M and CaTiSiO 5 phases after annealing at 900–1050 °C. • CTZ-45 annealing at 950 °C shows the lower leaching rates of B, Na and Nd than CTZ-0 and CTZ-55.

  10. Optimization of lanthanide borosilicate frit compositions for the immobilization of actinides using a Plackett-Burman/simplex algorithm design

    Energy Technology Data Exchange (ETDEWEB)

    Mesko, M.G. [Univ. of Missouri, Rolla, MO (United States); Meaker, T.F.; Ramsey, W.G.; Marra, J.C.; Peeler, D.K. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1997-12-31

    Immobilization by vitrification is one potential disposition option for a portion of the United States` excess plutonium inventory. Research has been performed at the Savannah River Site (SRS) to determine the optimum composition of a lanthanide borosilicate frit for the vitrification of plutonium using a Plackett-Burman design and simplex algorithm as a statistical tool. This technique uses various response variables to rank and optimize a composition. The variables used in this study correspond to homogeneity, durability, actinide solubility and devitrification after heat-treatment. The optimized frit composition was determined using a constant ThO{sub 2} loading of 20 wt%. No noticeable trends were followed with respect to the individual component which may indicate a relatively robust system able to accommodate variations in the feed. Batches containing various loadings of ThO{sub 2} were melted to determine if actinide solubility was improved in the optimized composition compared to that of a similar lanthanide borosilicate glass. No noticeable improvement in ThO{sub 2} solubility was realized as a result of using this optimization technique.

  11. Influence of Glass Property Restrictions on Hanford HLW Glass Volume

    International Nuclear Information System (INIS)

    Kim, Dong-Sang; Vienna, John D.

    2001-01-01

    A systematic evaluation of Hanford High-Level Waste (HLW) loading in alkali-alumino-borosilicate glasses was performed. The waste feed compositions used were obtained from current tank waste composition estimates, Hanford's baseline retrieval sequence, and pretreatment processes. The waste feeds were sorted into groups of like composition by cluster analysis. Glass composition optimization was performed on each cluster to meet property and composition constraints while maximizing waste loading. Glass properties were estimated using property models developed for Hanford HLW glasses. The impacts of many constraints on the volume of HLW glass to be produced at Hanford were evaluated. The liquidus temperature, melting temperature, chromium concentration, formation of multiple phases on cooling, and product consistency test response requirements for the glass were varied one- or many-at-a-time and the resultant glass volume was calculated. This study shows clearly that the allowance of crystalline phases in the glass melter can significantly decrease the volume of HLW glass to be produced at Hanford.

  12. Long-term leach rates of glasses containing actual waste

    International Nuclear Information System (INIS)

    Wiley, J.R.; LeRoy, J.H.

    1979-01-01

    Leach rates of borosilicate glasses that contained actual Savannah River Plant waste were measured. Leaching was done by water and by buffer solutions of pH 4, 7, and 9. Leach rates were then determined from the amount of 137 Cs, 90 Sr, and Pu released into the leach solutions. The cumulative fractions leached were fit to a mathematical model that included leaching by diffusion and glass dissolution

  13. A statistically designed matrix to evaluate solubility, impurity tolerance, and thermal stability of plutonium-bearing glasses

    International Nuclear Information System (INIS)

    Peeler, D.K.; Meaker, T.F.; Edwards, T.B.; McIntyre, D.S.

    1997-01-01

    In support of the Department of Energy's (DOE) Office of Fissile Material Disposition (OFDM) Program, Westinghouse Savannah River Company (WSRC) is evaluating a unique lanthanide borosilicate glass to immobilize excess plutonium and other heavy metals. The lanthanide borosilicate (LaBS) glass system met all FY96 programmatic planning objectives. Those objectives were focused on (1) demonstrating 10 wt% Pu solubility, and (2) meeting preliminary product performance criteria. Although 10 wt% Pu solubility was demonstrated with product performance exceeding high level waste glasses based on PCT results, the LaBS system was not optimized

  14. Aqueous corrosion of french R7T7 nuclear waste glass: selective then congruent dissolution by pH increase

    International Nuclear Information System (INIS)

    Advocat, T.; Vernaz, E.; Crovisier, J.L.

    1991-01-01

    A study of the corrosion of a borosilicate nuclear glass shows the strong effect of the pH on the dissolution mechanism. Acidic media lead to selective extraction of the glass modifier elements (Li, Na, Ca) as well as B, while dissolution is congruent under alkaline conditions. The silica dissolution rate significantly increases with increasing pH [fr

  15. Plutonium dioxide dissolution in glass

    Energy Technology Data Exchange (ETDEWEB)

    Vienna, J.D.; Alexander, D.L.; Li, Hong [and others

    1996-09-01

    In the aftermath of the Cold War, the U.S. Department of Energy`s (DOE) Office of Fissile Materials Disposition (OFMD) is charged with providing technical support for evaluation of disposition options for excess fissile materials manufactured for the nation`s defense. One option being considered for the disposition of excess plutonium (Pu) is immobilization by vitrification. The vitrification option entails immobilizing Pu in a host glass and waste package that are criticality-safe (immune to nuclear criticality), proliferation-resistant, and environmentally acceptable for long-term storage or disposal. To prove the technical and economic feasibility of candidate vitrification options it is necessary to demonstrate that PuO{sub 2} feedstock can be dissolved in glass in sufficient quantity. The OFMD immobilization program has set a Pu solubility goal of 10 wt% in glass. The life cycle cost of the vitrification options are strongly influenced by the rate at which PUO{sub 2} dissolves in glass. The total number of process lines needed for vitrification of 50 t of Pu in 10 years is directly dependent upon the time required for Pu dissolution in glass. The objective of this joint Pacific Northwest National Laboratory (PNNL) - Savannah River Technology Center (SRTC) study was to demonstrate a high Pu solubility in glass and to identify on a rough scale the time required for Pu dissolution in the glass. This study was conducted using a lanthanide borosilicate (LaBS) glass composition designed at the SRTC for the vitrification of actinides.

  16. Plutonium dioxide dissolution in glass

    International Nuclear Information System (INIS)

    Vienna, J.D.; Alexander, D.L.; Li, Hong

    1996-09-01

    In the aftermath of the Cold War, the U.S. Department of Energy's (DOE) Office of Fissile Materials Disposition (OFMD) is charged with providing technical support for evaluation of disposition options for excess fissile materials manufactured for the nation's defense. One option being considered for the disposition of excess plutonium (Pu) is immobilization by vitrification. The vitrification option entails immobilizing Pu in a host glass and waste package that are criticality-safe (immune to nuclear criticality), proliferation-resistant, and environmentally acceptable for long-term storage or disposal. To prove the technical and economic feasibility of candidate vitrification options it is necessary to demonstrate that PuO 2 feedstock can be dissolved in glass in sufficient quantity. The OFMD immobilization program has set a Pu solubility goal of 10 wt% in glass. The life cycle cost of the vitrification options are strongly influenced by the rate at which PUO 2 dissolves in glass. The total number of process lines needed for vitrification of 50 t of Pu in 10 years is directly dependent upon the time required for Pu dissolution in glass. The objective of this joint Pacific Northwest National Laboratory (PNNL) - Savannah River Technology Center (SRTC) study was to demonstrate a high Pu solubility in glass and to identify on a rough scale the time required for Pu dissolution in the glass. This study was conducted using a lanthanide borosilicate (LaBS) glass composition designed at the SRTC for the vitrification of actinides

  17. UK program: glasses and ceramics for immobilization of radioactive wastes for disposal

    International Nuclear Information System (INIS)

    Johnson, K.D.B.

    1979-01-01

    The UK Research Program on Radioactive Waste Management includes the development of processes for the conversion of high-level-liquid-reprocessing wastes from thermal and fast reactors to borosilicate glasses. The properties of these glasses and their behavior under storage and disposal conditions have been examined. Methods for immobilizing activity from other wastes by conversion to glass or ceramic forms are described. The UK philosophy of final solutions to waste management and disposal is presented

  18. The role of nuclear analytical techniques in the study of aqueous corrosion of glasses

    International Nuclear Information System (INIS)

    Trocellier, P.

    1984-01-01

    Direct observation of resonant nuclear reactions, backscattering spectrometry and X ray microanalysis with a nuclear microprobe were used to determine elementary depth profiles in the near surface region of leached glasses. Some computing programs required to interpretate the analytical information detected were built. Experimental conditions to characterize glass samples without secondary effects were defined; and the influence of some leaching parameters was studied to describe the first stages of aqueous corrosion of borosilicate glasses [fr

  19. Technical feasibility study for production of tailored multielectrode arrays and patterning of arranged neuronal networks.

    Science.gov (United States)

    Schürmann, Matthias; Shepheard, Norman; Frese, Natalie; Geishendorf, Kevin; Sudhoff, Holger; Gölzhäuser, Armin; Rückert, Ulrich; Kaltschmidt, Christian; Kaltschmidt, Barbara; Thomas, Andy

    2018-01-01

    In this manuscript, we first reveal a simple ultra violet laser lithographic method to design and produce plain tailored multielectrode arrays. Secondly, we use the same lithographic setup for surface patterning to enable controlled attachment of primary neuronal cells and help neurite guidance. For multielectrode array production, we used flat borosilicate glass directly structured with the laser lithography system. The multi layered electrode system consists of a layer of titanium coated with a layer of di-titanium nitride. Finally, these electrodes are covered with silicon nitride for insulation. The quality of the custom made multielectrode arrays was investigated by light microscopy, electron microscopy and X-ray diffraction. The performance was verified by the detection of action potentials of primary neurons. The electrical noise of the custom-made MEA was equal to commercially available multielectrode arrays. Additionally, we demonstrated that structured coating with poly lysine, obtained with the aid of the same lithographic system, could be used to attach and guide neurons to designed structures. The process of neuron attachment and neurite guidance was investigated by light microscopy and charged particle microscopy. Importantly, the utilization of the same lithographic system for MEA fabrication and poly lysine structuring will make it easy to align the architecture of the neuronal network to the arrangement of the MEA electrode.. In future studies, this will lead to multielectrode arrays, which are able to specifically attach neuronal cell bodies to their chemically defined electrodes and guide their neurites, gaining a controlled connectivity in the neuronal network. This type of multielectrode array would be able to precisely assign a signal to a certain neuron resulting in an efficient way for analyzing the maturation of the neuronal connectivity in small neuronal networks.

  20. Waste glass corrosion modeling: Comparison with experimental results

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1994-01-01

    Models for borosilicate glass dissolution must account for the processes of (1) kinetically-controlled network dissolution, (2) precipitation of secondary phases, (3) ion exchange, (4) rate-limiting diffusive transport of silica through a hydrous surface reaction layer, and (5) specific glass surface interactions with dissolved cations and anions. Current long-term corrosion models for borosilicate glass employ a rate equation consistent with transition state theory embodied in a geochemical reaction-path modeling program that calculates aqueous phase speciation and mineral precipitation/dissolution. These models are currently under development. Future experimental and modeling work to better quantify the rate-controlling processes and validate these models are necessary before the models can be used in repository performance assessment calculations

  1. Liquidus temperature and chemical durability of selected glasses to immobilize rare earth oxides waste

    Science.gov (United States)

    Mohd Fadzil, Syazwani; Hrma, Pavel; Schweiger, Michael J.; Riley, Brian J.

    2015-10-01

    Pyroprocessing is are processing method for managing and reusing used nuclear fuel (UNF) by dissolving it in an electrorefiner with a molten alkali or alkaline earth chloride salt mixture while avoiding wet reprocessing. Pyroprocessing UNF with a LiCl-KCl eutectic salt releases the fission products from the fuel and generates a variety of metallic and salt-based species, including rare earth (RE) chlorides. If the RE-chlorides are converted to oxides, borosilicate glass is a prime candidate for their immobilization because of its durability and ability to dissolve almost any RE waste component into the glass matrix at high loadings. Crystallization that occurs in waste glasses as the waste loading increases may complicate glass processing and affect the product quality. This work compares three types of borosilicate glasses in terms of liquidus temperature (TL): the International Simple Glass designed by the International Working Group, sodium borosilicate glass developed by Korea Hydro and Nuclear Power, and the lanthanide aluminoborosilicate (LABS) glass established in the United States. The LABS glass allows the highest waste loadings (over 50 mass% RE2O3) while possessing an acceptable chemical durability.

  2. Glass packages in interim storage

    International Nuclear Information System (INIS)

    Jacquet-Francillon, N.

    1994-10-01

    This report summarize the current state of knowledge concerning the behavior of type C waste packages consisting of vitrified high-level solutions produced by reprocessing spent fuel. The composition and the physical and chemical properties of the feed solutions are reviewed, and the vitrification process is described. Sodium alumino-borosilicate glass compositions are generally employed - the glass used at la Hague for LWR fuel solutions, for example, contains 45 % SiO 2 . The major physical, chemical, mechanical and thermal properties of the glass are reviewed. In order to allow their thermal power to diminish, the 3630 glass packages produced (as of January 1993) in the vitrification facilities at Marcoule and La Hague are placed in interim storage for several decades. The actual interim storage period has not been defined, as it is closely related to the concept and organization selected for the final destination of the packages: a geological repository. The glass behavior under irradiation is described. Considerable basic and applied research has been conducted to assess the aqueous leaching behavior of nuclear containment glass. The effects of various repository parameters (temperature, flow rate, nature of the environmental materials) have been investigated. The experimental findings have been used to specify a model describing the kinetics of aqueous corrosion of the glass. More generally all the ''source term'' models developed in France by the CEA or by ANDRA are summarized. (author). 152 refs., 33 figs

  3. Synthesis and characterization of acidic mesoporous borosilicate thin films.

    Science.gov (United States)

    Xiu, Tongping; Liu, Qian; Wang, Jiacheng

    2009-02-01

    Work on the synthesis and characterization of acidic wormhole-like ordered mesoporous borosilicate thin films (MBSTFs) on silicon wafers is described in this paper. The MBSTFs coated by the dip-coating method were prepared through an evaporation-induced self-assembly (EISA) process using nonionic block copolymers as structure-directing agents. Fourier transform infrared (FT-IR) spectroscopy confirmed the formation of borosiloxane bonds (Si-O-B). High-resolution transmission electron microscopy (HRTEM) and N2 sorption evidenced a wormhole-like mesoporous structure in the MBSTFs obtained. Scanning electron microscopy (SEM) images of the cross sections and surfaces of the samples showed that MBSTFs on silicon wafers were continuous, homogeneous and did not crack. The acidic properties of the MBSTFs were characterized by FT-IR spectra of chemisorbed pyridine. The MBSTFs thus prepared may find their future applications in many fields including chemical sensors, catalysis, optical coating, molecule separation, etc.

  4. Influence of iron ions on the structural properties of some inorganic glasses

    International Nuclear Information System (INIS)

    Music, S.; Gotic, M.; Popovic, S.; Grzeta, B.

    1987-01-01

    The effects of iron on the structural properties of Zn-borosilicate glass and Pb-metaphosphate glass were studied using x-ray diffraction, 57 Fe Moessbauer spectroscopy and IR spectroscopy. At high concentration of iron the crystallization of zinc ferrite in the glass matrix takes place. X-ray diffraction and 57 Fe Moessbauer spectroscopy showed that the amount of zinc ferrite in Zn-borosilicate glass decreases. In Pb-metaphosphate glass doped with high concentration of α-Fe 2 O 3 , the crystallization of Fe 3 (PO 4 ) 2 is pronounced. The assignments of IR band positions and the corresponding interpretation are given. The importance of this study for the technology of vitrification of high-level radioactive wastes is emphasized. (author) 31 refs.; 6 figs,.; 6 tabs

  5. Development of a new concept for controlling the thermal expansion of glass ceramic composites with tailored flowability demonstrated on the example high-temperature fuel cells; Entwicklung eines neuen Konzepts zur Steuerung der thermischen Ausdehnung von glaskeramischen Verbundwerkstoffen mit angepasster Fliessfaehigkeit am Beispiel der Hochtemperatur-Brennstoffzelle

    Energy Technology Data Exchange (ETDEWEB)

    Wanko, Eric

    2011-09-26

    In the joining technology, composite materials based on glass, glass ceramics (GC) and glass ceramic composites (GCC) become more and more important. Due to the increasingly required multi-functionality of the sealant material (for e.g. coefficient of expansion, flow ability, etc..), the developed sealant material used today is based on glass ceramic composites. With these, a good adhesion of the joining components, a good flow ability of the sealant material during the joining process and a good electrical insulation and mechanical strength have to be achieved. The joining process has to take place at temperatures < 900 C. The operation conditions of the SOFC are: 600 - 800 C under oxidizing as well as reducing atmospheric conditions. The present Thesis shows that, based on the use of database and thermochemical methods, sealing materials can be swiftly adjusted to all process and operation requirements. In order to do this especially, with regards of the thermo-mechanical properties of the developed sealant material (coefficient of expansion and flow ability) during the joining process, a new concept has been designed. Joining tests have been achieved on sandwich samples. The starting point of this new concept is a metal/glass matrix composite where the coefficient of expansion was controlled by dispersing a metal phase in the glass matrix. The newly developed concept is based on glass as a matrix and a crystalline phase as a filler material. It is essential that the crystalline phase and the glass matrix composition consist of the same thermodynamic co-existence area of the selected oxide base system. Here, the glass matrix has a lower liquidus temperature compared to the crystalline filler material, while the crystalline phase which consist of a higher coefficient of expansion is used alone to tailor the coefficient of expansion of the joining material. By incorporating a single crystalline phase into the selected glass matrix, the coefficient of expansion of

  6. sup 1 sup 1 B nutation NMR study of powdered borosilicates

    CERN Document Server

    Woo, A J; Han, D Y

    1998-01-01

    In this work, we applied the 1D sup 1 sup 1 B nutation NMR method for the analysis of the local structural environments in powdered borosilicates (SiO sub 2 -B sub 2 O sub 3). Spin dynamics during a rf irradiation for spin I=3/2 was analytically calculated with a density matrix formalism. Spectral simulation programs were written in MATLAB on a PC. Two borosilicates prepared by the sol-gel process at different stabilization temperature were used for the 1D sup 1 sup 1 B nutation NMR experiment. The sup 1 sup 1 B NMR parameters, quadrupole coupling constants (e sup 2 qQ/h) and asymmetry parameters (eta), for each borosilicate were extracted from the nonlinear least-squares fitting. The effects of heat treatments on the local structures of boron sites in borosilicates were discussed.

  7. Control of high-level radioactive waste-glass melters

    International Nuclear Information System (INIS)

    Bickford, D.F.; Coleman, C.J.

    1990-01-01

    The Defense Waste Processing Facility (DWPF) will immobilize Savannah River Site High Level Waste as a durable borosilicate glass for permanent disposal in a repository. The DWPF will be controlled based on glass composition. The following discussion is a preliminary analysis of the capability of the laboratory methods that can be used to control the glass composition, and the relationships between glass durability and glass properties important to glass melting. The glass durability and processing properties will be controlled by controlling the chemical composition of the glass. The glass composition will be controlled by control of the melter feed transferred from the Slurry Mix Evaporator (SME) to the Melter Feed Tank (MFT). During cold runs, tests will be conducted to demonstrate the chemical equivalence of glass sampled from the pour stream and glass removed from cooled canisters. In similar tests, the compositions of glass produced from slurries sampled from the SME and MFT will be compared to final product glass to determine the statistical relationships between melter feed and glass product. The total error is the combination of those associated with homogeneity in the SME or MFT, sampling, preparation of samples for analysis, instrument calibration, analysis, and the composition/property model. This study investigated the sensitivity of estimation of property data to the combination of variations from sampling through analysis. In this or a similar manner, the need for routine glass product sampling will be minimized, and glass product characteristics will be assured before the melter feed is committed to the melter

  8. Comparison of costs for solidification of high-level radioactive waste solutions: glass monoliths vs metal matrices

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, L.J.; Carlton, R.E.; Steindler, M.J.

    1981-05-01

    A comparative economic analysis was made of four solidification processes for liquid high-level radioactive waste. Two processes produced borosilicate glass monoliths and two others produced metal matrix composites of lead and borosilicate glass beads and lead and supercalcine pellets. Within the uncertainties of the cost (1979 dollars) estimates, the cost of the four processes was about the same, with the major cost component being the cost of the primary building structure. Equipment costs and operating and maintenance costs formed only a small portion of the building structure costs for all processes.

  9. High-frequency characteristics of glass/ceramic composite and alumina multilayer structures

    International Nuclear Information System (INIS)

    Niwa, K.; Suzuki, H.; Yokoyama, H.; Kamechara, N.; Tsubone, K.; Tanisawa, H.; Sugiki, H.

    1990-01-01

    This paper reports the transmission characteristics of glass/ceramic composite (borosilicate glass/alumina) and alumina multilayer structures examined. The triplate stripline formed in the glass/ceramic multilayer shows low conductor and dielectric loss. Alumina multilayer, however, has twice the transmission loss at 10 GHz, because the resistivity of W in the alumina multilayer is higher than the Cu in the glass/ceramic multilayer. Crosstalk between striplines in the glass/ceramics is less than -80 dB up to 11 GHz and 9 GHz for alumina

  10. Initial Examination of Low Velocity Sphere Impact of Glass Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Ferber, Mattison K [ORNL

    2012-06-01

    This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) sphere impact testing of two materials from the lithium aluminosilicate family reinforced with different amounts of ceramic particulate, i.e., glass-ceramic materials, SCHOTT Resistan{trademark}-G1 and SCHOTT Resistan{trademark}-L. Both materials are provided by SCHOTT Glass (Duryea, PA). This work is a follow-up to similar sphere impact studies completed by the authors on PPG's Starphire{reg_sign} soda-lime silicate glass and SCHOTT BOROFLOAT{reg_sign} borosilicate glass. A gas gun or a sphere-drop test setup was used to produce controlled velocity delivery of silicon nitride (Si{sub 3}N{sub 4}) spheres against the glass ceramic tile targets. Minimum impact velocities to initiate fracture in the glass-ceramics were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between sphere and target material. Quasistatic spherical indentation was also performed on both glass ceramics and their contact damage responses were compared to those of soda-lime silicate and borosilicate glasses. Lastly, variability of contact damage response was assessed by performing spherical indentation testing across the area of an entire glass ceramic tile. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Resistan{trademark}-L glass ceramic required the highest velocity of sphere impact for damage to initiate. Starphire{reg_sign} soda-lime silicate glass was second best, then Resistan{trademark}-G1 glass ceramic, and then BOROFLOAT{reg_sign} borosilicate glass. (2) Glass-ceramic Resistan{trademark}-L also required the largest force to initiate ring crack from quasi-static indentation. That ranking was followed, in descending order, by Starphire{reg_sign} soda-lime silicate glass, Resistan{trademark}-G1 glass ceramic, and BOROFLOAT{reg_sign} borosilicate glass

  11. Decontamination processes for waste glass canisters

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1982-01-01

    A Defense Waste Processing Facility (DWPF) is currently being designed to convert Savannah River Plant liquid, high-level radioactive waste into a solid form, such as borosilicate glass. To prevent the spread of radioactivity, the outside of the canisters of waste glass must have very low levels of smearable radioactive contamination before they are removed from the DWPF. Several techniques were considered for canister decontamination: high-pressure water spray, electropolishing, chemical dissolution, and abrasive blasting. An abrasive blasting technique using a glass frit slurry has been selected for use in the DWPF. No additional equipment is needed to process waste generated from decontamination. Frit used as the abrasive will be mixed with the waste and fed to the glass melter. In contrast, chemical and electrochemical techniques require more space in the DWPF, and produce large amounts of contaminated by-products, which are difficult to immobilize by vitrification

  12. Tailored ceramics. Chapter 5

    International Nuclear Information System (INIS)

    Haker, A.B.

    1988-01-01

    In the light of the broad variation in US high-level waste (HLW) types and the uncertainties in future waste production, research on the Rockwell International Science Center has focussed on developing a generic technology for the consolidation of high-level wastes into polyphase ceramics. The basic approach has been to 'tailor' wste compositions with chemical additives so that upon consolidation a dense ceramic assemblage is formed that chemically binds the waste species into known phases. This chapter deals with tailored ceramics for current and future high-level waste compositions. Section 2 gives a historical review of the development of tailored ceramics. Section 3 deals with tailored ceramics designed for specific HLW compositions and with microstructure and phase development. Section 4 discusses chemical and physical properties of tailored ceramic waste forms. In section 5 the various processing steps involved in converting HLW to polycrystalline ceramic forms are described. (author). 159 refs.; 20 figs.; 14 tabs

  13. Selective adsorption and release of cationic organic dye molecules on mesoporous borosilicates

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Manidipa; Pal, Nabanita; Bhaumik, Asim, E-mail: msab@iacs.res.in

    2012-08-01

    Mesoporous materials can play a pivotal role as a host material for delivery application to a specific part of a system. In this work we explore the selective adsorption and release of cationic organic dye molecules such as safranine T (ST) and malachite green (MG) on mesoporous borosilicate materials. The mesoporous silica SBA-15 and borosilicate materials (MBS) were prepared using non-ionic surfactant Pluronic P123 as template via evaporation induced self-assembly (EISA) method. After template removal the materials show high surface areas and in some cases ordered mesopores of dimensions ca. 6-7 nm. High surface area, mesoporosity and the presence of heteroatom (boron) help this mesoporous borosilicate material to adsorb high amount of cationic dye molecules at its surface from the respective aqueous solutions. Furthermore, the mesoporous borosilicate samples containing higher percentage adsorbed dyes show excellent release of ST or MG dye in simulated body fluid (SBF) solution at physiological pH = 7.4 and temperature 310 K. The adsorption and release efficiency of mesoporous borosilicate samples are compared with reference boron-free mesoporous pure silica material to understand the nature of adsorbate-adsorbent interaction at the surfaces. - Graphical abstract: Highly ordered 2D-hexagonal mesoporous borosilicate materials have been synthesized by using Pluronic P123 as template. The materials show very good adsorption and release of organic cationic dye molecules under physiological conditions. Highlights: Black-Right-Pointing-Pointer Highly ordered 2D-hexagonal mesoporous borosilicate. Black-Right-Pointing-Pointer Nonionic Pluoronic P123 templated mesoporous material. Black-Right-Pointing-Pointer Adsorption of organic dyes at the mesopore surface. Black-Right-Pointing-Pointer Controlled release of dyes under physiological pH and temperature. Black-Right-Pointing-Pointer Release of safranine T (ST) and malachite green (MG) dyes in simulated body fluids.

  14. Glass formulation for phase 1 high-level waste vitrification

    International Nuclear Information System (INIS)

    Vienna, J.D.; Hrma, P.R.

    1996-04-01

    The purpose of this study is to provide potential glass formulations for prospective Phase 1 High-Level Waste (HLW) vitrification at Hanford. The results reported here will be used to aid in developing a Phase 1 HLW vitrification request for proposal (RFP) and facilitate the evaluation of ensuing proposals. The following factors were considered in the glass formulation effort: impact on total glass volume of requiring the vendor to process each of the tank compositions independently versus as a blend; effects of imposing typical values of B 2 O 3 content and waste loading in HLW borosilicate glasses as restrictions on the vendors (according to WAPS 1995, the typical values are 5--10 wt% B 2 O 3 and 20--40 wt% waste oxide loading); impacts of restricting the processing temperature to 1,150 C on eventual glass volume; and effects of caustic washing on any of the selected tank wastes relative to glass volume

  15. High-temperature glasses for nuclear waste isolation

    Energy Technology Data Exchange (ETDEWEB)

    Bunnell, L.R.; Maupin, G.D.; Oma, K.H.

    1986-03-01

    As part of the effort to discover and evaluate viable second-generation waste forms, glasses with processing temperatures higher than the 1100 to 1200/sup 0/C used for reference borosilicate glasses are being examined. This approach allows the use of previously developed technology for producing nuclear waste glasses, with a few modifications. Low alkali high alumina-boron glasses processed at 1400/sup 0/C and containing 25 wt % simulated reprocessed commercial nuclear waste have been fabricated and evaluated for chemical durability. These glasses exhibited matrix dissolution rates at 90/sup 0/C in deionized water that are at least an order of magnitude lower than current reference glass compositions over a wide range of flow conditions. 6 refs., 5 figs.

  16. Conversion of ion-exchange resins, catalysts and sludges to glass with optional noble metal recovery using the GMODS process

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Beahm, E.C.

    1996-01-01

    Chemical processing and cleanup of waste streams (air and water) typically result in products, clean air, clean water, and concentrated hazardous residues (ion exchange resins, catalysts, sludges, etc.). Typically, these streams contain significant quantities of complex organics. For disposal, it is desirable to destroy the organics and immobilize any heavy metals or radioactive components into stable waste forms. If there are noble metals in the residues, it is desirable to recover these for reuse. The Glass Material Oxidation and Dissolution System (GMODS) is a new process that directly converts radioactive and hazardous chemical wastes to borosilicate glass. GMODS oxidizes organics with the residue converted to glass; converts metals, ceramics, and amorphous solids to glass; converts halides (eg chlorides) to borosilicate glass and a secondary sodium halide stream; and recovers noble metals. GMODS has been demonstrated on a small laboratory scale (hundreds of grams), and the equipment needed for larger masses has been identified

  17. Tailored Porous Materials

    Energy Technology Data Exchange (ETDEWEB)

    BARTON,THOMAS J.; BULL,LUCY M.; KLEMPERER,WALTER G.; LOY,DOUGLAS A.; MCENANEY,BRIAN; MISONO,MAKOTO; MONSON,PETER A.; PEZ,GUIDO; SCHERER,GEORGE W.; VARTULI,JAMES C.; YAGHI,OMAR M.

    1999-11-09

    Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol-gel derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

  18. Reduction of Glass Surface Reflectance by Ion Beam Surface Modification

    Energy Technology Data Exchange (ETDEWEB)

    Mark Spitzer

    2011-03-11

    This is the final report for DOE contract DE-EE0000590. The purpose of this work was to determine the feasibility of the reduction of the reflection from the front of solar photovoltaic modules. Reflection accounts for a power loss of approximately 4%. A solar module having an area of one square meter with an energy conversion efficiency of 18% generates approximately 180 watts. If reflection loss can be eliminated, the power output can be increased to 187 watts. Since conventional thin-film anti-reflection coatings do not have sufficient environmental stability, we investigated the feasibility of ion beam modification of the glass surface to obtain reduction of reflectance. Our findings are generally applicable to all solar modules that use glass encapsulation, as well as commercial float glass used in windows and other applications. Ion implantation of argon, fluorine, and xenon into commercial low-iron soda lime float glass, standard float glass, and borosilicate glass was studied by implantation, annealing, and measurement of reflectance. The three ions all affected reflectance. The most significant change was obtained by argon implantation into both low-iron and standard soda-lime glass. In this way samples were formed with reflectance lower than can be obtained with a single-layer coatings of magnesium fluoride. Integrated reflectance was reduced from 4% to 1% in low-iron soda lime glass typical of the glass used in solar modules. The reduction of reflectance of borosilicate glass was not as large; however borosilicate glass is not typically used in flat plate solar modules. Unlike conventional semiconductor ion implantation doping, glass reflectance reduction was found to be tolerant to large variations in implant dose, meaning that the process does not require high dopant uniformity. Additionally, glass implantation does not require mass analysis. Simple, high current ion implantation equipment can be developed for this process; however, before the process

  19. Er 3–Al2O3 nanoparticles doping of borosilicate glass

    Indian Academy of Sciences (India)

    2O3 nanoparticles synthetized by using a soft chemical method. A similar nanoparticle doping with modified chemical vapour deposition (MCVD) process was developed to increase the efficiency of the amplifying silica fibre in comparison to ...

  20. Er –Al2O3 nanoparticles doping of borosilicate glass

    Indian Academy of Sciences (India)

    Administrator

    1Tampere University of Technology, Department of Electronics and Communications Engineering,. Korkeakoulunkatu 3, FI-33720 Tampere, Finland. 2Johan Gadolin Process Chemistry ..... The Finnish. Funding Agency for Technology and Innovation. (TEKES) is acknowledged by nLIGHT for financial support. References.

  1. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Techer, I

    1999-07-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  2. Aluminum elution and precipitation in glass vials: effect of pH and buffer species.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2015-02-01

    Inorganic extractables from glass vials may cause particle formation in the drug solution. In this study, the ability of eluting Al ion from borosilicate glass vials, and tendencies of precipitation containing Al were investigated using various pHs of phosphate, citrate, acetate and histidine buffer. Through heating, all of the buffers showed that Si and Al were eluted from glass vials in ratios almost the same as the composition of borosilicate glass, and the amounts of Al and Si from various buffer solutions at pH 7 were in the following order: citrate > phosphate > acetate > histidine. In addition, during storage after heating, the Al concentration at certain pHs of phosphate and acetate buffer solution decreased, suggesting the formation of particles containing Al. In citrate buffer, Al did not decrease in spite of the high elution amount. Considering that the solubility profile of aluminum oxide and the Al eluting profile of borosilicate glass were different, it is speculated that Al ion may be forced to leach into the buffer solution according to Si elution on the surface of glass vials. When Al ions were added to the buffer solutions, phosphate, acetate and histidine buffer showed a decrease of Al concentration during storage at a neutral range of pHs, indicating the formation of particles containing Al. In conclusion, it is suggested that phosphate buffer solution has higher possibility of forming particles containing Al than other buffer solutions.

  3. A critical study on borosilicate glassware and silica-based QMA's in nucleophilic substitution with [18F]fluoride: influence of aluminum, boron and silicon on the reactivity of [18F]fluoride.

    Science.gov (United States)

    Svadberg, A; Clarke, A; Dyrstad, K; Martinsen, I; Hjelstuen, O K

    2011-02-01

    Leachables of borosilicate glassware and silica-based anion exchange columns (QMAs) may influence nucleophilic substitution with [(18)F]fluoride ([(18)F]F(-)). Aluminum, boron and silicon, all constituents of borosilicate glass, were found as water soluble leachables in a typical PET synthesis setup. Relevant ranges of the leachable quantities were studied based on an experimental design, in which species of the three elements were added to the labeling of the precursor for anti-1-amino-3-[(18)F]fluorocyclobutyl-1-carboxylic acid ([(18)F]FACBC). Levels of 0.4-2 ppm aluminum as AlCl(3) had a strong negative influence on labeling yield while 4-20 ppm of boron as KBO(2) and 50-250 ppm of silicon as Na(2)SiO(3) did not have a significant impact. Interesting interaction effects between the elements were observed, where particularly KBO(2) reduced the negative effect of AlCl(3) on labeling yield. It can be concluded that leachables of borosilicate glassware easily can influence nucleophilic substitution with n.c.a. [(18)F]F(-) and give variable yields. Copyright © 2010. Published by Elsevier Ltd.

  4. A critical study on borosilicate glassware and silica-based QMA's in nucleophilic substitution with [{sup 18}F]fluoride: influence of aluminum, boron and silicon on the reactivity of [{sup 18}F]fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Svadberg, A., E-mail: anders.svadberg@uit.n [University of Tromso, Institute of Pharmacy, Department of Pharmaceutics and Biopharmaceutics, N-9037 Tromso (Norway); Clarke, A.; Dyrstad, K.; Martinsen, I. [GE Healthcare MDx R and D, Nycoveien 2, NO-0401 Oslo (Norway); Hjelstuen, O.K. [University of Tromso, Institute of Pharmacy, Department of Pharmaceutics and Biopharmaceutics, N-9037 Tromso (Norway); GE Healthcare MDx R and D, Nycoveien 2, NO-0401 Oslo (Norway)

    2011-02-15

    Leachables of borosilicate glassware and silica-based anion exchange columns (QMAs) may influence nucleophilic substitution with [{sup 18}F]fluoride ([{sup 18}F]F{sup -}). Aluminum, boron and silicon, all constituents of borosilicate glass, were found as water soluble leachables in a typical PET synthesis setup. Relevant ranges of the leachable quantities were studied based on an experimental design, in which species of the three elements were added to the labeling of the precursor for anti-1-amino-3-[{sup 18}F]fluorocyclobutyl-1-carboxylic acid ([{sup 18}F]FACBC). Levels of 0.4-2 ppm aluminum as AlCl{sub 3} had a strong negative influence on labeling yield while 4-20 ppm of boron as KBO{sub 2} and 50-250 ppm of silicon as Na{sub 2}SiO{sub 3} did not have a significant impact. Interesting interaction effects between the elements were observed, where particularly KBO{sub 2} reduced the negative effect of AlCl{sub 3} on labeling yield. It can be concluded that leachables of borosilicate glassware easily can influence nucleophilic substitution with n.c.a. [{sup 18}F]F{sup -} and give variable yields.

  5. The effect of chromium oxide on the properties of simulated nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vojtech, O.; Sussmilch, J.; Urbanec, Z. [and others

    1996-02-01

    A study of the effect of chromium on the properties of selected glasses was performed in the frame of a Contract between Battelle, Pacific Northwest Laboratories and Nuclear Research Institute, ReZ. In the period from July 1994 to June 1995 two borosilicate glasses of special composition were prepared according to the PNL procedure and their physical and structural characteristics of glasses were studied. This Final Report contains a vast documentation on the properties of all glasses studied. For the preparation of the respective technology more detailed study of physico-chemical properties and crystallinity of investigated systems would be desirable.

  6. Oxidation behaviour of metallic glass foams

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, B.R. [Department of Materials Science and Engineering, 434 Dougherty Hall, University of Tennessee, Knoxville, TN 37996-2200 (United States)], E-mail: bbarnard@utk.edu; Liaw, P.K. [Department of Materials Science and Engineering, 434 Dougherty Hall, University of Tennessee, Knoxville, TN 37996-2200 (United States); Demetriou, M.D.; Johnson, W.L. [Department of Materials Science, Keck Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

    2008-08-15

    In this study, the effects of porosity on the oxidation behaviour of bulk-metallic glasses were investigated. Porous Pd- and Fe-based bulk-metallic glass (BMG) foams and Metglas ribbons were studied. Oxidizing experiments were conducted at 70 deg. C, and around 80 deg. C below glass-transition temperatures, (T{sub g}s). Scanning-electron microscopy/energy-dispersive spectroscopy (SEM/EDS) studies revealed little evidence of oxidation at 70 deg. C. Specimens exhibited greater oxidation at T{sub g} - 80 deg. C. Oxides were copper-based for Pd-based foams, Fe-, Cr-, and Mo-based for Fe-based foams, and Co-based with borosilicates likely for the Metglas. Pd-based foams demonstrated the best oxidation resistance, followed by Metglas ribbons, followed by Fe-based foams.

  7. Natural analogue study of volcanic glass

    International Nuclear Information System (INIS)

    Arai, T.; Yusa, Y.; Sasaki, N.; Tsunoda, N.; Takano, H.

    1989-02-01

    A considerable range in alteration rates of basaltic glasses in various environments has been reported in previous studies. However, these studies paid only cursory attention to the environmental conditions under which the glass had been altered. In this study, the alteration of basaltic glasses was investigated and the environmental conditions and the alteration rate were discussed. Two sample ages were represented: 280 years and 2800 years. Basaltic glasses and their alteration layers were analyzed by electron probe microanalyzer (EMPA) and the thickness of the alteration layers were measured by scanning electron microscope (SEM). The ground water collected near the sampling point of Zunazawa Scoria (2800 years) and the pore water of both samples were analyzed. The alteration temperature and flow rate of water are estimated to be about 13degC and 0.2 l/cm 2 /y respectively on the basis of meteorological data. The alteration layers of young aged basaltic glasses in freshwater conditions are similar to those of leached borosilicate glasses. The alteration rates of these basaltic glasses are estimated to be several μm/1000y. The elemental concentrations in the ground water can be roughly explained as the result of leaching of the glasses. (author)

  8. Effect of Uniformly and Nonuniformly Coated Al2O3 Nanoparticles over Glass Tube Heater on Pool Boiling

    Directory of Open Access Journals (Sweden)

    Nitin Doifode

    2016-01-01

    Full Text Available Effect of uniformly and nonuniformly coated Al2O3 nanoparticles over plain glass tube heater on pool boiling heat transfer was studied experimentally. A borosilicate glass tube coated with Al2O3 nanoparticle was used as test heater. The boiling behaviour was studied by using high speed camera. Result obtained for pool boiling shows enhancement in heat transfer for nanoparticle coated surface heater and compared with plain glass tube heater. Also heat transfer coefficient for nonuniformly coated nanoparticles was studied and compared with uniformly coated and plain glass tube. Coating effect of nanoparticles over glass tube increases its surface roughness and thereby creates more nucleation sites.

  9. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    Science.gov (United States)

    Boatner, Lynn A.; Sales, Brian C.

    1989-01-01

    Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

  10. Evolution of mechanical properties of silicate glasses: Impact of the chemical composition and effects of irradiation

    International Nuclear Information System (INIS)

    Barlet, Marina

    2014-01-01

    This thesis examines: (1) how the chemical composition changes the hardness, toughness, and stress corrosion cracking behavior in model pristine and (2) how external irradiation impact these properties. It is to be incorporated in the context of the storage of nuclear waste in borosilicate glass matrix, the structural integrity of which should be assessed. Eight simplified borosilicate glasses made of 3 oxides with modulated proportions (SiO 2 -B 2 O 3 -Na 2 O (SBN) have been selected and their hardness, toughness, and stress corrosion cracking behavior have been characterized prior and after irradiation. The comparative study of the non-irradiated SBN glasses provides the role played by the chemical composition. The sodium content is found to be the key parameter: As it increases, the glass plasticity increases, leading to changes in the mechanical response to strain. Hardness (Hv) and toughness (Kc) decrease since the flow under indenter increases. The analysis of the stress corrosion behavior evidences a clear shift of the SCC curves linked also to the glass plasticity. Four of the 8 simplified SBN glass systems highlight the influence of electron, light and heavy ions irradiations on the mechanical properties. Once again, the sodium content is a key parameter. It is found to inhibit the glass modification: Glasses with high sodium content are more stable. Ions irradiations highlight the predominant role of nuclear interaction in changing the glass properties. Finally, electronic interaction induced by helium and electron irradiation does not lead to the same structural/mechanical glasses variations. (author) [fr

  11. Simulation of Self-Irradiation of High-Sodium Content Nuclear Waste Glasses

    International Nuclear Information System (INIS)

    Pankov, Alexey S.; Ojovan, Michael I.; Batyukhnova, Olga G.; Lee, William E.

    2007-01-01

    Alkali-borosilicate glasses are widely used in nuclear industry as a matrix for immobilisation of hazardous radioactive wastes. Durability or corrosion resistance of these glasses is one of key parameters in waste storage and disposal safety. It is influenced by many factors such as composition of glass and surrounding media, temperature, time and so on. As these glasses contain radioactive elements most of their properties including corrosion resistance are also impacted by self-irradiation. The effect of external gamma-irradiation on the short-term (up to 27 days) dissolution of waste borosilicate glasses at moderate temperatures (30 deg. to 60 deg. C) was studied. The glasses studied were Magnox Waste glass used for immobilisation of HLW in UK, and K-26 glass used in Russia for ILW immobilisation. Glass samples were irradiated under γ-source (Co-60) up to doses 1 and 11 MGy. Normalised rates of elemental release and activation energy of release were measured for Na, Li, Ca, Mg, B, Si and Mo before and after irradiation. Irradiation up to 1 MGy results in increase of leaching rate of almost all elements from both MW and K-26 with the exception of Na release from MW glass. Further irradiation up to a dose of 11 MGy leads to the decrease of elemental release rates to nearly initial value. Another effect of irradiation is increase of activation energies of elemental release. (authors)

  12. Sulphate solubility and sulphate diffusion in oxide glasses: implications for the containment of sulphate-bearing nuclear wastes

    International Nuclear Information System (INIS)

    Lenoir, M.

    2009-09-01

    The thesis deals with sulphate solubility and sulphate diffusion in oxide glasses, in order to control sulphate incorporation and sulphate volatilization in nuclear waste glasses. It was conducted on simplified compositions, in the SiO 2 -B 2 O 3 -R 2 O (R = Li, Na, K, Cs), SiO 2 -B 2 O 3 -BaO and V 2 O 5 -B 2 O 3 -BaO systems. These compositions allowed us to study the influence of the nature of network-modifying ions (Li + , Na + , K + , Cs + or Ba 2+ ) and also of former elements (Si, B, V), on structure and properties of glasses. Sulphate volatility is studied in sodium borosilicate melts using an innovative technique of sulphate quantitation with Raman spectroscopy. This technique is useful to obtain kinetic curves of sulphate volatilization. The establishment of a model to fit these curves leads to the determination of diffusion coefficients of sulphate. These diffusion coefficients can thus be compared to diffusion coefficients of other species, determined by other techniques and presented in the literature. They are also linked to diffusion coefficients in relation with the viscosity of the melts. Concerning sulphate solubility in glasses, it depends on glass composition and on the nature of sulphate incorporated. Sulphate incorporation in alkali borosilicate glasses leads to the formation of a sulphate layer floating on top of the melt. Sulphate incorporation in barium borosilicate and boro-vanadate glasses leads to the crystallization of sulphate species inside the vitreous matrix. Moreover, sulphate solubility is higher in these glasses than in alkali borosilicates. Finally, exchanges between cations present in glasses and cations present in the sulphate phase are also studied. (author)

  13. Iron Phosphate Glasses: An Alternative for Vitrifying Certain Nuclear Wastes

    International Nuclear Information System (INIS)

    Day, Delbert E.; Ray, Chandra S.; Cheol-Woon Kim

    2004-01-01

    Vitrification of nuclear waste in a glass is currently the preferred process for waste disposal. DOE currently approves only borosilicate (BS) type glasses for such purposes. However, many nuclear wastes, presently awaiting disposal, have complex and diverse chemical compositions, and often contain components that are poorly soluble or chemically incompatible in BS glasses. Such problematic wastes can be pre-processed and/or diluted to compensate for their incompatibility with a BS glass matrix, but both of these solutions increases the wasteform volume and the overall cost for vitrification. Direct vitrification using alternative glasses that utilize the major components already present in the waste is preferable, since it avoids pre-treating or diluting the waste, and, thus, minimizes the wasteform volume and overall cost

  14. Devitrification of defense nuclear waste glasses: role of melt insolubles

    International Nuclear Information System (INIS)

    Bickford, D.F.; Jantzen, C.M.

    1985-01-01

    Time-temperature-transformation (TTT) curves have been determined for simulated nuclear waste glasses bounding the compositional range in the Defense Waste Processing Facility (DWPF). Formulations include all of the minor chemical elements such as ruthenium and chromium which have limited solubility in borosilicate glasses. Heterogeneous nucleation of spinel on ruthenium dioxide, and subsequent nucleation of acmite on spinel is the major devitrification path. Heterogeneous nucleation on melt insolubles causes more rapid growth of crystalline devitrification phases, than in glass free of melt insolubles. These studies point out the importance of simulating waste glass composition and processing as accurately as possible to obtain reliable estimates of glass performance. 11 refs., 8 figs., 1 tab

  15. Iron Phosphate Glasses: An Alternative for Vitrifying Certain Nuclear Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Delbert E. Day; Chandra S. Ray; Cheol-Woon Kim

    2004-12-28

    Vitrification of nuclear waste in a glass is currently the preferred process for waste disposal. DOE currently approves only borosilicate (BS) type glasses for such purposes. However, many nuclear wastes, presently awaiting disposal, have complex and diverse chemical compositions, and often contain components that are poorly soluble or chemically incompatible in BS glasses. Such problematic wastes can be pre-processed and/or diluted to compensate for their incompatibility with a BS glass matrix, but both of these solutions increases the wasteform volume and the overall cost for vitrification. Direct vitrification using alternative glasses that utilize the major components already present in the waste is preferable, since it avoids pre-treating or diluting the waste, and, thus, minimizes the wasteform volume and overall cost.

  16. Optical waveguides in magneto-optical glasses fabricated by proton implantation

    Science.gov (United States)

    Liu, Chun-Xiao; Li, Yu-Wen; Zheng, Rui-Lin; Fu, Li-Li; Zhang, Liao-Lin; Guo, Hai-Tao; Zhou, Zhi-Guang; Li, Wei-Nan; Lin, She-Bao; Wei, Wei

    2016-11-01

    Planar waveguides in magneto-optical glasses (Tb3+-doped aluminum borosilicate glasses) have been produced by a 550-keV proton implantation at a dose of 4.0×1016 ions/cm2 for the first time to our knowledge. After annealing at 260 °C for 1.0 h, the dark-mode spectra and near-field intensity distributions are measured by the prism-coupling and end-face coupling methods. The damage profile, refractive index distribution and light propagation mode of the planar waveguide are numerically calculated by SRIM 2010, RCM and FD-BPM, respectively. The effects of implantation on the structural and optical properties are investigated by Raman and absorption spectra. It suggests that the proton-implanted Tb3+-doped aluminum borosilicate glass waveguide is a good candidate for a waveguide isolator in optical fiber communication and all-optical communication.

  17. Gas microstrip detectors on polymer, silicon and glass substrates

    International Nuclear Information System (INIS)

    Barasch, E.F.; Demroff, H.P.; Drew, M.M.; Elliott, T.S.; Gaedke, R.M.; Goss, L.T.; Kasprowicz, T.B.; Lee, B.; Mazumdar, T.K.; McIntyre, P.M.; Pang, Y.; Smith, D.D.; Trost, H.J.; Vanstraelen, G.; Wahl, J.

    1993-01-01

    We present results on the performance of Gas Microstrip Detectors on various substrates. These include a 300 μm anode-anode pitch pattern on Tempax borosilicate glass and ABS/copolyether, a 200 μm pattern on Upilex ''S'' polyimide, Texin 4215, Tedlar, ion-implanted Kapton, orientation-dependent etched flat-topped silicon (''knife-edge chamber''), and iron-vanadium glass, and a 100 μm pitch pattern on Upilex ''S'' and ion-implanted Kapton. (orig.)

  18. Crystallization study of a glass used for fission product storage

    International Nuclear Information System (INIS)

    Morlevat, J.-P.; Uny, Gisele; Jacquet-Francillon, Noel.

    1981-06-01

    The vitreous matrix used in France is a borosilicate glass of low melting point allowing introduction of volatil fission products and of good chemical stability. However, like any glass, if storage temperature is higher than transformation temperature a partial crystallization can occur. Before final storage, it is important to determine of leaching by water eventually occuring on the choosen site is modified by crystalline phases. The aim of this study is the determination of the leaching rate and the identification of crystalline phases formed during thermal treatment and evaluation of its volumic fraction [fr

  19. Characterization of damage created by alpha disintegrations in radionuclear waste glass

    International Nuclear Information System (INIS)

    Jacquet-Francillon, N.; Mueller, P.

    1990-01-01

    Study of thermostimulated luminescence of an alpha irradiated glass used as radionuclear waste glass has revealed the formation of a structural defect induced by alpha irradiation. To detect this structural modification the thermostimulated signal of an alpha irradiated sample is recorded under certain conditions. The nature of generated defects has been established using synthetic glasses of more simple composition such as silica or boro-silicate glasses. Results obtained with these simple glasses are transposed to alpha irradiated radionuclear waste glass. The problem is to see how autoirradiated glass could evolve in time. For this purpose actinide-doped glasses are now being fabricated and specific thermostimulated luminescence equipment has been developed for this purpose

  20. Laser glass marking: influence of pulse characteristics

    Science.gov (United States)

    Rolo, Ana; Coelho, João; Pires, Margarida

    2005-09-01

    Laser glass marking is currently used in several glass materials for different purposes, such as bar codes for product tracking, brand logos or just decoration. Systems with a variety of different laser sources, with inherent power ranges, wavelengths and pulse regimes have been used, namely CO2, Nd:YAG, Excimer, Ti-Sapphire lasers. CO2 Lasers systems, although being a reliable tool for materials processing, and very compact in the case of sealed low power lasers, are usually associated with a localized thermal loading on the material, causing brittle materials like glass to crack around the irradiated area. In this experimental study a pulsed CO2 laser was used to direct marking the glass surface. The temporal characteristics of the laser pulse--pulse length, period and duty cycle were varied, and glass materials with different thermal properties were used in order to correlate the marking process--cracking or softening with or without material removal with the laser and material characteristics. Glass materials with major industrial application, such as soda-lima, borosilicate (PYREX) glasses and crystal have been investigated. Laser marked areas have been characterized in terms of surface optical properties, like diffuse and direct reflectance and transmittance for white light, directly related with marked surface quality.

  1. Critical review of glass performance modeling

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1994-07-01

    Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and its dissolution process

  2. Critical review of glass performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier, W.L. [Lawrence Livermore National Lab., CA (United States)

    1994-07-01

    Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and its dissolution process.

  3. Tailored Barium Swallow Study

    Science.gov (United States)

    ... Different textures of food are often given. The barium is a contrast material that makes the food and liquid show ... MRI Intravenous Contrast Information MRI with or without Contrast Small Bowel Follow Through (SBFT) Tailored Barium Swallow Study The Upper GI Study (GI Series) ...

  4. Characterization of the Defense Waste Processing Facility (DWPF) Environmental Assessment (EA) glass standard reference material

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.

    1992-01-01

    Liquid high-level nuclear waste at the Savannah River Site (SRS) will be immobilized by vitrification in borosilicate glass. The glass will be produced and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). Other waste form producers, such as West Valley Nuclear Services (WVNS) and the Hanford Waste Vitrification Project (HWVP), will also immobilize high-level radioactive waste in borosilicate glass. The canistered waste will be stored temporarily at each facility for eventual permanent disposal in a geologic repository. The Department of Energy has defined a set of requirements for the canistered waste forms, the Waste Acceptance Preliminary Specifications (WAPS). The current Waste Acceptance Preliminary Specification (WAPS) 1.3, the product consistency specification, requires the waste form producers to demonstrate control of the consistency of the final waste form using a crushed glass durability test, the Product Consistency Test (PCT). In order to be acceptable, a waste glass must be more durable during PCT analysis than the waste glass identified in the DWPF Envirorunental Assessment (EA). In order to supply all the waste form producers with the same standard benchmark glass, 1000 pounds of the EA glass was fabricated. The chemical analyses and characterization of the benchmark EA glass are reported. This material is now available to act as a durability, analytic, and/or redox Standard Reference Material (SRM) for all waste form producers

  5. Chapter 1. The characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan. The chemical composition of danburite ore of Ak-Arkhar Deposit was defined. The chemical composition of danburite ore concentrate of Ak-Arkhar Deposit was defined as well.

  6. Development Of Glass Matrices For HLW Radioactive Wastes

    International Nuclear Information System (INIS)

    Jantzen, C.

    2010-01-01

    Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process, e.g. melt waste plus glass forming frit additives and cast. A second reason that glass has become widely used for HLW is that the short range order (SRO) and medium range order (MRO) found in glass atomistically bonds the radionuclides and governs the melt properties such as viscosity, resistivity, sulphate solubility. The molecular structure of glass controls contaminant/radionuclide release by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. The molecular structure is flexible and hence accounts for the flexibility of glass formulations to waste variability. Nuclear waste glasses melt between 1050-1150 C which minimizes the volatility of radioactive components such as Tc 99 , Cs 137 , and I 129 . Nuclear waste glasses have good long term stability including irradiation resistance. Process control models based on the molecular structure of glass have been mechanistically derived and have been demonstrated to be accurate enough to control the world's largest HLW Joule heated ceramic melter in the US since 1996 at 95% confidence.

  7. DEVELOPMENT OF GLASS MATRICES FOR HLW RADIOACTIVE WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.

    2010-03-18

    Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process, e.g. melt waste plus glass forming frit additives and cast. A second reason that glass has become widely used for HLW is that the short range order (SRO) and medium range order (MRO) found in glass atomistically bonds the radionuclides and governs the melt properties such as viscosity, resistivity, sulphate solubility. The molecular structure of glass controls contaminant/radionuclide release by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. The molecular structure is flexible and hence accounts for the flexibility of glass formulations to waste variability. Nuclear waste glasses melt between 1050-1150 C which minimizes the volatility of radioactive components such as Tc{sup 99}, Cs{sup 137}, and I{sup 129}. Nuclear waste glasses have good long term stability including irradiation resistance. Process control models based on the molecular structure of glass have been mechanistically derived and have been demonstrated to be accurate enough to control the world's largest HLW Joule heated ceramic melter in the US since 1996 at 95% confidence.

  8. Impact of alpha-recoil damage on dissolution of thoriated glass

    International Nuclear Information System (INIS)

    Eyal, Y.; Ewing, R.C.

    1993-01-01

    Reaction of a seventeen-year old borosilicate glass containing 4 wt% ThO 2 with a bicarbonate-carbonate solution was investigated for times from a few minutes up to approximately one year. For the untreated glass, the initial 228-Th leach rate was enhanced relative to the initial 232-Th leach rate by 15--45%. This incongruent dissolution occurs due to the selective removal of radiogenic 228-Th nuclides from 228-Ra-recoil tracks, damaged regions in the aperiodic glass. Heating the glass at 650 C in air prior to leaching eliminates the 228-Th/232-Th fractionation. Similar enhanced dissolution of alpha-decay products may occur in nuclear waste glasses/groundwater systems; thus, actinide-containing glasses should be examined for alpha-recoil damage effects in order to insure satisfactory prediction of the long-term release of actinides from the nuclear waste glass

  9. Tin Valence and Local Environments in Silicate Glasses as Determined From X-ray Absorption Spectroscopy

    International Nuclear Information System (INIS)

    McKeown, D.; Buechele, A.; Gan, H.; Pegg, I.

    2008-01-01

    X-ray absorption spectroscopy (XAS) was used to characterize the tin (Sn) environments in four borosilicate glass nuclear waste formulations, two silicate float glasses, and three potassium aluminosilicate glasses. Sn K-edge XAS data of most glasses investigated indicate Sn4+O6 units with average Sn-O distances near 2.03 Angstroms. XAS data for a float glass fabricated under reducing conditions show a mixture of Sn4+O6 and Sn2+O4 sites. XAS data for three glasses indicate Sn-Sn distances ranging from 3.43 to 3.53 Angstroms, that suggest Sn4+O6 units linking with each other, while the 4.96 Angstroms Sn-Sn distance for one waste glass suggests clustering of unlinked Sn4+O6 units.

  10. The molten glass sewing machine

    Science.gov (United States)

    Brun, P.-T.; Inamura, Chikara; Lizardo, Daniel; Franchin, Giorgia; Stern, Michael; Houk, Peter; Oxman, Neri

    2017-04-01

    We present a fluid-instability-based approach for digitally fabricating geometrically complex uniformly sized structures in molten glass. Formed by mathematically defined and physically characterized instability patterns, such structures are produced via the additive manufacturing of optically transparent glass, and result from the coiling of an extruded glass thread. We propose a minimal geometrical model-and a methodology-to reliably control the morphology of patterns, so that these building blocks can be assembled into larger structures with tailored functionally and optically tunable properties. This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications'.

  11. Remote handling of canisters containing nuclear waste in glass at the Savannah River Plant

    International Nuclear Information System (INIS)

    Callan, J.E.

    1986-01-01

    The Defense Waste Processing Facility is being constructed at the Savannah River Plant at a cost of $870 million to immobilize the defense high-level radioactive waste. This radioactive waste is being added to borosilicate glass for later disposal in a federal repository. The borosilicate glass is poured into stainless steel canisters for storage. These canisters must be handled remotely because of their high radioactivity, up to 5000 R/h. After the glass has been poured into the canister which will be temporarily sealed, it is transferred to a decontamination cell and decontaminated. The canister is then transferred to the weld cell where a permanent cap is welded into place. The canisters must then be transported from the processing building to a storage vault on the plant until the federal repository is available. A shielded canister transporter (SCT) has been designed and constructed for this purpose. The design of the SCT vehicle allows the safe transport of a highly radioactive canister containing borosilicate glass weighing 2300 kg with a radiation level up to 5000 R/h from one building to another. The design provides shielding for the operator in the cab of the vehicle to be below 0.5 rem/h. The SCT may also be used to load the final shipping cask when the federal repository is ready to receive the canisters

  12. DWPF glass transition temperatures: What they are and why they are important

    International Nuclear Information System (INIS)

    Marra, S.L.; Jantzen, C.M.; Ramsey, A.A.

    1991-01-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site will immobilize high-level radioactive liquid waste in borosilicate glass. The glass will be poured into stainless steel canisters for eventual disposal in a geologic repository. The Department of Energy has defined a set of requirements for the DWPF canistered waste form which must be met in order to assure compatibility with, and acceptance by, the repository. These requirements are the Waste Acceptance Preliminary Specifications (WAPS). The WAPS require DWPF to report glass transition temperatures for the projected range of compositions. This information will be used by the repository to establish waste package design limits

  13. Modeling the Deformation-Failure Mechanisms of Thin Hollow Glass Microspheres

    Science.gov (United States)

    Garza-Cruz, Tryana V.; Nakagawa, Masami

    2009-06-01

    Thin Hollow Glass Microspheres (HGMs) are a potential candidate to insulate cryogenic tanks due to their high strength-to-weight ratio and thermal properties. In this study, HGMs were modeled using a Discrete Element Method (DEM) to simulate their deformation and fracture behavior. Due to lack of actual data, a chemical composition-based methodology was introduced to synthesize material properties that reproduce the mechanical properties of soda-lime-borosilicate glass. The modeled microsphere was subjected to a uniaxial compression test and failed due to buckling. This model captures some essential aspect of deformation-failure characteristics of a thin hollow glass microsphere.

  14. NMR Studies of Permanent Compression in Oxide Glasses

    DEFF Research Database (Denmark)

    Youngman, Randall E.; Svenson, Mouritz Nolsøe; Mauro, John C.

    useful tool for examining these changes in network structure, especially for boron-containing glasses, which are particularly sensitive to permanent compression. Here we describe studies based on hot isostatic compression of several different borate and borosilicate glasses, where changes in short......Pressure-induced structural rearrangement in oxide glasses is manifested by modification of both short- and intermediate-range structures, including changes to the local coordination numbers of network forming cations and alteration of the modifier environment. NMR spectroscopy is an especially...... of the network modifying sodium atoms, will be discussed. Such changes in network structure aid in understanding the pressure-induced properties of these glasses, such as density, elastic moduli, hardness and crack resistance....

  15. RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.

    2010-09-07

    High level radioactive wastes are being vitrified at the Savannah River Site for long term disposal. Many of the wastes contain sulfate at concentrations that can be difficult to retain in borosilicate glass. This study involves efforts to optimize the composition of a glass frit for combination with the waste to improve sulfate retention while meeting other process and product performance constraints. The fabrication and characterization of several series of simulated waste glasses are described. The experiments are detailed chronologically, to provide insight into part of the engineering studies used in developing frit compositions for an operating high level waste vitrification facility. The results lead to the recommendation of a specific frit composition and a concentration limit for sulfate in the glass for the next batch of sludge to be processed at Savannah River.

  16. Reaction of glass during gamma irradiation in a saturated tuff environment. Part 1. SRL 165 glass

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.K.; Fischer, D.F.; Gerding, T.J.

    1986-02-01

    The influence of gamma irradiation on the reaction of actinide-doped borosilicate glass (SRL 165) in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The following conclusions were reached. The reaction of, and subsequent actinide release from, the glass depends on the dynamic interaction between radiolysis effects, which cause the solution pH to become more acidic; glass reaction, which drives the pH more basic; and test component interactions that may extract glass components from solution. The use of large gamma irradiation dose rates to accelerate reactions that may occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons between the present results and data obtained by reacting similar glasses using MCC-1 and NNWSI rock cup procedures indicate that the irradiation conditions used in the present experiments do not dramatically influence the reaction rate of the glass. 8 figs., 9 tabs.

  17. Development and radiation stability of glasses for highly radioactive wastes

    International Nuclear Information System (INIS)

    Hall, A.R.; Dalton, J.T.; Hudson, B.; Marples, J.A.C.

    1976-01-01

    The variation of formation temperature, crystallizing behaviour and leach resistance with composition changes for sodium-lithium borosilicate glasses suitable for vitrifying Magnox waste are discussed. Viscosities have been measured between 400 and 1050 0 C. The principal crystal phases which occur have been identified as magnesium silicate, magnesium borate and ceria. The leach rate of polished discs in pure water at 100 0 C does not decrease with time if account is taken of the fragile siliceous layer that is observed to occur. The effect of 100 years' equivalent α- and β-irradiation on glass properties is discussed. Stored energy release experiments demonstrated that energy is released over a wide temperature range so that it cannot be triggered catastrophically. Temperatures required to release energy are dependent upon the original storage temperature. Helium release is by Fick's diffusion law up to at least 30% of the total inventory, with diffusion coefficients similar to those for comparable borosilicate glasses. Leach rates were not measurably affected by α-radiation. β-radiation in a Van de Graaff accelerator did not change physical properties, but irradiation in an electron microscope caused minute bubbles in lithium-containing glasses above 200 0 C. (author)

  18. Glass sealing

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  19. Radiation effects in glass and glass-ceramic waste forms for the immobilization of CANDU UO2 fuel reprocessing waste

    International Nuclear Information System (INIS)

    Tait, J.C.

    1993-05-01

    AECL has investigated three waste forms for the immobilization of high-level liquid wastes that would arise if used CANDU fuels were reprocessed at some time in the future to remove fissile materials for the fabrication of new power reactor fuel. These waste forms are borosilicate glasses, aluminosilicate glasses and titanosilicate glass-ceramics. This report discusses the potential effects of alpha, beta and gamma radiation on the releases of radionuclides from these waste forms as a result of aqueous corrosion by groundwaters that would be present in an underground waste disposal vault. The report discusses solid-state damage caused by radiation-induced atomic displacements in the waste forms as well as irradiation of groundwater solutions (radiolysis), and their potential effects on waste-form corrosion and radionuclide release. The current literature on radiation effects on borosilicate glasses and in ceramics is briefly reviewed, as are potential radiation effects on specialized waste forms for the immobilization of 129 I, 85 Kr and 14 C. (author). 104 refs., 9 tabs., 5 figs

  20. Natural glass analogues to alteration of nuclear waste glass: A review and recommendations for further study

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, W.F.

    1990-01-01

    The purpose of this report is to review previous work on the weathering of natural glasses; and to make recommendations for further work with respect to studying the alteration of natural glasses as it relates quantifying rates of dissolution. the first task was greatly simplified by the published papers of Jercinovic and Ewing (1987) and Byers, Jercinovic, and Ewing (1987). The second task is obviously the more difficult of the two and the author makes no claim of completeness in this regard. Glasses weather in the natural environment by reacting with aqueous solutions producing a rind of secondary solid phases. It had been proposed by some workers that the thickness of this rind is a function of the age of the glass and thus could be used to estimate glass dissolution rates. However, Jercinovic and Ewing (1987) point out that in general the rind thickness does not correlate with the age of the glass owing to the differences in time of contact with the solution compared to the actual age of the sample. It should be noted that the rate of glass dissolution is also a function of the composition of both the glass and the solution, and the temperature. Quantification of the effects of these parameters (as well as time of contact with the aqueous phase and flow rates) would thus permit a prediction of the consequences of glass-fluid interactions under varying environmental conditions. Defense high- level nuclear waste (DHLW), consisting primarily of liquid and sludge, will be encapsulated by and dispersed in a borosilicate glass before permanent storage in a HLW repository. This glass containing the DHLW serves to dilute the radionuclides and to retard their dispersion into the environment. 318 refs.

  1. Natural glass analogues to alteration of nuclear waste glass: A review and recommendations for further study

    International Nuclear Information System (INIS)

    McKenzie, W.F.

    1990-01-01

    The purpose of this report is to review previous work on the weathering of natural glasses; and to make recommendations for further work with respect to studying the alteration of natural glasses as it relates quantifying rates of dissolution. the first task was greatly simplified by the published papers of Jercinovic and Ewing (1987) and Byers, Jercinovic, and Ewing (1987). The second task is obviously the more difficult of the two and the author makes no claim of completeness in this regard. Glasses weather in the natural environment by reacting with aqueous solutions producing a rind of secondary solid phases. It had been proposed by some workers that the thickness of this rind is a function of the age of the glass and thus could be used to estimate glass dissolution rates. However, Jercinovic and Ewing (1987) point out that in general the rind thickness does not correlate with the age of the glass owing to the differences in time of contact with the solution compared to the actual age of the sample. It should be noted that the rate of glass dissolution is also a function of the composition of both the glass and the solution, and the temperature. Quantification of the effects of these parameters (as well as time of contact with the aqueous phase and flow rates) would thus permit a prediction of the consequences of glass-fluid interactions under varying environmental conditions. Defense high- level nuclear waste (DHLW), consisting primarily of liquid and sludge, will be encapsulated by and dispersed in a borosilicate glass before permanent storage in a HLW repository. This glass containing the DHLW serves to dilute the radionuclides and to retard their dispersion into the environment. 318 refs

  2. Specialty glass development for radiation shielding windows and nuclear waste immobilization

    International Nuclear Information System (INIS)

    Mandal, S.; Ghorui, S.; Roy Chowdhury, A.; Sen, R.; Chakraborty, A.K.; Sen, S.; Maiti, H.S.

    2015-01-01

    The technology of two important varieties of specialty glasses, namely high density Radiation Shielding Window (RSW) glass and specialty glass beads of borosilicate composition have been successfully developed in CGCRI with an aim to meet the countries requirement. Radiation Shielding Windows used in nuclear installations, are viewing devices, which allow direct viewing into radioactive areas while still providing adequate protection to the operating personnel. The glass blocks are stabilized against damage from radiation by introducing cerium in definite proportions. Considering the essentially of developing an indigenous technology to make the country self-sufficient for this critical item, CGCRI has taken up a major programme to develop high lead containing glasses required for RSWs under a MoD with BARC. On the other hand, the specialty glass bead of specific composition and properties is a critical material required for management of radioactive waste in a closed nuclear fuel cycle that is followed by India. During reprocessing of the spent nuclear fuel, high level radio-active liquid waste (HLW) is produced containing unwanted radio isotopes some of which remain radioactive for thousands of years. The need is to immobilize them within a molecular structure so that they will not come out and be released to the ambience and thereby needs to be resolved if nuclear power is to make a significant contribution to the country's power requirement. Borosilicate glass has emerged as the material of choice for immobilization due to its unique random network structure

  3. Growth of the high reflectivity Bi 2O 3 glass films by atmospheric pressure halide CVD

    Science.gov (United States)

    Takeyama, T.; Takahashi, N.; Nakamura, T.; Ito, S.

    2004-09-01

    We reported the results of an investigation into the preparation of amorphous Bi 2O 3 onto borosilicate glass substrate by means of atmospheric pressure halide chemical vapor deposition using BiI 3 and oxygen as a source materials. Obtained thin films lower than 475 °C was amorphous and it was almost transparent in infrared region. But the amorphous films are iodine-containing Bi 2O 3, as results of analysis by XRD and XPS.

  4. Morphology of altered layers of glasses

    Energy Technology Data Exchange (ETDEWEB)

    Deruelle, O. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee, 91 - Gif sur Yvette (France); Spalla, O.; Lambard, J. [CEA Saclay, Dept. de Recherche sur l' Etat Condense les Atomes et les Molecules, 91 - Gif sur Yvette (France); Barboux, Ph.; Ricol, St. [Ecole Polytechnique, PMC, 91 - Palaiseau (France); Ricol, St.; Vernaz, E. [CEA Valrho, Dir. de l' Energie Nucleaire, DEN, 30 - Marcoule (France)

    1997-07-01

    The alteration of the french nuclear waste glass R7T7 has been studied through chemical analysis, thermo-poro-metry and X-ray scattering. Pseudo-dynamic leaching was used, with daily renewal of the leaching solution. The behavior of the R77 glass has been compared to cesium borosilicate glasses with small amounts of Ca and Zr added. As compared to these simplified compositions, the R7T7 glass has a quasi-congruent leaching of Na, B and Si and strongly retains Ca and Zr. The altered layers are very porous (porosity > 40% ). The pore size increases with time to reach a constant value that is independent of the nature of the glass but that strongly depends on the method used for leaching. The pore radii are about 4 nm in pseudo-dynamic mode and 2 nm in static conditions. X-ray scattering indicate that the pores are compact with a sharp interface. Their origin is related to the quasi-equilibrium reaction of hydrolysis redeposition of silica. (authors)

  5. Properties of glass-bonded zeolite monoliths

    International Nuclear Information System (INIS)

    Lewis, M.A.; Fischer, D.F.; Murphy, C.D.

    1994-01-01

    It has been shown that mineral waste forms can be used to immobilize waste salt generated during the pyrochemical processing of spent fuel from the Integral Fast Reactor (IFR). Solid, leach resistant monoliths were formed by hot-pressing mixtures of salt-occluded zeolite A powders and glass frit at 990 K and 28 MPa. Additional samples have now been fabricated and tested. Normalized release rates for all elements, including iodide and chloride, were less than 1 g/m 2 d in 28-day tests in deionized water and in brine at 363 K (90 degrees C). Preliminary results indicate that these rates fall with time with both leachants and that the zeolite phase in the glass-bonded zeolite does not function as an ion exchanger. Some material properties were measured. The Poisson ratio and Young's modulus were slightly smaller in glass-bonded zeolite than in borosilicate glass. Density depended on zeolite fraction. The glass-bonded zeolite represents a promising mineral waste form for IFR salt

  6. Chemical durability of soda-lime-aluminosilicate glass for radioactive waste vitrification

    International Nuclear Information System (INIS)

    Eppler, F.H.; Yim, M.S.

    1998-01-01

    Vitrification has been identified as one of the most viable waste treatment alternatives for nuclear waste disposal. Currently, the most popular glass compositions being selected for vitrification are the borosilicate family of glasses. Another popular type that has been around in glass industry is the soda-lime-silicate variety, which has often been characterized as the least durable and a poor candidate for radioactive waste vitrification. By replacing the boron constituent with a cheaper substitute, such as silica, the cost of vitrification processing can be reduced. At the same time, addition of network intermediates such as Al 2 O 3 to the glass composition increases the environmental durability of the glass. The objective of this study is to examine the ability of the soda-lime-aluminosilicate glass as an alternative vitrification tool for the disposal of radioactive waste and to investigate the sensitivity of product chemical durability to variations in composition

  7. Canonical correlation of waste glass compositions and durability, including pH

    Energy Technology Data Exchange (ETDEWEB)

    Oeksoy, D.; Pye, L.D. (Alfred Univ., NY (United States)); Bickford, D.F.; Ramsey, W.G. (Westinghouse Savannah River Co., Aiken, SC (United States))

    1993-01-01

    Control of waste glass durability is a major concern in the immobilization of radioactive and mixed wastes. Leaching rate in standardized laboratory tests is being used as a demonstration of consistency of the response of waste glasses in the final disposal environment. The leaching of silicate and borosilicate glasses containing alkali or alkaline earth elements is known to be autocatalytic, in that the initial ion exchange of alkali in the glass for hydrogen ions in water results in the formation of OH and increases the pH of the leachate. The increased pH then increases the rate of silicate network attack, accelerating the leaching effect. In well formulated glasses this effect reaches a thermodynamic equilibrium when leachate saturation of a critical species, such as silica, or a dynamic equilibrium is reached when the pH shift caused by incremental leaching has negligible effect on pH. This report analyzes results of a seven leach test on waste glasses.

  8. Canonical correlation of waste glass compositions and durability, including pH

    Energy Technology Data Exchange (ETDEWEB)

    Oeksoy, D.; Pye, L.D. [Alfred Univ., NY (United States); Bickford, D.F.; Ramsey, W.G. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1993-05-01

    Control of waste glass durability is a major concern in the immobilization of radioactive and mixed wastes. Leaching rate in standardized laboratory tests is being used as a demonstration of consistency of the response of waste glasses in the final disposal environment. The leaching of silicate and borosilicate glasses containing alkali or alkaline earth elements is known to be autocatalytic, in that the initial ion exchange of alkali in the glass for hydrogen ions in water results in the formation of OH and increases the pH of the leachate. The increased pH then increases the rate of silicate network attack, accelerating the leaching effect. In well formulated glasses this effect reaches a thermodynamic equilibrium when leachate saturation of a critical species, such as silica, or a dynamic equilibrium is reached when the pH shift caused by incremental leaching has negligible effect on pH. This report analyzes results of a seven leach test on waste glasses.

  9. Composition and redox control of waste glasses: Recommendation for process control limit

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Plodinec, M.J.

    1986-01-01

    An electrochemical series of redox couples, originally developed for Savannah River Laboratory glass frit 131 (SRL-131) as a reference composition, has been extended to two other alkali borosilicate compositions that are candidate glasses for nuclear waste immobilization. Since no dramatic differences were ascertained in the redox chemistry of selected multivalent elements in SRL-131 versus that in Savannah River Laboratory glass frit 165 (SRL-165) and in West Valley glass number-sign 205 (WV-205), the comprehensive electrochemical series can readily be applied to a range of nuclear waste glass compositions. In order to alleviate potential problems with foaming and precipitation of insolubles during the processing of the nuclear waste in these glass melts, the [Fe 2+ ]/[Fe 3+ ] ratio of the melt should be between 0.1 and 0.5. 27 refs., 4 figs., 2 tabs

  10. Canonical correlation of waste glass compositions and durability, including pH

    International Nuclear Information System (INIS)

    Oeksoy, D.; Pye, L.D.; Bickford, D.F.; Ramsey, W.G.

    1993-01-01

    Control of waste glass durability is a major concern in the immobilization of radioactive and mixed wastes. Leaching rate in standardized laboratory tests is being used as a demonstration of consistency of the response of waste glasses in the final disposal environment. The leaching of silicate and borosilicate glasses containing alkali or alkaline earth elements is known to be autocatalytic, in that the initial ion exchange of alkali in the glass for hydrogen ions in water results in the formation of OH and increases the pH of the leachate. The increased pH then increases the rate of silicate network attack, accelerating the leaching effect. In well formulated glasses this effect reaches a thermodynamic equilibrium when leachate saturation of a critical species, such as silica, or a dynamic equilibrium is reached when the pH shift caused by incremental leaching has negligible effect on pH. This report analyzes results of a seven leach test on waste glasses

  11. Melter Glass Removal and Dismantlement

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, BS

    2000-10-31

    The U.S. Department of Energy (DOE) has been using vitrification processes to convert high-level radioactive waste forms into a stable glass for disposal in waste repositories. Vitrification facilities at the Savannah River Site (SRS) and at the West Valley Demonstration Project (WVDP) are converting liquid high-level waste (HLW) by combining it with a glass-forming media to form a borosilicate glass, which will ensure safe long-term storage. Large, slurry fed melters, which are used for this process, were anticipated to have a finite life (on the order of two to three years) at which time they would have to be replaced using remote methods because of the high radiation fields. In actuality the melters useable life spans have, to date, exceeded original life-span estimates. Initial plans called for the removal of failed melters by placing the melter assembly into a container and storing the assembly in a concrete vault on the vitrification plant site pending size-reduction, segregation, containerization, and shipment to appropriate storage facilities. Separate facilities for the processing of the failed melters currently do not exist. Options for handling these melters include (1) locating a facility to conduct the size-reduction, characterization, and containerization as originally planned; (2) long-term storing or disposing of the complete melter assembly; and (3) attempting to refurbish the melter and to reuse the melter assembly. The focus of this report is to look at methods and issues pertinent to size-reduction and/or melter refurbishment in particular, removing the glass as a part of a refurbishment or to reduce contamination levels (thus allowing for disposal of a greater proportion of the melter as low level waste).

  12. Immobilization of high level nuclear wastes in sintered glasses. Devitrification evaluation produced with different thermal treatments

    International Nuclear Information System (INIS)

    Messi de Bernasconi, N.B.; Russo, D.O.; Bevilacqua, M.E.; Sterba, M.E.; Heredia, A.D.; Audero, M.A.

    1990-01-01

    This work describes immobilization of high level nuclear wastes in sintered glass, as alternative way to melting glass. Different chemical compositions of borosilicate glass with simulate waste were utilized and satisfactory results were obtained at laboratory scale. As another contribution to the materials studies by X ray powder diffraction analysis, the devitrification produced with different thermal treatments, was evaluated. The effect of the thermal history on the behaviour of fission products containing glasses has been studied by several working groups in the field of high level waste fixation. When the glass is cooled through the temperature range from 800 deg C down to less than 400 deg C (these temperatures are approximates) nucleation and crystal growth can take place. The rate of crystallization will be maximum near the transformation point but through this rate may be low at lower temperatures, devitrification can still occur over long periods of time, depending on the glass composition. It was verified that there can be an appreciable increase in leaching in some waste glass compositions owing to the presence of crystalline phases. On the other hand, other compositions show very little change in leachability and the devitrified product is often preferable as there is less tendency to cracking, particularly in massive blocks of glass. A borosilicate glass, named SG7, which was developed specially in the KfK for the hot pressing of HLW with glass frit was studied. It presents a much enhanced chemical durability than borosolicate glass developed for the melting process. The crystallization behaviour of SG7 glass products was investigated in our own experiments by annealing sintered samples up to 3000 h at temperatures between 675 and 825 deg C. The samples had contained simulated waste with noble metals, since these might act as foreign nuclei for crystallization. Results on the extent of devitrification and time- temperature- transformation curves are

  13. Tailored Random Graph Ensembles

    International Nuclear Information System (INIS)

    Roberts, E S; Annibale, A; Coolen, A C C

    2013-01-01

    Tailored graph ensembles are a developing bridge between biological networks and statistical mechanics. The aim is to use this concept to generate a suite of rigorous tools that can be used to quantify and compare the topology of cellular signalling networks, such as protein-protein interaction networks and gene regulation networks. We calculate exact and explicit formulae for the leading orders in the system size of the Shannon entropies of random graph ensembles constrained with degree distribution and degree-degree correlation. We also construct an ergodic detailed balance Markov chain with non-trivial acceptance probabilities which converges to a strictly uniform measure and is based on edge swaps that conserve all degrees. The acceptance probabilities can be generalized to define Markov chains that target any alternative desired measure on the space of directed or undirected graphs, in order to generate graphs with more sophisticated topological features.

  14. The effects of the glass surface area/solution volume ratio on glass corrosion: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, W.L. [Argonne National Lab., IL (United States). Chemical Technology Div.

    1995-03-01

    This report reviews and summarizes the present state of knowledge regarding the effects of the glass surface area/solution volume (SA/V) ratio on the corrosion behavior of borosilicate waste glasses. The SA/V ratio affects the rate of glass corrosion through the extent of dilution of corrosion products released from the glass into the leachate solution: glass corrosion products are diluted more in tests conducted at low SA/V ratios than they are in tests conducted at high SA/V ratios. Differences in the solution chemistries generated in tests conducted at different SA/V ratios then affect the observed glass corrosion behavior. Therefore, any testing parameter that affects the solution chemistry will also affect the glass corrosion rate. The results of static leach tests conducted to assess the effects of the SA/V are discussed with regard to the effects of SA/V on the solution chemistry. Test results show several remaining issues with regard to the long-term glass corrosion behavior: can the SA/V ratio be used as an accelerating parameter to characterize the advanced stages of glass corrosion relevant to long disposal times; is the alteration of the glass surface the same in tests conducted at different SA/V, and in tests conducted with monolithic and crushed glass samples; what are the effects of the SA/V and the extent of glass corrosion on the disposition of released radionuclides? These issues will bear on the prediction of the long-term performance of waste glasses during storage. The results of an experimental program conducted at ANL to address these and other remaining issues regarding the effects of SA/V on glass corrosion are described. 288 refs., 59 figs., 16 tabs.

  15. Complexing Agents and pH Influence on Chemical Durability of Type I Molded Glass Containers.

    Science.gov (United States)

    Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

    2017-01-01

    Among the factors that affect the glass surface chemical durability, pH and complexing agents present in aqueous solution have the main role. Glass surface attack can be also related to the delamination issue causing glass particles' appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed. The present study emphasizes the possible synergy between a few complexing agents with pH on borosilicate glass chemical durability.Hydrolytic attack was performed in small-volume 23 mL type I glass containers autoclaved according to the European Pharmacopoeia or United States Pharmacopeia for 1 h at 121 °C, in order to enhance the chemical attack due to time, temperature, and the unfavorable surface/volume ratio. Solutions of 0.048 M or 0.024 M (M/L) of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid), together with sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ±0.05 units at fixed values 5.5, 6.6, 7, 7.4, 8, and 9 by LiOH diluted solution.Because silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by inductively coupled plasma atomic emission spectrophotometry. The work was completed by the analysis of the silicon release in the worst attack conditions of molded glass, soda lime type II glass, and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by scanning electron microscopy was finally performed to check for the surface status after the worst chemical attack condition by citric acid. LAY ABSTRACT: Glass, like every packaging material, can have some usage limits, mainly in basic pH solutions. The issue of glass surface degradation particles that appear in vials (delamination) has forced a number of drug product recalls in recent years

  16. Annihilation of the triplet excitons in the nanoporous glass matrices

    International Nuclear Information System (INIS)

    Afanasyev, D.A.; Ibrayev, N.Kh.; Saletsky, A.M.; Starokurov, Y.V.; Gun'ko, V.M.; Mikhalovsky, S.V.

    2013-01-01

    The spectra and kinetics of fluorescence decay of 1,2-benzanthracene (1,2-BA) molecular clusters adsorbed in nanoporous borosilicate glasses were investigated. It has been shown that the type of the decay kinetics of delayed fluorescence is determined by the annihilation of triplet excitons in crystalline and percolation clusters. The influence of an external magnetic field on the annihilation rate constant of triplet excitons in the adsorbed 1,2-BA molecules has been studied. The response of the molecular clusters to the magnetic field strongly depends on temperature, pore size and time scale of the observation. Clusters with the crystal structure dominate in the decay kinetics of triplet–triplet annihilation (TTA) and delayed fluorescence in the initial microsecond period of time after excitation. Amorphous clusters determine the form of decay kinetics of delayed fluorescence in the millisecond range. The increase in the pore size and concentration of the adsorbate lead to the dominance of crystalline components. The results presented here can be used to develop techniques for probing the structure of the adsorbed layer in nanoporous systems examining the effect of an external magnetic field on the annihilation delayed fluorescence (ADF) kinetics. Highlights: ► Molecular clusters of 1,2-benzanthracene adsorbed in nanoporous borosilicate glasses. ► Form of decay kinetics of delayed fluorescence. ► Magnetic field effects depend on temperature, pore size and observation time range. ► Clusters with crystal structure and amorphous clusters form in porous glasses

  17. Processing glass-pyrochlore composites for nuclear waste encapsulation

    International Nuclear Information System (INIS)

    Pace, S.; Cannillo, V.; Wu, J.; Boccaccini, D.N.; Seglem, S.; Boccaccini, A.R.

    2005-01-01

    Glass matrix composites have been developed as alternative materials to immobilize nuclear solid waste, in particular actinides. These composites are made of soda borosilicate glass matrix, into which particles of lanthanum zirconate pyrochlore are encapsulated in concentrations of 30 vol.%. The fabrication process involves powder mixing followed by hot-pressing. At the relatively low processing temperature used (620 deg. C), the pyrochlore crystalline structure of the zirconate, which is relevant for containment of radioactive nuclei, remains unaltered. The microstructure of the composites exhibits a homogeneous distribution of isolated pyrochlore particles in the glass matrix and strong bonding at the matrix-particle interfaces. Hot-pressing was found to lead to high densification (95% th.d.) of the composite. The materials are characterized by relatively high elastic modulus, flexural strength, hardness and fracture toughness. A numerical approach using a microstructure-based finite element solver was used in order to investigate the mechanical properties of the composites

  18. Colloidal glasses

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Colloidal glasses. Glassy state is attained when system fails to reach equilibrium due to crowding of constituent particles. In molecular glasses, glassy state is reached by rapidly lowering the temperature. In colloidal glasses, glassy state is reached by increasing the ...

  19. Complexing agents and pH influence on chemical durability of type I moulded glass containers.

    Science.gov (United States)

    Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

    2017-06-16

    Among the factors that affect the glass surface chemical durability, pH and complexing agents presence in aqueous solution have the main role (1). Glass surface attack can be also related to the delamination issue with glass particles appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed (2,3). The present study emphasizes the possible synergy between a few complexing agents with pH on the borosilicate glass chemical durability. Hydrolytic attack was performed in small volume 23 ml type I glass containers autoclaved according to EP or USP for 1 hour at 121°C, in order to enhance the chemical attack due to time, temperature and the unfavourable surface/volume ratio. 0,048 M or 0.024 M (moles/liter) solutions of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid) and sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ± 0,05 units at fixed values 5,5-6,6-7-7,4-8-9 by LiOH diluted solution. Since silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by ICPAES. The work was completed by the analysis of the silicon release in the worst attack conditions, of moulded glass, soda lime type II and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by SEM was finally performed to check for the surface status after the worst chemical attack condition by citric acid. Copyright © 2017, Parenteral Drug Association.

  20. Tailored thrombolytic therapy. A perspective

    NARCIS (Netherlands)

    M.L. Simoons (Maarten); A.E.R. Arnold (Alfred)

    1993-01-01

    textabstractBACKGROUND. In contrast with current standard regimens, it seems more appropriate to tailor thrombolytic therapy to individual patient characteristics. A proposed model for such tailored therapy is based on individual assessment of benefits and risks of thrombolytic therapy, taking into

  1. DEFENSE HIGH LEVEL WASTE GLASS DEGRADATION

    International Nuclear Information System (INIS)

    Ebert, W.

    2001-01-01

    The purpose of this Analysis/Model Report (AMR) is to document the analyses that were done to develop models for radionuclide release from high-level waste (HLW) glass dissolution that can be integrated into performance assessment (PA) calculations conducted to support site recommendation and license application for the Yucca Mountain site. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M andO 2000a). It specifically addresses the item, ''Defense High Level Waste Glass Degradation'', of the product technical work plan. The AP-3.15Q Attachment 1 screening criteria determines the importance for its intended use of the HLW glass model derived herein to be in the category ''Other Factors for the Postclosure Safety Case-Waste Form Performance'', and thus indicates that this factor does not contribute significantly to the postclosure safety strategy. Because the release of radionuclides from the glass will depend on the prior dissolution of the glass, the dissolution rate of the glass imposes an upper bound on the radionuclide release rate. The approach taken to provide a bound for the radionuclide release is to develop models that can be used to calculate the dissolution rate of waste glass when contacted by water in the disposal site. The release rate of a particular radionuclide can then be calculated by multiplying the glass dissolution rate by the mass fraction of that radionuclide in the glass and by the surface area of glass contacted by water. The scope includes consideration of the three modes by which water may contact waste glass in the disposal system: contact by humid air, dripping water, and immersion. The models for glass dissolution under these contact modes are all based on the rate expression for aqueous dissolution of borosilicate glasses. The mechanism and rate expression for aqueous dissolution are adequately understood; the analyses in this AMR were conducted to

  2. Sulphate solubility and sulphate diffusion in oxide glasses: implications for the containment of sulphate-bearing nuclear wastes; Solubilite et cinetiques de diffusion des sulfates dans differents verres d'oxydes: application au conditionnement des dechets nucleaires sulfates

    Energy Technology Data Exchange (ETDEWEB)

    Lenoir, M.

    2009-09-15

    The thesis deals with sulphate solubility and sulphate diffusion in oxide glasses, in order to control sulphate incorporation and sulphate volatilization in nuclear waste glasses. It was conducted on simplified compositions, in the SiO{sub 2}-B{sub 2}O{sub 3}-R{sub 2}O (R = Li, Na, K, Cs), SiO{sub 2}-B{sub 2}O{sub 3}-BaO and V{sub 2}O{sub 5}-B{sub 2}O{sub 3}-BaO systems. These compositions allowed us to study the influence of the nature of network-modifying ions (Li{sup +}, Na{sup +}, K{sup +}, Cs{sup +} or Ba{sup 2+}) and also of former elements (Si, B, V), on structure and properties of glasses. Sulphate volatility is studied in sodium borosilicate melts using an innovative technique of sulphate quantitation with Raman spectroscopy. This technique is useful to obtain kinetic curves of sulphate volatilization. The establishment of a model to fit these curves leads to the determination of diffusion coefficients of sulphate. These diffusion coefficients can thus be compared to diffusion coefficients of other species, determined by other techniques and presented in the literature. They are also linked to diffusion coefficients in relation with the viscosity of the melts. Concerning sulphate solubility in glasses, it depends on glass composition and on the nature of sulphate incorporated. Sulphate incorporation in alkali borosilicate glasses leads to the formation of a sulphate layer floating on top of the melt. Sulphate incorporation in barium borosilicate and boro-vanadate glasses leads to the crystallization of sulphate species inside the vitreous matrix. Moreover, sulphate solubility is higher in these glasses than in alkali borosilicates. Finally, exchanges between cations present in glasses and cations present in the sulphate phase are also studied. (author)

  3. Sol-gel processing of glasses and glass-ceramics for microelectronic packaging

    International Nuclear Information System (INIS)

    Sriram, M.A.; Kumta, P.N.

    1992-01-01

    In recent years considerable progress has been made in electronic packaging substrate technology. The future need of miniaturization of devices to increase the signal processing speeds calls for an increase in the device density requiring the substrates to be designed for better thermal, mechanical and electrical efficiency. Fast signal propagation with minimum delay requires the substrate to possess very low dielectric constant. Several glasses and glass-ceramic materials have been identified over the years which show good promise as candidate substrate materials. among these borophosphate and borophosphosilicate glass-ceramics have been recently identified to have the lowest dielectric constant. This paper reports that sol-gel processing has been used to synthesize borosilicate, borophosphosilicate and borophosphate glasses and glass-ceramics using inexpensive boron oxide and phosphorus pentoxide precursors. Preliminary results of the processing of these gels and the effect of volatility of boron alkoxide and its modification on the gel structure are described. X-ray diffraction, Differential thermal analyses and FTIR have been used to characterize the as-prepared and heat treated gels

  4. Network structure and thermal stability study of high temperature seal glass

    Science.gov (United States)

    Lu, K.; Mahapatra, M. K.

    2008-10-01

    High temperature seal glass has stringent requirement on glass thermal stability, which is dictated by glass network structures. In this study, a SrO-La2O3-Al2O3-B2O3-SiO2 based glass system was studied using nuclear magnetic resonance, Raman spectroscopy, and x-ray diffraction for solid oxide cell application purpose. Glass structural unit neighboring environment and local ordering were evaluated. Glass network connectivity as well as silicon and boron glass former coordination were calculated for different B2O3:SiO2 ratios. Thermal stability of the borosilicate glasses was studied after thermal treatment at 850 °C. The study shows that high B2O3 content induces BO4 and SiO4 structural unit ordering, increases glass localized inhomogeneity, decreases glass network connectivity, and causes devitrification. Glass modifiers interact with either silicon- or boron-containing structural units and form different devitrified phases at different B2O3:SiO2 ratios. B2O3-free glass shows the best thermal stability among the studied compositions, remaining stable after thermal treatment for 200 h at 850 °C.

  5. Nuclear waste glass product consistency test (PCT), Version 5.0

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

    1992-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached

  6. Transmission of fast highly charged ions through straight and tapered glass capillaries

    International Nuclear Information System (INIS)

    Ayyad, Asma M; Keerthisinghe, D; Kayani, A; Tanis, J A; Dassanayake, B S; Ikeda, T

    2013-01-01

    The transmission of 1 and 3 MeV protons through a borosilicate straight glass capillary and a tapered glass capillary was investigated. The straight capillary had a diameter of ∼0.18 mm and a length of ∼14.4 mm, while the tapered capillary had an inlet diameter of ∼0.71 mm, an outlet diameter of ∼0.10 mm and a length of ∼28 mm. The results show that the 1 and 3 MeV protons traverse through both samples without energy loss, while the tapered capillary showed better transmission than the straight capillary. (paper)

  7. Study of Structural Properties of Mesoporous Carbon From Fructose with Zinc Borosilicate Activator

    OpenAIRE

    Setianingsih, Tutik; Kartini, Indriana; Arryanto, Yateman

    2014-01-01

    Structural properties, including pore structure, functional group of carbon surface, and crystal structure of carbon built by zinc borosilicate (ZBS) and ZnCl2 (Z) have been investigated in this work. Physically, ZBS and ZnCl2 may act as template of carbon, whereas the Zn(II) cation act as chemical activator of carbonization. All precursors of ZBS (silicagel, boric acid, and ZnCl2) may act as catalysts of caramelization. The caramelization was conducted hydrothermally at 85oC and thermally 1...

  8. Platinoids and molybdenum in nuclear waste containment glasses: a structural study

    International Nuclear Information System (INIS)

    Le Grand, M.

    2000-01-01

    This work deals with the structure of borosilicate nuclear glasses and with some relationships between structure and macroscopic properties. Two types of elements which may disturb the industrial process - platinoids (Ru and Pd) and molybdenum - are central to this work. Platinoids induce weak modifications on the structure of the glass, causing a depolymerization of the glassy network, an increase of the [3] B/ [4] B ratio and a modification of the medium range order around Si between 3.3 and 4.5 angstrom. The modifications of viscosity and density induced by platinoids in the glass are not due to the structural effect of the platinoids. The increase of viscosity is attributed to needle shaped RuO 2 . It can be moderated by imposing reducing conditions during the elaboration of the glass. The slight difference between experimental and calculated densities is due to the increase of the volume percentage of bubbles in the glass with increasing platinoid content. Mo is either present in the glass as molybdic groupings, or mobilized in chemically complex molybdic crystalline phases. The chemical composition and mineralogy of these phases has been obtained using electronic microprobe data and XRD with Rietveld analysis. The distribution of the different elements between the crystalline phases and the glass is strongly influenced by the structural role of the various cations in the glass. The Mo present in the glass appears as MoO 4 tetrahedra, independent of the borosilicate network. The formation of the crystalline phases can be explained by the existence of a precursor in which the MoO 4 tetrahedra are concentrated in rich alkali and earth-alkali bearing areas of the glass. (author)

  9. Glass packages in interim storage; Les verres dans les stockages

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet-Francillon, N.

    1994-10-01

    This report summarize the current state of knowledge concerning the behavior of type C waste packages consisting of vitrified high-level solutions produced by reprocessing spent fuel. The composition and the physical and chemical properties of the feed solutions are reviewed, and the vitrification process is described. Sodium alumino-borosilicate glass compositions are generally employed - the glass used at la Hague for LWR fuel solutions, for example, contains 45 % SiO{sub 2}. The major physical, chemical, mechanical and thermal properties of the glass are reviewed. In order to allow their thermal power to diminish, the 3630 glass packages produced (as of January 1993) in the vitrification facilities at Marcoule and La Hague are placed in interim storage for several decades. The actual interim storage period has not been defined, as it is closely related to the concept and organization selected for the final destination of the packages: a geological repository. The glass behavior under irradiation is described. Considerable basic and applied research has been conducted to assess the aqueous leaching behavior of nuclear containment glass. The effects of various repository parameters (temperature, flow rate, nature of the environmental materials) have been investigated. The experimental findings have been used to specify a model describing the kinetics of aqueous corrosion of the glass. More generally all the ``source term`` models developed in France by the CEA or by ANDRA are summarized. (author). 152 refs., 33 figs.

  10. The current status of glass leaching studies in France

    International Nuclear Information System (INIS)

    Laude, F.

    1983-11-01

    Glass has been selected in France as the material used to confine the activity of fission product solutions, and a continuous vitrification process has been developed at the Marcoule Vitrification Facility (AVM), the first industrial plant. Borosilicate glass was chosen in various compositions for its properties: it is a homogeneous, non-porous material that incorporates appreciable quantities of most of the fission product oxides, and is only alterable at the surface interface layer. Glass thus constitutes the primary radioactivity containment barrier, and it is essential to determine its long-term behavior. Water constitutes the principal hazard during temporary or definitive storage of the glass blocks. Two types of inherent material properties are studied from the standpoint of glass stability under leaching conditions: - chemical durability; - radioactive containability with regard to the various radionuclides, fission products and especially the actinides. Durability tests are carried out in SOXHLET devices and the alteration rates are measured by the weight loss. The containability is measured by the leach rate, i.e. by the rate of activity loss into the water. Leaching tests are conducted for several major objectives: - selection of glass compositions (leach rates); - leaching mechanism studies (hydrolyzed layer characteristics, effects of temperature, pressure, pH, etc.); - long-term behavior studies (glass specimens doped with alpha-emitters); - simulation of geological repository environments [fr

  11. Filtration via Conventional Glass Fiber Filters in 15N2 Tracer Assays Fails to Capture All Nitrogen-Fixing Prokaryotes

    OpenAIRE

    Deniz Bombar; Ryan W. Paerl; Ruth Anderson; Lasse Riemann

    2018-01-01

    Biological dinitrogen fixation (BNF) represents a major input of reduced nitrogen (N) to the oceans. Accurate direct measurements of BNF rates are crucial for reliably determining the biogeochemical significance of diazotrophy at local and global scales. Traditionally, borosilicate glass fiber filters (GF/F, Whatman) with a nominal pore size of 0.7 μm are used to collect suspended particles by filtration after incubations with added 15N2 tracer. We carried out BNF experiments in the Baltic Se...

  12. Fabrication of a LP01 to LP02 mode converter embedded in bulk glass using femtosecond direct inscription

    Science.gov (United States)

    Mellah, Hakim; Bérubé, Jean-Philippe; Vallée, Réal; Zhang, Xiupu

    2018-03-01

    In this paper, we demonstrate a fabrication of an integrated mode converter that converts LP01 to LP02 for the C-band. The mode converter was directly inscribed in the bulk of a borosilicate glass using a femtosecond laser. The converter has an insertion loss of less than 1 dB for the entire C-band, suggesting more than 80% conversion efficiency.

  13. Recycle Glass in Foam Glass Production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  14. Cosmos & Glass

    DEFF Research Database (Denmark)

    Beim, Anne

    1996-01-01

    The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne.......The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne....

  15. Active Control of Tailored Laminates

    Data.gov (United States)

    National Aeronautics and Space Administration — Part of a proposed suite of technologies to enable a fully morphing seamless wing, this effort focuses on tailoring composite materials to enhance structural...

  16. Chemical Composition Measurements of LAWA44 Glass Samples

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Riley, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-11-15

    DOE is building the Hanford Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is temporarily stored in 177 underground tanks. Both low-activity and high-level wastes will then be vitrified into borosilicate glass using Joule-heated ceramic melters. Efforts are being made to increase the loading of Hanford tank wastes in the glass. One area of work is enhancing waste glass composition/property models and broadening the compositional regions over which those models are applicable. In this report, the Savannah River National Laboratory provides chemical analysis results for several samples of a simulated low-activity waste glass, LAWA44, provided by the Pacific Northwest National Laboratory as part of an ongoing development task. The measured chemical composition data are reported and compared with the targeted values for each component for each glass. A detailed review showed no indications of errors in the preparation or measurement of the study glasses. All of the measured sums of oxides for the study glasses fell within the interval of 97.9 to 102.6 wt %, indicating acceptable recovery of the glass components. Comparisons of the targeted and measured chemical compositions showed that the measured values for the glasses met the targeted concentrations within 10% for those components present at more than 5 wt %. It was noted that the measured B2O3 concentrations are somewhat above the targeted values for the study glasses. No obvious trends were observed with regard to the multiple melting steps used to prepare the study glasses, indicating that any potential effects of volatility were below measurable thresholds.

  17. Glass Dissolution Parameters: Update for Entsorgungsnachweis

    Energy Technology Data Exchange (ETDEWEB)

    Curti, E

    2003-11-01

    This document provides updated long-term corrosion rates for borosilicate glasses used in Switzerland as a matrix for high-level radioactive waste. The new rates are based on long-term leaching experiments conducted at PSI and are corroborated by recent investigations. The asymptotic rates have been determined through weighted linear regressions of the normalised mass losses, directly calculated from B and Li concentrations in the leaching solutions. Special attention was given to the determination of the analytical uncertainty of the mass losses. The sensitivity of the corrosion rates to analytical uncertainties and to other criteria (e.g. the choice of data points for the regressions) was also studied. A major finding was that the uncertainty of the corrosion rate mainly depends on the uncertainty of the specific glass surface area. The reference rates proposed for safety assessment calculations are 1.5 mg m{sup -2} d{sup -1} for BNFL glasses and 0.2 mg m{sup -2} d{sup -1} for Cogema glasses. The relevance of the proposed corrosion rates for repository conditions is shown based on the analysis of processes and parameters currently known to affect the long-term kinetics of silicate glasses. Specifically, recent studies indicate that potentially detrimental effects, notably the removal of silica from solution through adsorption on clay minerals, are transitory and will not affect the long-term corrosion rate of the Swiss reference glasses. Iron corrosion products are also known to bind silica, but present data are not sufficient to quantify their influence on the long-term rate. (author)

  18. Glass Dissolution Parameters: Update for Entsorgungsnachweis

    International Nuclear Information System (INIS)

    Curti, E.

    2003-11-01

    This document provides updated long-term corrosion rates for borosilicate glasses used in Switzerland as a matrix for high-level radioactive waste. The new rates are based on long-term leaching experiments conducted at PSI and are corroborated by recent investigations. The asymptotic rates have been determined through weighted linear regressions of the normalised mass losses, directly calculated from B and Li concentrations in the leaching solutions. Special attention was given to the determination of the analytical uncertainty of the mass losses. The sensitivity of the corrosion rates to analytical uncertainties and to other criteria (e.g. the choice of data points for the regressions) was also studied. A major finding was that the uncertainty of the corrosion rate mainly depends on the uncertainty of the specific glass surface area. The reference rates proposed for safety assessment calculations are 1.5 mg m -2 d -1 for BNFL glasses and 0.2 mg m -2 d -1 for Cogema glasses. The relevance of the proposed corrosion rates for repository conditions is shown based on the analysis of processes and parameters currently known to affect the long-term kinetics of silicate glasses. Specifically, recent studies indicate that potentially detrimental effects, notably the removal of silica from solution through adsorption on clay minerals, are transitory and will not affect the long-term corrosion rate of the Swiss reference glasses. Iron corrosion products are also known to bind silica, but present data are not sufficient to quantify their influence on the long-term rate. (author)

  19. Wastes based glasses and glass-ceramics

    Directory of Open Access Journals (Sweden)

    Barbieri, L.

    2001-12-01

    Full Text Available Actually, the inertization, recovery and valorisation of the wastes coming from municipal and industrial processes are the most important goals from the environmental and economical point of view. An alternative technology capable to overcome the problem of the dishomogeneity of the raw material chemical composition is the vitrification process that is able to increase the homogeneity and the constancy of the chemical composition of the system and to modulate the properties in order to address the reutilization of the waste. Moreover, the glasses obtained subjected to different controlled thermal treatments, can be transformed in semy-cristalline material (named glass-ceramics with improved properties with respect to the parent amorphous materials. In this review the tailoring, preparation and characterization of glasses and glass-ceramics obtained starting from municipal incinerator grate ash, coal and steel fly ashes and glass cullet are described.

    Realmente la inertización, recuperación y valorización de residuos que proceden de los procesos de incineración de residuos municipales y de residuos industriales son metas importantes desde el punto de vista ambiental y económico. Una tecnología alternativa capaz de superar el problema de la heterogeneidad de la composición química de los materiales de partida es el proceso de la vitrificación que es capaz de aumentar la homogeneidad y la constancia de la composición química del sistema y modular las propiedades a fin de la reutilización del residuo. En este artículo se presentan los resultados de vitrificación en que los vidrios fueron sometidos a tratamientos térmicos controlados diferentes, de manera que se transforman en materiales semicristalinos (también denominados vitrocerámicos con mejores propiedades respecto a los materiales amorfos originales. En esta revisión se muestra el diseño, preparación y caracterización de vidrios y vitrocerámicos partiendo de

  20. Chemical analysis of simulated high level waste glasses to support stage III sulfate solubility modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-17

    The U.S. Department of Energy (DOE), Office of Environmental Management (EM) is sponsoring an international, collaborative project to develop a fundamental model for sulfate solubility in nuclear waste glass. The solubility of sulfate has a significant impact on the achievable waste loading for nuclear waste forms within the DOE complex. These wastes can contain relatively high concentrations of sulfate, which has low solubility in borosilicate glass. This is a significant issue for low-activity waste (LAW) glass and is projected to have a major impact on the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Sulfate solubility has also been a limiting factor for recent high level waste (HLW) sludge processed at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). The low solubility of sulfate in glass, along with melter and off-gas corrosion constraints, dictate that the waste be blended with lower sulfate concentration waste sources or washed to remove sulfate prior to vitrification. The development of enhanced borosilicate glass compositions with improved sulfate solubility will allow for higher waste loadings and accelerate mission completion.The objective of the current scope being pursued by SHU is to mature the sulfate solubility model to the point where it can be used to guide glass composition development for DWPF and WTP, allowing for enhanced waste loadings and waste throughput at these facilities. A series of targeted glass compositions was selected to resolve data gaps in the model and is identified as Stage III. SHU fabricated these glasses and sent samples to SRNL for chemical composition analysis. SHU will use the resulting data to enhance the sulfate solubility model and resolve any deficiencies. In this report, SRNL provides chemical analyses for the Stage III, simulated HLW glasses fabricated by SHU in support of the sulfate solubility model development.

  1. Glass Glimpsed

    DEFF Research Database (Denmark)

    Lock, Charles

    2015-01-01

    Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology.......Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology....

  2. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  3. Thermally stable dexsil-400 glass capillary columns

    International Nuclear Information System (INIS)

    Maskarinec, M.P.; Olerich, G.

    1980-01-01

    The factors affecting efficiency, thermal stability, and reproducibility of Dexsil-400 glass capillary columns for gas chromatography in general, and for polycyclic aromatic hydrocarbons (PAHs) in particular were investigated. Columns were drawn from Kimble KG-6 (soda-lime) glass or Kimox (borosilicate) glass. All silylation was carried out at 200 0 C. Columns were coated according to the static method. Freshly prepared, degassed solutions of Dexsil-400 in pentane or methylene chloride were used. Thermal stability of the Dexsil 400 columns with respect to gas chromatography/mass spectrometry (GC/MS) were tested. Column-to-column variability is a function of each step in the fabrication of the columns. The degree of etching, extent of silylation, and stationary phase film thickness must be carefully controlled. The variability in two Dexsil-400 capillary column prepared by etching, silylation with solution of hexa methyl disilazone (HMDS), and static coating is shown and also indicates the excellent selectivity of Dexsil-400 for the separation of alkylated aromatic compounds. The wide temperature range of Dexsil-400 and the high efficiency of the capillary columns also allow the analysis of complex mixtures with minimal prefractionation. Direct injection of a coal liquefaction product is given. Analysis by GC/MS indicated the presence of parent PAHs, alkylated PAHs, nitrogen and sulfur heterocycles, and their alkylated derivatives. 4 figures

  4. Chemical states of molybdenum in radioactive waste glass

    International Nuclear Information System (INIS)

    Ishiguro, Katsuhiko; Kawanishi, Nobuo; Nagaki, Hiroshi; Naito, Aritsune

    1982-01-01

    In order to confirm an expectation that the chemical state of molybdenum in glass reflects the phase separation tendency of the yellow solid from the melt of borosilicate glass, simulated waste glasses were prepared, and ESCA analysis was performed using a commercially available electron spectrometer (PHI550 E) with an excitation source consisting of Mg Kα-ray. The effects of the concentration of Mo and FE 2 O 3 and the melting atmosphere (oxidizing or reducing) in which the samples were prepared on the chemical state of Mo and the solubility of MoO 3 were examined. From the observation of Mo spectra, it was shown that Mo in waste glass had several valencies, e.g., Mo(3), Mo(4), Mo(5) and Mo(6), while Mo in the yellow solid separated from the melts exhibited hexa-valent state, the peak intensity of higher valencies increased relatively with the increase of MoO 3 concentration, but the chemical state of Mo did not change remarkably around the solubility limit of MoO 3 , the melting atmosphere influenced on the Mo state in the waste glass, the peak intensity of Mo(6) increased relatively with the increasing Fe 2 O 3 concentration, and Mo in devitrified glass exhibited hexa-valent state. (Yoshitake, I.)

  5. Rare earth impact on glass structure and alteration kinetics

    International Nuclear Information System (INIS)

    Molieres, E.

    2012-01-01

    This work is related to the question of the geological deep repository of high-level waste glass. These wastes include fission products and minor actinides, elements which can be simulated by rare earths. As new glass compositions could enable increased rare earth concentrations, it is crucial to know and understand rare earth impact on glass structure on the one hand, and on glass alteration kinetics or their incorporation into an altered layer. This work studied simplified borosilicate glasses in order to limit synergetic effects between rare earths and other elements. Various complementary techniques were used to characterize pristine and altered glasses (solid-high resolution NMR, Raman spectroscopy, fluorescence, SIMS, SAXS). Firstly, the structural role of a rare earth is discussed and is compared to a calcium cation. The local environment of rare earths is also probed. Secondly, rare earth (nature and concentration) impact on several alteration regimes was studied (initial rate, rate drop). Then, after alteration, rare earth elements being retained within the altered layer, the structural impact of rare earth elements (and their local environment) in this alteration layer was also investigated. (author) [fr

  6. Selective functionalization of patterned glass surfaces

    NARCIS (Netherlands)

    Ploetz, E.; Visser, B.; Slingenbergh, W.; Evers, K.; Martinez-Martinez, D.; Pei, Y. T.; Feringa, B. L.; De Hosson, J. Th. M.; Cordes, T.; van Dorp, W. F.

    2014-01-01

    Tailored writing and specific positioning of molecules on nanostructures is a key step for creating functional materials and nano-optical devices, or interfaces for synthetic machines in various applications. We present a novel approach for the selective functionalization of patterned glass surfaces

  7. Modeling of Glass Making Processes for Improved Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Thomas P. Seward III

    2003-03-31

    The overall goal of this project was to develop a high-temperature melt properties database with sufficient reliability to allow mathematical modeling of glass melting and forming processes for improved product quality, improved efficiency and lessened environmental impact. It was initiated by the United States glass industry through the NSF Industry/University Center for Glass Research (CGR) at Alfred University [1]. Because of their important commercial value, six different types/families of glass were studied: container, float, fiberglass (E- and wool-types), low-expansion borosilicate, and color TV panel glasses. CGR member companies supplied production-quality glass from all six families upon which we measured, as a function of temperature in the molten state, density, surface tension, viscosity, electrical resistivity, infrared transmittance (to determine high temperature radiative conductivity), non-Newtonian flow behavior, and oxygen partial pres sure. With CGR cost sharing, we also studied gas solubility and diffusivity in each of these glasses. Because knowledge of the compositional dependencies of melt viscosity and electrical resistivity are extremely important for glass melting furnace design and operation, these properties were studied more fully. Composition variations were statistically designed for all six types/families of glass. About 140 different glasses were then melted on a laboratory scale and their viscosity and electrical resistivity measured as a function of temperature. The measurements were completed in February 2003 and are reported on here. The next steps will be (1) to statistically analyze the compositional dependencies of viscosity and electrical resistivity and develop composition-property response surfaces, (2) submit all the data to CGR member companies to evaluate the usefulness in their models, and (3) publish the results in technical journals and most likely in book form.

  8. Physicochemical Properties of Gold Nanostructures Deposited on Glass

    Directory of Open Access Journals (Sweden)

    Zdenka Novotna

    2014-01-01

    Full Text Available Properties of gold films sputtered onto borosilicate glass substrate were studied. UV-Vis absorption spectra were used to investigate optical parameters. XRD analysis provided information about the gold crystalline nanostructure, the texture, and lattice parameter and biaxial tension was also determined by the XRD method. The surface morphology was examined by atomic force microscopy (AFM; chemical structure of sputtered gold nanostructures was examined by X-ray photoelectron spectroscopy (ARXPS. The gold crystallites are preferentially [111] oriented on the sputtered samples. Gold deposition leads to dramatic changes in the surface morphology in comparison to pristine glass substrate. Oxygen is not incorporated into the gold layer during gold deposition. Experimental data on lattice parameter were also confirmed by theoretical investigations of nanoclusters using tight-binding potentials.

  9. Compositional Dependence of Solubility/Retention of Molybdenum Oxides in Aluminoborosilicate-Based Model Nuclear Waste Glasses.

    Science.gov (United States)

    Brehault, Antoine; Patil, Deepak; Kamat, Hrishikesh; Youngman, Randall E; Thirion, Lynn M; Mauro, John C; Corkhill, Claire L; McCloy, John S; Goel, Ashutosh

    2018-02-08

    Molybdenum oxides are an integral component of the high-level waste streams being generated from the nuclear reactors in several countries. Although borosilicate glass has been chosen as the baseline waste form by most of the countries to immobilize these waste streams, molybdate oxyanions (MoO 4 2- ) exhibit very low solubility (∼1 mol %) in these glass matrices. In the past three to four decades, several studies describing the compositional and structural dependence of molybdate anions in borosilicate and aluminoborosilicate glasses have been reported in the literature, providing a basis for our understanding of fundamental science that governs the solubility and retention of these species in the nuclear waste glasses. However, there are still several open questions that need to be answered to gain an in-depth understanding of the mechanisms that control the solubility and retention of these oxyanions in glassy waste forms. This article is focused on finding answers to two such questions: (1) What are the solubility and retention limits of MoO 3 in aluminoborosilicate glasses as a function of chemical composition? (2) Why is there a considerable increase in the solubility of MoO 3 with incorporation of rare-earth oxides (for example, Nd 2 O 3 ) in aluminoborosilicate glasses? Accordingly, three different series of aluminoborosilicate glasses (compositional complexity being added in a tiered approach) with varying MoO 3 concentrations have been synthesized and characterized for their ability to accommodate molybdate ions in their structure (solubility) and as a glass-ceramic (retention). The contradictory viewpoints (between different research groups) pertaining to the impact of rare-earth cations on the structure of aluminoborosilicate glasses are discussed, and their implications on the solubility of MoO 3 in these glasses are evaluated. A novel hypothesis explaining the mechanism governing the solubility of MoO 3 in rare-earth containing aluminoborosilicate

  10. Glass formulation requirements for DWPF coupled operations using crystalline silicotitanates

    International Nuclear Information System (INIS)

    Harbour, J.R.; Andrews, M.K.

    1997-01-01

    The design basis DWPF flowsheet couples the vitrification of two waste streams: (1) a washed sludge and (2) a hydrolyzed sodium tetraphenylborate precipitate product, PHA. The PHA contains cesium-137 which had been precipitated from the tank supernate with sodium tetraphenylborate. Smaller amounts of strontium and plutonium adsorbed on sodium titanate are also present with the PHA feed. Currently, DWPF is running a sludge-only flowsheet while working towards solutions to the problems encountered with In Tank Precipitation (ITP). The sludge loading for the sludge-only flowsheet and for the anticipated coupled operations is 28 wt% on an oxide basis. For the coupled operation, it is essential to balance the treatment of the two waste streams such that no supernate remains after immobilization of all the sludge. An alternative to ITP and sodium titanate is the removal of Cs-137, Sr-90, and plutonium from the tank supernate by ion exchange using crystalline silicotitanate (CST). This material has been shown to effectively sorb these elements from the supernate. It is also known that CST sorbs plutonium. The loaded CST could then be immobilized with the sludge during vitrification. It has recently been demonstrated that CST loadings approaching 70 wt% for a CST-only glass can be achieved using a borosilicate glass formulation which can be processed by the DWPF melter. Initial efforts on coupled waste streams with simulated DWPF sludge show promise that a borosilicate glass formulation can incorporate both sludge and CST. This paper presents the bases for research efforts to develop a glass formulation which will incorporate sludge and CST at loadings appropriate for DWPF operation

  11. ARTICLES: Polarization effects in birefringent fiber waveguides with an elliptic borosilicate cladding

    Science.gov (United States)

    Grigor'yants, V. V.; Zalogin, A. N.; Ivanov, G. A.; Isaev, Victor A.; Kozel, S. M.; Listvin, V. N.; Chamorovskiĭ, Yu K.

    1986-10-01

    Single-mode fiber waveguides with an elliptic borosilicate cladding were developed and their polarization characteristics were studied. It was found that the mode birefringence was independent of the radiation frequency and varied linearly with the fiber waveguide temperature. The length of the beats was ~10 mm at λ = 0.85μ, whereas the dispersion of the polarization modes was 300 psec/km. The losses were 5-10 dB/km at λ = 0.85μ and the mode coupling parameter was h = 2×10-4m-1. A study was made of the possibility of using single-mode fiber waveguides for the depolarization of nonmonochromatic radiation and also as tunable delay lines.

  12. Polarization effects in birefringent fiber-optic waveguides with an elliptical borosilicate cladding

    Science.gov (United States)

    Grigoriants, V. V.; Zalogin, A. N.; Ivanov, G. A.; Isaev, V. A.; Kozel, S. M.

    1986-10-01

    Single-mode fiber-optic waveguides (SFW) with an elliptical borosilicate cladding are developed and their polarization characteristics are studied. It is shown that their mode birefringence, while independent of the radiation frequency, depends linearly on the SFW temperature. The beat length is about 10 mm at a wavelength of 0.85 micron and the dispersion of the polarization modes is about 300 ps/km. The losses amount to 5-10 dB/km at 0.85 micron and the mode coupling parameter is 0.0002/m. Consideration is given to the possibility of using SFW for the depolarization of nonmonochromatic radiation and as tunable delay lines.

  13. Fabrication and characterization of MCC [Materials Characterization Center] approved testing material---ATM-2, ATM-3, and ATM-4 glasses

    International Nuclear Information System (INIS)

    Wald, J.W.

    1988-03-01

    Materials Characterization Center glasses ATM-2, ATM-3, and ATM-4 are designed to simulate high-level waste glasses that are likely to result from the reprocessing of commercial nuclear reactor fuels. The three Approved Testing Materials (ATMs) are borosilicate glasses based upon the MCC-76-68 glass composition. One radioisotope was added to form each ATM. The radioisotopes added to form ATM-2, ATM-3, and ATM-4 were 241 Am, 237 Np, and 239 Pu, respectively. Each of the ATM lots was produced in a nominal lot size of 450 g from feed stock melted in a nitrogen-atmosphere glove box at 1200/degree/C in a platinum crucible. Each ATM was then cast into bars. Analyzed compositions of these glasses are listed. The nonradioactive elements were analyzed by inductively coupled argon plasma atomic emission spectroscopy (ICP), and the radioisotope analyses were done by alpha energy analysis. Results are discussed. 7 refs., 3 figs., 5 tabs

  14. Understanding of the mechanical and structural changes induced by alpha particles and heavy ions in the French simulated nuclear waste glass

    International Nuclear Information System (INIS)

    Karakurt, G.; Abdelouas, A.; Guin, J.-P.; Nivard, M.; Sauvage, T.; Paris, M.; Bardeau, J.-F.

    2016-01-01

    Borosilicate glasses are considered for the long-term confinement of high-level nuclear wastes. External irradiations with 1 MeV He + ions and 7 MeV Au 5+ ions were performed to simulate effects produced by alpha particles and by recoil nuclei in the simulated SON68 nuclear waste glass. To better understand the structural modifications, irradiations were also carried out on a 6-oxides borosilicate glass, a simplified version of the SON68 glass (ISG glass). The mechanical and macroscopic properties of the glasses were studied as function of the deposited electronic and nuclear energies. Alpha particles and gold ions induced a volume change up to −0.7% and −2.7%, respectively, depending on the glass composition. Nano-indentations tests were used to determine the mechanical properties of the irradiated glasses. A decrease of about −22% to −38% of the hardness and a decrease of the reduced Young's modulus by −8% were measured after irradiations. The evolution of the glass structure was studied by Raman spectroscopy, and also 11 B and 27 Al Nuclear Magnetic Resonance (MAS-NMR) on a 20 MeV Kr irradiated ISG glass powder. A decrease of the silica network connectivity after irradiation with alpha particles and gold ions is deduced from the structural changes observations. NMR spectra revealed a partial conversion of BO 4 to BO 3 units but also a formation of AlO 5 and AlO 6 species after irradiation with Kr ions. The relationships between the mechanical and structural changes are also discussed. - Highlights: • Mechanical and structural properties of two borosilicate glass compositions irradiated with alpha particles and heavy ions were investigated. • Both kinds of particles induced a decrease of the hardness, reduced Young's modulus and density. • Electronic and nuclear interactions are responsible for the changes observed. • The evolution of the mechanical properties under irradiation is linked to the changes occured in the

  15. Effect of geologic repository parameters on aqueous corrosion of nuclear glass

    International Nuclear Information System (INIS)

    Tovena, I.; Advocat, T.; Jollivet, P.; Godon, N.; Vernaz, E.

    1995-01-01

    Twenty alumino-borosilicate glass compositions containing simulated fission product oxides were defined using the experimentation plan methodology. Three additional glass compositions were also tested. Monolithic glass corrosion tests in a dilute aqueous medium at 90 deg C indicated the variation range for the initial corrosion rates. Significant but only qualitative correlations were established between the initial corrosion rate and the molar fraction of glass network forming oxides (SiO 2 + Al 2 O 3 ), and between the initial rate and the (Na 2 O + Li 2 O + B 2 O 3 ) / (SiO 2 + Al 2 O 3 ) molar ratio in the glass. The experimentation plan allowed a polynomial model to be defined relating the initial corrosion rate at 90 deg C to the oxide concentrations in the glass. Although the model is theoretically capable of predicting the corrosion rates, it does not always account for the actual data measured during other experiments; this discrepancy may be attributable either to the presence of other chemical elements (MgO) or to CaO concentrations differing from the fixed value adopted for the experimentation plan. Glass powder corrosion tests designed to simulate advanced corrosion reaction progress, account for the wide variations in the dissolved glass quantities, although no correlation exists with the glass chemical composition. (authors). 49 refs., 4 figs., 34 tabs

  16. Effect of geologic repository parameters on aqueous corrosion of nuclear glass

    Energy Technology Data Exchange (ETDEWEB)

    Tovena, I.; Advocat, T.; Jollivet, P.; Godon, N.; Vernaz, E.

    1995-12-31

    Twenty alumino-borosilicate glass compositions containing simulated fission product oxides were defined using the experimentation plan methodology. Three additional glass compositions were also tested. Monolithic glass corrosion tests in a dilute aqueous medium at 90 deg C indicated the variation range for the initial corrosion rates. Significant but only qualitative correlations were established between the initial corrosion rate and the molar fraction of glass network forming oxides (SiO{sub 2} + Al{sub 2}O{sub 3}), and between the initial rate and the (Na{sub 2}O + Li{sub 2}O + B{sub 2}O{sub 3}) / (SiO{sub 2} + Al{sub 2}O{sub 3}) molar ratio in the glass. The experimentation plan allowed a polynomial model to be defined relating the initial corrosion rate at 90 deg C to the oxide concentrations in the glass. Although the model is theoretically capable of predicting the corrosion rates, it does not always account for the actual data measured during other experiments; this discrepancy may be attributable either to the presence of other chemical elements (MgO) or to CaO concentrations differing from the fixed value adopted for the experimentation plan. Glass powder corrosion tests designed to simulate advanced corrosion reaction progress, account for the wide variations in the dissolved glass quantities, although no correlation exists with the glass chemical composition. (authors). 49 refs., 4 figs., 34 tabs.

  17. Degradation of partially immersed glass: A new perspective

    Science.gov (United States)

    Chinnam, R. K.; Fossati, P. C. M.; Lee, W. E.

    2018-05-01

    The International Simple Glass (ISG) is a six-component borosilicate glass which was developed as a reference for international collaborative studies on high level nuclear waste encapsulation. Its corrosion behaviour is typically examined when it is immersed in a leaching solution, or when it is exposed to water vapour. In this study, an alternative situation is considered in which the glass is only partially immersed for 7 weeks at a temperature of 90 °C. In this case, half of the glass sample is directly in the solution itself, and the other half is in contact with a water film formed by condensation of water vapour that evaporated from the solution. This results in a different degradation behaviour compared to standard tests in which the material is fully immersed. In particular, whilst in standard tests the system reaches a steady state with a very low alteration rate thanks to the formation of a protective gel layer, in partially-immersed tests this steady state could not be reached because of the continuous alteration from the condensate water film. The constant input of ions from the emerged part of the sample caused a supersaturation of the solution, which resulted in early precipitation of secondary crystalline phases. This setup mimics storage conditions once small amounts of water have entered a glass waste form containing canister. It offers a more realistic outlook of corrosion mechanisms happening in such situations than standard fully-immersed corrosion tests.

  18. Development of an ASTM standard glass durability test, the Product Consistency Test (PCT), for high level radioactive waste glass

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.

    1994-01-01

    The nation's first, and the world's largest, facility to immobilize high-level nuclear waste in durable borosilicate glass has started operation at the Savannah River Site (SRS) in Aiken, South Carolina. The product specifications on the glass wasteform produced in the Defense Waste Processing Facility (DWPF) required extensive characterization of the glass product before actual production began and for continued characterization during production. To aid in this characterization, a glass durability (leach) test was needed that was easily reproducible, could be performed remotely on highly radioactive samples, and could yield results rapidly. Several standard leach tests were examined with a variety of test configurations. Using existing tests as a starting point, the DWPF Product Consistency Test (PCT was developed in which crushed glass samples are exposed to 90 ± 2 degree C deionized water for seven days. Based on extensive testing, including a seven-laboratory round robin and confirmatory testing with radioactive samples, the PCT is very reproducible, yields reliable results rapidly, and can be performed in shielded cell facilities with radioactive samples

  19. Spin glasses

    International Nuclear Information System (INIS)

    Fischer, K.H.; Hertz, J.A.

    1993-01-01

    Spin glasses, simply defined by the authors as a collection of spins (i.e., magnetic moments) whose low-temperature state is a frozen disordered one, represent one of the fascinating new fields of study in condensed matter physics, and this book is the first to offer a comprehensive account of the subject. Included are discussions of the most important developments in theory, experimental work, and computer modeling of spin glasses, all of which have taken place essentially within the last two decades. The first part of the book gives a general introduction to the basic concepts and a discussion of mean field theory, while the second half concentrates on experimental results, scaling theory, and computer simulation of the structure of spin glasses

  20. IR spectroscopic investigation of the structure of glasses containing a sol of burned radioactive by-products

    International Nuclear Information System (INIS)

    Stefanovskii, S.V.; Ivanov, I.A.; Gulin, A.N.

    1993-01-01

    On glassification of sols from the burning apparatus of radioactive by-products (RAB) using sodium borate, sodium silicate, or borosilicate flux, glassy materials suitable for long-time storage or final burying are obtained. Technological and ecologically important properties of glassified RAB are determined by their structure. In some preliminary results are presented of a study of the structure of silicate and borosilicate glasses containing a sol of concrete composition. In a real sol from technological apparatus the qualitative and quantitative relations of the ingredients vary within broad limits. The purpose of this work is a systematic investigation of the structure of sol-containing glassy materials depending on their composition using IR spectroscopy. 16 refs., 4 figs., 3 tabs

  1. Towards tailor-made participation

    DEFF Research Database (Denmark)

    Agger, Annika

    2012-01-01

    Public participation has become an important element of governance in many Western European countries. However, among scholars and practitioners there is a recognition that participatory governance processes tend to produce systematic exclusions. Knowledge about 'who' participates and 'how......' they participate can enhance our understanding of participatory processes. This paper presents some characterisations of citizens based on a review of the literature on participation. In addition, examples of how to tailor participation for different type of citizens are provided based on studies of urban...... regeneration programmes and local environmental initiatives in Denmark. The paper concludes that in order to broaden the inclusion of affected citizens, public authorities need to be tailor participation processes by applying distinct approaches to different types of citizens...

  2. Effects of alteration product precipitation on glass dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Neeway, James J.

    2014-06-01

    Understanding the mechanisms that control the durability of nuclear waste glass is paramount if reliable models are to be constructed so that the glass dissolution rate in a given geological repository can be calculated. Presently, it is agreed that (boro)silicate glasses dissolve in water at a rate dependent on the solution concentration of orthosilicic acid (H4SiO4) with higher [H4SiO4] leading to lower dissolution rates. Once the reaction has slowed as a result of the buildup of H4SiO4, another increase in the rate has been observed that corresponds to the precipitation of certain silica-bearing alteration products. However, it has also been observed that the concentration of silica-bearing solution species does not significantly decrease, indicating saturation, while other glass tracer elements concentrations continue to increase, indicating that the glass is still dissolving. In this study, we have used the Geochemist’s Workbench code to investigate the relationship between glass dissolution rates and the precipitation rate of a representative zeolitic silica-bearing alteration product, analcime [Na(AlSi2O6)∙H2O]. To simplify the calculations, we suppressed all alteration products except analcime, gibbsite (Al(OH)3), and amorphous silica. The pseudo-equilibrium-constant matrix for amorphous silica was substituted for the glass pseudo-equilibrium-constant matrix because it has been shown that silicate glasses act as a silica-only solid with respect to kinetic considerations. In this article, we present the results of our calculations of the glass dissolution rate at different values for the analcime precipitation rate constant and the effects of varying the glass dissolution rate constant at a constant analcime precipitation rate constant. From the simulations we conclude, firstly, that the rate of glass dissolution is dependent on the kinetics of

  3. The Effect of Caramelization and Carbonization Temperatures toward Structural Properties of Mesoporous Carbon from Fructose with Zinc Borosilicate Activator

    OpenAIRE

    Setianingsih, Tutik; Kartini, Indriana; Arryanto, Yateman

    2014-01-01

    Mesoporous carbon was prepared from fructose using zinc borosilicate (ZBS) activator. The synthesis involves caramelization and carbonization processes. The effect of both process temperature toward porosity and functional group of carbon surface are investigated in this research. The caramelization was conducted hydrothermally at 85 and 100 °C, followed by thermally 130 °C. The carbonization was conducted at various temperatures (450–750 °C). The carbon-ZBS composite were washed by using HF ...

  4. 4.2. The kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit. The dependence of nitric acid decomposition of calcined boric raw material for extraction of boron oxide on temperature (20-100 deg C) and process duration (15-60 minutes) was defined. It was defined that at temperature increasing the extraction rate of boron oxide increases from 20.8 to 78.6%.

  5. Summary Report: Glass-Ceramic Waste Forms for Combined Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Riley, Brian J.; Turo, Laura A.; Tang, Ming; Kossoy, Anna

    2011-09-23

    Glass-ceramic waste form development began in FY 2010 examining two combined waste stream options: (1) alkaline earth (CS) + lanthanide (Ln), and (2) + transition metal (TM) fission-product waste streams generated by the uranium extraction (UREX+) separations process. Glass-ceramics were successfully developed for both options however; Option 2 was selected over Option 1, at the conclusion of 2010, because Option 2 immobilized all three waste streams with only a minimal decrease in waste loading. During the first year, a series of three glass (Option 2) were fabricated that varied waste loading-WL (42, 45, and 50 mass%) at fixed molar ratios of CaO/MoO{sub 3} and B{sub 2}O{sub 3}/alkali both at 1.75. These glass-ceramics were slow cooled and characterized in terms of phase assemblage and preliminary irradiation stability. This fiscal year, further characterization was performed on the FY 2010 Option 2 glass-ceramics in terms of: static leach testing, phase analysis by transmission electron microscopy (TEM), and irradiation stability (electron and ion). Also, a new series of glass-ceramics were developed for Option 2 that varied the additives: Al{sub 2}O{sub 3} (0-6 mass%), molar ratio of CaO/MoO{sub 3} and B{sub 2}O{sub 3}/alkali (1.75 to 2.25) and waste loading (50, 55, and 60 mass%). Lastly, phase pure powellite and oxyapatite were synthesized for irradiation studies. Results of this fiscal year studies showed compositional flexibility, chemical stability, and radiation stability in the current glass-ceramic system. First, the phase assemblages and microstructure of all of the FY 2010 and 2011 glass-ceramics are very similar once subjected to the slow cool heat treatment. The phases identified in these glass-ceramics were oxyapatite, powellite, cerianite, and ln-borosilicate. This shows that variations in waste loading or additives can be accommodated without drastically changing the phase assemblage of the waste form, thus making the processing and performance

  6. Tailoring Earned Value Management. General Guidelines

    National Research Council Canada - National Science Library

    2002-01-01

    Partial Contents: General Principles, A Spectrum of Implementation, OMB Guidance, A Special Note about DOD, Risk Factors to Consider, How can EVMS be tailored, Tailor EVMS to Inherent Risk, Application Thresholds-DoD...

  7. Metallic glasses

    NARCIS (Netherlands)

    Schaafsma, Arjen Sybren

    1981-01-01

    It is shown in section 7.1. that the influence of topological disorder on the range of magnetic interactions in ferromagnetic transition metal-metalloid (TM-M) glasses, is much less than often assumed. This is demonstrated via a study of the temperature dependence of the average iron hyperfine field

  8. Evaluation of Photocatalytic Active Coatings on Sintered Glass Tubes by Methylene Blue

    Directory of Open Access Journals (Sweden)

    Colin Awungacha Lekelefac

    2013-01-01

    Full Text Available A comparative study between ten different photocatalytic active coatings was done. The effectiveness and photocatalytic activity of the coatings were studied by degradation experiments of methylene blue (MB dye under UV light illumination. The reactor design consisting of sintered glass packed in a borosilicate tube placed between two planar dielectric barrier discharge lamps (Osram Planon is reported for the first time. The coatings consisted of either titania, silica, or zinc on sintered borosilicate glass. The advantage of sol-gel in catalyst preparation was exploited to combine catalyst to act as cocatalyst. TiO2-P25 widely applied in suspension systems was effectively immobilized on sintered glass support with the aid of tetraethylorthosilicate (TEOS solution which acted as support material. Results indicated that TiO2-P25+SiO2, TiO2-P25+SiO2+Pt, and TiOSO4_30,6wt% films showed highest degradation rates close to 100% after 90 min illumination with degradation rates exceeding 50% after 30 minutes. TTIP+Pt showed lowest degradation rate.

  9. High rate operation of micro-strip gas chambers on diamond-coated glass

    CERN Document Server

    Bouclier, Roger; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Temmel, T; Cooke, R A; Donnel, S; Sastri, S A; Sonderer, N

    1996-01-01

    Very high rate operation of micro­strip gas chambers can be achieved using slightly conducting substrates. We describe preliminary measurements realized with detectors manufactured on boro-silicate glass coated, before the photo-lithographic processing, with a diamond layer having a surface resistivity of around 1014 ‡/o. Stable medium-term operation, and a rate capability largely exceeding the one obtained with identical plates manufactured on uncoated glass are demonstrated. If these results are confirmed by long-term measurements the diamond coating technology appears very attractive since it allows, with a moderate cost overhead, to use thin, commercially available glass with the required surface quality for the large-scale production of gas micro-strip detectors.

  10. Conversion of plutonium scrap and residue to boroilicate glass using the GMODS process

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.; Rudolph, J.; Elam, K.R.; Ferrada, J.J.

    1995-01-01

    Plutonium scrap and residue represent major national and international concerns because (1) significant environmental, safety, and health (ES ampersand H) problems have been identified with their storage; (2) all plutonium recovered from the black market in Europe has been from this category; (3) storage costs are high; and (4) safeguards are difficult. It is proposed to address these problems by conversion of plutonium scrap and residue to a CRACHIP (CRiticality, Aerosol, and CHemically Inert Plutonium) glass using the Glass Material Oxidation and Dissolution System (GMODS). CRACHIP refers to a set of requirements for plutonium storage forms that minimize ES ampersand H concerns. The concept is several decades old. Conversion of plutonium from complex chemical mixtures and variable geometries into a certified, qualified, homogeneous CRACHIP glass creates a stable chemical form that minimizes ES ampersand H risks, simplifies safeguards and security, provides an easy-to-store form, decreases storage costs, and allows for future disposition options. GMODS is a new process to directly convert metals, ceramics, and amorphous solids to glass; oxidize organics with the residue converted to glass; and convert chlorides to borosilicate glass and a secondary sodium chloride stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium (a plutonium surrogate), Zircaloy, stainless steel, and other materials to glass. GMODS is an enabling technology that creates new options. Conventional glassmaking processes require conversion of feeds to oxide-like forms before final conversion to glass. Such chemical conversion and separation processes are often complex and expensive

  11. Deep drawing simulation of Tailored Blanks

    NARCIS (Netherlands)

    van den Berg, Albert; Meinders, Vincent T.; Stokman, B.

    1998-01-01

    Tailored blanks are increasingly used in the automotive industry. A tailored blank consists of different metal parts, which are joined by a welding process. These metal parts usually have different material properties. Hence, the main advantage of using a tailored blank is to provide the right

  12. X-ray photoemission spectroscopy and ion backscattering analysis of leached simulated waste glass containing UO3

    International Nuclear Information System (INIS)

    Karim, D.P.; Lam, D.J.

    1980-01-01

    UO 3 has been dissolved into several complex borosilicate glasses including Battelle simulated waste glasses 76-68, 3008, and 76-101. The glass surfaces were examined before and after leaching using x-ray photoemission spectroscopy and backscattered ion beam profiling. Samples leached in distilled water showed enhanced surface layer concentrations of several elements including uranium, titanium, zinc, iron and rare earths. For the case of uranium in 76-101, a simple experiment involving leaching two glasses in the same container showed that this surface enhancement is probably not due to redeposition from solution. Similar samples behaved quite differently when leached in a pH = 3.5 nitric acid solution, showing a surface layer high in SiO 2

  13. Properties of α doped glasses referring to the long term disposal of solidified high level radioactive wastes

    International Nuclear Information System (INIS)

    Jacquet-Francillon, N.; Vernaz, E.

    1981-11-01

    The evolution of physical and chemical properties of α doped glasses has been investigated in samples in which the cumulated α dose was increasing in one case up to 3.10 18 α/g. The tests carried out up to now do not ascertain any harmful effects of α activity upon borosilicated glasses. The generated helium is kept occluded in the glass up to a given limit, and is then diffused. Leaching experiments brought to light some particular features concerning the leach rate of α emitters: this does not rise when the temperature or the SA/V ratio is increased, and in fact decreases when the renewing frequency of the water is lessened. Finally it is demonstrated that the majority of the leached α activity is in the form of insoluble material and can be trapped in an 8 μ filter. All these results are extremely encouraging in view of a geological disposal of α containing glasses

  14. Study of Structural Properties of Mesoporous Carbon From Fructose with Zinc Borosilicate Activator

    Directory of Open Access Journals (Sweden)

    Tutik Setianingsih

    2014-04-01

    Full Text Available Structural properties, including pore structure, functional group of carbon surface, and crystal structure of carbon built by zinc borosilicate (ZBS and ZnCl2 (Z have been investigated in this work. Physically, ZBS and ZnCl2 may act as template of carbon, whereas the Zn(II cation act as chemical activator of carbonization. All precursors of ZBS (silicagel, boric acid, and ZnCl2 may act as catalysts of caramelization. The caramelization was conducted hydrothermally at 85oC and thermally 130oC. The carbonization was conducted at 450oC. The resulted carbons were washed by using HF 48% solution, 1M HCl solution, and aquadest respectively. The solid products were characterized by using nitrogen gas adsorption, infrared spectrophotometry, X-ray diffraction, and Transmition Electron Microscopy. Result of research showed that ZBS built larger mesopore volume, larger pore domination of pore size, more hydrophobic carbon, and more amorf than ZnCl2.

  15. Strontium chloroapatite based glass-ceramics composites for nuclear waste immobilisation

    International Nuclear Information System (INIS)

    Jena, Hrudananda; Maji, Binoy Kumar; Asuvathraman, R.; Govindan Kutty, K.V.

    2013-01-01

    Apatites are naturally occurring minerals with a general formula of M 10 (PO 4 ) 6 X 2 , (M= Ca, Sr, Ba, X= OH, Cl, F) with a hexagonal crystal structure (S.G :P6 3 /m) and can accommodate alkaline earth and various other aliovalent cations and anions into its crystal structure. Apatites are also known to have high resistance to leaching of the constituent elements under geological conditions. It may not often be possible to immobilize the whole spectrum of the radioactive waste in a single phase M 10 (PO 4 ) 6 Cl 2 , then a combination of M-chloroapatite encapsulated in borosilicate glass (BSG) can immobilize most of the radwaste elements in the composite glass-ceramic matrix (glass bonded chloroapatite), thus utilizing the immobilizing efficiency of both the ceramic phase and glass. In the present study, the synthesis, characterization and thermo-physical property measurements of the Sr-chloroapatite (SrApCI) and some glass-bonded composites based on it have been investigated. The Sr-chloroapatite glass-ceramics were prepared by solid state reactions among stoichiometric concentrations of apatite forming reagents, 20 wt. % borosilicate glass (BSG), and known concentrations (10, 13 and 16 wt. %) of a simulated waste in chloride form. The products were characterized by XRD to confirm the formation of Sr 10 (PO 4 ) 6 Cl 2 and glass bonded-chloroapatite composites. The surface morphology and qualitative chemical composition of the powders were examined by SEM and EDX. Thermal expansion and glass transition temperature of the matrices were measured by dilatometry. Glass transition temperature of the glass-bonded composites was also examined by differential scanning calorimetry and differential thermal analysis. The 10-16 wt.% waste loaded matrices showed similar thermal expansion as that of SrApCI, indicating the thermal stability of the matrix to chloride waste immobilization. The glass transition temperature of the waste loaded matrices decreases on increasing the

  16. Baseline Glass Development for Combined Fission Products Waste Streams

    International Nuclear Information System (INIS)

    Crum, Jarrod V.; Billings, Amanda Y.; Lang, Jesse B.; Marra, James C.; Rodriguez, Carmen P.; Ryan, Joseph V.; Vienna, John D.

    2009-01-01

    Borosilicate glass was selected as the baseline technology for immobilization of the Cs/Sr/Ba/Rb (Cs), lanthanide (Ln) and transition metal fission product (TM) waste steams as part of a cost benefit analysis study.(1) Vitrification of the combined waste streams have several advantages, minimization of the number of waste forms, a proven technology, and similarity to waste forms currently accepted for repository disposal. A joint study was undertaken by Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) to develop acceptable glasses for the combined Cs + Ln + TM waste streams (Option 1) and Cs + Ln combined waste streams (Option 2) generated by the AFCI UREX+ set of processes. This study is aimed to develop baseline glasses for both combined waste stream options and identify key waste components and their impact on waste loading. The elemental compositions of the four-corners study were used along with the available separations data to determine the effect of burnup, decay, and separations variability on estimated waste stream compositions.(2-5) Two different components/scenarios were identified that could limit waste loading of the combined Cs + LN + TM waste streams, where as the combined Cs + LN waste stream has no single component that is perceived to limit waste loading. Combined Cs + LN waste stream in a glass waste form will most likely be limited by heat due to the high activity of Cs and Sr isotopes.

  17. Strontium borate glass: potential biomaterial for bone regeneration.

    Science.gov (United States)

    Pan, H B; Zhao, X L; Zhang, X; Zhang, K B; Li, L C; Li, Z Y; Lam, W M; Lu, W W; Wang, D P; Huang, W H; Lin, K L; Chang, J

    2010-07-06

    Boron plays important roles in many life processes including embryogenesis, bone growth and maintenance, immune function and psychomotor skills. Thus, the delivery of boron by the degradation of borate glass is of special interest in biomedical applications. However, the cytotoxicity of borate glass which arises with the rapid release of boron has to be carefully considered. In this study, it was found that the incorporation of strontium into borate glass can not only moderate the rapid release of boron, but also induce the adhesion of osteoblast-like cells, SaOS-2, thus significantly increasing the cyto-compatibility of borate glass. The formation of multilayers of apatite with porous structure indicates that complete degradation is optimistic, and the spread of SaOS-2 covered by apatite to form a sandwich structure may induce bone-like tissue formation at earlier stages. Therefore, such novel strontium-incorporated borosilicate may act as a new generation of biomaterial for bone regeneration, which not only renders boron as a nutritious element for bone health, but also delivers strontium to stimulate formation of new bones.

  18. Baseline Glass Development for Combined Fission Products Waste Streams

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Billings, Amanda Y.; Lang, Jesse B.; Marra, James C.; Rodriguez, Carmen P.; Ryan, Joseph V.; Vienna, John D.

    2009-06-29

    Borosilicate glass was selected as the baseline technology for immobilization of the Cs/Sr/Ba/Rb (Cs), lanthanide (Ln) and transition metal fission product (TM) waste steams as part of a cost benefit analysis study.[1] Vitrification of the combined waste streams have several advantages, minimization of the number of waste forms, a proven technology, and similarity to waste forms currently accepted for repository disposal. A joint study was undertaken by Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) to develop acceptable glasses for the combined Cs + Ln + TM waste streams (Option 1) and Cs + Ln combined waste streams (Option 2) generated by the AFCI UREX+ set of processes. This study is aimed to develop baseline glasses for both combined waste stream options and identify key waste components and their impact on waste loading. The elemental compositions of the four-corners study were used along with the available separations data to determine the effect of burnup, decay, and separations variability on estimated waste stream compositions.[2-5] Two different components/scenarios were identified that could limit waste loading of the combined Cs + LN + TM waste streams, where as the combined Cs + LN waste stream has no single component that is perceived to limit waste loading. Combined Cs + LN waste stream in a glass waste form will most likely be limited by heat due to the high activity of Cs and Sr isotopes.

  19. Time series with tailored nonlinearities

    Science.gov (United States)

    Räth, C.; Laut, I.

    2015-10-01

    It is demonstrated how to generate time series with tailored nonlinearities by inducing well-defined constraints on the Fourier phases. Correlations between the phase information of adjacent phases and (static and dynamic) measures of nonlinearities are established and their origin is explained. By applying a set of simple constraints on the phases of an originally linear and uncorrelated Gaussian time series, the observed scaling behavior of the intensity distribution of empirical time series can be reproduced. The power law character of the intensity distributions being typical for, e.g., turbulence and financial data can thus be explained in terms of phase correlations.

  20. Radiopaque strontium fluoroapatite glass-ceramics

    Directory of Open Access Journals (Sweden)

    Wolfram eHöland

    2015-10-01

    expansion (CTE. These glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications.The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs and optical characteristics.

  1. Durabilities and Microstructures of Radioactive Glasses to Immobilize Excess Actinides and Reprocessing Wastes at SRS

    International Nuclear Information System (INIS)

    Bibler, N.E.

    1995-01-01

    This paper presents results of an investigation of the microstructures and durabilities of glasses for immobilization of excess Pu, Am, and Cm, and of the reprocessing wastes at Savannah River Site (SRS). The reprocessing wastes will be vitrified in the Defense Waste Processing Facility (DWPF) at SRS. Another facility at SRS will be used for the Pu, Am, and Cm glasses. In this paper results are presented for a DWPF radioactive glass containing the actual fission product-actinide waste from one the million gallon storage tanks at SRS. This waste is the first radioactive sludge that will be processed in DWPF. The actinide glasses investigated had compositions based on a commercial borosilicate glass composition. All the glasses were so radioactive that they had to be prepared remotely in shielded cells and the analyses had to be performed in gloveboxes or radiobenches. Durabilities were measured using the ASTM C-1285 standard leach test. Results for four glasses are presented. The glasses are a DWPF type glass containing Tank 51 radioactive waste, two glasses containing 15 and 13 wt.percent Pu, respectively, and a glass containing Am and Cm. The radioactive DWPF glass contained 28 wtpercent waste from SRS Tank 51 and was homogeneous. The 15 wt percent Pu contained dissolved PuO2 and as well PuO2 crystals that were not dissolved but were trapped in the glass. The 13 wt percent Pu glass was homogenous. The Am/Cm glass contained <1 wt percent actinides and was homogenous. The PCT test indicated that B, Li, and Na were leaching congruently from the glass. Release rates for Tc-99 and Np-237 were also congruent while Cs-133, Th-232, U-238, and Pu-239 were slower. The two Pu glasses were 25 to 50 times more durable than the DWPF glass. B and Ba were leached congruently while Sm and Pu were lower. Release rates for B and Ba from the Am-Cm glass were equal and 27X lower than the DWPF glass

  2. Topological Approach for Predicting the Properties of Glasses

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, John C.; Yue, Yuanzheng

    and M.F. Thorpe around 1980. By further including the Gupta-Mauro temperature dependence of the constraints, the composition dependence of properties such as hardness and viscosity can be quantitatively predicted for oxide network glasses of industrial interest, such as borates and borosilicates......Predicting the properties of new materials prior to manufacturing is a topic attracting great industrial and scientific interest. Property prediction for ceramic materials is facilitated by the periodic short- and long-range order of crystals. However, for glassy systems the lack of long......-range order and the long time scales for relaxation greatly complicate the traditional modeling efforts. We show that the key for making progress has been to extract the key physics governing the macroscopic properties by using topological constraint theory, which was originally developed by J.C. Phillips...

  3. Immobilization of high-level wastes into sintered glass: 1

    International Nuclear Information System (INIS)

    Russo, D.O.; Messi de Bernasconi, N.; Audero, M.A.

    1987-01-01

    In order to immobilize the high-level radioactive wastes from fuel elements reprocessing, borosilicate glass was adopted. Sintering experiments are described with the variety VG 98/12 (SiO 2 , TiO 2 , Al 2 O 3 , B 2 O 3 , MgO, CaO and Na 2 O) (which does not present devitrification problems) mixed with simulated calcinated wastes. The hot pressing line (sintering under pressure) was explored in two variants 1: In can; 2: In graphite matrix with sintered pellet extraction. With scanning electron microscopy it is observed that the simulated wastes do not disolve in the vitreous matrix, but they remain dispersed in the same. The results obtained point out that the leaching velocities are independent from the density and from the matrix type employed, as well as from the fact that the wastes do no dissolve in the matrix. (M.E.L.) [es

  4. Clinical and surgical applications of smart glasses.

    Science.gov (United States)

    Mitrasinovic, Stefan; Camacho, Elvis; Trivedi, Nirali; Logan, Julia; Campbell, Colson; Zilinyi, Robert; Lieber, Bryan; Bruce, Eliza; Taylor, Blake; Martineau, David; Dumont, Emmanuel L P; Appelboom, Geoff; Connolly, E Sander

    2015-01-01

    With the increased efforts to adopt health information technology in the healthcare field, many innovative devices have emerged to improve patient care, increase efficiency, and decrease healthcare costs. A recent addition is smart glasses: web-connected glasses that can present data onto the lenses and record images or videos through a front-facing camera. In this article, we review the most salient uses of smart glasses in healthcare, while also denoting their limitations including practical capabilities and patient confidentiality. Using keywords including, but not limited to, ``smart glasses'', ``healthcare'', ``evaluation'', ``privacy'', and ``development'', we conducted a search on Ovid-MEDLINE, PubMed, and Google Scholar. A total of 71 studies were included in this review. Smart glasses have been adopted into the healthcare setting with several useful applications including, hands-free photo and video documentation, telemedicine, Electronic Health Record retrieval and input, rapid diagnostic test analysis, education, and live broadcasting. In order for the device to gain acceptance by medical professionals, smart glasses will need to be tailored to fit the needs of medical and surgical sub-specialties. Future studies will need to qualitatively assess the benefits of smart glasses as an adjunct to the current health information technology infrastructure.

  5. Platinoids and molybdenum in nuclear waste containment glasses: a structural study; Les platinoides et le molybdene dans des verres d'interet nucleaires: etude structurale

    Energy Technology Data Exchange (ETDEWEB)

    Le Grand, M. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification (DRRV), 30 - Marcoule (France)]|[Paris-7 Univ., 75 (France)

    2000-07-01

    This work deals with the structure of borosilicate nuclear glasses and with some relationships between structure and macroscopic properties. Two types of elements which may disturb the industrial process - platinoids (Ru and Pd) and molybdenum - are central to this work. Platinoids induce weak modifications on the structure of the glass, causing a depolymerization of the glassy network, an increase of the {sup [3]}B/{sup [4]}B ratio and a modification of the medium range order around Si between 3.3 and 4.5 angstrom. The modifications of viscosity and density induced by platinoids in the glass are not due to the structural effect of the platinoids. The increase of viscosity is attributed to needle shaped RuO{sub 2}. It can be moderated by imposing reducing conditions during the elaboration of the glass. The slight difference between experimental and calculated densities is due to the increase of the volume percentage of bubbles in the glass with increasing platinoid content. Mo is either present in the glass as molybdic groupings, or mobilized in chemically complex molybdic crystalline phases. The chemical composition and mineralogy of these phases has been obtained using electronic microprobe data and XRD with Rietveld analysis. The distribution of the different elements between the crystalline phases and the glass is strongly influenced by the structural role of the various cations in the glass. The Mo present in the glass appears as MoO{sub 4} tetrahedra, independent of the borosilicate network. The formation of the crystalline phases can be explained by the existence of a precursor in which the MoO{sub 4} tetrahedra are concentrated in rich alkali and earth-alkali bearing areas of the glass. (author)

  6. Radiological analysis of plutonium glass batches with natural/enriched boron

    International Nuclear Information System (INIS)

    Rainisch, R.

    2000-01-01

    The disposition of surplus plutonium inventories by the US Department of Energy (DOE) includes the immobilization of certain plutonium materials in a borosilicate glass matrix, also referred to as vitrification. This paper addresses source terms of plutonium masses immobilized in a borosilicate glass matrix where the glass components include both natural boron and enriched boron. The calculated source terms pertain to neutron and gamma source strength (particles per second), and source spectrum changes. The calculated source terms corresponding to natural boron and enriched boron are compared to determine the benefits (decrease in radiation source terms) for to the use of enriched boron. The analysis of plutonium glass source terms shows that a large component of the neutron source terms is due to (a, n) reactions. The Americium-241 and plutonium present in the glass emit alpha particles (a). These alpha particles interact with low-Z nuclides like B-11, B-10, and O-17 in the glass to produce neutrons. The low-Z nuclides are referred to as target particles. The reference glass contains 9.4 wt percent B 2 O 3 . Boron-11 was found to strongly support the (a, n) reactions in the glass matrix. B-11 has a natural abundance of over 80 percent. The (a, n) reaction rates for B-10 are lower than for B-11 and the analysis shows that the plutonium glass neutron source terms can be reduced by artificially enriching natural boron with B-10. The natural abundance of B-10 is 19.9 percent. Boron enriched to 96-wt percent B-10 or above can be obtained commercially. Since lower source terms imply lower dose rates to radiation workers handling the plutonium glass materials, it is important to know the achievable decrease in source terms as a result of boron enrichment. Plutonium materials are normally handled in glove boxes with shielded glass windows and the work entails both extremity and whole-body exposures. Lowering the source terms of the plutonium batches will make the handling

  7. Product consistency testing of three reference glasses in stainless steel and perfluoroalkoxy resin vessels

    International Nuclear Information System (INIS)

    Olson, K.M.; Smith, G.L.; Marschman, S.C.

    1995-03-01

    Because of their chemical durability, silicate glasses have been proposed and researched since the mid-1950s as a medium for incorporating high-level radioactive waste (HLW) generated from processing of nuclear materials. A number of different waste forms were evaluated and ranked in the early 1980s; durability (leach resistance) was the highest weighted factor. Borosilicate glass was rated the best waste form available for incorporation of HLW. Four different types of vessels and three different glasses were used to study the possible effect of vessel composition on durability test results from the Production Consistency Test (PCT). The vessels were 45-m 304 stainless steel vessels, 150-m 304 L stainless steel vessels, and 60-m perfluoroalkoxy (PFA) fluoropolymer resin vessels. The three glasses were the Environmental Assessment glass manufactured by Corning Incorporated and supplied by Westinghouse Savannah River company, and West Valley Nuclear Services reference glasses 5 and 6, manufactured and supplied by Catholic University of America. Within experimental error, no differences were found in durability test results using the 3 different glasses in the 304L stainless steel or PFA fluoropolymer resin vessels over the seven-day test period

  8. Tailor-welded blanks and their production

    Science.gov (United States)

    Yan, Qi

    2005-01-01

    Tailor welded blanks had been widely used in the automobile industry. A tailor welded blank consists of several flat sheets that were laser welded together before stamping. A combination of different materials, thickness, and coatings could be welded together to form a blank for stamping car body panels. As for the material for automobile industry, this technology was one of the development trend for automobile industry because of its weight reduction, safety improvement and economical use of materials. In this paper, the characters and production of tailor welded blanks in the market were discussed in detail. There had two major methods to produce tailor welded blanks. Laser welding would replace mesh seam welding for the production of tailor welded blanks in the future. The requirements on the edge preparation of unwelded blanks for tailor welded blanks were higher than the other steel processing technology. In order to produce the laser welded blank, there had the other process before the laser welding in the factory. In the world, there had three kinds of patterns for the large volume production of tailor welded blanks. In China, steel factory played the important role in the promotion of the application of tailor welded blanks. The competition for the supply of tailor welded blanks to the automobile industry would become fierce in the near future. As a result, the demand for the quality control on the production of tailor welded blanks would be the first priority concern for the factory.

  9. Effect of Fe2O3/ZnO on two glass compositions for solidification on Swedish nuclear wastes

    International Nuclear Information System (INIS)

    Nogues, J.L.; Hench, L.L.

    1981-11-01

    Low melting alkaliborosilicate glasses have been considered for use in the immobilization of high level radioactive wastes for years. A recent study comparing the surface behavior of two nuclear waste glasses concluded that ''Addition of Fe 2 O 3 to a soda borosilicate nuclear waste glass significantly reduces damage by water attack because of a Fe-rich film that forms on the glass surface''. However, in the previous study there were significant differences in the concentration of SiO 2 , B 2 O 3 , CaO and simulated fission products in the glasses which made it impossible to ascribe the improved leach resistance solely to Fe 2 O 3 content. Thus, the objective of the present investigation is to compare the leaching and surface behavior of two nuclear waste glasses which differ only by the substitution of Fe 2 O 3 for some of the ZnO in the glass. By this comparison the authors hope to establish whether Fe 2 O 3 provides a unique contribution to improvements in the leach resistance of these complex glasses. Both glass compositions studied are compatible with the low melting temperature, 0 C, required for the French AVM Process. The quantity of simulated waste products is 9%, characteristic of the Swedish nuclear waste program. (Auth.)

  10. Quantitative estimation of electro-osmosis force on charged particles inside a borosilicate resistive-pulse sensor.

    Science.gov (United States)

    Ghobadi, Mostafa; Yuqian Zhang; Rana, Ankit; Esfahani, Ehsan T; Esfandiari, Leyla

    2016-08-01

    Nano and micron-scale pore sensors have been widely used for biomolecular sensing application due to its sensitive, label-free and potentially cost-effective criteria. Electrophoretic and electroosmosis are major forces which play significant roles on the sensor's performance. In this work, we have developed a mathematical model based on experimental and simulation results of negatively charged particles passing through a 2μm diameter solid-state borosilicate pore under a constant applied electric field. The mathematical model has estimated the ratio of electroosmosis force to electrophoretic force on particles to be 77.5%.

  11. Interfacial bonding and friction in silicon carbide (filament)-reinforced ceramic- and glass-matrix composites

    International Nuclear Information System (INIS)

    Bright, J.D.; Shetty, D.K.

    1989-01-01

    This paper reports interfacial shear strength and interfacial sliding friction stress assessed in unidirectional SiC-filament-reinforced reaction-bonded silicon nitride (RBSN) and borosilicate glass composites and 0/90 cross-ply reinforced borosilicate glass composite using a fiber pushout test technique. The interface debonding load and the maximum sliding friction load were measured for varying lengths of the embedded fibers by continuously monitoring the load during debonding and pushout of single fibers in finite-thickness specimens. The dependences of the debonding load and the maximum sliding friction load on the initial embedded lengths of the fibers were in agreement with nonlinear shear-lag models. An iterative regression procedure was used to evaluate the interfacial properties, shear debond strength (τ d ), and sliding friction stress (τ f ), from the embedded fiber length dependences of the debonding load and the maximum frictional sliding load, respectively. The shear-lag model and the analysis of sliding friction permit explicit evaluation of a coefficient of sliding friction (μ) and a residual compressive stress on the interface (σ 0 ). The cross-ply composite showed a significantly higher coefficient of interfacial friction as compared to the unidirectional composites

  12. Operation of microstrip gas chambers manufactured on glass coated with high resistivity diamond-like layers

    CERN Document Server

    Boimska, B; Dominik, Wojciech; Hoch, M; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

    1997-01-01

    We describe recent observations and measurements realized with micro-strip gas chambers (MSGCs) manufactured on boro-silicate glass coated with a thin layer of diamond-like carbon (DLC) having a surface resistivity around 4.10$^{16}\\Omega/\\Box$. The role of the back-pla electrode configuration and potential in the detector performance has been studied. Even for this very high resistivity of the coatings, MSGCs operate differently from those manufactured on bare boro-silicate glass; the charge gain increases with the radiation flux for counting rates above 103 Hz/mm2, reaching a value 60% higher for 105 Hz/mm2. This behavior does not depend on the presence and potential of the back plane electrode; however, both maximum gain and rate capability are influenced by the drift field. From this study, compared with measurements realized previously with other detectors, we deduce that for stable high rate operation of MSGCs the resistivity of the coating should not exceed ~10$^{15}\\Omega/\\Box$.

  13. Temperature-dependent evolution of RbBSi2O6 glass into crystalline Rb-boroleucite according to X-ray diffraction data

    International Nuclear Information System (INIS)

    Levin, Aleksandr A.; Filatov, Stanislav K.; Krzhizhanovskaya, Maria G.; Paufler, Peter; Bubnova, Rimma S.; Russian Academy of Sciences, St. Petersburg; Meyer, Dirk C.; Technische Univ. Bergakademie Freiberg

    2013-01-01

    The temperature-dependent evolution of the glass into a crystalline phase is studied for a rubidium borosilicate glass of composition 16.7 Rb 2 O . 16.7 B 2 O 3 . 66.6 SiO 2 employing X-ray diffraction (XRD) data. A glass sample was prepared by melt quenching from 1500 within 0.5 hour. The glass sample was step-wise annealed at 13 distinct temperatures from 300 C up to 900 C for 1 h at every annealing step. To investigate changes in the glass structure, angle-dispersive XRD was applied by using an energy-resolving semiconductor detector. The radial distribution functions (RDFs) were calculated at every stage. For polycrystalline states the crystal structure of the samples with different thermal history was refined using the Rietveld method. Comparing correlation distances estimated from RDFs of glass and polycrystalline samples and mean interatomic distances calculated for polycrystalline samples by using atomic coordinates after Rietveld refinement, it is concluded that the borosilicate glass under study is converted into the crystalline state in the temperature range of 625-750 C (i.e. in the temperature range close to the glass transition range 620-695 C as determined by differential scanning calorimetry by using of heating rate of 20 K/min) at an average heating rate of about 0.35 K/min. When the heating rate is increased up to 10 or 20 K/min, the crystallisation temperature shifts sharply up to 831-900 C and 878-951 C, respectively. XRD data give evidence that distinctive traces of cubic RbBSi 2 O 6 appear from glass at about 625 C and a two-phase range exists up to 750 C. After annealing at higher temperatures (800-900 C) the crystal structure practically does not change any more. (orig.)

  14. Thermodynamical modeling of nuclear glasses: coexistence of amorphous phases

    International Nuclear Information System (INIS)

    Adjanor, G.

    2007-11-01

    Investigating the stability of borosilicate glasses used in the nuclear industry with respect to phase separation requires to estimate the Gibbs free energies of the various phases appearing in the material. In simulation, using current computational resources, a direct state-sampling of a glassy system with respect to its ensemble statistics is not ergodic and the estimated ensemble averages are not reliable. Our approach consists in generating, at a given cooling rate, a series of quenches, or paths connecting states of the liquid to states of the glass, and then in taking into account the probability to generate the paths leading to the different glassy states in ensembles averages. In this way, we introduce a path ensemble formalism and calculate a Landau free energy associated to a glassy meta-basin. This method was validated by accurately mapping the free energy landscape of a 38-atom glassy cluster. We then applied this approach to the calculation of the Gibbs free energies of binary amorphous Lennard-Jones alloys, and checked the correlation between the observed tendencies to order or to phase separate and the computed Gibbs free energies. We finally computed the driving force to phase separation in a simplified three-oxide nuclear glass modeled by a Born-Mayer-Huggins potential that includes a three-body term, and we compared the estimated quantities to the available experimental data. (author)

  15. Leach rate studies on glass containing actual radioactive waste

    International Nuclear Information System (INIS)

    Walker, D.D.; Wiley, J.R.; Dukes, M.D.; LeRoy, J.H.

    1980-01-01

    Borosilicate glass containing radioactive wastes from the Savannah River Plant have been leached for 900 days. The International Standards Organization's (ISO) static leach test procedure was used on glass buttons in various leachants. Leach rates based on 90 Sr and 137 Cs analyses were similar: 2 x 10 -8 to 3 x 10 -8 g/(cm 2 )(d) in distilled water, 1 x 10 -8 to 3 x 10 -7 g/(cm 2 )(d) in pH 7 buffer, 3 x 10 -7 to 7 x 10 -7 g/(cm 2 )(d) in pH 9 buffer, and 7 x 10 -6 to 8 x 10 -5 g/(cm 2 )(d) in pH 4 buffer. Rates based on Pu analyses were the same as above in distilled water and pH 9 buffer, but were lower by an order of magnitude in pH 4 and pH 7 buffers. Almost all leach rates remained constant between 200 and 900 days of leaching. Increasing the concentration of the buffering agents had no effect on the leach rates at pH 7 (phosphate) and pH 9 (carbonate), but dramatically increased the rates at pH 4 (acetate). Leach rates did not differ significantly between high aluminum and high iron waste glasses

  16. Control of high level radioactive waste-glass melters

    International Nuclear Information System (INIS)

    Bickford, D.F.; Choi, A.S.

    1991-01-01

    Slurry Fed Melters (SFM) are being developed in the United States, Europe and Japan for the conversion of high-level radioactive waste to borosilicate glass for permanent disposal. The high transition metal, noble metal, nitrate, organic, and sulfate contents of these wastes lead to unique melter redox control requirements. Pilot waste-glass melter operations have indicated the possibility of nickel sulfide or noble-metal fission-product accumulation on melter floors, which can lead to distortion of electric heating patterns, and decrease melter life. Sulfide formation is prevented by control of the redox chemistry of the melter feed. The redox state of waste-glass melters is determined by balance between the reducing potential of organic compounds in the feed, and the oxidizing potential of gases above the melt, and nitrates and polyvalent elements in the waste. Semiquantitative models predicting limitations of organic content have been developed based on crucible testing. Computerized thermodynamic computations are being developed to predict the sequence and products of redox reactions and is assessing process variations. Continuous melter test results have been compared to improved computer staged-thermodynamic-models of redox behavior. Feed chemistry control to prevent sulfide and moderate noble metal accumulations are discussed. 17 refs., 3 figs

  17. Glass/ceramic coatings for implants

    Science.gov (United States)

    Tomsia, Antoni P [Pinole, CA; Saiz, Eduardo [Berkeley, CA; Gomez-Vega, Jose M [Nagoya, JP; Marshall, Sally J [Larkspur, CA; Marshall, Grayson W [Larkspur, CA

    2011-09-06

    Glass coatings on metals including Ti, Ti6A14V and CrCo were prepared for use as implants. The composition of the glasses was tailored to match the thermal expansion of the substrate metal. By controlling the firing atmosphere, time, and temperature, it was possible to control the reactivity between the glass and the alloy and to fabricate coatings (25-150 .mu.m thick) with excellent adhesion to the substrate. The optimum firing temperatures ranged between 800 and 840.degree. C. at times up to 1 min in air or 15 min in N.sub.2. The same basic technique was used to create multilayered coatings with concentration gradients of hydroxyapatite (HA) particles and SiO.sub.2.

  18. Crystallization In Multicomponent Glasses

    International Nuclear Information System (INIS)

    Kruger, A.A.; Hrma, P.R.

    2009-01-01

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  19. CRYSTALLIZATION IN MULTICOMPONENT GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; HRMA PR

    2009-10-08

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  20. Mechanisms and application of the Excimer laser doping from spin-on glass sources for USJ fabrication

    Science.gov (United States)

    Coutanson, S.; Fogarassy, E.; Venturini, J.

    2006-04-01

    In this work was investigated numerically and experimentally a simple laser doping method employing borosilicate (BSG) glass films as dopant sources which are deposited onto Si by the spin-coating technique. Both short (20 ns) and long (200 ns) pulse duration Excimer laser beams were used to deposit a large amount of energy in short time onto the near-surface region. Under suitable conditions, the irradiation leads to surface melting and dopant incorporation by liquid phase diffusion from the surface. Boron distribution profiles in the two-pulse duration regimes were studied as well as their electrical properties, and the junction formation of less than 25 nm in depth was demonstrated.

  1. Bioactive and Thermally Compatible Glass Coating on Zirconia Dental Implants

    Science.gov (United States)

    Kirsten, A.; Hausmann, A.; Weber, M.; Fischer, J.

    2015-01-01

    The healing time of zirconia implants may be reduced by the use of bioactive glass coatings. Unfortunately, existing glasses are either bioactive like Bioglass 45S5 but thermally incompatible with the zirconia substrate, or they are thermally compatible but exhibit only a very low level of bioactivity. In this study, we hypothesized that a tailored substitution of alkaline earth metals and alkaline metals in 45S5 can lead to a glass composition that is both bioactive and thermally compatible with zirconia implants. A novel glass composition was analyzed using x-ray fluorescence spectroscopy, dilatometry, differential scanning calorimetry, and heating microscopy to investigate its chemical, physical, and thermal properties. Bioactivity was tested in vitro using simulated body fluid (SBF). Smooth and microstructured glass coatings were applied using a tailored spray technique with subsequent thermal treatment. Coating adhesion was tested on implants that were inserted in bovine ribs. The cytocompatibility of the coating was analyzed using L929 mouse fibroblasts. The coefficient of thermal expansion of the novel glass was shown to be slightly lower (11.58·10–6 K–1) than that of the zirconia (11.67·10–6 K–1). After storage in SBF, the glass showed reaction layers almost identical to the bioactive glass gold standard, 45S5. A process window between 800 °C and 910 °C was found to result in densely sintered and amorphous coatings. Microstructured glass coatings on zirconia implants survived a minimum insertion torque of 60 Ncm in the in vitro experiment on bovine ribs. Proliferation and cytotoxicity of the glass coatings was comparable with the controls. The novel glass composition showed a strong adhesion to the zirconia substrate and a significant bioactive behavior in the SBF in vitro experiments. Therefore, it holds great potential to significantly reduce the healing time of zirconia dental implants. PMID:25421839

  2. Bioactive and thermally compatible glass coating on zirconia dental implants.

    Science.gov (United States)

    Kirsten, A; Hausmann, A; Weber, M; Fischer, J; Fischer, H

    2015-02-01

    The healing time of zirconia implants may be reduced by the use of bioactive glass coatings. Unfortunately, existing glasses are either bioactive like Bioglass 45S5 but thermally incompatible with the zirconia substrate, or they are thermally compatible but exhibit only a very low level of bioactivity. In this study, we hypothesized that a tailored substitution of alkaline earth metals and alkaline metals in 45S5 can lead to a glass composition that is both bioactive and thermally compatible with zirconia implants. A novel glass composition was analyzed using x-ray fluorescence spectroscopy, dilatometry, differential scanning calorimetry, and heating microscopy to investigate its chemical, physical, and thermal properties. Bioactivity was tested in vitro using simulated body fluid (SBF). Smooth and microstructured glass coatings were applied using a tailored spray technique with subsequent thermal treatment. Coating adhesion was tested on implants that were inserted in bovine ribs. The cytocompatibility of the coating was analyzed using L929 mouse fibroblasts. The coefficient of thermal expansion of the novel glass was shown to be slightly lower (11.58 · 10(-6) K(-1)) than that of the zirconia (11.67 · 10(-6) K(-1)). After storage in SBF, the glass showed reaction layers almost identical to the bioactive glass gold standard, 45S5. A process window between 800 °C and 910 °C was found to result in densely sintered and amorphous coatings. Microstructured glass coatings on zirconia implants survived a minimum insertion torque of 60 Ncm in the in vitro experiment on bovine ribs. Proliferation and cytotoxicity of the glass coatings was comparable with the controls. The novel glass composition showed a strong adhesion to the zirconia substrate and a significant bioactive behavior in the SBF in vitro experiments. Therefore, it holds great potential to significantly reduce the healing time of zirconia dental implants. © International & American Associations for Dental

  3. The use of glass powder as a partial Portland cement replacement

    Science.gov (United States)

    Pokorný, Jaroslav; Pavlíková, Milena; Tydlitát, Vratislav; Scheinherrová, Lenka; Rovnaníková, Pavla; Pavlík, Zbyšek

    2017-07-01

    Finely grinded waste glass powder can become material having suitable properties from the point of view of particle size and pozzolanic activity. Glass powder incorporation into cement paste and cement-based composites can bring improvement in porous structure resulting in increased mechanical strength and durability characteristics. On this account, two types of recycled glass powder are investigated in the presented paper as a possible partial Portland cement substitutes in cement blends. For raw glass powders, basic physical parameters and chemical composition are measured. The studied glass powders are applied as 5, 10 and 20 mass% of Portland cement replacement in cement paste mix composition, whereas water/binder ratio of 0.3 is used for all studied pastes. Fresh paste mixtures are characterized using initial and final setting time measurement. For hardened pastes cured 28 days in water, bulk density, matrix density, total open porosity and mechanical properties represented by flexural and compressive strength are accessed. Portlandite consumption by the pozzolanic reaction is monitored with TGA. The obtained results show effectiveness of a borosilicate glass powder that acts as a pozzolanic active admixture. This resulted in improvement of mechanical characteristics for cement substitution up to 10 mass%.

  4. On the Coordination of Actinides and Fission Products in Silicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Haddi, Anne; /Marne la Vallee U.; Farges, Francois; /Marne la Vallee U. /Museum Nat. Hist., Paris /Stanford U., Geo. Environ. Sci.; Trocellier, Patrick; /Saclay; Curti,; /Paul Scherrer Inst.; Harfouche, Messaoud; /Marne la Vallee U.; Brown, Gordon E.; /Stanford U., Geo. Environ. Sci. /SLAC, SSRL

    2006-12-13

    The local structure around Th, U, Ce and Nd in leached silicate glasses was examined using XAFS spectroscopy at their L3 edges and also at the K edge of Fe, Co, Ni, Zr and Mo. Pellets of inactive borosilicate glasses with a simplified or a complex composition were leached statically at 90 C, at pH buffered to 0 or 6 for 28 days (surface/volume, S/V, ratios of 0.1 cm{sup -1}). These glasses are compared to another SON68 sample (denoted ''SP1'' in this paper) that was statically leached for 12 years under similar conditions, except for a higher S/V of 12 cm{sup -1} and a higher unconstrained pH of 9.6. The speciation of Fe, Co, Ni, Zr and Mo in the simple and the complex unleached are similar. In the statically leached glasses, the speciation of these transition metals is mostly identical to in the unleached glasses, except in the gels formed at the surface of the glasses leached at low pH, where large speciation differences are observed. Surface precipitates, especially for Fe (as ferrihydrite), Mo (possibly sidwillite) and Th (as ThO{sub 2}) were detected. Finally, the drying of the gels considerably affects the metal speciation by enhancing metal polymerization.

  5. A completely transparent, adhesively bonded soda-lime glass block masonry system

    Directory of Open Access Journals (Sweden)

    F. Oikonomopoulou

    2015-01-01

    Full Text Available A pioneering, all transparent, self-supporting glass block facade is presented in this paper. Previously realized examples utilize embedded metal components in order to obtain the desired structural performance despite the fact that these elements greatly affect the facade’s overall transparency level. Undeniably, the oxymoron ‘transparency and strength’ remains the prime concern in such applications. In this paper, a new, innovative structural system for glass block facades is described, which demonstrably meets both criteria. The structure is exclusively constructed by monolithic glass blocks, bonded with a colourless, UV-curing adhesive, obtaining thus a maximum transparency. In addition, the desired structural performance is achieved solely through the masonry system, without any opaque substructure. Differing from previous realized projects, solid soda-lime glass blocks are used rather than borosilicate ones. This article provides an overview of the integrated architectural and structural design and discusses the choice of materials. The structural verification of the system is demonstrated. The results show that the adhesively bonded glass block structure has the required self-structural behaviour, but only if strict tolerances are met in the geometry of the glass blocks.

  6. Doping influence by some transition elements on the irradiation effects in nuclear waste glasses

    International Nuclear Information System (INIS)

    Florent, Olivier

    2006-06-01

    High-level waste glasses are submitted to auto-irradiation. Modelling it using external irradiations on simple glasses revealed defects production and non negligible structural changes. This thesis aims at determining the impact of a more complex composition on these effects, especially the influence of adding polyvalent transition metals. Silicate, soda-lime and alumino-borosilicate glasses are doped with different iron, chromium and manganese concentrations then β irradiated at different doses up to 10 9 Gy. Non doped glasses show an increase of their density and polymerisation coupled with a molecular oxygen and point defects production. Adding 0.16 mol% Fe decreases the amount of defects by 85 % and all irradiation effects. A Fe 3+ reduction is also observed by EPR, optical absorption and indirectly by Raman spectroscopy. A higher than 0.32 mol% Fe concentration causes complete blockage of the evolution of polymerisation, density and defect production. The same results are obtained on chromium or manganese doped glasses. An original in situ optical absorption device shows the quick decrease of Fe 3+ amount to a 25 % lower level during irradiation. Stopping irradiation causes a lower decrease of 65 %, suggesting a dynamic (h 0 /e-) consuming equilibrium. He + and Kr 3+ ions and γ irradiated glasses tend to confirm these phenomena for all kind of irradiation with electronic excitations. (author)

  7. Conversion of Nuclear Waste to Molten Glass: Cold-Cap Reactions in Crucible Tests

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kai [Pacific Northwest National Laboratory, Richland Washington 99352; Hrma, Pavel [Pacific Northwest National Laboratory, Richland Washington 99352; Rice, Jarrett A. [Pacific Northwest National Laboratory, Richland Washington 99352; Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland Washington 99352; Riley, Brian J. [Pacific Northwest National Laboratory, Richland Washington 99352; Overman, Nicole R. [Pacific Northwest National Laboratory, Richland Washington 99352; Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland Washington 99352; Vance, E.

    2016-05-23

    The feed-to-glass conversion, which comprises complex chemical reactions and phase transitions, occurs in the cold-cap zone during nuclear waste vitrification. Knowledge of the chemistry and physics of feed-to-glass conversion will help us control the conversion path by changing the melter feed makeup to maximize the glass production rate. To investigate the conversion process, we analyzed heat-treated samples of a simulated high-level waste feed using X-ray diffraction, electron probe microanalysis – wavelength dispersive X-ray spectroscopy, leaching tests, and residual anion analysis. Feed dehydration, gas evolution, and borate phase formation occurred at temperatures below 700 °C before the emerging glass-forming melt was completely connected. Above 800 °C, intermediate aluminosilicate phases and quartz particles were gradually dissolving in the continuous borosilicate melt, which expanded into transient foam. Knowledge of the chemistry and physics of feed-to-glass conversion will help us control the conversion path by changing the melter feed makeup to maximize the glass production rate.

  8. A completely transparent, adhesively bonded soda-lime glass block masonry system

    Directory of Open Access Journals (Sweden)

    Faidra Oikonomopoulou

    2015-06-01

    Full Text Available A pioneering, all transparent, self-supporting glass block facade is presented in this paper. Previously realized examples utilize embedded metal components in order to obtain the desired structural performance despite the fact that these elements greatly affect the facade’s overall transparency level. Undeniably, the oxymoron ‘transparency and strength’ remains the prime concern in such applications. In this paper, a new, innovative structural system for glass block facades is described, which demonstrably meets both criteria. The structure is exclusively constructed by monolithic glass blocks, bonded with a colourless, UV-curing adhesive, obtaining thus a maximum transparency. In addition, the desired structural performance is achieved solely through the masonry system, without any opaque substructure. Differing from previous realized projects, solid soda-lime glass blocks are used rather than borosilicate ones. This article provides an overview of the integrated architectural and structural design and discusses the choice of materials. The structural verification of the system is demonstrated. The results show that the adhesively bonded glass block structure has the required self-structural behaviour, but only if strict tolerances are met in the geometry of the glass blocks.  

  9. Fabrication and characterization of MCC approved testing material - ATM-8 glass

    International Nuclear Information System (INIS)

    Wald, J.W.

    1985-10-01

    The Materials Characterization Center (MCC) Approved Testing Material ATM-8 is a borosilicate glass that incorporates elements typical of high-level waste (HLW) resulting from the reprocessing of commercial nuclear reactor fuel. Its composition is based upon the simulated HLW glass type 76-68 (Mendel, J.E. et al., 1977, Annual Report of the Characteristics of High-Level Waste Glasses, BNWL-2252, Pacific Northwest Laboratory, Richland, Washington), to which depleted uranium, technetium-99, neptunium-237 and plutonium-239 have been added at moderate to low levels. The glass was requested by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. It was produced by the MCC at the Pacific Northwest Laboratory (PNL) operated for the Department of Energy (DOE) by Battelle Memorial Institute. ATM-8 glass was produced in April of 1984, and is the second in a series of testing materials for NNWSI. This report discusses its fabrication (starting materials, batch and glass preparation, measurement and testing equipment, other equipment, procedures, identification system and materials availability and storage, and characterization (bulk density) measurements, chemical analysis, microscopic examination, and x-ray diffraction analysis. 4 refs., 2 figs., 10 tabs

  10. Understanding the effects of alpha self-irradiation on the glass structure by coupling spectroscopic studies and atomistic modeling

    International Nuclear Information System (INIS)

    Bureau, G.

    2008-12-01

    Our objective was to assess irradiation effects on nuclear containment glass in order to guarantee glass performance when subjected to high alpha decay doses. Experimental studies and molecular dynamics modeling provided a better understanding of the impact of cumulative alpha decay on the structural behavior of complex nuclear glass formulations and of simplified glass models. A mechanism typical of sodium borosilicate glass was identified in response to nuclear interactions or ballistic collisions. The glass local order is slightly modified by the conversion of a fraction of the boron atoms from coordination number IV to III, releasing charge-compensating alkali ions that become available as network modifiers, and resulting in a slight increase in the number of non bridging oxygen atoms. The medium-range order shifts toward increasing disorder in the glass as indicated by broadening of the angular, radial, and size distributions. A model of accumulated quasi-thermal quenching is proposed to account for these changes, based on the two steps describing the reaction of the glass to the alpha decay recoil nucleus: a cascade generates a ballistic phase that completely destabilizes the glass structure with no short and medium-range order, resulting in the loss of the initial structure; glass reconstruction is controlled only by the 'quenching rate' in the displacement cascade, i.e. by its thermal history and the corresponding relaxation options. From this standpoint the final glass structure is the consequence of the ballistic changes and the regenerative capacity of the glass structure, resulting in a higher fictive-temperature glass corresponding to the structural changes identified in this study. (author)

  11. Formability of stainless steel tailored blanks

    DEFF Research Database (Denmark)

    Bagger, Claus; Gong, Hui; Olsen, Flemming Ove

    2004-01-01

    In a number of systematic tests, the formability of tailored blanks consisting of even and different combinations of AISI304 and AISI316 in thickness of 0.8 mm and 1.5 mm have been investigated. In order to analyse the formability of tailored blanks with different sheet thickness, a method based ...

  12. Fabrication and characterization of MCC approved testing material - ATM-12 glass

    International Nuclear Information System (INIS)

    Wald, J.W.

    1985-10-01

    The Materials Characterization Center (MCC) Approved Testing Material ATM-12 is a borosilicate glass that incorporates elements typical of high-level waste (HLW) resulting from the reprocessing of commercial nuclear reactor fuels. The composition has been adjusted to match that predicted for HLW type 76-68 glass at an age of 300 y. Radioactive constituents contained in this glass include depleted uranium, 99 Tc, 237 Np, 239 Pu, and 241 Am. The glass was produced by the MCC at the Pacific Northwest Laboratory (PNL). ATM-12 glass ws produced from July to November of 1984 at the request of the Nevada Nuclear Waste Site Investigations (NNWSI) Program and is the third in a series of glasses produced for NNWSI. Most of the glass produced was in the form of cast bars; special castings and crushed material were also produced. Three kilograms of ATM-12 glass were produced from a feedstock melted in a nitrogen-atmosphere glove box at 1150 0 C in a platinum crucible, and formed into stress-annealed rectangular bars and the special casting shapes requested by NNWSI. Bars of ATM-12 were nominally 1.9 x 1.9 x 10 cm, with an average mass of 111 g each. Nineteen bars and 37 special castings were made. ATM-12 glass has been provided to the NNWSI Program, in the form of bars, crushed powder and special castings. As of August 1985 approximately 590 g of ATM-12 is available for distribution. Requests for materials or services related to this glass should be directed to the Materials Characterization Center Program Office, PNL

  13. Tunable Room Temperature Second Harmonic Generation in Glasses Doped with CuCI Nanocrystalline Quantum Dots

    Energy Technology Data Exchange (ETDEWEB)

    Thantu, Napoleon; Schley, Robert Scott; B. L. Justus

    2003-05-01

    Two-photon excited emission centered at 379-426 nm in photodarkening borosilicate glass doped with CuCl nanocrystalline quantum dots at room temperature has been observed. The emission is detected in the direction of the fundamental near-infrared beam. Time- and frequency-resolved measurements at room temperature and 77 K indicate that the emission is largely coherent light characteristic of second harmonic generation (SHG). An average conversion efficiency of ~10-10 is obtained for a 2 mm thick sample. The observed SHG can originate in the individual noncentrosymmetric nanocrystals, leading to a bulk-like contribution, and at the nanocrystal-glass interface, leading to a surface contribution. The bulk-like conversion efficiency is estimated using previously reported values of coherence length (5m) and bulk nonlinear susceptibility. This bulk-like conversion efficiency estimate is found to be smaller than the measured value, suggesting a more prominent surface contribution.

  14. Fixation by ion exchange of toxic materials in a glass matrix

    International Nuclear Information System (INIS)

    Simmons, C.J.; Simmons, J.H.; Macedo, P.B.; Litovitz, T.A.

    1982-01-01

    A process is reported for reacting a porous silicate or borosilicate glass or silica gel with alkali metal cations, Group lb cations and/or ammonium cations bonded to the silicon through divalent oxygen linkages on the internal surfaces of the pores. Ion exchange of the cations with toxic or radioactive cations was possible resulting in a distribution of internal silicon-bonded toxic cation oxide groups within the pores of the glass or silica gel. The ion exchange reaction may be done successfully with acidic, neutral or alkaline pH solutions. The aim of the immobilization is for permanent storage of hazardous materials such as Hg 2+ , Hg + , Cd 2+ , Tl + , Pb 2+ and radioactive cations

  15. Assessment of processes, facilities, and costs for alternative solid forms for immobilization of SRP defense waste

    International Nuclear Information System (INIS)

    Dunson, J.B. Jr.; Eisenberg, A.M.; Schuyler, R.L. III; Haight, H.G. Jr.; Mello, V.E.; Gould, T.H. Jr.; Butler, J.L.; Pickett, J.B.

    1982-03-01

    A quantitative merit evaluation which assesses the relative difficulty of remote processing of Savannah River Plant high-level wastes for seven alternative waste forms is presented. The reference borosilicate glass process is rated as the simplest, followed by FUETAP concrete. The other processes evaluated in order of increasing complexity were: glass marbles in a lead matrix, high-silica glass, crystalline ceramic (Synroc-D and tailored ceramic), and coated ceramic particles. Cost appraisals are summarized for the borosilicate glass, high-silica glass, and ceramic waste form processing facilities

  16. Processability analysis of candidate waste forms

    International Nuclear Information System (INIS)

    Gould, T.H. Jr.; Dunson, J.B. Jr.; Eisenberg, A.M.; Haight, H.G. Jr.; Mello, V.E.; Schuyler, R.L. III.

    1982-01-01

    A quantitative merit evaluation, or processability analysis, was performed to assess the relative difficulty of remote processing of Savannah River Plant high-level wastes for seven alternative waste form candidates. The reference borosilicate glass process was rated as the simplest, followed by FUETAP concrete, glass marbles in a lead matrix, high-silica glass, crystalline ceramics (SYNROC-D and tailored ceramics), and coated ceramic particles. Cost estimates for the borosilicate glass, high-silica glass, and ceramic waste form processing facilities are also reported

  17. Recycling of Glass

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Damgaard, Anders

    2011-01-01

    Glass is used for many purposes, but in the waste system glass is predominantly found in terms of beverage and food containers with a relatively short lifetime before ending up in the waste. Furthermore there is a large amount of flat glass used in building materials which also ends up in the waste...... system; this glass though has a long lifetime before ending up in the waste. Altogether these product types add up to 82% of the production of the European glass industry (IPCC, 2001). Recycling of glass in terms of cleaning and refilling of bottles as well as the use of broken glass in the production...... of new glass containers is well established in the glass industry. This chapter describes briefly howglass is produced and howwaste glass is recycled in the industry. Quality requirements and use of recycled products are discussed, as are the resource and environmental issues of glass recycling....

  18. Structure and Degradation Behaviour of Calcium Phosphate Glasses

    International Nuclear Information System (INIS)

    Silva, A M B; Correia, R N; Fernandes, M H V; Oliveira, J M M

    2011-01-01

    Some studies have shown a relationship between glass structure and in vitro mineralization, generally associated with the rate of glass degradation, nature of released ions and subsequent Ca-P precipitation on glass surfaces when immersed in a Simulated Body Fluid (SBF). The knowledge of the ionic species distribution in glasses and of the involved bond strengths can be used to assess the in vitro behaviour of a glass. The role of ions such as silicon or titanium is of major importance for the development of new compositions and also for the control of glass degradation behaviour. A comparative study with two calcium phosphate glasses series was performed: Both glasses series - one with Si and another with Ti - include P 2 O 5 and alkaline earth ions in their compositions. Surface reactivity of glasses from the SiO 2 -containing system have been studied in SBF showing the precipitation of a Ca-P surface layer that increases with increasing MgO/CaO ratio. In glasses from the TiO 2 -containing series it is shown that the increase of TiO 2 contributes for the stabilization of the glass network thus allowing the control of their degradation rate when immersed in SBF. The relationship between structural features of these calcium-phosphate glasses and their degradation behaviour in SBF is discussed in terms of the structural role of Si and Ti ions. It is concluded that glasses with less interconnected species favour the Ca-P surface precipitation. The understanding of this relationship in synthetic physiological fluids is expected to allow the tailoring of glass degradation rates in complex biological systems.

  19. Structure and Degradation Behaviour of Calcium Phosphate Glasses

    Science.gov (United States)

    Silva, A. M. B.; Oliveira, J. M. M.; Correia, R. N.; Fernandes, M. H. V.

    2011-10-01

    Some studies have shown a relationship between glass structure and in vitro mineralization, generally associated with the rate of glass degradation, nature of released ions and subsequent Ca-P precipitation on glass surfaces when immersed in a Simulated Body Fluid (SBF). The knowledge of the ionic species distribution in glasses and of the involved bond strengths can be used to assess the in vitro behaviour of a glass. The role of ions such as silicon or titanium is of major importance for the development of new compositions and also for the control of glass degradation behaviour. A comparative study with two calcium phosphate glasses series was performed: Both glasses series - one with Si and another with Ti - include P2O5 and alkaline earth ions in their compositions. Surface reactivity of glasses from the SiO2-containing system have been studied in SBF showing the precipitation of a Ca-P surface layer that increases with increasing MgO/CaO ratio. In glasses from the TiO2-containing series it is shown that the increase of TiO2 contributes for the stabilization of the glass network thus allowing the control of their degradation rate when immersed in SBF. The relationship between structural features of these calcium-phosphate glasses and their degradation behaviour in SBF is discussed in terms of the structural role of Si and Ti ions. It is concluded that glasses with less interconnected species favour the Ca-P surface precipitation. The understanding of this relationship in synthetic physiological fluids is expected to allow the tailoring of glass degradation rates in complex biological systems.

  20. Elaboration of new ceramic composites containing glass fibre production wastes

    International Nuclear Information System (INIS)

    Rozenstrauha, I.; Sosins, G.; Krage, L.; Sedmale, G.; Vaiciukyniene, D.

    2013-01-01

    Two main by-products or waste from the production of glass fibre are following: sewage sludge containing montmorillonite clay as sorbent material and ca 50 % of organic matter as well as waste glass from aluminium borosilicate glass fibre with relatively high softening temperature (> 600 degree centigrade). In order to elaborate different new ceramic products (porous or dense composites) the mentioned by-products and illitic clay from two different layers of Apriki deposit (Latvia) with illite content in clay fraction up to 80-90 % was used as a matrix. The raw materials were investigated by differential-thermal (DTA) and XRD analysis. Ternary compositions were prepared from mixtures of 15 - 35 wt % of sludge, 20 wt % of waste glass and 45 - 65 wt % of clay and the pressed green bodies were thermally treated in sintering temperature range from 1080 to 1120 degree centigrade in different treatment conditions. Materials produced in temperature range 1090 - 1100 degree centigrade with the most optimal properties - porosity 38 - 52 %, water absorption 39 -47 % and bulk density 1.35 - 1.67 g/cm 3 were selected for production of porous ceramics and materials showing porosity 0.35 - 1.1 %, water absorption 0.7 - 2.6 % and bulk density 2.1 - 2.3 g/cm 3 - for dense ceramic composites. Obtained results indicated that incorporation up to 25 wt % of sewage sludge is beneficial for production of both ceramic products and glass-ceramic composites according to the technological properties. Structural analysis of elaborated composite materials was performed by scanning electron microscopy(SEM). By X-ray diffraction analysis (XRD) the quartz, diopside and anorthite crystalline phases were detected. (Author)

  1. Recent advances in phosphate laser glasses for high power applications

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.H.

    1996-05-14

    Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm{sup 3} have been made and methods for continuous melting laser glass are under development.

  2. Recent advances in phosphate laser glasses for high power applications

    International Nuclear Information System (INIS)

    Campbell, J.H.

    1996-01-01

    Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm 3 have been made and methods for continuous melting laser glass are under development

  3. Study of powellite-rich glass-ceramics for nuclear waste immobilization

    International Nuclear Information System (INIS)

    Taurines, T.

    2012-01-01

    MoO 3 is poorly soluble in borosilicate glasses which can lead to the crystallization of undesired phases when its concentration or the charge load (minor actinides and fission products concentration) is too high. Crystallization control is needed to guarantee good immobilization properties. We studied powellite-rich glass-ceramics obtained from a simplified nuclear glass in the system SiO 2 - B 2 O 3 - Na 2 O - CaO - Al 2 O 3 - MoO 3 - RE 2 O 3 (RE = Gd, Eu, Nd) by various heat treatments. Rare earth elements (REE) were added as minor actinides surrogates and as spectroscopic probes. The influence of MoO 3 and RE 2 O 3 content on powellite (CaMoO 4 ) crystallization was investigated. Various glass-ceramics (similar residual glass + powellite) were obtained with large crystal size distributions. Phase separation due to molybdenum occurs during quenching when [MoO 3 ] ≥ 2.5 mol%. We showed that increasing the rare earth content can suppress the phase separation due to molybdenum but it leads to spinodal decomposition of the residual glass. Furthermore, we studied the effects of parent glass complexifying and the insertion of Gd 3+ ions into the powellite structure. In order to understand the influence of microstructure on evolutions under β-irradiation, we studied point defects creation and structural changes. We showed that the damage induced by electronic excitations in the glass-ceramics is driven by the damage in the residual glass. (author) [fr

  4. High content silicate porous glasses used for radioactive wastes storage: preparation and characterization of the spinodal decomposition

    International Nuclear Information System (INIS)

    Ventura, P.C.S.

    1983-01-01

    The phase separation behavior via spinodal decomposition of two sodium borosilicate glasses has been studied having the following compositions in weight %: Glass A: 8% Na 2 O - 32% B 2O3 - 60% Si O 2 Glass 8% B: Na 2 O -27% B 2 O 3 - 65% Si O 2 . The growth of the mean size r of the minor phase microstructure has been determined as a function of both the time length (0-100 hours) and the heat treatment by analyzing temperature 580, 600 0 C of the glass sample images obtained with a Scanning Electron Microscope. The results are in good agreement with the theory of Lifshitz-Slyozov which predict a growth of the minor phase microstructure via a diffusion controlled process through the insoluble phase such that r-bar = A o t e - ΔE/R T. The activation energy ΔE and the pre-exponential factor A o of the diffusion process were found ΔE = 58,8 kCal/mol; A o = 8,42 x 10 21 Angstrom 3 /h for the glass A and ΔE = 92,6 kCal/mol; A o = 4,84 x 10 29 Angstrom 3 /h for the glass B. The distribution curves of the microstructure size allowed to suggest for the glasses under study the most adequate heat treatments to absorbs after the leaching of the soluble phase. (author)

  5. Determination of long-lived fission products and actinides in Savannah River site HLW sludge and glass for waste acceptance

    International Nuclear Information System (INIS)

    Bibler, N.E.; Boyce, W.T.; Coleman, C.J.

    1997-01-01

    Savannah River Site (SRS) is currently immobilizing the radioactive, caustic, high-level waste sludge in Tank 51 into a borosilicate glass for disposal in a geologic repository. A requirement for repository acceptance is that SRS report the concentrations of certain fission product and actinide radionuclides in the glass. This paper presents measurements of many of these concentrations in both Tank 51 sludge and the final glass. The radionuclides were measured by inductively coupled plasma - mass spectrometry and α, β, and γ counting methods. Examples of the radionuclides are Sr-90, Cs-137, U-238, Pu-239, and Cm-244. Concentrations in the glass are 3.1 times lower due to dilution of the sludge with a nonradioactive glass forming frit in the vitrification process. Results also indicated that in both the sludge and glass the relative concentrations of the long lived fission products insoluble in caustic area in proportion to their yields from the fission of U-235 in the SRS reactors. This allowed the calculation of a fission yield scaling factor. This factor in addition to the sludge dilution factor can be used to estimate concentrations of waste acceptance radionuclides that cannot be measured in the glass

  6. Joining Dental Ceramic Layers With Glass

    Science.gov (United States)

    Saied, MA; Lloyd, IK; Haller, WK; Lawn, BR

    2011-01-01

    Objective Test the hypothesis that glass-bonding of free-form veneer and core ceramic layers can produce robust interfaces, chemically durable and aesthetic in appearance and, above all, resistant to delamination. Methods Layers of independently produced porcelains (NobelRondo™ Press porcelain, Nobel BioCare AB and Sagkura Interaction porcelain, Elephant Dental) and matching alumina or zirconia core ceramics (Procera alumina, Nobel BioCare AB, BioZyram yttria stabilized tetragonal zirconia polycrystal, Cyrtina Dental) were joined with designed glasses, tailored to match thermal expansion coefficients of the components and free of toxic elements. Scanning electron microprobe analysis was used to characterize the chemistry of the joined interfaces, specifically to confirm interdiffusion of ions. Vickers indentations were used to drive controlled corner cracks into the glass interlayers to evaluate the toughness of the interfaces. Results The glass-bonded interfaces were found to have robust integrity relative to interfaces fused without glass, or those fused with a resin-based adhesive. Significance The structural integrity of the interfaces between porcelain veneers and alumina or zirconia cores is a critical factor in the longevity of all-ceramic dental crowns and fixed dental prostheses. PMID:21802131

  7. Composition effects on synthetic glass alteration mechanisms: Part 1. Experiments

    International Nuclear Information System (INIS)

    Rajmohan, Natarajan; Frugier, P.; Gin, St.

    2010-01-01

    Alteration of nuclear waste glasses and silicate minerals is governed by complex processes regulated by several coupled mechanisms. Among these processes is reactive mass transfer through the amorphous gel layer (known as the passivating reactive interphase (PRI) in case of a rate-limiting effect) located between the pristine glass and the bulk solution. In order to assess the influence of the glass composition and the pH on the properties of the PRI, and thus on the nuclear glass durability, an experimental leaching study was performed on borosilicate glass samples with or without Ca, Al, and Zr. Experiments were conducted to understand the influence of the pH and glass composition on the solvated cation diffusion coefficient within the PRI and to generate data for calibration of a PRI solubility model (not presented here). All the experiments were carried out at high S/V ratios so that silicon rapidly reached apparent saturated conditions and the PRI could form: in such conditions glass alteration is controlled only by diffusion of water and dissolved species through the PRI and by precipitation of crystallized secondary phases. The constituents in the PRI and the crystallized secondary phases depend to a large extent on the glass composition and pH. Alkali metal (Na) or preferentially alkaline earth (Ca) elements are retained in the PRI for charge compensation of Al and Zr. The apparent diffusion coefficient calculated from the release of boron, a good tracer, varies with the pH from less than 4 * 10 -22 to 9 * 10 -18 m 2 s -1 in the studied glasses. These very low diffusion coefficients decrease as the pH increases. Concerning the PRI composition we show that Si, Al, Ca and Zr have strong interactions and thus major consequences on the glass durability. Our findings indicate that the SiO 2 aq activity is relatively constant and independent of the pH below pH 9, followed by a drop at pH 10. In addition, the activity of SiO 2 aq is affected by the glass

  8. Continuous tailoring activities in software engineering

    OpenAIRE

    Ribaud , Vincent; Saliou , Philippe

    2004-01-01

    International audience; Software activities belong to different processes. Tailoring software processes aims to relate the operational software processes of an organization to the effective project. With the information technology industry moving ever faster, established positions are undergoing constant evolutionary change. The failure of a complex tailoring process of a management information system is reported. There is a need to adopt software processes that can operate under constant cha...

  9. Immobilisation of radio cesium loaded ammonium molybdo phosphate in glass matrices

    International Nuclear Information System (INIS)

    Yalmali, Vrunda S.; Singh, I.J.; Sathi Sasidharan, N.; Deshingkar, D.S.

    2004-11-01

    Long half life and easy availability from high level wastes make 137 Cesium most economical radiation source. High level liquid waste processing for 137 Cesium removal has become easier due to development of Cesium specific granulated ammonium molybdophosphate (AMP) composite. In such applications, resulting spent composite AMP itself represents high active solid waste and immobilization of these materials in cement may not be acceptable. Studies on immobilization of 137 Cs loaded AMP were taken up in order to achieve twin goals of increasing safety and minimizing processing costs of the final matrix. Studies indicated that phosphate modified sodium borosilicate SPNM glasses prepared under usual oxidizing conditions are not suitable for immobilization of 137 Cs loaded on AMP .Phosphate glasses containing Na 2 O, P 2 O 5 , B 2 O 3 , Fe 2 O 3 , Al 2 O 3 and SiO 2 as major constituents are capable of incorporating 6 to 8 % AMP. The Normalized Leach rates of these glasses for sodium, cesium, boron and silica are 10 -4 to 10 -6 gm/cm 2 /day which are comparable to or better than those reported for NBS glasses incorporating HLW. Homogeneity of the final matrix was confirmed by x-ray diffraction analysis. Further studies on characterization of these glasses would establish their acceptability. (author)

  10. Environment and oxidation state of molybdenum in simulated high level nuclear waste glass compositions

    Science.gov (United States)

    Short, R. J.; Hand, R. J.; Hyatt, N. C.; Möbus, G.

    2005-04-01

    Alkali borosilicate glasses containing between 20 and 35 wt% of a simulated high level nuclear waste stream with varying Li2O contents were melted under neutral (air) and reducing (nitrogen/hydrogen) conditions. XRD analysis of the as-cast glasses showed a tendency for the products to remain amorphous when melted under neutral conditions and for metallic silver to develop in the reduced melts. EXAFS analysis revealed (MoO4)2- tetrahedra in all glasses regardless of the sparge applied during melting. The glasses were heat treated to simulate an interruption to the cooling system used to prevent heat build-up in the vitrified product store. Powellite-type molybdate phases were found to develop in the heat treated samples and formed at lower waste loadings in glasses sparged with a reducing gas. A reduction in the quantity of Li2O lead to a reduction in the quantity of powellite-type molybdate phases. EDS showed the primary molybdate phase to be high in Sr and rare earth elements and TEM indicated that the presence of silver metal encouraged molybdate formation.

  11. Nuclear waste glass product consistency test (PCT): Version 7.0. Revision 3

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.

    1994-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Product Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Product Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 7.0 of the PCT procedure is attached. This draft version has been submitted to ASTM for full committee (C26, Nuclear Fuel Cycle) ballot after being balloted successfully through subcommittee C26.13 on Repository Waste Package Materials Testing.

  12. Nuclear waste glass product consistency test (PCT): Version 7.0. Revision 3

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.

    1994-06-01

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Product Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Product Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 7.0 of the PCT procedure is attached. This draft version has been submitted to ASTM for full committee (C26, Nuclear Fuel Cycle) ballot after being balloted successfully through subcommittee C26.13 on Repository Waste Package Materials Testing

  13. On confirmation of abandonment of imported waste (glass solidified bodies) outside business places

    International Nuclear Information System (INIS)

    1996-01-01

    Electric power companies entrust the reprocessing of spent fuel generated from nuclear power stations to COGEMA in France, and in April, 1995, 28 high level radioactive wastes (glass solidified bodies) generated by the reprocessing were returned. When these glass solidified wastes are abandoned in the waste management facility of Japan Nuclear Fuel Service Co., it was decided to receive the confirmation of the prime minister on the measures based on the relevant law. Four electric power companies submitted the application and the explanation paper. As to the contents of the glass solidified wastes, the technical inspection was carried out by Bureau Veritas. Considering that this import of glass solidified wastes is the first in Japan, Science and Technology Agency carried out the measurement of all 28 wastes. The results are reported. It was confirmed that the measures for the abandonment taken by four electric power companies conform to the stipulation. The contents of the confirmation are reported in the order of the stipulation. These wastes were solidified with borosilicate glass in 5 mm thick stainless steel vessels, and the welding was done properly. (K.I.)

  14. Alternative solid forms for Savannah River Plant defense waste

    International Nuclear Information System (INIS)

    Stone, J.A.; Goforth, S.T.; Smith, P.K.

    1980-01-01

    Solid forms and processes were evaluated for immobilization of SRP high-level radioactive waste, which contains bulk chemicals such as hydrous iron and aluminium oxides. Borosilicate glass currently is the best overall choice. High-silica glass, tailored ceramics, and coated ceramics are potentially superior products, but require more difficult processes

  15. lead glass brick

    CERN Multimedia

    When you look through the glass at a picture behind, the picture appears raised up because light is slowed down in the dense glass. It is this density (4.06 gcm-3) that makes lead glass attractive to physicists. The refractive index of the glass is 1.708 at 400nm (violet light), meaning that light travels in the glass at about 58% its normal speed. At CERN, the OPAL detector uses some 12000 blocks of glass like this to measure particle energies.

  16. Diopside-Fluorapatite-Wollastonite Based Bioactive Glasses and Glass-ceramics =

    Science.gov (United States)

    Kansal, Ishu

    content has been tested successfully both in vivo and in preliminary clinical trials. But this work needs to be continued and deepened. The dispersing of fine glass particles in aqueous media or in other suitable solvents, and the study of the most important factors that affect the rheology of the suspensions are essential steps to enable the manufacture of porous structures with tailor-made hierarchical pores by advanced processing techniques such as Robocasting.

  17. UV laser radiation-induced modifications and microstructuring of glass

    Science.gov (United States)

    Talkenberg, Marc; Kreutz, Ernst-Wolfgang; Horn, Alexander; Jacquorie, Michael; Poprawe, Reinhart

    2002-06-01

    Modifications and microstructures are generated on the surface and in the volume of silicate glasses using pulsed UV laser radiation of small pulse length. During the interaction of pulsed excimer laser radiation and frequency-trippled Nd:YAG laser radiation with intensities below the removal-threshold of the cerium- and silver-doped multi-component silicate glass absorption centers in the UV are induced. Subsequent thermal treatment and wet chemical etching results in crystallization of the laser-illuminated absorbing region and in the fabrication of microstructures on the surface. Processing of sodalime- and boro-silicate glass with pulsed ArF excimer laser radiation and frequency-doubled Nd:YAG laser radiation with intensities above the removal-threshold leads to microstructures including the generation of microcracks on the surface and in the bulk. The dynamics and the transmission of the expanding plasma and changes in the refractive index of the glass are investigated with speckle photography using the pump and probe method. The determination of plasma emission and crack generation is carried out using high speed and Nomarski photography. Morphological and chemical properties of the debris generated under defined processing gas atmospheres are investigated with REM, white light interferometry, XPS and EPMA. Induced absorption and changes of the crystalline- phase are probed using optical-spectroscopy and XRD as well REM. On the basis of these investigations the processes of the generation of induced absorption centers and crystallization on the one hand and the generation of cracks and debris on the other hand as well as the quality of the produced microstructures is discussed.

  18. Stress-induced birefringence control in femtosecond laser glass welding

    Science.gov (United States)

    Gstalter, M.; Chabrol, G.; Bahouka, A.; Serreau, L.; Heitz, J.-L.; Taupier, G.; Dorkenoo, K.-D.; Rehspringer, J.-L.; Lecler, S.

    2017-11-01

    Glass welding by femtosecond laser pulses causes microscopic structural modifications, affecting the refractive index due to residual stress. Locally induced birefringence is studied by photoelasticimetry using a polarized light microscope. The study is performed on borosilicate thin glass plates using an industrial femtosecond laser generating 300 fs pulses at 500 kHz, with a 100 mm focusing length F-theta lens allowing fast welding. For low-energy deposition, the principal birefringence axes are determined to be homogenous along the seam and perpendicular and parallel to the laser scanning direction. Tensile stress is induced in the laser scanning direction by the welding seams. The induced birefringence is determined to be equivalent for in-volume irradiated track and welding seams. An inhomogeneity of the birefringence within the seam is observed for the first time at high-energy deposition. The distribution of the birefringence can be controlled with the laser scanning patterns. The amount of residual stress is measured by compensating the local birefringence. The birefringence Δ n is estimated at 2.4 × 10^{-4}, corresponding to a residual stress amount around 59 MPa. The influence of the welding geometry is also illustrated.

  19. Thermal and physicochemical properties important for the long term behavior of nuclear waste glasses

    Science.gov (United States)

    Matzke, Hj.; Vernaz, E.

    High level nuclear waste from reprocessing of spent nuclear fuel has to be solidified in a stable matrix for safe long-time storage. Vitrification in borosilicate glasses is the technique accepted worldwide as the best combination of engineering constraints from fabrication and physicochemical properties of the matrix. A number of different glasses was developed in different national programs. The criteria and the reasons for selecting the final compositions are described briefly. Emphasis is placed on the French product R7T7 and on thermal and physicochemical properties though glasses developed in other national projects (e.g., the German product GP 98/12, etc.) are also treated. The basic physical and mechanical properties and the chemical durability of the glass in contact with water are described. The basic mechanisms of aqueous corrosion are discussed and the evolving modelling of the leaching process is dealt with, as well as effects of container material, backfill, etc. The thermal behavior has also been studied and extensive data exist on diffusion of glass constituents (Na) and of interesting elements of the waste such as the alkalis Rb and Cs or the actinides U and Pu, as well as on crystallization processes in the glass during storage at elevated temperatures. Emphasis is placed on the radiation stability of the glasses, based on extensive studies using short-lived actinides (e.g., 244Cm) or ion implantation to produce the damage expected during long storage at an accelerated rate. The radiation stability is shown to be very good, if realistic damage conditions are used. The knowledge accumulated in the past years is used to evaluate and predict the long-term evolution of the glass under storage conditions.

  20. Effect of low dose electron beam irradiation on the alteration layer formed during nuclear glass leaching

    Energy Technology Data Exchange (ETDEWEB)

    Mougnaud, S., E-mail: sarah.mougnaud@gmail.com [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Tribet, M. [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Renault, J.-P. [NIMBE, CNRS, CEA, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Jollivet, P. [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Panczer, G. [Institut Lumière Matière, UMR 5306, Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Charpentier, T. [NIMBE, CNRS, CEA, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Jégou, C. [CEA Marcoule, DEN, DTCD, SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France)

    2016-12-15

    This investigation concerns borosilicate glass leaching mechanisms and the evolution of alteration layer under electron beam irradiation. A simple glass doped with rare earth elements was selected in order to access mechanistic and structural information and better evaluate the effects of irradiation. It was fully leached in initially pure water at 90 °C and at high glass surface area to solution volume ratio (S/V = 20 000 m{sup −1}) in static conditions. Under these conditions, the system quickly reaches the residual alteration rate regime. A small particle size fraction (2–5 μm) was sampled in order to obtain a fairly homogeneous altered material enabling the use of bulk characterization methods. External irradiations with 10 MeV electrons up to a dose of 10 MGy were performed either before or after leaching, to investigate respectively the effect of initial glass irradiation on its alteration behavior and the irradiation stability of the alteration layer. Glass dissolution rate was analyzed by regular leachate samplings and the alteration layer structure was characterized by Raman, luminescence (continuous or time-resolved), and {sup 29}Si MAS NMR and EPR spectroscopy. It was shown that the small initial glass evolutions under irradiation did not induce any modification of the leaching kinetic nor of the structure of the alteration layer. The alteration process seemed to “smooth over” the created defects. Otherwise, the alteration layer and initial glass appeared to have different behaviors under irradiation. No Eu{sup 3+} reduction was detected in the alteration layer after irradiation and the defect creation efficiency was much lower than for initial glass. This can possibly be explained by the protective role of pore water contained in the altered material (∼20%). Moreover, a slight depolymerization of the silicon network of the altered glass under irradiation with electrons was evidenced, whereas in the initial glass it typically

  1. Glass and nuclear wastes

    International Nuclear Information System (INIS)

    Sombret, C.

    1982-10-01

    Glass shows interesting technical and economical properties for long term storage of solidified radioactive wastes by vitrification or embedding. Glass composition, vitrification processes, stability under irradiation, thermal stability and aqueous corrosion are studied [fr

  2. Microstructuring of glasses

    CERN Document Server

    Hülsenberg, Dagmar; Bismarck, Alexander

    2008-01-01

    As microstructured glass becomes increasingly important for microsystems technology, the main application fields include micro-fluidic systems, micro-analysis systems, sensors, micro-actuators and implants. And, because glass has quite distinct properties from silicon, PMMA and metals, applications exist where only glass devices meet the requirements. The main advantages of glass derive from its amorphous nature, the precondition for its - theoretically - direction-independent geometric structurability. Microstructuring of Glasses deals with the amorphous state, various glass compositions and their properties, the interactions between glasses and the electromagnetic waves used to modify it. Also treated in detail are methods for influencing the geometrical microstructure of glasses by mechanical, chemical, thermal, optical, and electrical treatment, and the methods and equipment required to produce actual microdevices.

  3. Measurement of optical glasses

    International Nuclear Information System (INIS)

    Nicolau-Rebigan, S.

    1978-11-01

    The possibilities of measurement of the optical glasses parameters needed in building optical devices especially in lasers devices are presented. In the first chapter the general features of the main optical glasses as well as the modalities of obtaining them are given. Chapter two defines the optical glass parameters, and the third chapter describes the measuring methods of the optical glass parameters. Finally, the conclusions which point out the utilization of this paper are presented. (author)

  4. Experimental study of the hydrothermal alteration of a chemical analogue of the French nuclear glass in a thermal gradient: characterization of newly formed phases and of matter transfers

    International Nuclear Information System (INIS)

    Poinssot, Christophe

    1994-01-01

    As the most dangerous radioactive wastes are to be stored in deep geological layers after having been packaged in barrels made of borosilicate glasses, this research report addresses the study of the alteration of such glasses through the study of a chemical analogue. In order to experimentally model phenomena involved within a storage, the studied glass has been submitted to different thermal gradients between 320 and 150 C and during 3 to 5 months. These gradients comply with those met about the parcels, and allows the spatial evolution of the waste parcel at a given moment, as well as the evolution in time (progressive cooling of wastes) to be simultaneously simulated. The different phases formed within the gradient have been studied and characterized by scanning electronic microscopy, semi-quantitative microanalysis, and X-ray micro-diffraction [fr

  5. Radiopaque Strontium Fluoroapatite Glass-Ceramics

    Science.gov (United States)

    Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

    2015-01-01

    expansion (CTE). These glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications. The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs, and optical characteristics. PMID:26528470

  6. Radiopaque Strontium Fluoroapatite Glass-Ceramics.

    Science.gov (United States)

    Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

    2015-01-01

    glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications. The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs, and optical characteristics.

  7. Aqueous corrosion mechanisms of the nuclear glass R7T7. Experimental approach. Kinetics and thermodynamic simulation

    International Nuclear Information System (INIS)

    Advocat, T.

    1991-01-01

    An inactive borosilicate glass made of about 30 oxides is studied. The composition was developed by the CEA for encapsulation of calcinated fission product solutions from reprocessing. Hydration energy of glass is first calculated for 8 glasses and results are compared to experimental data. Dissolution of R7T7 glass is examined at 90 0 C in a large range of pH and S/V ratios (glass surface/solution volume). In dilute media (S/V = 0.1 cm -1 ) dissolution is selective at acid pH and stoichiometric at basic pH. In alkaline media dissolution rate increases with pH. Corrosion products, generally amorphous or badly crystallized are observed on glass surface. For high S/V ratios (4, 20, 80 and 200 cm -1 ) the very low dissolution rate is explained by saturation. Orthosilic acid controls corrosion kinetics. A kinetic equation is proposed taking into account pH, S/V ratio and dissolved silica concentration. Geochemical consequences of R7T7 dissolution are modelled at 100 0 C and 90 0 C. Affinity of dissolution reaction depends upon many factors (pH, silica concentration, nature and crystallinity of secondary phases. Reaction affinity is not constant for the long-term [fr

  8. Technique for Machining Glass

    Science.gov (United States)

    Rice, S. H.

    1982-01-01

    Process for machining glass with conventional carbide tools requires a small quantity of a lubricant for aluminum applied to area of glass to be machined. A carbide tool is then placed against workpiece with light pressure. Tool is raised periodically to clear work of glass dust and particles. Additional lubricant is applied as it is displaced.

  9. Radiation effects on oxide glasses: Importance of energy deposition and relaxation processes

    International Nuclear Information System (INIS)

    Mir, Anamul-Haq

    2015-01-01

    Nuclear waste glass matrices during their disposal will be subjected to self-irradiation by beta and alpha decays. Beta emitting radionuclides due to their short half life time will be the dominant radiation source only during first few hundred years of the disposal, whereas the alpha decays constitute a long term radiation source. Due to intense beta decay and associated gamma rays, the glass matrices can attain temperatures up to 300 C during state 1. The temperature during stage 2 will mainly be defined by the repository conditions. The present work focused on studying the response of various glasses (borosilicate glasses of nuclear waste interest and amorphous silica) to electron irradiation (to understand the response of the pristine glasses to beta decays), single ion beam irradiations with light and heavy ions over a wide stopping power and fluence range (to study the response of the pristine glasses as a function of the electronic and nuclear energy loss so as to establish the necessary conditions for simulating the alpha and recoil nuclei damage), sequential electron-ion irradiations (to understand the impact of the intense beta decay damage during stage 1 on subsequent alpha decay during stage 2, and double ion beam sequential and simultaneous irradiations (to understand the interaction of the alpha particles with recoil nuclei pre-damaged glass and vice versa). The pristine and irradiated samples were characterized using Raman spectroscopy, NMR spectroscopy, micro and nano indentation, AFM, interferometry and ToF-SIMS. Apart from the experimental work, Inelastic Thermal Spike Model (iTSM) for ion track formation was extended to borosilicate glasses to study the possibility of ion track formation in nuclear waste glass matrices. The model was used to study the impact of matrix temperature and stored energy on the ion track threshold, which is otherwise difficult to study experimentally. During electron irradiation, the response of the glasses was found to

  10. The behavior of silicon and boron in the surface of corroded nuclear waste glasses: an EFTEM study

    International Nuclear Information System (INIS)

    Buck, E. C.; Smith, K. L.; Blackford, M. G.

    1999-01-01

    Using electron energy-loss filtered transmission electron microscopy (EFTEM), we have observed the formation of silicon-rich zones on the corroded surface of a West Valley (WV6) glass. This layer is approximately 100-200 nm thick and is directly underneath a precipitated smectite clay layer. Under conventional (C)TEM illumination, this layer is invisible; indeed, more commonly used analytical techniques, such as x-ray energy dispersive spectroscopy (EDS), have failed to describe fully the localized changes in the boron and silicon contents across this region. Similar silicon-rich and boron-depleted zones were not found on corroded Savannah River Laboratory (SRL) borosilicate glasses, including SRL-EA and SRL-51, although they possessed similar-looking clay layers. This study demonstrates a new tool for examining the corroded surfaces of materials

  11. Environmental Testing of Tritium-Phosphor Glass Vials for Use in Long-Life Radioisotope Power Conversion Units

    Science.gov (United States)

    Zemcov, Michael; Cardona, Pedro; Parkus, James; Patru, Dorin; Yost, Valerie

    2017-01-01

    Power generation in extreme environments, such as the outer solar system, the night side of planets, or other low-illumination environments, currently presents a technology gap that challenges NASA's ambitious scientific goals. We are developing a radioisotope power cell (RPC) that utilizes commercially available tritium light sources and standard 1.85 eV InGaP2 photovoltaic cells to convert beta particle energy to electric energy. In the test program described here, we perform environmental tests on commercially available borosilicate glass vials internally coated with a ZnS luminescent phosphor that are designed to contain gaseous tritium in our proposed power source. Such testing is necessary to ensure that the glass containing the radioactive tritium is capable of withstanding the extreme environments of launch and space for extended periods of time.

  12. The Economy of Persistence: Mario the Tailor

    Directory of Open Access Journals (Sweden)

    Prudence Black

    2016-03-01

    Full Text Available Mario Conte has had a tailor shop in King Street, Newtown since the mid 1960s. Taking an interview with Mario as its point of departure, this article describes the persistence of a skilled worker whose practices and techniques remain the same in a world that has long changed. While inattentive to what rules might be used to decorate a shop window, Mario continues to make and sew in the way that he learnt in post-war Italy. Mario’s persistence could be described as all the skills and other elements that need to be in place to keep him working, in particular the tradition of tailoring techniques he has remained true to over the last fifty years. The hand stitching of his tailoring is like a metronome of that persistence.

  13. Tailored Codes for Small Quantum Memories

    Science.gov (United States)

    Robertson, Alan; Granade, Christopher; Bartlett, Stephen D.; Flammia, Steven T.

    2017-12-01

    We demonstrate that small quantum memories, realized via quantum error correction in multiqubit devices, can benefit substantially by choosing a quantum code that is tailored to the relevant error model of the system. For a biased noise model, with independent bit and phase flips occurring at different rates, we show that a single code greatly outperforms the well-studied Steane code across the full range of parameters of the noise model, including for unbiased noise. In fact, this tailored code performs almost optimally when compared with 10 000 randomly selected stabilizer codes of comparable experimental complexity. Tailored codes can even outperform the Steane code with realistic experimental noise, and without any increase in the experimental complexity, as we demonstrate by comparison in the observed error model in a recent seven-qubit trapped ion experiment.

  14. QUALIFICATION OF A RADIOACTIVE HIGH ALUMINUM GLASS FOR PROCESSINGIN THE DEFENSE WASTE PROCESSING FACILITY AT THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, N; John Pareizs, J; Tommy Edwards,T; Charles02 Coleman, C; Charles Crawford, C

    2008-01-29

    At the Savannah River Site (SRS) the Defense Waste Processing Facility (DWPF) has been immobilizing SRS's radioactive high level waste (HLW) sludge into a borosilicate glass for approximately eleven years. Currently the DWPF is immobilizing HLW sludge in Sludge Batch 4 (SB4). Each sludge batch is nominally two million liters of HLW and produces nominally five hundred stainless steel canisters 0.6 meters in diameter and 3 meters tall filled with the borosilicate glass. In SB4 and earlier sludge batches, the Al concentration has always been rather low, (less than 9.5 weight percent based on total dried solids). It is expected that in the future the Al concentrations will increase due to the changing composition of the HLW. Higher Al concentrations could introduce problems because of its known effect on the viscosity of glass melts and increase the possibility of the precipitation of nepheline in the final glass and decrease its durability. In 2006 Savannah River National Laboratory (SRNL) used DWPF processes to immobilize a radioactive HLW slurry containing 14 weight percent Al to ensure that this waste is viable for future DWPF processing. This paper presents results of the characterization of the high Al glass prepared in that demonstration. At SRNL, a sample of the processed high Al HLW slurry was mixed with an appropriate glass frit as performed in the DWPF to make a waste glass containing nominally 30% waste oxides. The glass was prepared by melting the frit and waste remotely at 1150 C. The glass was then characterized by: (1) determining the chemical composition of the glass including the concentrations of several actinide and U-235 fission products; (2) calculating the oxide waste loading of the glass based on the chemical composition and comparing it to that of the target; (3) determining if the glass composition met the DWPF processing constraints such as glass melt viscosity and liquidus temperature along with a waste form affecting constraint that

  15. Multiple Glass Ceilings

    OpenAIRE

    Russo, Giovanni; Hassink, Wolter

    2011-01-01

    Both vertical (between job levels) and horizontal (within job levels) mobility can be sources of wage growth. We find that the glass ceiling operates at both margins. The unexplained part of the wage gap grows across job levels (glass ceiling at the vertical margin) and across the deciles of the intra-job-level wage distribution (glass ceiling at the horizontal margin). This implies that women face many glass ceilings, one for each job level above the second, and that the glass ceiling is a p...

  16. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  17. Immobilized TiO2on glass spheres applied to heterogeneous photocatalysis: photoactivity, leaching and regeneration process.

    Science.gov (United States)

    Cunha, Deivisson Lopes; Kuznetsov, Alexei; Achete, Carlos Alberto; Machado, Antonio Eduardo da Hora; Marques, Marcia

    2018-01-01

    Heterogeneous photocatalysis using titanium dioxide as catalyst is an attractive advanced oxidation process due to its high chemical stability, good performance and low cost. When immobilized in a supporting material, additional benefits are achieved in the treatment. The purpose of this study was to develop a simple protocol for impregnation of TiO 2 -P25 on borosilicate glass spheres and evaluate its efficiency in the photocatalytic degradation using an oxidizable substrate (methylene blue), in a Compound Parabolic Concentrator (CPC) reactor. The assays were conducted at lab-scale using radiation, which simulated the solar spectrum. TiO 2 leaching from the glass and the catalyst regeneration were both demonstrated. A very low leaching ratio (0.03%) was observed after 24 h of treatment, suggesting that deposition of TiO 2 resulted in good adhesion and stability of the photocatalyst on the surface of borosilicate. This deposition was successfully achieved after calcination of the photocatalyst at 400 °C (TiO 2 -400 °C). The TiO 2 film was immobilized on glass spheres and the powder was characterized by scanning electron microscopy (SEM), X-ray diffraction and BET. This characterization suggested that thermal treatment did not introduce substantial changes in the measured microstructural characteristics of the photocatalyst. The immobilized photocatalyst degraded more than 96% of the MB in up to 90 min of reaction. The photocatalytic activity decreased after four photocatalytic cycles, but it was recovered by the removal of contaminants adsorbed on the active sites after washing in water under UV-Vis irradiation. Based on these results, the TiO 2 -400 °C coated on glass spheres is potentially a very attractive option for removal of persistent contaminants present in the environment.

  18. Development and modification of glass membranes for aggressive gas separations

    Energy Technology Data Exchange (ETDEWEB)

    Lindbraaten, Arne

    2004-07-01

    Chlorine as a chemical is widespread in industry and found in a great variety of processes ranging from water purification to plastic production. In this thesis, a magnesium production factory was chosen as an example because it involved both chlorine - air separation and hydrogen -hydrogen chloride separation. Previously, various types of membrane materials have been tested out for their applicability in the chosen process. The materials previously tested either lacked sufficient membrane performance or sufficient membrane stability. As an attempt to improve both the membrane performance and stability, glass membranes are used in this thesis. Glass membranes are prepared from a borosilicate glass, via a phase separation followed by an acid leaching route. By choosing the appropriate phase separation temperature and acid to glass ratio, the membrane can be produced with an average pore diameter of 2 nm (or 4 nm). However, the 2 nm average pore size is still too large to separate gases with separation selectivities beyond the selectivities predicted from Knudsen diffusion theory. If the pores are narrowed, the selectivity may be raised while the flux hopefully is maintained. The narrowing of the pores was done by a silane coupling to the surface OH-groups on the glass. The silane coupling agent is of the dimethyl-acyl-chlorosilane type, where the length of the acyl chain varies from 1 carbon up to 18 carbons. Glass fibres are also tested in this work, which are produced without phase separation and their average pore size is smaller than the surface-modified glasses. To be able to compare the performance of the various membranes, performance measurements are performed and these measurements are evaluated by the separation power (product of the selectivity and the permeability of the fastest permeating compound). Because of the harsh chlorine or hydrogen chloride environment, to which the membranes are exposed in this work, the membrane stability is at least as

  19. Localized chemistry of 99Tc in simulated low activity waste glass

    Science.gov (United States)

    Weaver, Jamie L.

    A priority of the United States Department of Energy (DOE) is to dispose of the nuclear waste accumulated in the underground tanks at the Hanford Nuclear Reservation in Richland, WA. Incorporation and stabilization of technetium (99Tc) from these tanks into vitrified waste forms is a concern to the waste glass community and DOE due to 99Tc's long half-life ( 2.13˙105 y), and its high mobility in the subsurface environment under oxidizing conditions. Working in collaboration with researchers at Pacific Northwest National Laboratory (PNNL) and other national laboratories, plans were formulated to obtain first-of-a-kind chemical structure determination of poorly understood and environmentally relevant technetium compounds that relate to the chemistry of the Tc in nuclear waste glasses. Knowledge of the structure and spectral signature of these compounds aid in refining the understanding of 99Tc incorporation into and release from oxide based waste glass. In this research a first-of-its kind mechanism for the behavior of 99Tc during vitrification is presented, and the structural role of Tc(VII) and (IV) in borosilicate waste glasses is readdressed.

  20. The Production of Advanced Glass Ceramic HLW Forms using Cold Crucible Induction Melter

    Energy Technology Data Exchange (ETDEWEB)

    Veronica J Rutledge; Vince Maio

    2013-10-01

    Cold Crucible Induction Melters (CCIMs) will favorably change how High-Level radioactive Waste (from nuclear fuel recovery) is treated in the 21st century. Unlike the existing Joule-Heated Melters (JHMs) currently in operation for the glass-based immobilization of High-Level Waste (HLW), CCIMs offer unique material features that will increase melt temperatures, increase throughput, increase mixing, increase loading in the waste form, lower melter foot prints, eliminate melter corrosion and lower costs. These features not only enhance the technology for producing HLW forms, but also provide advantageous attributes to the waste form by allowing more durable alternatives to glass. This paper discusses advantageous features of the CCIM, with emphasis on features that overcome the historical issues with the JHMs presently utilized, as well as the benefits of glass ceramic waste forms over borosilicate glass waste forms. These advantages are then validated based on recent INL testing to demonstrate a first-of-a-kind formulation of a non-radioactive ceramic-based waste form utilizing a CCIM.

  1. Removal of platinum group metals contained in molten glass using copper

    International Nuclear Information System (INIS)

    Uruga, Kazuyoshi; Sawada, Kayo; Arita, Yuji; Enokida, Youichi; Yamamoto, Ichiro

    2007-01-01

    Removal of platinum group metals (PGMs) such as Pd, Ru, and RuO 2 from molten glass by using various amounts of liquid Cu was done as a basic study on a new vitrification process for a high-level radio-active waste. We prepared two types of borosilicate glasses containing PGMs and Cu, respectively. These glasses were mixed together and heated at 1,473 K for 4h in Ar atmosphere. More than 95% of Pd were removed as a spherical metal button composed of Pd-Cu alloy when Cu was added in an amount 0.5 times the weight of Pd. Nearly 95% of Ru was also removed as a spherical button with 2.5-5 times as much Cu addition as Ru in weight. Ruthenium oxide was reduced to metallic Ru by a reaction with Cu in the molten glass. The removal fraction was increased by increasing the amount of Cu and reached 63% when Cu addition was 7.5 times as much as RuO 2 in weight. By addition of Si as a reducing agent, nearly 90% of Pd and Ru were removed with Cu and Si metal composites even under O 2 :Ar=20:80 (v/v) condition. (author)

  2. Femtosecond Nanostructuring of Glass with Optically Trapped Microspheres and Chemical Etching.

    Science.gov (United States)

    Shakhov, A; Astafiev, A; Gulin, A; Nadtochenko, V

    2015-12-16

    Laser processing with optically trapped microspheres is a promising tool for nanopatterning at subdiffraction-limited resolution in a wide range of technological and biomedical applications. In this paper, we investigate subdiffraction-limited structuring of borosilicate glass with femtosecond pulses in the near-field of optically trapped microspheres combined with chemical postprocessing. The glass surface was processed by single laser pulses at 780 nm focused by silica microspheres and then subjected to selective etching in KOH, which produced pits in the laser-affected zones (LAZs). Chemical postprocessing allowed obtaining structures with better resolution and reproducibility. We demonstrate production of reproducible pits with diameters as small as 70 nm (λ/11). Complex two-dimensional structures with 100 nm (λ/8) resolution were written on the glass surface point by point with microspheres manipulated by optical tweezers. Furthermore, the mechanism of laser modification underlying selective etching was investigated with mass spectrum analysis. We propose that the increased etching rate of laser-treated glass results from changes in its chemical composition and oxygen deficiency.

  3. SUMMARY OF FY11 SULFATE RETENTION STUDIES FOR DEFENSE WASTE PROCESSING FACILITY GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Edwards, T.

    2012-05-08

    This report describes the results of studies related to the incorporation of sulfate in high level waste (HLW) borosilicate glass produced at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). A group of simulated HLW glasses produced for earlier sulfate retention studies was selected for full chemical composition measurements to determine whether there is any clear link between composition and sulfate retention over the compositional region evaluated. In addition, the viscosity of several glasses was measured to support future efforts in modeling sulfate solubility as a function of predicted viscosity. The intent of these studies was to develop a better understanding of sulfate retention in borosilicate HLW glass to allow for higher loadings of sulfate containing waste. Based on the results of these and other studies, the ability to improve sulfate solubility in DWPF borosilicate glasses lies in reducing the connectivity of the glass network structure. This can be achieved, as an example, by increasing the concentration of alkali species in the glass. However, this must be balanced with other effects of reduced network connectivity, such as reduced viscosity, potentially lower chemical durability, and in the case of higher sodium and aluminum concentrations, the propensity for nepheline crystallization. Future DWPF processing is likely to target higher waste loadings and higher sludge sodium concentrations, meaning that alkali concentrations in the glass will already be relatively high. It is therefore unlikely that there will be the ability to target significantly higher total alkali concentrations in the glass solely to support increased sulfate solubility without the increased alkali concentration causing failure of other Product Composition Control System (PCCS) constraints, such as low viscosity and durability. No individual components were found to provide a significant improvement in sulfate retention (i.e., an increase of the magnitude

  4. Toward Molecular Engineering of Polymer Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Freed, Karl F. [Univ. of Chicago, IL (United States); Xu, Wen-Sheng [Univ. of Chicago, IL (United States); Dudowicz, Jacek B. [Univ. of Chicago, IL (United States); Douglas, Jack F. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States)

    2017-04-05

    Glass formation has been central to fabrication technologies since the dawn of civilization. Glasses not only encompass window panes, the insulation in our homes, the optical fibers supplying our cable TV, and vessels for eating and drinking, but they also include a vast array of ‘‘plastic’’ polymeric materials. Glasses find applications in high technology (e.g., producing microelectronic materials, etc., amorphous semiconductors), and recent advances have created ‘‘plastic metallic glasses’’ that are promising for fabricating everyday structural materials. Many commercially relevant systems, such as microemulsions and colloidal suspensions, have complex molecular structures and thus solidify by glass formation. Despite the importance of understanding the fundamental nature of glass formation for the synthesis of new materials, a predictive molecular theory has been lacking. Much of our understanding of glass formation derives from the analysis of experimental data, a process that has uncovered a number of interesting universal behaviors, namely, relations between properties that are independent of molecular details. However, these empirically derived relations and their limitations remain to be understood on the basis of theories, and, more importantly, there is strong need for theories of the explicit variation with molecular system to enable the rational design and tailoring of new materials. We have recently developed the generalized entropy theory, the only analytic, theory that enables describing the dependence of the properties of glass-formation on monomer molecular structures. These properties include the two central quantities of glass formation, the glass transition temperature and the glass fragility parameter, material dependent properties that govern how a material may be processed (e.g., by extrusion, ink jet, molding, etc.) Our recent works, which are further described below, extend the studies of glass formation in polymer systems

  5. Biocompatible glass-ceramic materials for bone substitution.