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Sample records for borosilicates

  1. Introduction - Acid decomposition of borosilicate ores

    International Nuclear Information System (INIS)

    The complex processing of mineral raw materials is an effective way for the extraction of valuable components. One of these raw materials are borosilicate ores from which the boric acid, aluminium and iron salts and building materials can be obtained. In the Institute of Chemistry of the Academy of Sciences of the Republic of Tajikistan the flowsheets of the processing of borosilicate raw materials by acid and chloric methods were elaborated. The acid methods of decomposition of borosilicate ores of Ak-Arkhar Deposit were considered in present monograph. The carried out researches on elaboration of physicochemical aspects and technological acid methods allowed to define the optimal ways of extraction of valuable products from borosilicate raw materials of Tajikistan.

  2. 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...

  3. 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: 3.453, year: 2014

  4. Photoluminescent properties of nanocrystallized zinc borosilicate glasses

    Czech Academy of Sciences Publication Activity Database

    Chen, G.; Nikl, Martin; Solovieva, Natalia; Beitlerová, Alena; Rao, J.; Yang, Y.; Zhang, Y.; Jiang, X.; Zhu, C.

    2004-01-01

    Roč. 38, - (2004), s. 771-774. ISSN 1350-4487 R&D Projects: GA MŠk(CZ) 1P04ME716 Institutional research plan: CEZ:AV0Z1010914 Keywords : zinc borosilicate glass * scintillating material * luminescence * nanosized crystals Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.664, year: 2004

  5. The mechanism of borosilicate glass corrosion revisited

    Science.gov (United States)

    Geisler, Thorsten; Nagel, Thorsten; Kilburn, Matt R.; Janssen, Arne; Icenhower, Jonathan P.; Fonseca, Raúl O. C.; Grange, Marion; Nemchin, Alexander A.

    2015-06-01

    Currently accepted mechanistic models describing aqueous corrosion of borosilicate glasses are based on diffusion-controlled hydrolysis, hydration, ion exchange reactions, and subsequent re-condensation of the hydrolyzed glass network, leaving behind a residual hydrated glass or gel layer. Here, we report results of novel oxygen and silicon isotope tracer experiments with ternary Na borosilicate glasses that can be better explained by a process that involves the congruent dissolution of the glass, which is spatially and temporally coupled to the precipitation and growth of an amorphous silica layer at an inwardly moving reaction interface. Such a process is thermodynamically driven by the solubility difference between the glass and amorphous silica, and kinetically controlled by glass dissolution reactions at the reaction front, which, in turn, are controlled by the transport of water and solute elements through the growing corrosion zone. Understanding the coupling of these reactions is the key to understand the formation of laminar or more complex structural and chemical patterns observed in natural corrosion zones of ancient glasses. We suggest that these coupled processes also have to be considered to realistically model the long-term performance of silicate glasses in aqueous environments.

  6. Irradiation effects on borosilicate waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, F.P.

    1980-06-01

    The effects of alpha decay on five borosilicate glasses containing simulated nuclear high-level waste oxides were studied. Irradiations carried out at room temperature were achieved by incorporating 1 to 8 wt % /sup 244/Cm/sub 2/O/sub 3/ in the glasses. Density changes and stored-energy build-up saturated at doses less than 2 x 10/sup 21/ alpha decays/kg. Damage manifested by stored energy was completely annealed at 633/sup 0/K. Positive and negative density changes were observed which never exceeded 1%. Irradiation had very little effect on mechanical strength or on chemical durability as measured by aqueous leach rates. Also, no effects were observed on the microstructure for vitreous waste glasses, although radiation-induced microcracking could be achieved on specimens that had been devitrified prior to irradiation.

  7. Potassium borosilicate glasses: Phase separation and structon types

    International Nuclear Information System (INIS)

    The dc electrical resistivity of potassium borosilicate glasses was measured in the temperature range from 323 to 623K. The conduction mechanism was of ionic type. The composition and heat treatment effects on the conduction mechanism were studied. The results obtained were interpreted in terms of a previously proposed phase separation model. The possible different structon types of potassium borosilicate glasses were postulated according to the Huggins structon theory. (author)

  8. Dolomite effect on borosilicate glass alteration

    International Nuclear Information System (INIS)

    Highlights: ► Dolomite is a common mineral of clayey formations considered for radioactive waste disposals. ► Borosilicate glass/dolomite interaction have been studied by batch tests and solid analysis. ► Mg provided by dolomite combines with Si from glass to yield secondary Mg–silicates. ► This precipitation increases glass alteration, though in a moderate manner. ► Geochemical modeling allows to quantify the alteration mechanisms involved. - Abstract: Dolomite (CaMg(CO3)2) is one of the common rock-forming minerals in many geological media, in particular in clayey layers that are currently considered as potential host formations for a deep radioactive waste disposal facility. Magnesium in solution is one of the elements known to potentially enhance the alteration of nuclear glasses. The alteration of borosilicate glasses with dolomite as a Mg-bearing mineral source was investigated for 8 months in batch tests at 90 °C. Glass composition effects were investigated through two compositions (SiBNaAlCaZrO and SiBNaAlZrO) differing in their Ca content. The Ca-rich glass alteration is slightly enhanced in the presence of dolomite compared to the alteration observed in pure water. This greater alteration is explained by the precipitation of Mg silicate phases on the dolomite and glass surfaces. In contrast, the Ca-free glass alteration decreases in the presence of dolomite compared to the alteration observed in pure water. This behavior is explained by Ca incorporation in the amorphous layer (formed during glass alteration) coming from dolomite dissolution. Calcium acts as a layer reorganizer and limits glass alteration by reducing the diffusion of reactive species through the altered layer. Modeling was performed using the GRAAL model implemented within the CHESS/HYTEC geochemical code to discriminate and interpret the mechanisms involved in glass/dolomite interactions. Magnesium released by dolomite dissolution reacts with silica provided by glass

  9. Surface chemistry and durability of borosilicate glass

    International Nuclear Information System (INIS)

    Important glass-water interactions are poorly understood for borosilicate glass radioactive waste forms. Preliminary results show that glass durability is dependent on reactions occurring at the glass-solution interface. CSG glass (18.2 wt. % Na2O, 5.97 wt. % CaO, 11.68 wt. % Al2O3, 8.43 wt. % B2O3, and 55.73 wt. % SiO2) dissolution and net surface H+ and OH- adsorption are minimal at near neutral pH. In the acid and alkaline pH regions, CSG glass dissolution rates are proportional to [H+]adsorbed2 and [OH-]adsorbed0.8, respectively. In contrast, silica gel dissolution and net H+ and OH- adsorption are minimal and independent of pH in acid to neutral solutions. In the alkaline pH region, silica gel dissolution is proportional to [OH-]adsorbed0.9adsorbed. Although Na adsorption is significant for CSG glass and silica gel in the alkaline pH regions, it is not clear if it enhances dissolution, or is an artifact of depolymerization of the framework bonds

  10. Borosilicate glass alteration driven by magnesium carbonates

    International Nuclear Information System (INIS)

    Highlights: ► We studied borosilicate glass/hydromagnesite interaction. ► Magnesium silicate precipitation increases glass alteration. ► Geochemical modeling allows to quantify the alteration mechanisms involved. - Abstract: The alteration of simplified synthetic glass, representative of the French reference nuclear glass R7T7, in presence of hydromagnesite has been experimentally investigated and modeled. Magnesium in solution is known to potentially enhance glass alteration; nuclear glass clayed host rocks contain magnesium and can dissolve to maintain the concentration of magnesium in solution. For modeling purposes, it was suitable to study a simple system. Hydromagnesite was therefore chosen as a simple model mineral in order to check the influence of an Mg-rich mineral on glass alteration. Since the models use thermodynamic and kinetic parameters measured in pure water and pH-buffered solutions, changing the solution composition or adding minerals is a key step towards the validation of the modeling assumptions before using the model for predictive purposes. Experiments revealed that glass alteration is enhanced in presence of hydromagnesite. Modeling was performed using the GRAAL model implemented within the CHESS/HYTEC reactive transport code. Modeling proved useful both for explaining the mechanisms involved and quantifying the impact on glass alteration: Mg coming from hydromagnesite dissolution reacts with Si provided by the glass in order to form magnesium silicates. This reaction decreases the pH down to neutral conditions where magnesium silicates are more soluble than at the natural alkali pH imposed by glass or hydromagnesite dissolution. The driving force of the magnesium silicate precipitation is eventually the interdiffusion of alkali within the altered amorphous glass layer as this mechanism consumes protons. The model’s ability to describe the concentrations of elements in solution and formed solids whatever the glass

  11. Er3+-Yb3+ codoped borosilicate glass for optical thermometry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Infrared to green up-conversion emissions centered at the wavelengths of about 524 and 550 nm of the Er3+-Yb3+ codoped borosilicate glass are recorded,using a 978 nm semiconductor laser diode(LD) as an excitation source.The fluorescence intensity ratio(FIR) of the green up-conversion emissions at about 524 and 550 nm in the Er3+-Yb3+ codoped borosilicate glass has been studied as a function of temperature over the temperature range of 295-873 K.The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions are approximately 0.0038 K-1 and 0.2 K,respectively.It is demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er3+-Yb3+ codoped borosilicate glass plays a major role in temperature measurement.

  12. Utilization of borosilicate glass for transuranic waste immobilization

    International Nuclear Information System (INIS)

    Incinerated transuranic waste and other low-level residues have been successfully vitrified by mixing with boric acid and sodium carbonate and heating to 10500C in a bench-scale continuous melter. The resulting borosilicate glass demonstrates excellent mechanical durability and chemical stability

  13. Radiolysis of hexane absorbing on borosilicate surface research

    International Nuclear Information System (INIS)

    The radiolysis process of hexane absorbing on borosilicate with various hydration degree is being investigated. Samples of borosilicate were treated by thermal vacuum at and T=493 K and P=1.33·10-4 Pa. The absorption of water and hexane was carried out on manometric equipment at 77 K temperature. An irradiation was conducted by γ-rays from 60Co source in the sealed in ampoules at 77 K with 10 kGy dose. In the irradiated samples the ESR spectrum with wide range that is characteristic for irradiated alkanes in the absorbing condition was observed. With increase of temperature of registration narrowing lines and improved sanction connected to recombination processes of radicals was observed. With increase of a hydration of a surface the redistribution and reduction of intensity separate component of a spectrum was observed. It specifies formation and stabilization bonding of radicals at smaller filling of a surface borosilicate. To reveal structure of radiolysis products IR spectra of desorbed from a borosilicate surface gas products were received at 333 K. In the field of low-frequency deformation of fluctuations CH2-groups the doublet strip with maxima was observed at 790 cm-1 and 770 cm-1 which is referred to low-molecular of radiolysis products

  14. Using of borosilicate glass waste as a cement additive

    Science.gov (United States)

    Han, Weiwei; Sun, Tao; Li, Xinping; Sun, Mian; Lu, Yani

    2016-08-01

    Borosilicate glass waste is investigated as a cement additive in this paper to improve the properties of cement and concrete, such as setting time, compressive strength and radiation shielding. The results demonstrate that borosilicate glass is an effective additive, which not only improves the radiation shielding properties of cement paste, but also shows the irradiation effect on the mechanical and optical properties: borosilicate glass can increase the compressive strength and at the same time it makes a minor impact on the setting time and main mineralogical compositions of hydrated cement mixtures; and when the natural river sand in the mortar is replaced by borosilicate glass sand (in amounts from 0% to 22.2%), the compressive strength and the linear attenuation coefficient firstly increase and then decrease. When the glass waste content is 14.8%, the compressive strength is 43.2 MPa after 28 d and the linear attenuation coefficient is 0.2457 cm-1 after 28 d, which is beneficial for the preparation of radiation shielding concrete with high performances.

  15. Wetting behavior of lead borosilicates on ceramic substrates

    International Nuclear Information System (INIS)

    Wetting characteristics of several lead silicates. lead borates, and lead borosilicates, on alumina, beryllia, aluminum nitride, silicon nitride and silicon carbide substrates, were investigated. Both polycrystalline and single crystal substrates behavior of the liquids was studied with the sensile drop method, and optical and SEM/EDAX microscopy was used for examining interfaces. The results are discussed in relating to interfacial properties and bonding

  16. Ultrashort laser pulse induced nanogratings in borosilicate glass

    International Nuclear Information System (INIS)

    We report on nanogratings inscribed by repetitive femtosecond laser pulses into the bulk of borosilicate glass. The irradiation produces small nanopores (10–20 nm thick) which start to self-organize in gratings as well as elongated sheets of up to 400 nm length. A quantitative description of the grating structure and its development are obtained by a combination of focused ion beam milling, scanning electron microscopy, and small angle X-ray scattering (SAXS). The SAXS partial invariant of the thin sheets is found to correlate well with the measured optical retardance. Compared to fused silica nanogratings borosilicate glass shows a much smaller retardance due to re-annealing of pores. In addition, the nanograting period strongly deviates from the well-known λ/2n prediction. We could observe periods down to 60 nm (at an inscribing wavelength of 800 nm). This has not been observed yet in other glasses.

  17. Direct conversion of halogen-containing wastes to borosilicate glass

    International Nuclear Information System (INIS)

    Glass has become a preferred waste form worldwide for radioactive wastes: however, there are limitations. Halogen-containing wastes can not be converted to glass because halogens form poor-quality waste glasses. Furthermore, halides in glass melters often form second phases that create operating problems. A new waste vitrification process, the Glass Material Oxidation and dissolution System (GMODS), removes these limitations by converting halogen-containing wastes into borosilicate glass and a secondary, clean, sodium-halide stream

  18. Locale structure around heteroatoms in alumino- and borosilicates for catalysis

    OpenAIRE

    Nagendrachar Garaga, Mounesha

    2013-01-01

    While alumino- and borosilicate materials have paramount importance in catalysis, the molecular origin of their activity is not completely understood. This is mainly because the incorporation of heteroatoms into the silicate framework deteriorates the molecular order by generating local disorder that is particularly difficult to establish. Because of its local vision of ordered and disordered environments, solid-state nuclear magnetic resonance (NMR) can play a key role to solve this long-sta...

  19. Ultrafast laser fabrication of submicrometer pores in borosilicate glass

    OpenAIRE

    An, Ran; Uram, Jeffrey D.; Yusko, Erik C.; Ke, Kevin; Mayer, Michael; Hunt, Alan J.

    2008-01-01

    We demonstrate rapid fabrication of submicrometer-diameter pores in borosilicate glass using femtosecond laser machining and subsequent wet-etch techniques. This approach allows direct and repeatable fabrication of high-quality pores with diameters of 400–800 nm. Such small pores coupled with the desirable electrical and chemical properties of glass enable sensitive resistive-pulse analysis to determine the size and concentration of macromolecules and nanoparticles. Plasma-enhanced chemical v...

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

    International Nuclear Information System (INIS)

    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-1 was scaled to the sum of the integrated bands between 800 and 1200 cm-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. 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

  2. Leaching of borosilicate glasses incorporating H.L. radioactive wastes

    International Nuclear Information System (INIS)

    The european community commission organized in the period 1983-84 an international round robin test aiming at the evaluation of a method for controlling the high-temperature leaching resistance of borosilicate glasses incorporating high-level radioactive wastes. The radwaste experimental processes laboratory of the COMB/MEPIS Division, in collaboration with the Analytical Chemistry Laboratory of the TIB/CHI Division, partecipated to this round robin test with other 12 european and 2 extra european laboratories. In this paper the main results obtained in thi partecipation are reported

  3. Frottement interne des verres de borates et de borosilicates alcalins

    OpenAIRE

    Phalippou, J.; Jabra, R.; Zarzycki, J.

    1980-01-01

    Les spectres de frottement interne des verres de borates alcalins ont été étudiés en fonction de la température. Ces spectres, contrairement à ceux des silicates et phosphates alcalins, ne montrent pas de second maximum (haute température). Il en est de même pour certains borosilicates alcalins. L'étude structurale de ces matériaux et en particulier du type de groupements hydroxyles qui peuvent y être rencontrés, nous incite à penser que le second maximum de frottement interne est dû à la pré...

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

    DEFF Research Database (Denmark)

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

    measurements, we present a two-state statistical mechanical model of boron speciation in which addition of network modifiers leads to a competition between the formation of nonbridging oxygen and the conversion of boron from trigonal to tetrahedral configuration. Using this model, we derive a detailed...... 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...

  5. 3.3. The kinetics of sulfuric acid decomposition of calcined borosilicate ore

    International Nuclear Information System (INIS)

    Present article is devoted to kinetics of sulfuric acid decomposition of calcined borosilicate ore. The experimental data of kinetics of extraction of boron oxide from calcined borosilicate ore at sulfuric acid decomposition were obtained at 30-95 deg C temperature ranges and process duration from 15 to 60 minutes.

  6. Barium borosilicate glass as a matrix for the uptake of dyes

    International Nuclear Information System (INIS)

    Barium borosilicate (BBS) and sodium borosilicate (SBS) glass samples, prepared by the conventional melt-quench method, were used for the uptake of Rhodamine 6G dye from aqueous solution. The experimental conditions were optimized to get maximum uptake and was found to be 0.4 mg of dye per gram of BBS glass sample. For the same network former to modifier ratio, barium borosilicate glasses are found to have improved extent of uptake for the dye molecules from aqueous solutions compared to sodium borosilicate glasses. Based on 29Si MAS NMR studies on these glasses, it is inferred that significantly higher number of non-bridging oxygen atoms present in barium borosilicate glasses compared to sodium borosilicate glasses is responsible for its improved uptake of Rhodamine 6G dye. 11B MAS NMR studies have confirmed the simultaneous existence of boron in BO3 and BO4 configurations in both barium borosilicate and sodium borosilicate glasses. The luminescence studies have established that the dye molecule is incorporated into the glass matrix through ion exchange mechanism by replacing the exchangeable ions like Na+/Ba2+ attached with the non-bridging oxygen atoms present in the glass.

  7. Chapter 3. Sulfuric acid decomposition of borosilicate ores. 3.1. Decomposition of borosilicate ores by sulfuric acid

    International Nuclear Information System (INIS)

    Present article is devoted to decomposition of borosilicate ores by sulfuric acid. The sulfuric acid decomposition of borate ores of Ak-Arkhar Deposit was studied. The possibility of multipurpose utilization of borate ores was shown. The influence of process duration on the rate of oxides (B2O3, Fe2O3 and Al2O3) extraction was studied as well. In order to reach the complete decomposition of oxides from danburite ore the dependence of rate of oxides decomposition on concentration of sulfuric acid was studied. The optimal conditions of sulfuric acid decomposition of danburite ores were proposed.

  8. Moessbauer spectroscopic study of potassium borosilicate glasses at low temperatures

    International Nuclear Information System (INIS)

    The Moessbauer technique at the liquid nitrogen temperature (78 K) was applied to the estimation of nonbridging oxygens in FeO4, BO4, and SiO4 units in potassium borosilicate glasses. Moessbauer spectra consist of a quadrupole doublet and a hyperfine structure due to Fe3+ ions with tetrahedral symmetry. The hyperfine structure is attributed to a relaxation effect because magnetic susceptibility measurements revealed the glasses to be paramagnetic in the temperature range 78 - 295 K. A linear decrease in the absorption area and a similar decrease in the internal magnetic field for the hyperfine structure were observed with an increase in the alkali content of glasses. The decrease is ascribed to a formation of non-bridging oxygen at the site adjacent to iron, because the mean life-time of the internal magnetic field produced by 3d-electrons of iron is considered to decrease with increasing thermal vibration of the iron and neighboring oxygens. Fractions of non-bridging oxygens obtained from the reduction rate of the absorption area of hyperfine structure are in good agreement with earlier results for borate glasses with the same K2O/B2O3 ratios, in the alkali region of 8 - 20 mol% where the borosilicate glasses are essentially considered to be borate glasses diluted with SiO2. (author)

  9. Boron Speciation in Soda-Lime Borosilicate Glasses Containing Zirconium

    International Nuclear Information System (INIS)

    Boron speciation was investigated in soda-lime borosilicate glass containing zirconium. In such compositions, competition between charge compensators (here, sodium and calcium) can occur for the compensation of tetrahedral boron or octahedral zirconium units. 11B MAS NMR is particularly suitable for obtaining data on preferential compensation behavior that directly affects the boron coordination number. In addition to the classical proportions of tri- and tetrahedral boron, additional data can be obtained on the contributions involved in these two coordination numbers. An approach is described here based on simultaneous MAS spectrum analysis of borosilicate glass with variable Zr/Si and Ca/Na ratios at two magnetic field strengths (11. 7 and 18. 8 T), with constraints arising from MQMAS spectroscopy, detailed analysis of satellite transitions, and spin-echo experiments. New possibilities of 11B NMR were presented for improving the identification and quantification of the different contributions involved in tri- and tetrahedral boron coordination. Both NMR and Raman revealed a trend of decreased tetrahedral boron proportion with the increase of Ca/Na ratio or the Zr/Si ratio. This strongly suggests that zirconium compensation takes preference over boron compensation, and that zirconium and boron are both compensated mainly by sodium rather than calcium. (authors)

  10. 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. PMID:19441565

  11. Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

    International Nuclear Information System (INIS)

    Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper

  12. Modeling and simulation of the cooling process of borosilicate glass

    International Nuclear Information System (INIS)

    For a better understanding of the thermomechanical behavior of glasses used for nuclear waste vitrification, the cooling process of a bulk borosilicate glass is modeled using the finite element code Abaqus. During this process, the thermal gradients may have an impact on the solidification process. To evaluate this impact, the simulation was based on thermal experimental data from an inactive nuclear waste package. The thermal calculations were made within a parametric window using different boundary conditions to evaluate the variations of temperature distributions for each case. The temperature differences throughout the thickness of solidified glass were found to be significantly non-uniform throughout the package. The temperature evolution in the bulk glass was highly responsive to the external cooling rates applied; thus emphasizing the role of the thermal inertia for this bulky glass cast. (authors)

  13. Study on leaching mechanism of sodium borosilicate glass microspheres

    International Nuclear Information System (INIS)

    Sodium borosilicate glasses find applications in heavy water plants, in nuclear waste immobilization, glass to metal sealing and various others fields. These glasses are found to be durable in corrosive ambient. Aim of the present work is to see the initial leaching mechanism/kinetics on sodium borosilicate glass microspheres. For this, glass with composition (mol%) 16.6Na2O-17.4 B2O3-66.0SiO2 was synthesized by melt-quench method. The studies were carried out at accelerated conditions of 120°C at different exposure hours, maximum upto 55 hrs in distilled water (DW). Studies on accelerated conditions helps in predicting long-term durability of the glass. The glass was taken in the form of micro spheres of 75 - 125 micron range. Glass microspheres were selected for the study as they have the advantage of maximum surface area. Their weight loss and surface study using SEM and SAXS were carried out intermittently. The weight loss observed was negligible even after 55 hrs of exposure at 120°C in DW. The interesting phenomenon of leaching were observed by SEM and SAXS studies. Initially few pore formation on the surface of spheres which grew in size and numerals followed by layer removal were observed by SAXS. On the removal of outer layer, inner exposed surface were leached in a similar pattern with pore formation. Initially only a few spheres were leached and gradually the intensity of leached spheres increased which was observed by SEM studies. The elemental analysis of the surface of leached and unleached spheres were carried out. The analysis showed the decrease in concentration of sodium on the leached layer. (author)

  14. 3.6. The kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore

    International Nuclear Information System (INIS)

    Present article is devoted to kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore. The experimental data of kinetics of extraction of boron oxide from danburite at sulfuric acid decomposition were obtained at 20-90 deg C temperature range and process duration 15-90 minutes. The flowsheet of obtaining of boric acid from borosilicate ores of Ak-Arkhar Deposit by sulfuric acid method was proposed.

  15. 2.2. The kinetics of hydrochloric-acid decomposition of calcined borosilicate ore

    International Nuclear Information System (INIS)

    Present article is devoted to kinetics of hydrochloric-acid decomposition of calcined borosilicate ore. The experimental data of dependence of hydrochloric-acid decomposition of calcined borosilicate ore for boron oxide extraction on temperature (30-95 deg C) and process duration (15-60 min) were considered. It was defined that at temperature increasing the boron oxide extraction increases from 28.9 till 53.2%. The constants of decomposition rate of calcined ore were calculated.

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

    International Nuclear Information System (INIS)

    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)

  17. Behavior of sodium borosilicate glasses under compression using molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kilymis, D. A.; Ispas, S., E-mail: simona.ispas@univ-montp2.fr [Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier, F-34095 Montpellier (France); Delaye, J.-M. [CEA, DEN, DTCD, SECM, F-30207 Bagnols-sur-Cèze (France)

    2015-09-07

    We have performed classical molecular dynamics simulations in order to study the changes under compression in the local and medium range structural properties of three sodium borosilicate glasses with varying sodium content. These glasses have been isostatically compressed up to 20 GPa and then decompressed in order to analyze the different mechanisms that affect densification, alongside with the permanent modifications of the structure after a full compression/decompression cycle. The results show that the atomic packing is the prominent characteristic that governs the amount of densification in the glass, as well as the setup of the permanent densification. During compression, the bulk modulus increases linearly up to approximately 15 GPa and more rapidly for higher pressures, a behavior which is reflected on the rate of increase of the average coordination for B and Na. Radial distribution functions at different pressures during the cycle help to quantify the amount of distortions in the elementary structural units, with a pronounced shortening of the Na–Na and Na–O bond lengths during compression. A subsequent decomposition of the glassy matrix into elementary Voronoi volumes verifies the high compressibility of Na-rich regions.

  18. 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.

  19. Enhancing cerium and plutonium solubility by reduction in borosilicate glass

    Science.gov (United States)

    Cachia, J.-N.; Deschanels, X.; Den Auwer, C.; Pinet, O.; Phalippou, J.; Hennig, C.; Scheinost, A.

    2006-06-01

    High-level radioactive wastes produced by spent fuel reprocessing containing fission and activation products as well as actinides are incorporated in a borosilicate glass. To ensure optimum radionuclide containment, the resulting glass must be as homogeneous as possible. Microscopic heterogeneity can arise from various processes including the excess loading of an element above its solubility limit. The current actinide loading limit is 0.4 wt%. Work is in progress to assess the actinide solubility in these glasses, especially for plutonium. Initially the actinides were simulated by lanthanides and hafnium. The results show that trivalent elements (La, Gd) exhibit greater solubility than tetravalent elements (Pu, Hf). Cerium is an interesting element because its oxidation state varies from IV to III depending on the process conditions, such as the temperature and redox potential of the melt. In order to quantify the solubility increase, cerium-doped glass samples were melted under reducing conditions by adding a reducing agent. The solubility observed at 1473 K increased significantly from 0.95 to 13.00 wt%. Several reducing compounds have been tested. This paper deals with this study and the application to reduce Pu(IV) to Pu(III). The reduction state was characterized by X-ray absorption spectroscopy (XANES) for plutonium and by chemical analysis for cerium. The material homogeneity was verified by optical and scanning electron microscopy. Preliminary findings concerning the reduction of Pu-doped glasses fabricated in hot cells are also discussed.

  20. Methanobactin-Promoted Dissolution of Cu-Substituted Borosilicate Glass

    Science.gov (United States)

    Kulczycki, E.; Fowle, D. A.; Knapp, C.; Graham, D. W.; Roberts, J. A.

    2006-12-01

    Mineral weathering processes play a major role in the global cycling of carbon and metals and there is an increasing realization that subsurface microbial activity may be a key factor regulating specific biogeochemical reactions and their rates. Methanobactin (mb) is an extracellular copper-binding compound excreted by methanotrophs who require copper to regulate methane oxidation. Cu that is available to the cell regulates the expression and activity of pMMO versus sMMO (particulate versus soluble methane monooxygenase, respectively), which are key enzymes responsible for methane oxidation. The primary focus of this study is to determine the effect of mb-promoted dissolution of Cu-substituted glass at low temperature and near neutral pH conditions, using batch dissolution experiments with and without the methanotroph, Methylonsinus trichosporium OB3b. Methanobactin promotes the weathering of Cu-substituted borosilicate glasses at rates faster than control experiments without methanobactin. Glasses with lower concentrations of copper (80 ppm) or no copper are dissolved more rapidly than those containing larger amounts of copper (800 ppm). Within the first 2 hours of reactivity, a greater quantity of mb appears to sorb onto the glass surface at higher copper concentrations and may limit mass transfer of Cu to solution. Furthermore gene expression in M. trichosporium OB3b, using real-time RT-PCR techniques, indicate that pmoA expression is influenced by mb in presence of Cu containing solid phases. These findings demonstrate that this methanotroph can directly access mineral-bound Cu and suggests that methane oxidation rates may be directly linked to mineral weathering in near-surface geologic settings.

  1. Borosilicate glass as a matrix for the immobilization of Savannah River Plant waste

    International Nuclear Information System (INIS)

    The reference waste form for immobilization of Savannah River Plant (SRP) waste is borosilicate glass. In the reference process, waste is mixed with glass-forming chemicals and melted in a Joule-heated ceramic melter at 11500C. Waste glass made with actual or simulated waste on a small scale and glass made with simulated waste on a large scale confirm that the current reference process and glass-former composition are able to accommodate all SRP waste compositions and can produce a glass with: high waste loading; low leach rates; good thermal stability; high resistance to radiation effects; and good impact resistance. Borosilicate glass has been studied as a matrix for the immobilization of SRP waste since 1974. This paper reviews the results of extensive characterization and performance testing of the glass product. These results show that borosilicate glass is a very suitable matrix for the immobilization of SRP waste. 18 references, 3 figures, 10 tables

  2. ORIGEN-S (α,n) neutron source spectra in borosilicate glass containing HLW

    International Nuclear Information System (INIS)

    There is growing interest in the methodology and computational software for evaluating the (α,n) source spectra produced in mixtures of high-level waste (HLW) and borosilicate glass. The need for this development has been seen in previous work involving the analysis of HLW in borosilicate glass. Descriptions and applications of the ORIGEN-S method of computing neutron source spectra by both (α,n) reactions and spontaneous fission of UO2 spent fuel have been reported previously. This summary presents a significant expansion of the ORIGEN-S (α,n) model to include alpha interactions with the light elements of borosilicate glass. The Battelle/Office of Nuclear Waste Isolation requested this model extension. There is an associated interest in the use of Oak Ridge National Lab. shielding codes for analyzing HLW systems

  3. Speciation of U and Am in sol-gel derived borosilicate glasses by photoluminescence lifetime spectroscopy

    International Nuclear Information System (INIS)

    Borosilicate glasses are intended to be the barrier in between the high level nuclear waste and the geosphere. The oxidation state and the coordination geometry of a particular element in the glass influences its solubility, migration and complexation behavior, which in turn influences its long term leaching behavior. In this context, uranium and americium containing barium borosilicate glasses were prepared by sol-gel route and the speciation studies of U and Am in the glasses were carried out using photoluminescence lifetime spectroscopic technique. It was observed that in the matrix the uranium is stabilised as (UO6)6- and the americium as Am3+. (author)

  4. LIQUIDUS TEMPERATURE OF HIGH-LEVEL WASTE BOROSILICATE GLASSES WITH SPINEL PRIMARY PHASE

    Science.gov (United States)

    Liquidus temperatures (TL) were measured for high-level waste (HLW) borosilicate glasses covering a Savannah River composition region. The primary crystallization phase for most glasses was spinel, a solid solution of trevorite (NiFe2O4) with other oxides (FeO, MnO, and Cr2O3). T...

  5. Monte Carlo Simulations of Coupled Diffusion and Surface Reactions during the Aqueous Corrosion of Borosilicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kerisit, Sebastien N.; Pierce, Eric M.; Ryan, Joseph V.

    2015-01-01

    Borosilicate nuclear waste glasses develop complex altered layers as a result of coupled processes such as hydrolysis of network species, condensation of Si species, and diffusion. However, diffusion has often been overlooked in Monte Carlo models of the aqueous corrosion of borosilicate glasses. Therefore, three different models for dissolved Si diffusion in the altered layer were implemented in a Monte Carlo model and evaluated for glasses in the compositional range (75-x) mol% SiO2 (12.5+x/2) mol% B2O3 and (12.5+x/2) mol% Na2O, where 0 ≤ x ≤ 20%, and corroded in static conditions at a surface-to-volume ratio of 1000 m-1. The three models considered instantaneous homogenization (M1), linear concentration gradients (M2), and concentration profiles determined by solving Fick’s 2nd law using a finite difference method (M3). Model M3 revealed that concentration profiles in the altered layer are not linear and show changes in shape and magnitude as corrosion progresses, unlike those assumed in model M2. Furthermore, model M3 showed that, for borosilicate glasses with a high forward dissolution rate compared to the diffusion rate, the gradual polymerization and densification of the altered layer is significantly delayed compared to models M1 and M2. Models M1 and M2 were found to be appropriate models only for glasses with high release rates such as simple borosilicate glasses with low ZrO2 content.

  6. Structural aspects of barium borosilicate glasses containing thorium and uranium oxides

    International Nuclear Information System (INIS)

    Barium borosilicate glasses incorporated with 15.86 wt% ThO2 and containing different amounts of uranium oxide were prepared by conventional melt quench method. Based on 29Si and 11B magic angle spinning nuclear magnetic resonance (MAS NMR) studies, it has been confirmed that uranium oxide incorporation is associated with distortion of borosilicate network as revealed by the increase in the relative concentration of Q2 structural units of silicon as well as the increase in the quadrupolar coupling constant (C q) of BO3 structural units. The increased number of non-bridging oxygen atoms brought about by the increase in Q2 structural units of silicon facilitates the incorporation of both uranium and thorium ions in the sites created by non-bridging oxygen atoms (network modifying positions) in the glass. Uranium oxide incorporation above 7.5 wt% resulted in the phase separation of ThO2 as revealed by the X-ray diffraction studies. The present study focuses on the structural changes with the borosilicate network of barium borosilicate glasses brought about by the introduction of thorium and uranium ions

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

    International Nuclear Information System (INIS)

    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-1 was scaled to the sum of the integrated bands between 800 and 1200 cm-1, bands that are assigned to Qn 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)

  8. 3.4. Sulfuric acid decomposition of borosilicate ores (concentrate) of Ak-Arkhar Deposit of Tajikistan

    International Nuclear Information System (INIS)

    Present article is devoted to sulfuric acid decomposition of borosilicate ores (concentrate) of Ak-Arkhar Deposit of Tajikistan. The reaction of borosilicate ores decomposition by sulfuric acid was studied at 20-120 deg C temperature ranges at concentration of H2SO4 from 45 to 50 mass %. It was defined that at temperature increasing the extraction rate of oxides increases: B2O3 - 30.02% and Fe2O3 - 50.58%. The dependence of extraction rate of components from borosilicate ores (concentrate) at sulfuric acid decomposition on temperature, process duration, sulfuric acid concentration was studied as well. The optimal conditions of sulfuric acid decomposition of borosilicate ores (concentrate) were proposed.

  9. Laser Induced Damage Studies in Borosilicate Glass Using nanosecond and sub nanosecond pulses

    CERN Document Server

    Rastogi, Vinay; Munda, D S

    2016-01-01

    The damage mechanism induced by laser pulse of different duration in borosilicate glass widely used for making confinement geometry targets which are important for laser driven shock multiplication and elongation of pressure pulse, is studied. We measured the front and rear surface damage threshold of borosilicate glass and their dependency on laser parameters. In this paper, we also study the thermal effects on the damage diameters, generated at the time of plasma formation. These induced damage width, geometries and microstructure changes are measured and analyzed with optical microscope, scanning electron microscope and Raman spectroscopy. The results show that at low energies symmetrical damages are found and these damage width increases nonlinearly with laser intensity. The emitted optical spectrum during the process of breakdown is also investigated and is used for the characterization of emitted plasma such as plasma temperature and free electron density. Optical emission lines from Si I at 500 nm, Si ...

  10. Effect of heat pretreatment on foaming of simulated nuclear waste in a borosilicate glass melt

    International Nuclear Information System (INIS)

    Foaming of Savannah River nuclear waste glass was studied in situ. Simulated nuclear waste was heat-treated at 8000 to 12000C and either mixed with a granular borosilicate frit or pressed into compacts and then brought into contact with molten borosilicate glass. The batches were heated at constant rate up to 11500C in quartz crucibles; the process was recorded photographically. Compacts foamed at 40 K and loose batches at 200 to 400 K below the heat-treatment temperature. The volume of melt for loose batches expanded up to 2.75 times and that of compacts up to 2.1 times if the heat-treatment temperature was below 10500C; heat-treatment temperatures above 11500C resulted in a significantly lower foam height. A minimum foam stability was recorded for heat-treatment temperatures of 10000 to 11000C

  11. Immobilization of simulated high-level liquid wastes in sintered borosilicate, aluminosilicate and aluminoborosilicate glasses

    International Nuclear Information System (INIS)

    The purpose of this paper is to report on the results obtained with different vitreous materials: a German borosilicate glass (VG98/12), its local counterpart (Simil VG), a natural aluminosilicate volcanic glass (VV), and two German aluminoborosilicate glasses (SG7 and SG8), with incorporated simulated high-level liquid wastes (HLLW), LWR and PHWR types. The optimal conditions for pressure and pressureless sintering are given, as well as the simulation, formulation and preparation of the simulated HLLW type PHWR, as well as the corrosion and thermal behavior of the waste forms obtained. Leaching rates of aluminosilicate (VV) and aluminoborosilicate (SG7) glasses were about 10-2 g m-2 d-1, that is one order of magnitude lower than those for borosilicate glasses. The devitrification of aluminoborosilicate glass (SG7) increased leaching rate by a factor of 3 for Mo. (orig.)

  12. Profile Control of a Borosilicate-Glass Groove Formed by Deep Reactive Ion Etching

    CERN Document Server

    Akashi, T

    2008-01-01

    Deep reactive ion etching (DRIE) of borosilicate glass and profile control of an etched groove are reported. DRIE was carried out using an anodically bonded silicon wafer as an etching mask. We controlled the groove profile, namely improving its sidewall angle, by removing excessively thick polymer film produced by carbonfluoride etching gases during DRIE. Two fabrication processes were experimentally compared for effective removal of the film : DRIE with the addition of argon to the etching gases and a novel combined process in which DRIE and subsequent ultrasonic cleaning in DI water were alternately carried out. Both processes improved the sidewall angle, and it reached 85o independent of the mask-opening width. The results showed the processes can remove excessive polymer film on sidewalls. Accordingly, the processes are an effective way to control the groove profile of borosilicate glass.

  13. Removal of OH Absorption Bands Due to Pyrohydrolysis Reactions in Fluoride-Containing Borosilicate Glasses

    Science.gov (United States)

    Kobayashi, Keiji

    1997-05-01

    The purpose of this study is to decrease and to remove OH ions and H2O in borosilicate glasses. Fluoride-containing borosilicate glasses followed by dry-air-bubbling showed the significant decrease of OH absorption bands around 3500 cm-1. The decrease of OH absorption bands was elucidated by the use of pyrohydrolysis reactions in these glasses where fluoride ions react with OH ions or H2O during melting. The rates of the decrease of OH absorption bands substantially depend on high valence cations of fluorides. Particularly, the decrease rates of OH absorption coefficients were in the order of ZrF4-containing glass>AlF3-containing glass>ZnF2-containing glass. ZrF4-containing glass treated by dry-air-bubbling showed a good capability to remove OH absorption band. Fluoride-containing glasses showed the low flow point in comparison with fluoride-free glasses.

  14. Gamma-ray shielding and structural properties of barium-bismuth-borosilicate glasses

    Science.gov (United States)

    Bootjomchai, Cherdsak; Laopaiboon, Jintana; Yenchai, Chadet; Laopaiboon, Raewat

    2012-07-01

    The attenuation coefficients of barium-bismuth-borosilicate glasses have been measured for gamma-ray photon energies of 662, 1173 and 1332 keV using a narrow beam transmission geometry. These coefficients were then used to obtain the values of mass attenuation coefficients, effective atomic number, effective electron density and mean free path. Good agreement has been observed between experimental and theoretical values of these parameters. From the obtained results it is reported here that from the barium-bismuth-borosilicate glasses are better shields to gamma-radiations in comparison to the standard radiation shielding concretes from the shielding point of view. The molar volume, FTIR and acoustic investigations have been used to study the structural properties of the prepared glass system. The obtained results reveal that the formation of non-bridging oxygens occurs at higher concentration of Bi2O3.

  15. Durability of borosilicate glass compositions for the immobilisation of the UK's separated plutonium stocks

    International Nuclear Information System (INIS)

    Several glass compositions are currently under investigation for immobilisation of the separated PuO2 that has been produced as a result of civil nuclear fuel reprocessing in the UK. Whilst a final decision on the fate of what ultimately will be over 100 tonnes of plutonium has yet to be made, all options for the disposition of this material are currently being investigated by Nexia Solutions Ltd on behalf of the Nuclear Decommissioning Authority (NDA). As one of the immobilisation options, vitrification in borosilicate glass could potentially provide a criticality-safe and stable waste form with durability suitable for long term storage and subsequent repository disposal. From an initial experimental survey of potential candidates, three borosilicate compositions were selected for a more detailed study of the waste loading and chemical durability: lanthanide borosilicate (LaBS), alkali tin silicate (ATS) and high-lanthanide alkali borosilicate (modified-MW). In these inactive tests, hafnium was used as the surrogate for plutonium. This paper describes a range of static leach tests that were undertaken in order to understand the overall durability of the waste forms, as well as the release rates of the Pu surrogate when compared to any neutrons poisons present in the glass. For the LaBS compositions it was found that the release rate of gadolinium was potentially slightly higher than that of hafnium, although both were as low as 10-5 to 10-6 g m2 day -1. The potential implications for long-term repository behaviour are discussed. (authors)

  16. Characteristics of potential borosilicate glass compositions for high-level waste solidification in several countries

    International Nuclear Information System (INIS)

    Characteristics of various borosilicate glass compositions for high-level waste solidification were evaluated. There is possibility of returning to Japan the solidified high-level wastes in overseas fuel reprocessing by entrustment. In order to study the technical problems in receiving the solidified products, various potential compositions in several countries were examined. The following properties were evaluated for the basic data in preparation of the total criteria: melting characteristic, density, thermal conductivity, thermal expansion coefficient, softening temperature and leach rate. (author)

  17. Electron irradiation effect on bubble formation and growth in a sodium borosilicate glass

    International Nuclear Information System (INIS)

    In this study, the authors studied simultaneous and intermittent electron irradiation effects on bubble growth in a simple sodium borosilicate glass during Xe ion implantation at 200 C. Simultaneous electron irradiation increases the average bubble size in the glass. This enhanced diffusion is also shown by the migration of Xe from bubbles into the matrix when the sample is irradiated by an electron beam after the Xe implantation

  18. Chemical durability of lead borosilicate glass matrix under simulated geological conditions

    International Nuclear Information System (INIS)

    The lead borosilicate glass has been developed for vitrification of High Level Waste (HLW) stored at Trombay. This waste is contains especially high contents of sodium, uranium sulphate and iron. The glasses containing HLW are to be ultimately disposed into deep geological repositories. Long term leach rates under simulated geological conditions need to be evaluated for glass matrix. Studies were taken up to estimate the lead borosilicate glass WTR-62 matrix for chemical durability in presence of synthetic ground water. The leachant selected was based on composition of ground water sample near proposed repository site. In the first phase of these tests, the experiments were conducted for short duration of one and half month. The leaching experiments were conducted in presence of a) distilled water b) synthetic ground water c) synthetic ground water containing granite, bentonite and ferric oxide and d) synthetic ground water containing humic acid at 1000C. The leachate samples were analysed by pHmetry , ion chromatography and UV -VIS spectrophotometry. The normalised leach rates for lead borosilicate WTR- 62 glass matrix based on silica, boron and sulphate analyses of leachates were of the order of 10-3 to 10-5 gms/cm2/day for 45 days test period in presence of synthetic ground water as well as in presence of other materials likely to be present along with synthetic ground water. These rates are comparable to those of sodium borsilicate glass matrices reported in literature. It is known that the leach rates of glass matrix decrease with longer test durations due to formation of leached layer on its surface. The observed leach rates of lead borosilicate WTR- 62 glass matrix for 45 day tests under simulated geological conditions were found to be sufficiently encouraging to take up long term tests for evaluating its performances under repository conditions. (author)

  19. Effect of heat treatment on the infrared absorption spectra of strontium-sodium-borosilicate glass

    International Nuclear Information System (INIS)

    Infrared absorption spectra of the prepared strontium-sodium-borosilicate glass (SiO2 80%-Na2O 12.5%-B2O3 5%-SrO 2.5%) are studied in the frequency range 200-4000 cm-1, where strontium oxide was introduced on partial replacement of soda in sodium-borosilicate glass, to show the effect of divalent metal oxide introduced on the structural units SiO4, BO4, and BO3 within the network structure of strontium-sodium-borosilicate glass, in the temperature range 27-800 degC. The deformation of SiO4 tetrahedra is investigated by using the baseline method, the temperature dependence of the relative integrated intensity, the relaxation time, and rotational energy barrier of this glass proved that the glassy phase is transformed to crystalline phase at 500 degC. A slight shift occurs in the strongest bands of SiO4 tetrahedra to higher frequencies, with temperature increase, which indicates an increase in the force constants between the components of the glass network structure. The increase of the absorbance in the temperature range 600-800 degC indicates strengthening of the SiO4 bonds. (author)

  20. Intrinsic dosimetry: Elemental composition effects on the thermoluminescence of commercial borosilicate glass

    International Nuclear Information System (INIS)

    Intrinsic dosimetry is the method of measuring total absorbed dose received by the walls of a container holding radioactive material. By considering this dose in tandem with the physical characteristics of the radioactive material housed within the container, this method can provide enhanced pathway information for interdicted radioactive samples. Thermoluminescence (TL) dosimetry was used to measure ionizing radiation dose effects on stock borosilicate glass. Differences in TL glow curve shape and intensity were observed for glasses from different geographical origins. The different TL signatures strongly correlated with the concentration of alkaline earth metals and the ratio of sodium to the total amount of alkali metal present in the borosilicate glass. -- Highlights: • Thermoluminescence (TL) properties of borosilicate were compared with composition. • TL glow curves were modeled using peaks centered at 120, 160, 225, 300, and 340 °C. • Overall TL intensity correlated with the sodium : total alkali metal content. • The 120 °C peak negatively correlated with the alkaline earth concentration. • The 160 °C peak negatively correlated with the concentration of K, Ce, and Ti

  1. Development of borosilicate glass compositions for the immobilisation of the UK's separated plutonium stocks

    International Nuclear Information System (INIS)

    The UK inventory of separated civil plutonium is expected to exceed 100 tonnes by 2010. Whilst the majority of this could be used in the manufacture of MOx (Mixed Oxide) fuel in future power generation scenarios, options for the disposal of surplus plutonium are currently being investigated by Nexia Solutions Ltd on behalf of the UK's Nuclear Decommissioning Authority (NDA). One of the options being considered is immobilisation in a durable glass matrix followed by long term storage and subsequent final repository disposal. A preliminary experimental survey assessed a selection of potential glass systems on the basis of Pu-surrogate (cerium) loading, durability, and ease of processing. Following this, a number of borosilicate compositions have been taken forward into a more detailed investigation in order to fully qualify their potential for Pu-immobilisation. The selected compositions are lanthanide borosilicate (LaBS), alkali tin silicate (ATS) and high-lanthanide alkali borosilicate (modified-MW). For this second series of experiments, hafnium was selected as the Pu surrogate, and a study of the potential waste loading as a function of temperature for the three selected compositions is described in this paper. Furthermore, several variations of the LaBS composition were fabricated in order to investigate the effect of total lanthanide content on melting temperature. The benchmark of 10 wt% HfO2 incorporation is achievable for all three glasses with temperatures of 1200, 1300 and 1400 deg. C required for ATS, modified-MW and LaBS respectively. (authors)

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

    International Nuclear Information System (INIS)

    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. Process for the fabrication of hollow core solenoidal microcoils in borosilicate glass

    International Nuclear Information System (INIS)

    We report the fabrication of solenoidal microcoils with hollow core embedded within two 100 µm thick borosilicate glass wafers. The main process steps are the reactive ion etching of borosilicate glass, anodic wafer bonding, copper metal organic chemical vapor deposition (Cu MOCVD) and electroless galvanization. Our motivation stems from the need for a reliable, precise fabrication method of microcoils for high-resolution magnetic resonance imaging (MRI). For reduced loss at high-frequency operation, glass, with a lower dielectric constant as compared to silicon, was chosen as a substrate material. Simultaneously, this offers MRI sample observation owing to its optical transparency. Further essential parameters for the coil design were the need for small coil dimensions, a high filling factor (region of interest within the coil occupied by the sample/overall coil volume), and low-loss electrical connectability to external devices. In an attempt to achieve those requirements, the reported process demonstrates the combination of front- and backside borosilicate glass RIE of small dimensional features (down to 10 µm wall thickness) with subsequent conformal metallization of the 3D solenoidal coil by means of Cu MOCV and electroless galvanization

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

    Science.gov (United States)

    Bafna, Jayesh A.; Soni, Gautam V.

    2016-01-01

    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. PMID:27285088

  5. 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

  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. 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 the...... fraction of BO4 tetrahedra can be obtained by fitting the experimental data with linear combinations of the reference spectra. The BO4 fractions (N4) obtained by EELS are consistent with those from 11B MAS NMR spectra, suggesting that EELS can be an alternative and convenient way to determine the N4...

  8. Molecular dynamics study of structural changes versus deposited energy dose in a sodium borosilicate glass

    International Nuclear Information System (INIS)

    The accumulation of cascades modeled by molecular dynamics in a sodium borosilicate glass allowed us to simulate the evolution of various macroscopic and structural properties up to the level of a stabilization plateau for the highest deposited nuclear energy doses. Marples' model was used to fit the glass volume expansion to the deposited energy dose, giving the damaged volume per projectile. The volume parameter from this model approximates the cascade core volume, suggesting that the underlying mechanisms of volume expansion are contained in the cascade core and are thus related to the highest-energy events: atom ejection and thermal quenching

  9. 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.

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

    International Nuclear Information System (INIS)

    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

  11. Plutonium silicate alteration phases produced by aqueous corrosion of borosilicate glass

    International Nuclear Information System (INIS)

    Borosilicate glasses loaded with ∼10 wt % plutonium were found to produce plutonium-silicate alteration phases upon aqueous corrosion under a range of conditions. The phases observed were generally rich in lanthanide (Ln) elements and were related to the lanthanide orthosilicate phases of the monoclinic Ln2SiO5 type. The composition of the phases was variable regarding [Ln]/[Pu] ratio, depending upon type of corrosion test and on the location within the alteration layer. The formation of these phases likely has implications for the incorporation of plutonium into silicate alteration phases during corrosion of titanate ceramics, high-level waste glasses, and spent nuclear fuel

  12. The Coordination State of B and Al of Borosilicate Glass by IR Spectra

    Institute of Scientific and Technical Information of China (English)

    WAN Junpeng; CHENG Jinshu; LU Ping

    2008-01-01

    The IR spectra of R2O-RO-B2O3-SiO2 and R2O-RO-B2O3-Al2O3-SiO2 glasses were tested for the study of coordination state of B, Al and their content. The results show that no matter Na2O/B2O3>1,=1, or<1, both [Bo3] and destroyed Si-O bond exist in glass structure; the addition of Al2O3 to borosilicate glass reduced both the number of non-bridging oxygen in the silicate network and the number of [BO4] units.

  13. 5.3. The kinetics of acetic acid decomposition of calcined borosilicate concentrate

    International Nuclear Information System (INIS)

    Present article is devoted to kinetics of acetic acid decomposition of calcined borosilicate concentrate. The experimental data of kinetics of boron oxide extraction from the calcined danburite concentrate at acetic acid decomposition was obtained at 30-90 deg C temperature ranges and 15-60 minutes process duration. It was defined that at temperature increasing the extraction rate of boron oxide from the calcined danburite concentrate significantly increases. The influence of extraction rate of boron oxide on process duration at acetic acid decomposition was studied.

  14. Underground migration of long-lived radionuclides leached from a borosilicate glass matrix

    International Nuclear Information System (INIS)

    A programme on the safety analysis linked to the geological disposal of radioactive wastes is under study at the Joint Research Centre of the Commission of the European Communities at Ispra. In relation to the migration of radionuclides in the terrestrial environment following a possible release from the repository, specific experimental studies are being developed in order to provide the necessary input data for the risk assessment models. The present paper reports the results of studies performed with neptunium, plutonium, americium and technetium isotopes leached from a borosilicate glass simulating the vitrified high-level wastes. In order to simulate the expected conditions of glass leaching and underground transport in the laboratory, a water pathway is established which flows over the radioactive glass and then through columns containing typical soil samples. The columns are examined during the experiment by gamma scanning or cut into thin sections at the end of the run and the distribution profile of radioisotopes measured. Experimental results obtained on soil columns are compared with data obtained using filtering membranes and ion exchange resins. These experiments using borosilicate glass demonstrate the relative importance of colloidal filtration by the geological porous medium. Following fixation it has been shown that slow rate processes probably account for the continuous small release of the radioactivity observed in the laboratory system. This long-term behaviour of colloids during the continuous percolation of groundwater is interpreted, taking into account complex ion formation with inorganic ligands present in natural waters. (author)

  15. Dielectric behaviour of (Ba,Sr)TiO3 perovskite borosilicate glass ceramics

    International Nuclear Information System (INIS)

    Various perovskite (Ba,Sr)TiO3 borosilicate glasses were prepared by rapid melt-quench technique in the glass system ((Ba1-xSrx).TiO3)-(2SiO2.B2O3)-(K2O)-(La2O3). On the basis of differential thermal analysis results, glasses were converted into glass ceramic samples by regulated heat treatment schedules. The dielectric behaviour of crystallized barium strontium titanate borosilicate glass ceramic samples shows diffuse phase transition. The study depicts the dielectric behaviour of glass ceramic sample BST5K1L0.2S814. The double relaxation was observed in glass ceramic samples corresponding 80/20% Ba/Sr due to change in crystal structure from orthorhombic to tetragonal and tetragonal to cubic with variation of temperature. The highest value of dielectric constant was found to be 48289 for the glass ceramic sample BST5K1L0.2S814. The high value of dielectric constant attributed to space charge polarization between the glassy phase and perovskite phase. Due to very high value of dielectric constant, such glass ceramics are used for high energy storage devices. La2O3 acts as nucleating agent for crystallization of glass to glass ceramics and enhances the dielectric constant and retarded dielectric loss. Such glass ceramics can be used in high energy storage devices such as barrier layer capacitors, multilayer capacitors etc. (author)

  16. Er3+–Al2O3 nanoparticles doping of borosilicate glass

    Indian Academy of Sciences (India)

    Jonathan Massera; Laeticia Petit; Joona Koponen; Benoit Glorieux; Leena Hupa; Mikko Hupa

    2015-09-01

    Novel borosilicate glasses were developed by adding in the glass batch Er3+–Al2O3 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 using MCVD and solution doping. It was shown that with the melt quench technique, a Er3+–Al22O3 nanoparticle doping neither leads to an increase in the Er3+ luminescence properties nor allows one to control the rare-earth chemical environment in a borosilicate glass. The site of Er3+ in the Er3+–Al2O3 nanoparticle containing glass seems to be similar as in glasses with the same composition prepared using standard raw materials. We suspect the Er3+ ions to diffuse from the nanoparticles into the glass matrix. There was no clear evidence of the presence of Al2O3 nanoparticles in the glasses after melting.

  17. 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.

  18. The Effect of Sm2O3 on the Chemical Stability of Borosilicate Glass and Glass Ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongqiang; WANG Mitang; LI Mei; WANG Ming; LIU Quansheng

    2014-01-01

    Sm2O3 containing zinc-borosilicate glass and glass ceramics were prepared by melt quenching method, and the effect of Sm2O3 and micro-crystallization on the chemical stability of borosilicate glass was explored. DTA analysis showed that the endothermic peak and exothermic peak of basic glass changed from 635℃and 834℃to 630℃and 828℃respectively as a result of the doping of Sm2O3. XRD analysis showed the promoting effect of Sm2O3 on crystallization ability of this glass. The cumulative mass loss of base glass, Sm2O3 containing glass, glass ceramic and Sm2O3 containing glass ceramic was 0.289, 0.253, 0.329, 0.269 mg/mm2 respectively after 26 days corrosion in alkali solution, and 1.293, 1.290, 0.999, 1.040 mg/mm2 respectively in acidic erosion medium. Micro-crystallization decreased and improved the alkali and acid resistance of borosilicate glass respectively, the addition of Sm2O3 increased the alkali resistance of base glass and glass ceramics, and the slight effect of Sm2O3 on the acid resistance of borosilicate glass was also observed.

  19. X-Ray excited and photoluminescence of CdS1-xSex nanocrystals embedded in borosilicate glass matrix

    Directory of Open Access Journals (Sweden)

    Gomonnai A.V.

    2001-03-01

    Full Text Available The performed experimental studies of X-ray excited and photoluminescence, optical absorption and Raman scattering of CdS1-xSex nanocrystals, embedded in borosilicate glass matrix, have enabled the nanocrystal parameters (chemical composition, average radius, acceptor levels energy depth, electron-hole Coulomb interaction energy is to be determined.

  20. Characteristics of borosilicate glass media fabricated by melting HEPA filter media with inorganic additives

    International Nuclear Information System (INIS)

    HEPA filters are widely used in the nuclear fields as a final off-gas cleaning unit. To assess the applicability of vitrification technology either to treat used filter media or to produce borosilicate glass medium for the solidification of alpha-contaminated wastes, various waste glasses of different compositions were fabricated by melting mixture of HEPA filter media and inorganic additives. Physicochemical properties such as microhardness, density, thermal expansion, and short-term leaching behavior were characterized. XRD analysis showed that amorphous glasses were formed for a wide range of mixing ratio. Leach resistances, measured by PCT-B leach tests, were superior to that of EA (Environmental Assessment) glass. Other properties were similar to those of glass media used for the vitrification of high-level radioactive wastes in foreign countries

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

    International Nuclear Information System (INIS)

    Composite concept in materials science can be conveniently applied in the waste treatment technology to construct specific tailor madecomposite 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

  2. Elastic properties investigation of gamma-radiated barium lead borosilicate glass using ultrasonic technique

    International Nuclear Information System (INIS)

    Highlights: → Change in acoustical parameter due to composition effect and irradiation effect. → Changes in the structure of the glass (BO3 → BO4) due to the effect of radiation. → Structural changes in the BO3 to BO4 have a more compactness structure. - Abstract: The ultrasonic velocities were measured in barium lead borosilicate glass samples of different compositions before and after irradiation with γ-rays. Measurements were carried out at room temperature and 4 MHz frequency using ultrasonic technique. The ultrasonic velocities data of glass samples have been used to find the elastic modulus and micro-hardness. Densities of glass samples were measured by Archimedes's principle using n-hexane as immersion liquid. It was found that ultrasonic velocity, elastic modulus and micro-hardness increase with increasing barium oxide content and increasing γ-radiation dose.

  3. Advanced HLW management strategies employing both synroc and borosilicate glass waste-forms

    International Nuclear Information System (INIS)

    Recent resurgence of interest in waste partitioning permits the consideration of advanced strategies for Righ-level waste (HLW) management based on exploitation of Synroc in conjunction with borosilicate glass. The synergies resulting from the complementary of these waste-forms and their respective process technologies opens up the opportunity to reduce the overall volume of conditioned HLW for geological disposal. The paper provides a summary of the salient features of Synroc and discusses strategies for the conditioning of partitioned wastes from the reprocessing of UOX and MOX fuels from nuclear power generation. The discussion will also explore potential in U.S. defence waste remediation and disposition of excess fissile materials such as Pu. (authors)

  4. Influence of bicarbonate ions and redox conditions on the surface composition of a leached borosilicate glass

    International Nuclear Information System (INIS)

    A serie of short leaching tests have been performed on a borosilicate glass (I117) up to a maximum of 40 days. The tests were performed in a closed system in oxic and anoxic conditions and in presence of bicarbonate ions. The bicarbonate ions do not influence the mass losses while the oxic condition gives rise to an higher mass losses. Surface analysis was performed on the surface layer for the elements uranium and iron. Uranium is always depleted at the surface of the samples. It appears that adsorption and diffusion in the layer play an important part in the uranium released. Iron on the contrary is enriched so that solubility of the formed species are responsible of its concentration

  5. Operating Range for High Temperature Borosilicate Waste Glasses: (Simulated Hanford Enveloped)

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad, J.; Ramsey, W. G.; Toghiani, R. K.

    2003-02-24

    The following results are a part of an independent thesis study conducted at Diagnostic Instrumentation and Analysis Laboratory-Mississippi State University. A series of small-scale borosilicate glass melts from high-level waste simulant were produced with waste loadings ranging from 20% to 55% (by mass). Crushed glass was allowed to react in an aqueous environment under static conditions for 7 days. The data obtained from the chemical analysis of the leachate solutions were used to test the durability of the resulting glasses. Studies were performed to determine the qualitative effects of increasing the B2O3 content on the overall waste glass leaching behavior. Structural changes in a glass arising due to B2O3 were detected indirectly by its chemical durability, which is a strong function of composition and structure. Modeling was performed to predict glass durability quantitatively in an aqueous environment as a direct function of oxide composition.

  6. Thermal and structural studies on barium borosilicate glasses containing sulphate ions

    International Nuclear Information System (INIS)

    Borosilicate glasses having composition SiO2)0.416(B2O3)0.208 (Na2O)0.218(BaO)0.157 containing up to 4 mol % sulphate ions were prepared by conventional melt-quench method. Incorporation of sulphate ions in the glass has been found to weaken the glass network as revealed by the decrease in the glass transition temperatures. Based on 29Si and 11B magic angle spinning nuclear magnetic resonance (MAS NMR) studies, it has been established that the silicate network undergoes slight depolymerisation while the boron structural units remained unaffected with sulphate addition in the glass. Above 4 mol % incorporation of sulphate ions resulted in the devitrification of the glass. (author)

  7. Borosilicate glass (α,n) sources used with ORIGEN-type calculations

    International Nuclear Information System (INIS)

    The major part of the neutron source in vitrified high-level waste is produced from the actinide α-particle emission interacting with the light elements in borosilicate glass. Models applying thick target (α,n) yield data have been developed for the ALPHN code and ORIGEN-S at the Oak Ridge National Laboratory. The method requires the relation between the (α,n) yields and the stopping powers of elements, which are constituents in a mixture, and the total (α,n) yield of the mixture. An example is given of results computed by ALPHN, listing the calculated (α,n) sources for each α-particle emitter in addition to the total. An example computed by ORIGEN-S is given, showing both the total (α,n) spectrum and the total neutron spectrum, including spontaneous fission. A discussion of the limited validation work is also provided

  8. Characteristics of borosilicate glass media fabricated by melting HEPA filter media with inorganic additives

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I. T.; Kim, H. Y.; Park, K. I.; Park, H. S.; Kim, J. H. [KAERI, Taejon (Korea, Republic of)

    1999-05-01

    HEPA filters are widely used in the nuclear fields as a final off-gas cleaning unit. To assess the applicability of vitrification technology either to treat used filter media or to produce borosilicate glass medium for the solidification of alpha-contaminated wastes, various waste glasses of different compositions were fabricated by melting mixture of HEPA filter media and inorganic additives. Physicochemical properties such as microhardness, density, thermal expansion, and short-term leaching behavior were characterized. XRD analysis showed that amorphous glasses were formed for a wide range of mixing ratio. Leach resistances, measured by PCT-B leach tests, were superior to that of EA (Environmental Assessment) glass. Other properties were similar to those of glass media used for the vitrification of high-level radioactive wastes in foreign countries.

  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. Borosilicate glass (α,n) sources used with ORIGEN-type calculations

    International Nuclear Information System (INIS)

    The major part of the neutron sources in vitrified high level waste is produced from the actinide α-particle emission interacting with the light elements in borosilicate glass. Models applying thick target (α,n) yield data have been developed for the ALPHN code and ORIGEN-S at the Oak Ridge national Laboratory. The method requires the relation between the (α,n) yields and the stopping powers of elements, which are constituents in a mixture, and the total (α,n) yield of the mixture. An example is shown of results computed by ALPHN, listing the calculated (α,n) sources for each α-particle emitter in addition to the total. In this paper an example computed by ORIGEN-S is given, showing both the total (α,n) spectrum and the total neutron spectrum, including spontaneous fission. A discussion of the limited validation work is also provided

  11. 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.

  12. 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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  16. 4.2. The kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    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%.

  17. Sol–gel synthesis and optical properties of CuGaS2 quantum dots embedded in sodium borosilicate glass

    International Nuclear Information System (INIS)

    Highlights: • The CuGaS2 quantum dots doped sodium borosilicate glass was prepared by sol–gel methods. • The obtained glass was investigated by XRD, (S)TEM and XPS. • Tetragonal crystalline phase of CuGaS2 quantum dots with spherical shape were formed uniformly in the glass matrix. • The third-order optical nonlinearity was investigated by Z-scan technique. - Abstract: I–III–VI2 ternary semiconductor CuGaS2 quantum dots embedded in sodium borosilicate glass matrix were synthesized by combining the sol–gel process and heat treatment in H2S gas. The structure and morphology of the obtained glass were studied by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results showed that tetragonal crystalline phase of CuGaS2 quantum dots with spherical shape were formed uniformly in the sodium borosilicate glass matrix, and the sizes ranged from 5 to 25 nm with an average particle size of 12.75 nm. The optical nonlinearity was studied using Z-scan technique employing 200 fs at the wavelength of 800 nm. The glass doped with CuGaS2 quantum dots exhibited large third-order optical nonlinear susceptibility χ(3) of 1.60 × 10−9 esu

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

    International Nuclear Information System (INIS)

    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 (SiO2: 30.5 wt%, B2O3: 20.0 wt%, Na2O: 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. Dependence of water resistance multicomponent sodium-borosilicate glasses on their composition

    International Nuclear Information System (INIS)

    Regularities affecting chemical stability of multicomponent sodium-borosilicate glasses have been revealed. Glass of the composition (mass %): 16.6 Na2O; 18.7 B2O3; 36.1 SIO2; 1.3 Al2O3; 5.7 Fe2O3; 5.1 CaO; 2.9 FeO; 6.5 MnO; 2.5 Li2O; 0.8 K2O; 3.5 CaF2 above 100-1.5 CoO have been chosen as initial one. Chemical glass stability with respect to water was determined on powder fractions of 0.50-0.85 mm and 3 g mass, which was affected with 150 ml boiling water during 2.0 h. Powder after tests was washed and dried to a constant weight at 110 deg C. Loss of powder mass in percents was an index of water resistance. It is shown that Na2O replacement with BaO and K2O causes considerable increase of water resistance as compared with a source glass

  20. Third-order Nonlinear Optical Properties of Silver Quantum Dots Doped in Sodium Borosilicate Glass

    Directory of Open Access Journals (Sweden)

    ZHAO Xiu-Li, LIANG Xiao-Juan, LUO Hong-Yan, CHEN Zhao-Ping, XIANG Wei-Dong

    2013-09-01

    Full Text Available Silver quantum dots doped in sodium borosilicate glass were synthesized through Sol-Gel method using tetraethyl orthosilicate (TEOS, boracic acid, metallic sodium as precursors. X-ray powder diffraction (XRD analyses revealed that silver quantum dots were cubic crystalline phase; size and distribution of the quantum dots were measured by transmission electron microscope (TEM as well as high-resolution transmission electron microscope (HRTEM. The results showed that spherical shape formed uniformly in the glass, and the size of these quantum dots ranged from 5 nm to 13 nm. Ultraviolet-visible (UV-Vis absorption spectrometer obtained surface plasma resonance (SPR absorption peaks as that of the Ag quantum dots at about 406 nm. Nonlinear optical properties of silver quantum dots doped glass were investigated by using Z-scan technique at the wavelength of 800 nm with femtosecond Ti: sapphire laser radiation. The values of nonlinear refraction index γ, nonlinear absorption coefficient β and the third-order nonlinear optical susceptibility χ(3 of the glass were estimated to be –1.72×10-17 m2/W, 9.96×10-11 m/W, 1.01×10-11 esu, respectively.

  1. Radiation-induced paramagnetic defects as structural probes of pure silica and borosilicate glasses

    International Nuclear Information System (INIS)

    The short-range structure of high-purity SiO2 and B2O3-3SiO2 glasses has been studied by electron spin resonance (ESR) using γ-ray-induced defects as probes. Specific defects studied in silica include the familiar silicon E' centre (an oxygen-vacancy defect) and several oxygen-associated hole centres (OHCs). In the borosilicate glass the defects comprise the SiE' centre, the boron oxygen hole centre (BOHC), and a newly-discovered structural analogue of the SiE' centre, the boron E' centre. The derived structural information includes (1) the nature and quantity of quenched-in structural defects, (2) the degree of clustering of boron or alkali at defect sites, and (3) the average magnitude of structural distortions brought about by vitreous disorder. These estimates are based on careful computer simulations of the observed ESR spectra, taking into account the occurrence of distributions in energy level splittings which give rise to statistical distributions in spin Hamiltonian parameters. One of the most striking findings is the fact that the average variation in (defect)-A-O bond angle (A = Si or B) over the ensemble of E' sites in a given glass sample is always 0. It is inferred that tetrahedral SiO4 units without oxygen vacancies are at least this perfect. (author)

  2. Structure and chemical durability of barium borosilicate glass-ceramics containing zirconolite and titanite crystalline phases

    Science.gov (United States)

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

    2015-11-01

    In order to increase the solubility of actinides in the glass matrix, the effects of CaO, TiO2, and ZrSiO4 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.

  3. 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.

  4. Ultrafast opacity in borosilicate glass induced by picosecond bursts of laser-driven ions

    CERN Document Server

    Dromey, B; Adams, D; Prasad, R; Kakolee, K F; Stefanuik, R; Nersisyan, G; Sarri, G; Yeung, M; Ahmed, H; Doria, D; Dzelzainis, T; Jung, D; Kar, S; Marlow, D; Romagnani, L; Correa, A A; Dunne, P; Kohanoff, J; Schleife, A; Borghesi, M; Currell, F; Riley, D; Zepf, M; Lewis, C L S

    2014-01-01

    Direct investigation of ion-induced dynamics in matter on picosecond (ps, 10-12 s) timescales has been precluded to date by the relatively long nanosecond (ns, 10-9 s) scale ion pulses typically provided by radiofrequency accelerators1. By contrast, laser-driven ion accelerators provide bursts of ps duration2, but have yet to be applied to the study of ultrafast ion-induced transients in matter. We report on the evolution of an electron-hole plasma excited in borosilicate glass by such bursts. This is observed as an onset of opacity to synchronised optical probe radiation and is characterised by the 3.0 +/- 0.8 ps ion pump rise-time . The observed decay-time of 35 +/- 3 ps i.e. is in excellent agreement with modelling and reveals the rapidly evolving electron temperature (>10 3 K) and carrier number density (>10 17cm-3). This result demonstrates that ps laser accelerated ion bursts are directly applicable to investigating the ultrafast response of matter to ion interactions and, in particular, to ultrafast pu...

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

    International Nuclear Information System (INIS)

    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

  6. Leach behavior of high-level borosilicate glasses under deep geological environment

    International Nuclear Information System (INIS)

    This report presents an overview of the activities in high-level radioactive waste glass which is considered as the most practicable form of waste, and also is intended to be used in the disposal of national high-level radioactive waste in future. Leach theory of waste glass and the leach effects of ground water, metal barrier, buffer materials and rocks on the waste glass were reviewed. The leach of waste glass was affected by various factors such as composition, pH and Eh of ground water, temperature, pressure, radiation and humic acid. The crystallization, crack, weathering and the formation of altered phases of waste glass which is expected to occur in real disposal site were reviewed. The results of leaching in laboratory and in-situ were compared. The behaviors of radioactive elements leached from waste glass and the use of basalt glass for the long-term natural analogue of waste glass were also written in this report. The appraisal of durability of borosilicate waste glass as a waste media was performed from the known results of leach test and international in-situ tests were introduced. (author). 134 refs., 15 tabs., 24 figs

  7. Evolutions of Molecular Oxygen Formation and Sodium Migration in Xe Ion Irradiated Borosilicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang; Zhang, Duofei F.; Lv, Peng; Zhang, Jiandong; Du, Xing; Yuan, Wei; Nan, Shuai; Zhu, Zihua; Wang, Tieshan

    2016-07-23

    The modifications of a commercial borosilicate glass induced by Xe ion irradiation have been studied by Raman spectroscopy and ToF-SIMS depth profiling. A decrease in the average Si–O–Si angle, an increase in the population of three-membered rings and an increase of the glass polymerization are evidenced. The molecular oxygen appears in the irradiated glasses after the irradiation fluence reaches approximately 1015 ions/cm2. The O2 concentration decreaseswith the depth of irradiated glass at the ion fluence of 2 × 1016 ions/cm2. A sodiumdepleted layer at the surface and a depleted zone at around the penetration depth of 5 MeV Xe ions are observed. The thickness of the sodium depleted layer increases with the irradiation fluence. Moreover, comparing with previous results after electron and Ar ion irradiation, it can be concluded that the nuclear energy deposition can partially inhibit the formation of molecular oxygen and increase the threshold value of electron energy deposition for the molecular oxygen formation.

  8. Supported TiO2 on Borosilicate Glass Plates for Efficient Photocatalytic Degradation of Fenamiphos

    Directory of Open Access Journals (Sweden)

    A. El Yadini

    2014-01-01

    Full Text Available Supported titanium dioxide (TiO2 was investigated for the photodegradation of the insecticide fenamiphos in water. The photocatalyst was immobilised on borosilicate glass plates and the kinetics of degradation were studied in a stirred tank reactor under UV irradiation. Two types of TiO2, for example, Millennium PC500 (100% anatase and Degussa P25 (80% anatase, 20% rutile, were used. Their activities have been based on the rates of insecticide disappearance. Experiments were investigated to evaluate the effect of pH and initial concentrations of fenamiphos as well as catalyst doses on the photocatalytic degradation of fenamiphos. Kinetic parameters were experimentally determined and an apparent first-order kinetic was observed. For photolysis process of fenamiphos, two photoproducts were identified and characterized using high performance liquid chromatography/mass spectrometry (HPLC/MS. The plausible mechanism of photolysis involved is the oxidation of sulfonamide group. In presence of photocatalyst TiO2, photodegradation was observed. Under identical conditions, Degussa P25 shows higher photocatalytic activity in regard to PC500 Millennium and complete degradation was observed after 180 min.

  9. Leach behavior of high-level borosilicate glasses under deep geological environment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Soo; Chun, Kwan Sik; Park, Hyun Soo

    1998-02-01

    This report presents an overview of the activities in high-level radioactive waste glass which is considered as the most practicable form of waste, and also is intended to be used in the disposal of national high-level radioactive waste in future. Leach theory of waste glass and the leach effects of ground water, metal barrier, buffer materials and rocks on the waste glass were reviewed. The leach of waste glass was affected by various factors such as composition, pH and Eh of ground water, temperature, pressure, radiation and humic acid. The crystallization, crack, weathering and the formation of altered phases of waste glass which is expected to occur in real disposal site were reviewed. The results of leaching in laboratory and in-situ were compared. The behaviors of radioactive elements leached from waste glass and the use of basalt glass for the long-term natural analogue of waste glass were also written in this report. The appraisal of durability of borosilicate waste glass as a waste media was performed from the known results of leach test and international in-situ tests were introduced. (author). 134 refs., 15 tabs., 24 figs

  10. Luminescence properties of Gd{sup 3+}-doped borosilicate scintillating glass

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chunmei [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Patent Examination Cooperation HuBei Center of The Patent Office, SIPO, Wuhan, HuBei 430070 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Liu, Shuang [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Liu, Liwan [Shanghai University, Shanghai 201800 (China); Chen, Dan Ping, E-mail: dpchen2008@aliyun.com [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2015-04-15

    Gd{sup 3+}-doped borosilicate glasses are prepared in different melting atmosphere. Absorption spectra, decay time, luminescence spectra under UV and X-ray excitation are investigated. With melting atmosphere changing from air to CO, the luminescence intensities of Gd{sup 3+} at 313 nm under the excitation of UV and X-ray are both enhanced. This mainly results from the reduction of Gd{sup 3+}, which is validated by electron paramagnetic resonance (EPR). The optimal Gd{sub 2}O{sub 3} content for the glasses prepared under CO atmosphere is 7.5 mol%, whose integral scintillation efficiency is 20% compared with Bi{sub 4}Ge{sub 3}O{sub 12}. - Highlights: • Glasses with various Gd{sub 2}O{sub 3} contents are prepared in the air or CO atmosphere. • The glasses show stronger photoluminescence and radioluminescence intensity. • High integral scintillation efficiency obtained for the prepared glass is 20% of BGO.

  11. Influence of processing conditions on the glass-crystal transition into borosilicate glasses

    International Nuclear Information System (INIS)

    The precipitation of a crystalline phase in glass is observed when one element exceeds its loading limit (i.e.: solubility limit). In this work we have studied the solubility of different actinides and surrogates (lanthanides and hafnium) in borosilicate glass used for the immobilization of the high-level nuclear waste (HLW glasses). The results obtained show an increase of the solubility limits of these elements with the processing temperature and the redox potential of the melt. The elements at the oxidation state (III) exhibit a higher solubility than the element at oxidation state (IV). In this framework, cerium is an interesting element because its oxidation state tunes from (IV) to (III) as a function of the processing conditions. It is shown that the solubility of cerium can be multiplied by a factor of 20 at 1100 C. degrees. In order to have a better understanding of the mechanisms that underline the evolution of the solubility, XAFS and NMR investigation has been undertaken. Trivalent elements present the characteristics of network-modified cations while tetravalent elements look like network-former cations

  12. 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.

  13. Low temperature sintering and performance of aluminum nitride/borosilicate glass

    Institute of Scientific and Technical Information of China (English)

    Hong-sheng ZHAO; Lei CHEN; Nian-zi GAO; Kai-hong ZHANG; Zi-qiang LI

    2009-01-01

    Aluminum nitride (AlN)/borosilicate glass composites were prepared by the tape casting process and hot-press sin-tered at 950 ℃ with AlN and SiO2-B2O3-ZnO-Al2O3-Li2O glass as starting materials. We characterized and analyzed the variation of the microstructure, bulk density, porosity, dielectric constant, thermal conductivity and thermal expansion coefficient (TEC) of the ceramic samples as a function of AlN content. Results show that AlN and SiO2-B2O3-ZnO-Al2O3-Li2O glass can be sintered at 950 ℃, and ZnAl2O4 and Zn2SiO4 phase precipitated to form glass-ceramic. The performance of the ceramic samples was de-termined by the composition and bulk density of the composites. Lower AlN content was found redounding to liquid phase sin-tering, and higher bulk density of composites can be accordingly obtained. With the increase of porosity, corresponding decreases were located in the dielectric constant, thermal conductivity and TEC of the ceramic samples. When the mass fraction of AlN was 40%, the ceramic samples possessed a low dielectric constant (4.5~5.0), high thermal conductivity (11.6 W/(m·K)) and a proper TEC (3.0×10K-1, which matched that of silicon). The excellent performance makes this kind of low temperature co-fired ce-ramic a promising candidate for application in the micro-electronics packaging industry.

  14. Visible to deep ultraviolet range optical absorption of electron irradiated borosilicate glass

    Science.gov (United States)

    Wang, Tie-Shan; Duan, Bing-Huang; Tian, Feng; Peng, Hai-Bo; Chen, Liang; Zhang, Li-Min; Yuan, Wei

    2015-07-01

    To study the room-temperature stable defects induced by electron irradiation, commercial borosilicate glasses were irradiated by 1.2 MeV electrons and then ultraviolet (UV) optical absorption (OA) spectra were measured. Two characteristic bands were revealed before irradiation, and they were attributed to silicon dangling bond (E’-center) and Fe3+ species, respectively. The existence of Fe3+ was confirmed by electron paramagnetic resonance (EPR) measurements. After irradiation, the absorption spectra revealed irradiation-induced changes, while the content of E’-center did not change in the deep ultraviolet (DUV) region. The slightly reduced OA spectra at 4.9 eV was supposed to transform Fe3+ species to Fe2+ species and this transformation leads to the appearance of 4.3 eV OA band. By calculating intensity variation, the transformation of Fe was estimated to be about 5% and the optical absorption cross section of Fe2+ species is calculated to be 2.2 times larger than that of Fe3+ species. Peroxy linkage (POL, ≡Si-O-O-Si≡), which results in a 3.7 eV OA band, is speculated not to be from Si-O bond break but from Si-O-B bond, Si-O-Al bond, or Si-O-Na bond break. The co-presence defect with POL is probably responsible for 2.9-eV OA band. Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. lzujbky-2014-16).

  15. Dissolution of borosilicate glasses under repository conditions of pressure and temperature

    International Nuclear Information System (INIS)

    This paper described laboratory experimental work in progress in the UK to examine the mechanisms of fluid buffered interactions of materials at possible repository temperatures and pressures and aims at proposing limiting temperature values for a disposal facility from the geochemist's viewpoint. At present work is concentrated on reconnaissance experiments on dissolution rates of the vitrified waste form and the changes in near-field granite surface chemistry and fissure properties which will have a bearing on nuclide adsorption immediately after release. The major conclusions: in all of the experiments the fluid state remained as liquid since temperatures never exceeded 3740C, under these subcritical conditions pressure decreases dissolution rate; the ability to extrapolate dissolution rate from values of 1000C to about 2000C, together with the maintenance of physical integrity indicate that the glasses studied are likely to be stable and predictable in leach behavior to temperatures well in excess of those currently being considered for disposal; Glass 209 dissolves more slowly over a wide pressure and temperature spectrum than does glass 189, although the latter is easier to fabricate; dissolution rate decreases with increasing time. The principal conclusions of this study so far is that experimental application of realistic repository hydrothermal PT conditions indicate for the first time that current formulations of borosilicate glass would appear to provide for an adequate waste disposal medium which would maintain stability and predictable behavior over a wider pressure and temperature spectrum than previously realized, allowing sme latitude in both pre-disposal storage period and eventual loading at the time of disposal

  16. Preparation and optical properties of sodium borosilicate glasses containing Sb nanoparticles

    International Nuclear Information System (INIS)

    Highlights: • The Sb nanoparticles doped in Na2O–B2O3–SiO2 glass were prepared by sol–gel methods. • Obtained glass was investigated by structural and optical measurements. • The glass was crystalline with a rhombohedral structure of Sb. • An absorption peak centered on 566 nm has been observed in doping glass. • The third-order optical nonlinearity was investigated by femtosecond Z-scan technique. - Abstract: Sb nanoparticles have been successfully prepared from SbCl3 in sodium borosilicate (Na2O–B2O3–SiO2) glass matrix by sol–gel method, involving metallic sodium as sodium source, boric acid as boron source and SiO2 come from hydrolysis of tetraethoxysilane. The feasibility of process conditions were analyzed by using Fourier Transform Infrared (FT-IR), thermal gravimetric (TG), and nuclear magnetic resonance (NMR). X-ray diffraction (XRD) study revealed that the rhombohedral structure of metal Sb have formed in the glass. The particle was found to be spherical shaped and highly monodispersed with an average size of about 32.63 nm as analyzed from transmission electron microscopy (TEM). The surface plasmon resonance (SPR) of Sb nanoparticle was studied from the UV–Vis absorption. The nonlinear optical properties were studied by using the Z-scan technique with a Ti:sapphire laser at 800 nm. Results showed that the third-order optical nonlinear susceptibility χ(3) of the glass was determined to be 4.85 × 10−11 esu

  17. Preparation and Optical Properties of Er3+ -Doped Gadolinium Borosilicate Glasses

    Institute of Scientific and Technical Information of China (English)

    Sun Jiangting; Zhang Jiahua; Chen Baojiu; Lu Shaozhe; Ren Xinguang; Wang Xiaojun

    2005-01-01

    Er3+-doped Gd2 O3 -SiO2 -B2 O3 -Na2O glasses were prepared, and formation range of glass of Gd2 O3 -SiO2 -B2O3 system was experimentally obtained. It is found that the glass phase can be formed only when the content of SiO2 is 0~50%(molar fraction), Gd2O3 is 0~30%(molar fraction) and B2 O3 is above 20%(molar fraction) in this glass system. The glass can also be obtained but becomes translucent at the contents of 60%(molar fraction) SiO2 and 30% Gd2O3 , or at the contents of 60%(molar fraction) SiO2 and 30%(molar fraction) B2O3. There is no glass phase formed in other glass components. Glass forming ability for Gd2O3 content of 10%, was characterized by the value of β, the parameter of crystallization tendency, which is 0.32~1.76, obtained from the differential thermal analysis. The absorption and emission cross section, the J-O parameters Ωt(2,4,6) and radiative transition probabilities were calculated by using the theory of McCumber and Judd-Ofelt. The emission properties at 1.5 μm of the samples are discussed with the product of full width at half maximum and stimulated emission cross section. It can be seen that the value of the FWHM×σepeak product in the prepared glass is more than those of germanate, silicate and phosphate glasses. Furthermore, the maximum value of the product among these glasses reported in this work is close to that of oxyfluoride silicate glass. Therefore, the Er3+-doped gadolinium borosilicate glass in this paper is a candidate for broadband erbium doped fiber amplifiers.

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

    International Nuclear Information System (INIS)

    This work is devoted to the study of a rare earth alumino borosilicate glass, which molar composition is 61,81 SiO2 - 3,05 Al2O3 - 8,94 B2O3 - 14,41 Na2O - 6,33 CaO - 1,90 ZrO2 - 3,56 Nd2O3, 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 [AlO4]- and [BO4]- species. The neodymium local environment could be probed by optical absorption and EXAFS spectroscopies which enabled to better understand the insertion mode of Nd3+ 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 Ca2Nd8(SiO4)6O2. In particular, this work underlined the important role of both alkaline earth and rare earth cations on the crystallization of the apatite phase. (author)

  19. Gadolinium borosilicate glass-bonded Gd-silicate apatite: a glass-ceramic nuclear waste form for actinides

    International Nuclear Information System (INIS)

    A Gd-rich crystalline phase precipitated in a sodium gadolinium alumino-borosilicate glass during synthesis. The glass has a chemical composition of 45.4-31.1 wt% Gd2O3, 28.8-34.0 wt% SiO2,10.8-14.0 wt% Na2O, 4.3-5.9 wt% Al2O3, and 10.8-14.9 wt% B2O3. Backscattered electron images revealed that the crystals are hexagonal, elongated, acicular, prismatic, skeletal or dendritic, tens of μm in size, some reaching 200 μm in length. Electron microprobe analysis confirmed that the crystals are chemically homogeneous and have a formula of NaGd9(SiO4)6O2 with minor B substitution for Si. The X-ray diffraction pattern of this phase is similar to that of lithium gadolinium silicate apatite. Thus, this hexagonal phase is a rare earth silicate with the apatite structure. We suggest that this Gd-silicate apatite in a Gd-borosilicate glass is a potential glass-ceramic nuclear waste form for actinide disposition. Am, Cm and other actinides can easily occupy the Gd-sites. The potential advantages of this glass-ceramic waste form include: 1) both the glass and apatite can be used to immobilize actinides, 2) silicate apatite is thermodynamically more stable than the glass, 3) borosilicate glass-bonded Gd-silicate apatite is easily fabricated, and 4) the Gd is an effective neutron absorber.Copyright (2001) Material Research Society

  20. A space imaging concept based on a 4m structured spun-cast borosilicate monolithic primary mirror

    Science.gov (United States)

    West, S. C.; Bailey, S. H.; Bauman, S.; Cuerden, B.; Granger, Z.; Olbert, B. H.

    2010-07-01

    Lockheed Martin Corporation (LMC) tasked The University of Arizona Steward Observatory (UASO) to conduct an engineering study to examine the feasibility of creating a 4m space telescope based on mature borosilicate technology developed at the UASO for ground-based telescopes. UASO has completed this study and concluded that existing launch vehicles can deliver a 4m monolithic telescope system to a 500 km circular orbit and provide reliable imagery at NIIRS 7-8. An analysis of such an imager based on a lightweight, high-performance, structured 4m primary mirror cast from borosilicate glass is described. The relatively high CTE of this glass is used to advantage by maintaining mirror shape quality with a thermal figuring method. Placed in a 290 K thermal shroud (similar to the Hubble Space Telescope), the orbit averaged figure surface error is 6nm rms when earth-looking. Space-looking optical performance shows that a similar thermal conditioning scheme combined with a 270 K shroud achieves primary mirror distortion of 10 nm rms surface. Analysis shows that a 3-point bipod mount will provide launch survivability with ample margin. The primary mirror naturally maintains its shape at 1g allowing excellent end-to-end pre-launch testing with e.g. the LOTIS 6.5m Collimator. The telescope includes simple systems to measure and correct mirror shape and alignment errors incorporating technologies already proven on the LOTIS Collimator. We have sketched a notional earth-looking 4m telescope concept combined with a wide field TMA concept into a DELTA IV or ATLAS 552 EELV fairing. We have combined an initial analysis of launch and space performance of a special light-weighted honeycomb borosilicate mirror (areal density 95 kg/m2) with public domain information on the existing launch vehicles.

  1. TRPLS (Time Resolved Photoluminescence) studies of U and Am in sol-gel derived alkali barium borosilicate glass

    International Nuclear Information System (INIS)

    Speciation studies of U and Am in alkali barium borosilicate glasses, prepared via sol-gel route were carried out using time resolved photoluminescence (TRPLS) spectroscopic technique. The PL spectrum of the uranium containing glass showed green emission band at 540 nm without any vibronic structure along with excitation peaks at 275, 323, 348 and 412 nm. These data indicated the presence of uranium as uranate (UO6)6- in the glass matrix. Am was stabilized in the matrix in its trivalent form which was confirmed from its excitation, emission and decay time data. (author)

  2. Comparative transportation risk assessment for borosilicate-glass and ceramic forms for immobilization of SRP Defense waste

    International Nuclear Information System (INIS)

    It is currently planned to immobilize the SRP high-level nuclear waste in solid form and then ship it from SRP to a federal repository. This report compared transportation operations and risks for SRP high-level waste in a borosilicate glass form and in a ceramic form. Radiological and nonradiological impacts from normal transport and from potential accidents during transit were determined using the Defense Waste Process Facility Environmental Impact Statement (DWPF EIS) as the source of basic data. Applicable regulations and some current regulatory uncertainties are also discussed

  3. Improvement in laser micromachinability of borosilicate glass by electric-field-assisted solid-state ion exchange

    International Nuclear Information System (INIS)

    In order to improve the laser machinability of borosilicate glass, copper ions were doped to the glass surface by electric-field-assisted solid-state ion-exchange method. The nanosecond ultraviolet laser irradiation of copper-containing regions produced flat, smooth and defect-free holes because of their high optical absorptions. However, the shapes of the holes were drastically degraded when the processed hole bottoms reached ion penetration depths. Therefore, well-designed and controlled ion distribution was necessary for the high-accuracy fabrication of microcomponents.

  4. 信息动态%Spectral Analysis of Ho3+ -doped and Ho3+, Yb3+, Er3+ Co-doped Up-conversion Luminescence Borosilicate Glass

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A series of holmium ions doped borosilicate glass, including Ho3+ -doped, Ho3+/ Er3+ -doped, Ho3+/ Y Yb3+-doped and Ho3 Yb3 YEr3+ -doped galss, have been prepared by high-temperature melting. The up-conversion excitation spectra and emission spectra of the samples decrease. The analysis result reveals that both the intensities of excitation spectra and emission spectra were weaken with the Ho3+ concentration. The spectral intensities of Ho3+/Yb3+ -doped borosilicate glass increase with the increase of Ho3+ concentration because of the sensitization of Yb3+. The excitation and emission spectra intensities of Ho3+/Yb3 +/Er3+-doped borosilicate glass are weak, and the reason is the energy transfers from Ho3+ ions to Er3+ ions through energy resonant transfer process. Meanwhile the luminescence mechanism of broadband emission peaked at 550 nm is analyzed.

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

    International Nuclear Information System (INIS)

    Graphical abstract: Photographs of undoped (SiO2)50 (Na2O)25 (B2O3)25 (SiNaB) glass and transition metal ion-doped (TM)0.5 (SiO2)49.5 (Na2O)25 (B2O3)25 glass samples. - Highlights: • 3d transition metal ion (from Ti to Zn) doped SiO2-Na2O-B2O3 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: SiO2-Na2O-B2O3 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. Optical properties of 3d transition metal ion-doped sodium borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Hongli [School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, Guangdong (China); Tanner, Peter A., E-mail: peter.a.tanner@gmail.com [Department of Science and Environmental Studies, The Hong Kong Institute of Education, 10 Lo Ping Road, Tai Po, N.T., Hong Kong Special Administrative Region (Hong Kong)

    2015-03-15

    Graphical abstract: Photographs of undoped (SiO{sub 2}){sub 50} (Na{sub 2}O){sub 25} (B{sub 2}O{sub 3}){sub 25} (SiNaB) glass and transition metal ion-doped (TM){sub 0.5} (SiO{sub 2}){sub 49.5} (Na{sub 2}O){sub 25} (B{sub 2}O{sub 3}){sub 25} glass samples. - Highlights: • 3d transition metal ion (from Ti to Zn) doped SiO{sub 2}-Na{sub 2}O-B{sub 2}O{sub 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{sub 2}-Na{sub 2}O-B{sub 2}O{sub 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.

  7. X-ray absorption studies of bismuth valence and local environments in borosilicate waste glasses

    International Nuclear Information System (INIS)

    Highlights: ► Bi in high level nuclear waste glasses was of interest due to melt foaming issues. ► Bi was also found associated with phosphate in some samples. ► X-ray absorption spectroscopy found similar Bi bonding within all glasses studied. ► The glasses contain Bi3+O3 environments with average Bi–O distances near 2.13 Å. ► No Bi-phosphate glass domains nor any link between Bi and melt foaming were observed. - Abstract: X-ray absorption spectra (XAS) were collected and analyzed to characterize bismuth (Bi) environments in borosilicate glass formulations developed for the immobilization of high level nuclear wastes (HLW), from the bismuth phosphate process. Therefore, the structural role of Bi in these glasses is of interest; in addition in the present study, more particular interest in Bi originated from unusual foaming that was observed during melt cooling, where it was initially suspected that Bi3+ reduction to Bi0 may generate oxygen that caused the foaming. Observations from scanning electron microscopy of some HLW glass samples indicated a Bi-phosphate association. Bi LIII XAS of 13 Bi-containing waste glass formulations of various compositions were measured that exhibited varying degrees of melt foaming. The Bi XAS are similar for all glasses investigated, and indicate Bi3+O3 nearest-neighbor environments with Bi–O distances near 2.13 Å. This environment is similar to the most localized Bi coordination characteristics in the crystalline Bi-silicates, eulytite (Bi4Si3O12) and bismutoferrite (BiFe2Si2O8OH). However, the Bi-environments in the glasses are distinctly different from the Bi-site in crystalline BiPO4; therefore, XAS indicates no evidence of Bi-phosphate domains in the glasses measured. No XAS evidence was observed in any of the glasses investigated for Bi clustering, such as metallic Bi, or Bi–O–Bi bonding. Since the local Bi environments look similar for all glasses investigated, Bi XAS data and analyses show no association

  8. Determination of boron concentration in borosilicate glass, boron carbide and graphite samples by conventional wet-chemical and nuclear analytical methods

    International Nuclear Information System (INIS)

    Boron is an important element in nuclear technology. A comparative study was carried out for the determination of boron in borosilicate glass, boron carbide and graphite samples by wet-chemical and nuclear analytical methods. Wet chemical methods namely titrimetry, Inductively Coupled Plasma Mass Spectrometry and ICP Optical Emission Spectrometry and nuclear analytical methods namely Particle Induced Gamma-Ray Emission and Nuclear Reaction Analysis were used. Boron concentrations were in trace (mg kg-1) level in graphite and percentage level in borosilicate glass and boron carbide. (author)

  9. Formation of molecular clusters of selenium as an alternative to precipitation of CdSe nanoparticles in a borosilicate glass

    International Nuclear Information System (INIS)

    Solid-state precipitation in a borosilicate glass is a well-elaborated technique for obtaining II-VI semiconductor nanocrystals. The obtained nanocrystal size depends on the growth conditions (heat treatment temperature and duration). Here we present Raman evidence for an alternative process, precipitation of molecular clusters of selenium, which is also possible at certain growth conditions. Decoloured CdSe-doped borosilicate glass samples were subjected to thermal treatment at 625 to 700 C during 2 to 12 h. Resonant micro-Raman measurements were performed using a Dilor XY 800 spectrometer and different Ar+ laser lines for excitation. Besides the CdSe LO and 2LO phonon bands, the Raman spectra of the samples obtained at thermal treatment duration and temperature beyond the range, most suitable for the formation of CdSe nanocrystals, contained pronounced features at 323 and 646 cm-1. Based on their frequency positions, widths, intensities, and resonant behaviour, these features are attributed to Se2 clusters being formed in the glass during the thermal treatment.

  10. β-irradiation effect in alumino-borosilicate glasses: the role of RE co-doping (RE = Sm, Gd)

    International Nuclear Information System (INIS)

    The effect of Sm and Gd co-doping on the structural modifications of β-irradiated alumino-borosilicate glasses has been studied by electron paramagnetic resonance (ESR) and Raman spectroscopy. The ESR spectra showed that the relative amount of Gd3+ ions occupying network former positions (Gd[n.f.]3+) follows a nonlinear behavior as a function of the Sm/Gd ratio. This suggests that co-doping favors the occupation by Gd3+ ions of the network former positions rather than the modifier positions in alumino-borosilicate glasses. The appearance of a super-hyperfine structure of ESR lines attributed to boron-oxygen hole centers (BOHC) with increasing Sm/Gd ratio was observed. This suggests that Gd3+ ions are diluted in the vicinity of the BOHC defects. The concentration of defects created by irradiation reveals a nonlinear dependence on Sm and Gd co-doping for the lowest irradiation dose (105 Gy). Therefore, co-doping also affects the defect creation processes at least at the lowest irradiation dose. Raman spectroscopy measurements suggest that the irradiation-induced structural changes vary nonlinearly with the Sm/Gd ratio. In fact, the shift of the Si-O-Si bending vibration modes reveals a clear minimum for samples containing equal amounts of Sm and Gd (1: 1) in the investigated glasses. (authors)

  11. Synthesis, characterization, and third-order nonlinear optical properties of copper quantum dots embedded in sodium borosilicate glass

    International Nuclear Information System (INIS)

    Highlights: ► The sodium borosilicate glass doped Cu quantum dots have been prepared by sol–gel route. ► The crystal structure and composition of as-prepared glass were investigated by XRD and XPS. ► Size and distribution of indium nanocrystals was determined by TEM and STEM. ► The third-order optical nonlinearity was investigated by using Z-scan technique. - Abstract: Copper quantum dots embedded in sodium borosilicate glass matrix were fabricated and analyzed in terms of their structural, chemical, and optical properties. X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that copper quantum dots were in face-centered-cubic crystalline phase and in the metallic state. Size and distribution of the quantum dots were measured by transmission electron microscopy (TEM) as well as high-resolution transmission electron microscopy (HRTEM). The results showed spherical shape have formed uniformly in the glass, and the size of these quantum dots were range from 1.5 to 5 nm with the average particle size about 2.7 nm. The third-order nonlinear optical properties of copper quantum dots doped glass were investigated by using Z-scan technique at the wavelength of 800 nm with femtosecond Ti: sapphire laser radiation. The value of third-order optical nonlinear susceptibility χ(3) of the glass was estimated to be 2.41 × 10−11 esu.

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

    International Nuclear Information System (INIS)

    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 90 C 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

  13. Ultraflat-top midinfrared coherent broadband supercontinuum using all normal As2S5-borosilicate hybrid photonic crystal fiber

    Science.gov (United States)

    Ben Salem, Amine; Diouf, Mbaye; Cherif, Rim; Wague, Ahmadou; Zghal, Mourad

    2016-06-01

    We report more than two octave spanning mid-IR flat-top supercontinuum (SC) generation using all normal As2S5-borosilicate hybrid photonic crystal fiber. Our design is based on a chalcogenide As2S5 photonic crystal fiber (PCF), where the first ring composed of six air holes is made by borosilicate glass. By injecting 50-fs pulses with 1.6 nJ energy at 2.5 μm in the all normal dispersion (ANDi) regime, a flat-top broadband SC extending from 1 to 5 μm with high-spectral flatness of 8 dB is obtained in only 4-mm fiber length. To the best of our knowledge, we present the broadest flat mid-IR spectrum generated in the ANDi regime of an optical fiber. The self-phase modulation and the optical wave breaking are identified as the main broadening mechanisms. The obtained broadband light source can be potentially used in the field of spectroscopy and in high-resolution optical coherent tomography owing to the high-spectral SC flatness generated by our designed fiber.

  14. 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.

  15. Positive and Negative Mixed Glass Former Effects in Sodium Borosilicate and Borophosphate Glasses Studied by (23)Na NMR.

    Science.gov (United States)

    Storek, Michael; Adjei-Acheamfour, Mischa; Christensen, Randilynn; Martin, Steve W; Böhmer, Roland

    2016-05-19

    Glasses with varying compositions of constituent network formers but constant mobile ion content can display minima or maxima in their ion transport which are known as the negative or the positive mixed glass former effect, MGFE, respectively. Various nuclear magnetic resonance (NMR) techniques are used to probe the ion hopping dynamics via the (23)Na nucleus on the microscopic level, and the results are compared with those from conductivity spectroscopy, which are more sensitive to the macroscopic charge carrier mobility. In this way, the current work examines two series of sodium borosilicate and sodium borophosphate glasses that display positive and negative MGFEs, respectively, in the composition dependence of their Na(+) ion conductivities at intermediate compositions of boron oxide substitution for silicon oxide and phosphorus oxide, respectively. A coherent theoretical analysis is performed for these glasses which jointly captures the results from measurements of spin relaxation and central-transition line shapes. On this basis and including new information from (11)B magic-angle spinning NMR regarding the speciation in the sodium borosilicate glasses, a comparison is carried out with predictions from theoretical approaches, notably from the network unit trap model. This comparison yields detailed insights into how a variation of the boron oxide content and thus of either the population of silicon or phosphorus containing network-forming units with different charge-trapping capabilities leads to nonlinear changes of the microscopic transport properties. PMID:27092392

  16. Corrosion testing of a plutonium-loaded lanthanide borosilicate glass made with Frit B

    International Nuclear Information System (INIS)

    Laboratory tests were conducted with a lanthanide borosilicate (LaBS) glass made with Frit B and added PuO2 (the glass is referred to herein as Pu LaBS-B glass) to measure the dependence of the glass dissolution rate on pH and temperature. These results are compared with the dependencies used in the Defense HLW Glass Degradation Model that was developed to account for HLW glasses in total system performance assessment (TSPA) calculations for the Yucca Mountain repository to determine if that model can also be used to represent the release of radionuclides from disposed Pu LaBS glass by using either the same parameter values that are used for HLW glasses or parameter values specific for Pu LaBS glass. Tests were conducted by immersing monolithic specimens of Pu LaBS-B glass in six solutions that imposed pH values between about pH 3.5 and pH 11, and then measuring the amounts of glass components released into solution. Tests were conducted at 40, 70, and 90 C for 1, 2, 3, 4, and 5 days at low glass-surface-area-to-solution volume ratios. As intended, these test conditions maintained sufficiently dilute solutions that the impacts of solution feedback effects on the dissolution rates were negligible in most tests. The glass dissolution rates were determined from the concentrations of Si and B measured in the test solutions. The dissolution rates determined from the releases of Si and B were consistent with the 'V' shaped pH dependence that is commonly seen for borosilicate glasses and is included in the Defense HLW Glass Degradation Model. The rate equation in that model (using the coefficients determined for HLW glasses) provides values that are higher than the Pu LaBS-B glass dissolution rates that were measured over the range of pH and temperature values that were studied (i.e., an upper bound). Separate coefficients for the rate expression in acidic and alkaline solutions were also determined from the test results to model Pu LaBS-B glass dissolution directly. The

  17. GLASS FABRICATION AND PRODUCT CONSISTENCY TESTING OF LANTHANIDE BOROSILICATE FRIT B COMPOSITION FOR PLUTONIUM DISPOSITION

    Energy Technology Data Exchange (ETDEWEB)

    Marra, J

    2006-01-19

    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 a leading candidate 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. 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. Therefore, the objectives of this present task were to fabricate plutonium loaded LaBS Frit B glass and perform additional 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 B 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) and for additional performance testing at Argonne National Laboratory (ANL) and Pacific Northwest National Laboratory (PNNL). The glass was 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 with varying exposed surface area and test durations. The leachates from these tests were analyzed to determine the dissolved concentrations of key elements. Acid stripping of leach vessels was performed to determine the concentration of the glass constituents that may have sorbed on the vessels during leach testing. Additionally, the

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

    International Nuclear Information System (INIS)

    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 (Ca2RE8(SiO4)6O2) or molybdenum-rich phases (CaMoO4, Na2MoO4) 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 SiO2-B2O3-Al2O3-Na2O-CaO-MoO3-Nd2O3 system and derived from the composition of the HTC glass at 22,5 wt. % in FPA. The impact of the presence of platinoid elements (RuO2 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 Ca2Nd8(SiO4)6O2 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)

  19. High thermal neutron flux effects on structural and macroscopic properties of alkali-borosilicate glasses used as neutron guide substrate

    Science.gov (United States)

    Boffy, R.; Peuget, S.; Schweins, R.; Beaucour, J.; Bermejo, F. J.

    2016-05-01

    The behaviour of four alkali-borosilicate glasses under homogeneous thermal neutron irradiation has been studied. These materials are used for the manufacturing of neutron guides which are installed in most facilities as devices to transport neutrons from intense sources such as nuclear reactors or spallation sources up to scientific instruments. Several experimental techniques such as Raman, NMR, SANS and STEM have been employed in order to understand the rather different macroscopic behaviour under irradiation of materials that belong to a same glass family. The results have shown that the remarkable glass shrinking observed for neutron doses below 0.5 ·1018 n/cm2 critically depends upon the presence of domains where silicate and borate network do not mix.

  20. Interaction of borosilicate glass and granodiorite at 1000C, 50 MPa: implications for models of radionuclide release

    International Nuclear Information System (INIS)

    The interaction of a simulated borosilicate waste glass, granodiorite and deionized water at 1000C, 50 MPa under closed system experimental conditions has revealed the rapid achievement of steady-state fluid concentrations for many chemical components of interest, (e.g., SiO2, La) and their rates of release from the near-field would be most appropriately modelled by a function of solubility and groundwater flow-rate. The conversion of these solubilities into conventional leach-rates has shown over five orders of magnitude range in relative release rates and emphasizes the need for source-term models to consider each radionuclide separately in terms of mechanisms of release

  1. A kinetic model for borosilicate glass dissolution based on the dissolution affinity of a surface alteration layer

    International Nuclear Information System (INIS)

    A kinetic model for the dissolution of borosilicate glass is used to predict the dissolution rate of a nuclear waste glass. In the model, the glass dissolution rate is controlled by the rate of dissolution of an alkali-depleted amorphous surface (gel) layer. Our model predicts that all components concentrated in the surface layer, affect glass dissolution rates. The good agreement between predicted and observed elemental dissolution rates suggests that the dissolution rate of the gel layer limits the overall rate of glass dissolution. The model predicts that the long-term rate of glass dissolution will depend mainly on ion concentrations in solution, and therefore on the secondary phases which precipitate and control ion concentrations. 10 refs., 5 figs., 1 tab

  2. Color-converted remote phosphor prototype of a multiwavelength excitable borosilicate glass for white light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    Tian Hua; Liu Ji-Wen; Qiu Kun; Song Jun; Wang Da-Jian

    2012-01-01

    We report a unique red light-emitting Eu-doped borosilicate glass to convert color for warm white light-emitting diodes.This glass can be excited from 394 nm-peaked near ultraviolet light,466 nm-peaked blue light,to 534 nm-peaked green light to emit the desired red light with an excellent transmission in the wavelength range of 400-700 nm which makes this glass suitable for color conversion without a great cost of luminous power loss.In particular,when assembling this glass for commercial white light-emitting diodes,the tested results show that the color rendering index is improved to 84 with a loss of luminous power by 12 percent at average,making this variety of glass promising for inorganic "remote-phosphor" color conversion.

  3. Mechanical and structural studies on sodium borosilicate glasses doped with Er2O3 using ultrasonic velocity and FTIR spectroscopy

    International Nuclear Information System (INIS)

    Sodium borosilicate glasses doped with different mol% content of Er2O3 have been prepared by rapid-quenching method. Ultrasonic velocities (both longitudinal and shear) measurements have been carried out at room temperature and at ultrasonic frequency of 4 MHz. Elastic moduli, Debye temperature, softening temperature, and Poisson's ratio have been obtained as a function of Er2O3 modifier content. Results show that the above-mentioned parameters have very slight change with the change of Er2O3 mol% content. Based on FTIR spectroscopy and theoretical (bond compression) model, quantitative analysis has been carried out in order to obtain more information about the structure of these glasses. The study indicated that the structure of these glasses is mainly composed of SiO4 units with four bridging oxygens (Q4), and with three bridging and one nonbridging oxygens (Q3)

  4. Color-converted remote phosphor prototype of a multiwavelength excitable borosilicate glass for white light-emitting diodes

    International Nuclear Information System (INIS)

    We report a unique red light-emitting Eu-doped borosilicate glass to convert color for warm white light-emitting diodes. This glass can be excited from 394 nm-peaked near ultraviolet light, 466 nm-peaked blue light, to 534 nm-peaked green light to emit the desired red light with an excellent transmission in the wavelength range of 400–700 nm which makes this glass suitable for color conversion without a great cost of luminous power loss. In particular, when assembling this glass for commercial white light-emitting diodes, the tested results show that the color rendering index is improved to 84 with a loss of luminous power by 12 percent at average, making this variety of glass promising for inorganic “remote-phosphor” color conversion

  5. Effect of composition and temperature on viscosity and electrical conductivity of borosilicate glasses for Hanford nuclear waste immobilization

    International Nuclear Information System (INIS)

    Viscosity and electrical conductivity of 79 simulated borosilicate glasses in the expected range of compositions to be produced in the Hanford Waste Vitrification Plant were measured within the temperature span from 950 to 1250 degree C. The nine major oxide components were SiO2, B2O3, Li2O, Na2O, CaO, MgO, Fe2O3, Al2O3, and ZrO2. The test compositions were generated statistically. The data were fitted by Fulcher and Arrhenius equations with temperature coefficients being multilinear functions of the mass fractions of the oxide components. Mixture models were also developed for the natural logarithm of viscosity and that of electrical conductivity at 1150 degree C. Least squares regression was used to obtain component coefficients for all the models

  6. Mild solvothermal synthesis and characterization of ZnO crystals with various morphologies on borosilicate glass substrate

    Science.gov (United States)

    Long, Tengfa; Takabatake, Kouta; Yin, Shu; Sato, Tsugio

    2009-01-01

    ZnO crystals with various morphologies were successfully prepared on borosilicate glass substrate in mild solution. Water and 50 vol% ethylene glycol aqueous solution were used as reaction solvents to investigate the crystal growth behavior. The effects of solvents and reaction time on the properties of crystals were investigated by Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD) analysis, photoluminescence spectroscopy, and photocatalytic characterization. The results indicated that the addition of ethylene glycol led to uniform crystal growth; however, the ZnO crystals synthesized in water possessed more excellent photoluminescence and photocatalytic activities. About 4.25%, 6.38% and 29.78% of 1 ppm NO x gas could be continuously removed under irradiation of light wavelength >510, >410 and >290 nm, respectively.

  7. The geochemical interactions of simulated borosilicate waste glass, granite and water at 100-3500C and 50MPa

    International Nuclear Information System (INIS)

    Four interactions experiments involving a simulated borosilicate waste glass, granite and deionised water have been carried out at 1000, 1500, 2000 and 3500C at a total pressure of 50 MPa to simulate the near-field geochemistry of a high level waste repository in granite. Experiments were conducted in gold-titanium cell, direct sampling autoclaves for run durations of 200 days (1000, 1500 and 2000C) and 30 days (3500C), during which time solution samples were extracted for the analysis of 25 chemical species. Solid phases retrieved at the end of the experiments were examined using X-ray diffraction and scanning electron microscopy. The high temperature speciation characteristics and degrees of mineral saturation of the fluids were investigated using the geochemical software packages, EQ3 and SOLMNEQ. (author)

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

    International Nuclear Information System (INIS)

    Upconversion behaviour has been studied in various matrices and fine powders of SrTiO3 by previous workers. In present work, Er3+/Yb3+ were doped in appropriate ratio in SrO.TiO2 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 Er3+/Yb3+:SrO.TiO2 borosilicate glasses with same amount of Er2O3 and Yb2O3 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, Sr3Ti2O7, Ti10O19 and SrTiO3, TiO2 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

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

    International Nuclear Information System (INIS)

    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)

  10. Acquisition of rheological and calorimetric properties of borosilicate glass to determine the free energy of formation

    International Nuclear Information System (INIS)

    No fundamental thermodynamic data, such as the entropy ΔfS T) and enthalpy ΔfH T) of formation are currently available for nuclear borosilicate glasses. They are necessary to assess the glass thermodynamic stability in water, one of the most important potential long-term glass alteration vectors. Three glass composition ranges were investigated: - 8 compositions ranging from a ternary B2O3-SiO2--Na2O (BSN) glass to the simulated SON 68 industrial glass for containment of high active nuclear wastes after reprocessing spent uranium oxide fuel from light water reactors. The basic BSN glass was gradually modified with the additives: Al2O3, CaO, ZrO2, Ce2O3, Li2O and Fe2O3, and non-radioactive surrogate fission product oxides. - A second using another BSN ternary glass to which Al2O3, MgO and a group of non-radioactive surrogate fission product oxides, representative of natural uranium GCR fuel, were added. - A third range consisting of various BSN ternary glass compositions. All the glass specimens were fabricated by melting the oxides, carbonates anal nitrates at 1273 to 1473 K in a platinum crucible. Experimental methods based on calorimetry and viscosimetry techniques were used to determine the heat capacity Cp of each glass composition, a necessary parameter in addition to the known heat capacities of the basic glass component oxides, for calculating ΔfS T) and ΔfS T). The heat capacity Cp was measured between 273 K and 1480 K through a combination of three experimental devices: a low-temperature adiabatic calorimeter, a differential scanning calorimeter, and an ice calorimeter. The glass configuration entropy Sconf(Tg) necessary to obtain the glass entropy of formation (Eqn.(3)) was determined from tile glass rheological properties. A low-temperature viscosimeter was used to measure the strain ε of a glass specimen subjected to a given uniaxial stress σ to determine the viscosity η. A Couette viscosimeter was used to measure low viscosities at up to 1700 K

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

    International Nuclear Information System (INIS)

    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 m2/g and 100 m2/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 pH90deg.C and the higher the glass alteration. As shown in Fig. 1, the pH90deg.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 pH90deg.C of 5.2, whereas the test made with the glass alone led to a pH90deg.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 the concentrations

  12. Incorporation of Fines and Noble Metals into HLW Borosilicate Glass: Industrial Responses to a Challenging Issue - 13056

    Energy Technology Data Exchange (ETDEWEB)

    Chauvin, E.; Chouard, N.; Prod' homme, A. [AREVA, AREVA NC, Paris (France); Boudot, E. [AREVA, AREVA NC, La Hague (France); Gruber, Ph.; Pinet, O. [CEA Marcoule LCV, France (France); Grosman, R. [AREVA, SGN, Paris (France)

    2013-07-01

    During the early stages of spent fuel reprocessing, the fuel rods are cut and dissolved to separate the solid metallic parts of the rods (cladding and end pieces) from the radioactive nitric acid solution containing uranium, plutonium, minor actinides and fission products (FP). This solution contains small, solid particles produced during the shearing process. These small particles, known as 'fines', are then separated from the liquid by centrifugation. At the La Hague plant in France, the fines solution is transferred to the vitrification facilities to be incorporated into borosilicate glass along with the highly radioactive FP solution. These fines are also composed of Zr, Mo and other noble metals (i.e. Ru, Pd, Rh, etc.) that are added before vitrification to the the FP solution that already contained noble metals. As noble metals has the potential to modify the glass properties (including viscosity, electrical conductivity, etc.) and to be affected by sedimentation inside the melter, their behavior in borosilicate glass has been studied in depth over the years by the AREVA and CEA teams which are now working together in the Joint Vitrification Laboratory (LCV). At La Hague, the R7 vitrification facility started operation in 1989 using induction-heated metallic melter technology and was quickly followed by the T7 vitrification facility in 1992. Incorporating the fines into glass has been a challenge since operation began, and has given rise to several R and D studies resulting in a number of technological enhancements to improve the mixing capability of the melters (multiple bubbling technology and mechanical stirring in the mid-90's). Nowadays, the incorporation of fines into R7T7 glass is well understood and process adaptations are deployed in the La Hague facilities to increase the operating flexibility of the melters. The paper will briefly describe the fines production mechanisms, give details of the resulting fines characteristics, explain

  13. Rhenium Solubility In Borosilicate Nuclear Waste Glass Implications For The Processing And Immobilization Of Technetium-99 (And Supporting Information With Graphical Abstract)

    International Nuclear Information System (INIS)

    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 ∼ 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 ∼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.

  14. 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.

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

    OpenAIRE

    ABDELLAH CHORFA; NABIL BELKHIR; FAUSTO RUBIO; JUAN RUBIO

    2012-01-01

    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 s...

  16. Infrared and x-ray photoelectron spectroscopic studies on sodium borosilicate glass interacted with thermally oxidized aluminides formed on alloy 690

    International Nuclear Information System (INIS)

    Thermally oxidized aluminides formed on Ni-Cr-Fe based superalloy 690 substrates were subjected to interaction with sodium borosilicate melt (used as matrices for immobilization of high-level radioactive liquid waste) at 1248 K for 192 hours. After the interaction, Fourier-transform infrared (FT-IR) spectroscopy analysis of glass samples indicated the incorporation of Al in the glass network. X-ray photoelectron spectroscopy (XPS) of glass specimens revealed modified glass structure. (author)

  17. 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)

  18. 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)

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

    International Nuclear Information System (INIS)

    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. 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

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

    Science.gov (United States)

    Kim, Miae; Heo, Jong

    2015-12-01

    Glass-ceramics containing calcium neodymium(cerium) oxide silicate [Ca2Nd8-xCex(SiO4)6O2] 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 2.64·10-6 g m-2 for Ce ion and 2.19·10-6 g m-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.

  1. Chemical durability of alkali-borosilicate glasses studied by analytical SEM, IBA, isotopic-tracing and SIMS

    International Nuclear Information System (INIS)

    Simple and complex alkali-borosilicate glasses were submitted to aqueous corrosion at room temperature, 60 and 90 deg. C in solutions with pH ranging between 0 and 12. Analytical scanning electron microscopy (SEM), ion beam analysis (IBA) techniques, isotopic tracing and secondary ion mass-depth profiling (SIMS) have been used to investigate the variations of the surface composition of glass. In acidic medium, the glass surface is generally covered by a thick hydrated silica layer, mobile elements like Li, Na and B and transition elements (Fe, Zr, Mo, etc.) are strongly depleted. Near pH 7, relative enrichments of aluminium, iron and rare earths are shown together with strong Li, Na and B depletions. In basic medium, the glass surface exhibits relative enrichments of the major part of transition metals (from Cr to U) whereas mobile elements seem to be kept close to their nominal concentration level at the glass surface and Si is severely impoverished. Hydrogen incorporated at the glass surface after leaching is much more immobile in neutral and basic media than in acid medium

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

    International Nuclear Information System (INIS)

    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 (Eu3+ and Nd3+). 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 2,3.1013 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)

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

    International Nuclear Information System (INIS)

    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)

  4. A comparative study by Molecular Dynamics of the ballistic effects and the thermal quenching effects in a sodium borosilicate glass

    International Nuclear Information System (INIS)

    The understanding of the aging under irradiation of nuclear glasses requires to study the induced changes at the atomic scale. A sodium borosilicate glass has been modeled by molecular dynamics and then submitted to low energies (4 keV) cascades series. Between each cascade, the structural evolutions have been analyzed and have shown a linear correlation between the glass swelling and its polymerization degree. The deep analysis of the different units constituting the glass shows that the lattice depolymerization instigated by the damage is mainly induced by the BO4 units conversion to BO3 and by the increase of the non bridging oxygen number. On account of the established structural changes, a comparison of the structural effects induced by irradiation to those generated by thermal quenching has been carried out. For that, the same glass has been prepared with various quench velocities (5*1012 and 1014 k.s-1) and the different structures obtained have been analyzed. It has been shown an increase of the BO3 units to the detriment of the BO4 units when the quench velocity increases, as well the non-bridging oxygen number. Thus qualitatively, the irradiation effects lead to structural consequences equivalent to those induced by thermal quenching effects. (O.M.)

  5. Impact of soda-lime borosilicate glass composition on water penetration and water structure at the first time of alteration

    International Nuclear Information System (INIS)

    In this study, the impact of soda-lime borosilicate glass composition and particularly the effect of charge compensators such Ca and Na and, of network formers such Si and Zr, on water penetration and water structure at the first time of alteration were investigated. Two non-destructive techniques were combined: the Fourier transform infrared spectroscopy in attenuated total reflection geometry to precise the predominant alteration mechanisms and assess the water structure in altered zone and the grazing incidence X-ray reflectometry to determine the thickness of the altered glass zone allowing to calculate the water diffusion coefficients through the glasses. The results of glass alteration at pH = 3 and 30 degrees C have shown that hydrolysis was the predominant mechanism after few seconds for glass having a high amount of non-binding oxygen. For the other glasses, which for the diffusion was the limiting reaction, the calculated water diffusion coefficients were comprised between 10-21 and 10-19 m2.s-1 and vary as a function of glass composition. An activation energy of 76.9 kJ.mol-1 was calculated and appears to be higher than inert gas diffusion through the glass highlighting that water molecules strongly interact with the glass matrix. (authors)

  6. A dynamic fatigue study of soda-lime silicate and borosilicate glasses using small scale indentation flaws

    International Nuclear Information System (INIS)

    The dynamic fatigue characteristics of two glasses, soda-lime silicate and borosilicate, in water have been studied using a controlled indentation flaw technique. It is argued that the indentation approach offers several advantages over more conventional fatigue testing procedures: (i) the reproducibility of data is relatively high, eliminating statistics as a basis of analysis: (ii) the flaw ultimately responsible for failure is well defined and may be conveniently characterised before and after (and during, if necessary) the strength test; (iii) via adjustment of the indentation load, the size of the flaw can be suitably predetermined. Particular attention is devoted to the third point because of the facility it provides for systematic investigation of the range of flaw sizes over which macroscopic crack behaviour remains applicable. The first part of the paper summarises the essential fracture mechanics theory of the extension of an indentation flaw to failure. In the next part of the paper the results of dynamic fatigue tests on glass rods in distilled water are described. Data are obtained for Vickers indentation loads in the range 0.05 to 100 N, corresponding to contact dimensions of 2 to 100 μm. Finally, the implications of the results in relation to the response of 'natural' flaws are discussed. (author)

  7. Analysis of barium borosilicate glass matrix for uranium determination by using ns-IR-LIBS in air and Ar atmosphere

    International Nuclear Information System (INIS)

    In this paper, an attempt to explore the use of laser induced breakdown spectroscopy (LIBS) technique for determination of uranium in the vitrified simulated high level barium borosilicate waste glass matrix was made with a commercial portable LIBS system. The emission spectrum of the waste glass being very complex, detailed study was done for proper choice of the emission lines. Investigations were carried out to optimize the experimental parameters like laser energy and acquisition delay time for the analysis. Calibration curves were obtained for two emission lines of U in these glasses. Effect of Ar atmosphere was also studied and the signal intensity was found to be ∝5 times higher than in air atmosphere. The emission lines used for normalization with vast difference in the upper energy level compared to the line of interest were found to give poor precision in air. In the Ar atmosphere, this effect was found to be much less significant and such emission lines can be used as an internal standard to achieve precise calibration curves. LIBS approach will be useful for real time determination of U in such samples, eliminating quantitative dissolution step required in many other analytical techniques like solution based ICP-MS/OES.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

  10. Investigation on radiation shielding parameters of bismuth borosilicate glass from 1 keV to 100 GeV

    International Nuclear Information System (INIS)

    Highlights: ► Radiation shielding parameters of bismuth borosilicate glasses have been investigated. ► The energy variation of effective atomic number was observed. ► Shielding properties of glasses are better than some standard shielding materials. - Abstract: The radiation shielding parameters of (50 − x)SiO2: 15B2O3: 2Al2O3: 10CaO: 23Na2O: xBi2O3 glass systems (where x = 0, 5, 10, 15 and 20 mol%) were theoretically calculated using WinXCom program. The characteristics of radiation shielding parameters for the glass systems of different bismuth compositions were found to be dependent on energy regions. At low-energy region, the radiation shielding parameters show several discontinuous jumps correspond to photoelectric absorption edges. At medium-energy region, the radiation shielding parameters are almost constant and the effective atomic number is close to the mean atomic number, dominated by Compton scattering process. In high-energy regions, pair production becomes the main interaction process and tends to be constant over energy. The mean free paths of the glasses were compared with several standard shielding concretes and it had been shown with lower values of MFP (from 10 MeV to 100 GeV) than serpentite, odinary, chromite, ferrite and barite except for the glass systems with 0 and 5 mol% of Bi2O3. The investigation was carried out to explore the advantages of the glass systems in radiation shielding applications

  11. Kinetics and mechanisms of the conversion of silicate (45S5), borate, and borosilicate glasses to hydroxyapatite in dilute phosphate solutions.

    Science.gov (United States)

    Huang, Wenhai; Day, Delbert E; Kittiratanapiboon, Kanisa; Rahaman, Mohamed N

    2006-07-01

    Bioactive glasses with controllable conversion rates to hydroxyapatite (HA) may provide a novel class of scaffold materials for bone tissue engineering. The objective of the present work was to comprehensively characterize the conversion of a silicate bioactive glass (45S5), a borate glass, and two intermediate borosilicate glass compositions to HA in a dilute phosphate solution at 37 degrees Celsius. The borate glass and the borosilicate glasses were derived from the 45S5 glass by fully or partially replacing the SiO(2) with B(2)O(3). Higher B(2)O(3) content produced a more rapid conversion of the glass to HA and a lower pH value of the phosphate solution. Whereas the borate glass was fully converted to HA in less than 4 days, the silicate (45S5) and borosilicate compositions were only partially converted even after 70 days, and contained residual SiO(2) in a Na-depleted core. The concentration of Na(+) in the phosphate solution increased with reaction time whereas the PO(4) (3-) concentration decreased, both reaching final limiting values at a rate that increased with the B(2)O(3) content of the glass. However, the Ca(2+) concentration in the solution remained low, below the detection limit of atomic absorption, throughout the reaction. Immersion of the glasses in a mixed solution of K(2)HPO(4) and K(2)CO(3) produced a carbonate-substituted HA but the presence of the K(2)CO(3) had little effect on the kinetics of conversion to HA. The kinetics and mechanisms of the conversion process of the four glasses to HA are compared and used to develop a model for the process. PMID:16770542

  12. Effect of Eu{sub 2}O{sub 3} concentration on luminescent properties of Ce/Tb/Eu co-doped calcium borosilicate glass for white LED

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Linjiao; Lei, Xiaohua, E-mail: xhlei@cqu.edu.cn; Du, Xiaoqing; Jin, Lei; Chen, Weimin; Feng, Yong’an

    2013-10-15

    Luminescent properties of Ce/Tb/Eu co-doped calcium borosilicate glass were investigated through excitation and emission spectra, fluorescence lifetimes and colorimetric analysis. The spectra results show that the concentration quenching of Eu{sup 3+} ions occurs when the concentration of Eu{sub 2}O{sub 3} ranges from 0.75 mol% to 1.00 mol% and Ce{sup 3+}, Tb{sup 3+} and Eu{sup 2+} ions are all the donors which can transfer energy to Eu{sup 3+}. It can be indicated from the analysis of lifetimes that through nonradiative transition, Tb{sup 3+} ions can accept energy from Eu{sup 2+} ions and also transfer energy to Eu{sup 3+} ions. Furthermore, the colorimetric analysis show that the correlated color temperatures (CCT) of Ce/Tb/Eu co-doped calcium borosilicate glass can be adjusted from cold white to warm white by controlling the concentration of Eu{sub 2}O{sub 3}. -- Highlights: • Effect of Eu{sub 2}O{sub 3} concentration was investigated from the excitation and emission spectra, the fluorescence lifetimes and the colorimetric analysis. • The energy transfers from Ce{sup 3+}, Tb{sup 3+} and Eu{sup 2+} ions to Eu{sup 3+} ions were discussed. • Tb{sup 3+} can accept energy from Eu{sup 2+} and transfer energy to Eu{sup 3+} with different Eu{sub 2}O{sub 3} concentrations. • The CCTs of Ce/Tb/Eu co-doped calcium borosilicate glass can be adjusted from cold white to warm white by controlling the concentration of Eu{sub 2}O{sub 3}.

  13. Effect of boron oxide addition on the Nd3+ environment in a Nd-rich soda-lime alumino-borosilicate glass

    International Nuclear Information System (INIS)

    The environment of Nd3+ ions has been studied using optical absorption spectroscopy and EXAFS at the Nd-L3-edge, in a series of soda lime alumino-borosilicate glasses with increasing B2O3 content. The proportion of BO4 units has been determined by 11B MAS NMR in an equivalent glass series with La3+ ions replacing the majority of Nd3+ ions, and complementary information has been obtained by measuring the Nd3+ decay fluorescence times in these latter glasses. In these glasses with low Al2O3 content, the R' ratio, with R' = [Na2O(exc)]/[B2O3] and [Na2O(exc)] = [Na2O] - [Al2O3] - [ZrO2], plays a key role in controlling the structural organization and crystallization resistance, in a similar way as the R ratio in the Dell and Bray model of sodium borosilicate glasses. At R'≥ 0.5, the Nd3+ ions are located in a mixed silicate-borate environment and, by slow cooling of the melt, they tend to crystallize within a silicate apatite phase close to the Ca2Nd8(SiO4)6O2 composition. At R' ≤ 0.5, the structural results are compatible with Nd3+ ions located in a borate-type environment (not excluding Si neighbors), and, by slow cooling of the melt, they segregate with Ca2+ ions within a Si-depleted separated borosilicate phase. (authors)

  14. 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.

  15. 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)

    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

  16. A container closure system that allows for greater recovery of radiolabeled peptide compared to the standard borosilicate glass system

    International Nuclear Information System (INIS)

    Objectives: Often peptides used in synthesis of radiopharmaceutical PET tracers are lipophilic and adhere to the walls of container closure systems (CCS) such that costly peptide and product are not fully recoverable after synthesis occurs. This investigation compares a standard United States Pharmacopeia (USP) Type I borosilicate glass CCS to a cyclic polyolefin copolymer Crystal Zenith® (CZ) CCS, for 68Ga-chloride and 68Ga-DOTATOC ([68Ga] Ga-DOTA-D-Phe1-Tyr3-octreotide) retention in the reaction vial after labeling. Methods: 68Gallium labeling of DOTATOC was conducted by adding 68Ga-chloride, 2 M HEPES (4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid) or 0.75 M sodium acetate, and 1–30 µg of DOTATOC into the CZ or glass CCS. The reaction mixture was heated for 15 min and cooled to room temperature. The crude reaction mixture was then withdrawn via syringe, for final processing. The CCS was then assayed using a dose calibrator to determine the amount of retained 68Ga-DOTATOC. Statistical significance was assessed using an unpaired Student's t-test. Results: In all experiments (n=72) with various amounts of peptide and different buffering systems, the CZ CCS retained less activity than the glass CCS. Using 2 M HEPES and 15 µg or 30 µg of DOTATOC, the CZ CCS retained approximately 10% less of the labeled DOTATOC compared to the glass CCS (p68Ga-chloride. Conclusion: For applications involving the labeling of peptides such as 68Ga-DOTATOC, the CZ CCS compared to the glass CCS, results in an improved recovery of product. - Highlights: • We examined the adhesion of 68Ga-DOTATOC to glass and CZ CCS. • The adhesion of the 68Ga-DOTATOC was 10% less in CZ CCS compared to glass CCS. • Overall recovery of 68Ga-DOTATOC reaction solution is higher in CZ CCS than glass CCS. • Adhesion to the CCS is due to 68Ga-DOTATOC, not 68Ga-chloride

  17. Deep wet etching of borosilicate glass and fused silica with dehydrated AZ4330 and a Cr/Au mask

    International Nuclear Information System (INIS)

    This research highlights a superior glass-wet-etch technique which enables a glass wafer to be etched for more than 20 h in 49 wt% hydrofluoric acid (HF) only with Cr/Au film and a common positive photoresist, AZ4330. We demonstrated that pits on the wet-etched glass wafer were generated not only due to HF diffusion through the Cr/Au film but also due to pinholes on the Cr/Au films created by the diffusion of the Cr/Au etchant through a photoresist etching-mask during the Cr/Au wet etching process. These two types of diffusion, HF diffusion and Cr/Au etchant diffusion, were eliminated by the thermal curing of a photoresist (PR), AZ4330, before the Cr/Au wet etching process. The curing process allowed the PR to dehydrate, increased the hydrophobicity, and prevented the diffusion of the hydrophilic HF and Cr/Au etchant. Optimization of the curing process was performed, showing that curing at 130 °C for 20 min was the proper condition. With the optimized process, a 525 µm thick borosilicate glass wafer was penetrated with 49%wt HF. A fused silica wafer 525 µm thick was also wet-etched and penetrated with 49 wt% HF at 10 h. Moreover, no pits were found in wet etching of the fused silica for 20 h in 49 wt% HF. These findings demonstrate that the proposed technique allows the wet etching of a glass wafer for more than 20 h in 49%wt HF, the best result thus far. We fabricated a glass substrate with a 217.0 µm deep cavity and a penetrating through-via using the proposed technique, proving the feasibility of the product as an optical component with a surface roughness of 45.5 Å in the cavity. (paper)

  18. Study of phase separation and crystallization phenomena in soda-lime borosilicate glass enriched in MoO3

    International Nuclear Information System (INIS)

    Molybdenum oxide immobilization (MoO3, as fission product) is one of the major challenges in the nuclear glass formulation issues for high level waste solutions conditioning since many years, these solutions arising from spent nuclear fuel reprocessing. Phase separation and crystallisation processes may arise in molten glass when the MoO3 content is higher than its solubility limit that may depend on glass composition. Molybdenum combined with other elements such as alkali and alkaline-earth may form crystalline molybdates, known as 'yellow phases' in nuclear glasses which may decrease the glass durability. In order to confine high level wastes (HLW) such as the fission product solutions arising from the reprocessing of high burn-up UOX-type nuclear spent fuels, a new glass composition (HLW glass) is being optimized. This work is devoted to the study of the origin and the mechanism of phase separation and crystallization phenomena induced by molybdenum oxide incorporation in the HLW glass. From microstructural and structural point of view, the molybdenum oxide behavior was studied in glass compositions belonging to the SiO2-B2O3- Na2O-CaO simplified system which constituted basis for the HLW glass formulation. The structural role of molybdenum oxide in borosilicate network explaining the phase separation and crystallization tendency was studied through the coupling of structural (95Mo, 29Si, 11B, 23Na MAS NMR, XRD) and microstructural (SEM, HRTEM) analysis techniques. The determination of phase separation (critical temperature) and crystallization (liquidus temperature) appearance temperatures by in situ viscosimetry and Raman spectroscopy experiments allowed us to propose a transformation scenario during melt cooling. These processes and the nature of the crystalline phases formed (CaMoO4, Na2MoO4) that depend on the evolution of MoO3, CaO and B2O3 contents were correlated with changes of sodium and calcium cations proportions in the environment of molybdate

  19. Studies of local structure of Cm3+ in borosilicate glass using laser and x-ray spectroscopic methods and computational modeling

    International Nuclear Information System (INIS)

    The local environment of Cm3+ in a borosilicate glass has been probed by a combination of laser spectroscopy, structural modeling, and extended x-ray absorption fine structure (EXAFS) spectroscopy. The Stark splitting for the Cm f-f state transitions is significantly larger than the inhomogeneous line broadening that results from the disordered environment. As a result, the Cm optical spectrum can be fit using an effective operator Hamiltonian to obtain a set of crystal-field parameters. The fitting procedure, which requires the use of a descent-in-symmetry approach, provides a set of parameters for a best fit within tetragonal symmetry. These parameters are then linked to the local environment of Cm through exchange-charge modeling (ECM) of crystal field interactions. Cm in our borosilicate glass is best modeled with six oxygen ions with approximately tetragonal symmetry, and at an average distance of 2.31 (3) Aa. The results of crystal-field modeling are supported by EXAFS results. (c) 2000 American Institute of Physics

  20. 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)

    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 27Al and 31P 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 11B MAS, 29Si MAS and in situ 29Si{11B} REAPDOR NMR spectroscopy. (authors)

  1. USACE FUSRAP Maywood Team Identifies Challenges and Initiates Alternate Solutions Relating to the Radiochemical Analysis of Borosilicate Fiber Filters for Isotopes of Uranium and Thorium

    International Nuclear Information System (INIS)

    This presentation discusses the primary purposes of particulate radionuclide air monitoring at the US Army Corps of Engineers (USACE) Formerly Utilized Sites Remediation Program (FUSRAP) Maywood Superfund Site (FMSS), the challenges encountered by the team when standard radiochemistry analytical methods are attempted on borosilicate fiber filter samples, the surrogate evaluations used when sample specific isotopic analysis is unsuccessful, and current strategies for overcoming radiochemistry method deficiencies. Typical borosilicate fiber filter sample preparation procedures including tracer spike and digestion methods and their impact on uranium and thorium data quality are of particular interest. Analytes discussed include isotopic uranium (U-234, U-235, and U-238) and isotopic thorium (Th-228, Th-230, and Th-232). Efforts to obtain reproducible and defensible results also included discussions with commercial laboratory radiochemistry managers as well as industry experts. This presentation may benefit sites that use similar sample collection and analysis techniques, utilize data that may have unidentified method-related issues with diminished data quality, or have a similar isotopic signature. (authors)

  2. Sol–gel synthesis of silver nanocrystals embedded in sodium borosilicate monolithic transparent glass with giant third-order optical nonlinearities

    International Nuclear Information System (INIS)

    Highlights: • We prepared Ag-doped sodium borosilicate monolithic glass. • The influence of temperature on the SPR absorption peak intensity was studied. • Nonlinear optical properties of the glass were investigated. • A mechanism for the formation of Ag quantum dots glass was proposed. - Abstract: We report the preparation of uniform spherical shape silver nanocrystals doped sodium borosilicate monolithic transparent glass by sol–gel method. The characterization of the resulting Ag nanocrystals was accomplished by using X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectrum. Surface plasma resonance absorption peaks of the silver nanocrystals glass at about 406 nm have been obtained from ultraviolet–visible absorption spectrometer and their intensity is changed with different heat treatment temperatures. We have investigated the nonlinear optical properties of silver quantum dots doped glass using Z-scan technique. Third-order nonlinear optical susceptibility χ(3) of the glass was estimated to be 1.01 × 10−11 esu. In particular, a mechanism for the formation of Ag quantum dots glass is proposed. This work will significantly promote the obtained material applications in optical devices

  3. First investigations of the influence of IVB elements (Ti, Zr, and Hf) on the chemical durability of soda-lime borosilicate glasses

    International Nuclear Information System (INIS)

    The influence of IVB elements (Zr, Ti, and Hf) on the glass structure and on the alteration kinetics of soda-lime borosilicate glasses has been studied at various stages of glass leaching corresponding to the initial dissolution rate, rate drop, and residual rate regimes. The effect of these elements on the limiting mechanisms of the glass durability as well as the chemistry of both solution and alteration layer are inter-related, depending on the reaction progress. The effect of IVB elements on the glass structure was investigated using 11B MAS NMR. The IVB elements are compensated primarily by Na rather than Ca, at the expense of tetra-coordinated boron. The addition of HfO2 or ZrO2 decreases the initial dissolution rate in a similar way. Moreover, adding ZrO2 limits the rate drop in saturated media. The initial dissolution rate decrease is less significant when Ti is added, and a quick drop of the dissolution rate is observed up to 4 mol% TiO2. At low IVB element concentration, glasses containing Ti and Zr show different residual rates arising from the precipitation of magadiite (Na2Si14O29 center dot 11H2O), at the surface of Ti-bearing glasses. The influence of IVB elements on glass alteration indicates that, unlike Ti, Zr and Hf plays a similar role in the structure of borosilicate glasses. (authors)

  4. A novel interferometric dilatometer in the 4–300 K temperature range: thermal expansion coefficient of SRM-731 borosilicate glass and stainless steel-304

    International Nuclear Information System (INIS)

    We present a newly designed heterodyne interferometric dilatometer for the measurement of the coefficient of thermal expansion of solids in the 4–300 K temperature range. The instrument can measure non-monotonic thermal expansion curves and has an accuracy better than 200 nm across the whole 4–300 K measurement range. The compensation for the misalignment of the interferometer design and the configuration of the sample holder make the instrument suitable to carry out measurements on any kind of sample that can be produced in a bar or rod shape. The measurement of a standard SRM-731 borosilicate glass and an SS-304 sample are presented and compared with literature data. (paper)

  5. Preparation, characterization and standard molar enthalpy of formation of BaO containing sodium borosilicate glasses and its comparison with international standard glass

    International Nuclear Information System (INIS)

    High level radioactive liquid waste (HLW) generated during reprocessing of spent nuclear fuel is immobilized in sodium borosilicate (NBS) glasses. Addition of BaO in NBS glass helps to improve the solubility of ThO2 in glass matrix. The knowledge of thermodynamic stability of glasses used for immobilization of HLW is important in predicting their long term stability. Several BaO substituted NBS glass samples were prepared by melt-quench technique and characterized by XRD, DTA, MAS-NMR. The standard molar enthalpy of formation of BaO substituted NBS glasses and the International Standard Glass (ISG) were determined. This work is done with an understanding that even though the above glass matrices are metastable in nature and meaningful measurement of equilibrium thermodynamic data is difficult; the information on relative thermodynamic stability data of NBS glasses with varying compositions prepared exactly in similar fashion will be helpful in deciding the most stable matrix for nuclear waste disposal

  6. Intense upconversion luminescence of Er3+/Yb3+ codoped oxyfluoride borosilicate glass ceramics containing Ba2GdF7 nanocrystals

    Institute of Scientific and Technical Information of China (English)

    ZHAO

    2010-01-01

    Er3+/Yb3+-codoped transparent oxyfluoride borosilicate glass ceramics containing Ba2GdF7 nanocrystals were prepared and spectroscopic properties of rare earth ions were investigated.Fluoride nanocrystals Ba2GdF7 were successfully precipitated in glass matrix,which was confirmed by X-ray diffraction(XRD)and transmission electron microscopy(TEM)results.In comparison with the as-made precursor,significant enhancement ofupconversion luminescence was observed in the Er3+/Yb3+codoped oxyfluoride glass ceramics,which may be due to the variation of coordination environment around Er3+and Yb3+ions after crystallization.The transition mechanisms of the green and red upconversion luminescence were ascribed to a two-photon process,and that of the blue upconversion luminescence was a three-photon process.

  7. Fractionnement chimique au sein d'une vitrocéramique borosilicate enrichie en molybdène et comportement sous irradiation de powellite monocristalline

    OpenAIRE

    Wang, Xiaochun

    2013-01-01

    Ce travail porte sur le fractionnement des produits de fission et les actinides mineurs (simulées par des terres rares) dans une vitrocéramique borosilicate riche en molybdène contenant des cristallites de powellite (CaMoO4) étudié par techniques d'analyse élémentaire (LIBS, LA-ICP-MS, et l'EMPA). Il a été montré que des terres rares et Sr (émetteur bêta) sont incorporés préférentiellement dans la phase powellite, tandis que Al, Fe, Zr, Zn et Cs (sources bêta-decay) restent dans le verre. Le ...

  8. Elaboration and experimental study of the Borosilicate glass GP 98/12 for the vitrification of the radioactive wastes of KfKarlsruhe Centre (R.F.A.)

    International Nuclear Information System (INIS)

    The transformation into a vitrified block of highly radioactive liquid wastes is actually the best solution for the storage in long run. In West Germany, the research institute in the field of nuclear energy (KfK) has been oriented in this way by developing industrial processes of vitrification and by following studies on the behaviour of the final products. For the fission products, the chosen glasses present good stability characteristics and are used as a first barrier during confinement. Our work, which is part of the research program on radioactive waste vitrification, consists of preparing borosilicate glass GP 98/12 and studying physical and chemical characteristics. We have also contributed to the development and the realization of glass blocks sampling system prepared at pilot scale

  9. In-situ characterization of femtosecond laser-induced crystallization in borosilicate glass using time-resolved surface third-harmonic generation

    International Nuclear Information System (INIS)

    Coherent phonon dynamics in condensed-phase medium are responsible for important material properties including thermal and electrical conductivities. We report a structural dynamics technique, time-resolved surface third-harmonic generation (TRSTHG) spectroscopy, to capture transient phonon propagation near the surface of polycrystalline CaF2 and amorphous borosilicate (BK7) glass. Our approach time-resolves the background-free, high-sensitivity third harmonic generation (THG) signal in between the two crossing near-IR pulses. Pronounced intensity quantum beats reveal the impulsively excited low-frequency Raman mode evolution on the femtosecond to picosecond timescale. After amplified laser irradiation, danburite-crystal-like structure units form at the glass surface. This versatile TRSTHG setup paves the way to mechanistically study and design advanced thermoelectrics and photovoltaics

  10. Effect of X-ray irradiation on the optical absorption of SdSe1−xTex nanocrystals embedded in borosilicate glass

    International Nuclear Information System (INIS)

    The effect of X-ray irradiation on the optical absorption spectra of CdSe1−xTex nanocrystals embedded in a borosilicate matrix is studied. The observed blue shift of the absorption edge and bleaching of the confinement-related features in the spectra are related to X-ray induced negative ionization of the nanocrystals with charge transfer across the nanocrystal/matrix interface. The radiation-induced changes are observed to recover after longer post-irradiation storage at room temperature. - Highlights: ► Absorption edge of glass-embedded CdSe1−x Tex nanocrystals is blue shifted under X-ray irradiation. ► Radiation-induced bleaching bands appear at the position of HOMO-LUMO transitions. ► The reason is charge transfer between the nanocrystals and radiation-induced centres in the glass. ► Contrary to photoionization, this is a long-lived process (over 2000 h).

  11. Modification of molybdenum structural environment in borosilicate glasses with increasing content of boron and calcium oxide by 95Mo MAS NMR

    International Nuclear Information System (INIS)

    In nuclear borosilicate glasses, when molybdenum is in too high concentration and when it combines with other elements such as alkali and alkaline-earth elements it may form crystalline molybdates, including sodium molybdate, Na2MoO4, during melt cooling. In a nuclear vitrification context, the origin of this phenomenon must be understood to control and to avoid the appearance of this water-soluble crystalline phase. The solubility limit of MoO3 was found to be 2.5 mol% in a simplified SiO2-B2O3-Na2O-CaO nuclear glass at about 1300 degrees C. Higher MoO3 concentrations induced liquid phase separation followed by crystallization of Na2MoO4 and CaMoO4. This study assessed the impact of increasing the CaO and B2O3 content on the tendency of the melts to crystallize and the impact on the glass network structure. Structural analysis (Mo-95 MAS NMR and B-11 MAS NMR) of several glass series and standard SiO2-Na2O-MoO3 or SiO2-CaO-MoO3 glass showed that the nature of the crystallized phases that may appear during cooling of the melt can be controlled by correlation of the proportion of Na+ cations remaining free in the glass network with the soda/lime environment of tetrahedral MoO42- entities. (authors)

  12. Modification of Molybdenum Structural Environment in Borosilicate Glasses with Increasing Content of Boron and Calcium Oxide by 95Mo MAS NMR

    International Nuclear Information System (INIS)

    In nuclear borosilicate glasses, when molybdenum is in too high concentration and when it combines with other elements such as alkali and alkaline-earth elements it may form crystalline molybdates, including sodium molybdate, Na2MoO4, during melt cooling. In a nuclear vitrification context, the origin of this phenomenon must be understood to control and to avoid the appearance of this water-soluble crystalline phase. The solubility limit of MoO3 was found to be 2.5 mol% in a simplified SiO2-B2O3-Na2O-CaO nuclear glass at about 1300 degrees C. Higher MoO3 concentrations induced liquid phase separation followed by crystallization of Na2MoO4 and CaMoO4. This study assessed the impact of increasing the CaO and B2O3 content on the tendency of the melts to crystallize and the impact on the glass network structure. Structural analysis (95Mo MAS NMR and 11B MAS NMR) of several glass series and standard SiO2-Na2O-MoO3 or SiO2-CaO-MoO3 glass showed that the nature of the crystallized phases that may appear during cooling of the melt can be controlled by correlation of the proportion of Na+ cations remaining free in the glass network with the soda/lime environment of tetrahedral MoO42- entities. (authors)

  13. Optical parameters of Nd3+:Er3+:Yb3+co-doped borosilicate glasses and their energy transfers at high temperature

    Institute of Scientific and Technical Information of China (English)

    Li Cheng-Ben; Li Shu-Feng; Dong Bin; Cheng Yu-Qi; Yin Hai-Tao; Yang Jing; Chen Yu

    2011-01-01

    This paper reports that a series of Nd3+:Er3+:yb3+ co-doped borosilicate glasses have been prepared and their absorption spectra measured. The J-O intensity parameters Ωk (k = 2, 4, 6), spontaneous radiative lifetime Τrad,spontaneous transition probability A, fluorescence branching ratio β and oscillator strength fed of the Nd3+ ions at room temperature are calculated based on Judd-Ofelt (J-O) theory. The temperature dependence of the up-conversion photoluminescence characteristics in a Nd3+:Er3+:yb3+ co-doped sample is studied under a 978 nm semiconductor laser excitation, and the energy transfer mechanisms among Yb3+, Er3+ and Nd3+ ions are analysed. The results show that the J-O intensity parameters Ω2 increase when the Nd3+ concentration of the Nd3+:Er3+:yb3+ co-doped boresilicate glasses increases. The possibility of spontaneous transition is small and lifetimes are long at levels of 4F5/2and 4F3/2. The intensity of Nd3+ emissions at 595, 691, 753, 813 and 887 nm are markedly enhanced when the sample temperature exceeds 400 K. The reasons being the cooperation of the secondary sensitization from Er3+ to Nd3+ and the contribution of a multi-phonon.

  14. Effects of the iron content and redox state on the structure of sodium borosilicate glasses: A Raman, Moessbauer and boron K-edge XANES spectroscopy study

    International Nuclear Information System (INIS)

    The structure of iron-bearing sodium borosilicate glasses with up to 10 mol% FeO has been investigated in the range 0.15 ≤ Fe3+/SFe ≤ 0.95. According to Moessbauer spectroscopy, Fe3+ and Fe2+ are mainly in tetrahedral and octahedral coordination, respectively, although other coordination states exist for both cations. From XANES experiments, we conclude that increasing Fe content and varying redox states have only a minor effect on the relative proportions of BO3 and BO4 units. In Raman spectra, a decrease of the proportion of BO4 species present in danburite-like units (Na2O.B2O3.2SiO2) is found upon increasing iron content and oxidizing state. Whereas the insensitivity of the overall boron speciation to iron content and redox state points to weak interactions between boron and iron, the changes affecting BO4 species do indicate a more subtle interplay between Fe3+ and the other tetrahedrally coordinated cations (Si,B) because of the competition between tetrahedral Fe3+ and B3+ for charge compensation by Na+. (authors)

  15. Dynamics of iron-bearing borosilicate melts: Effects of melt structure and composition on viscosity, electrical conductivity and kinetics of redox reactions

    International Nuclear Information System (INIS)

    The dynamic properties of a series of iron-bearing sodium borosilicate melts have been investigated to determine how structure and composition control viscosity, electrical conductivity and the kinetics of iron redox reactions and, thus, atomic mobility as involved in these different processes. For this purpose, four compositions with 67 mol% SiO2 and B2O3 contents ranging from 0 to 22 mol% have been studied. In addition to viscosity and electrical conductivity, we have determined the kinetics of the iron redox reaction by isothermal iron K-edge XANES and Raman spectroscopy experiments performed as a function of time from 710 to 1570 K. Substitution of sodium for boron at constant SiO2 content first causes transformation of BO3 triangles into BO4 tetrahedra until an excess of sodium induces instead melt depolymerization. These changes in the degree of polymerization and boron coordination lead to a maximum in oxygen diffusivity at around 18 mol% B2O3, and correlatively, to a viscosity minimum. Because this change of trigonal into tetrahedral boron requires charge compensation of B3+ by cations such as Na+ ions, the mobility of Na+ decreases and reduces the rate of oxidation. In addition, the decreasing fraction of Na+ ions and their change from a free to a charge compensating role explain the decreasing redox diffusivities and electrical conductivities of the samples. (authors)

  16. Mechanism for formation of NaBH4 proposed as low-pressure process for storing hydrogen in borosilicate glass–sodium solid system: a hydrogen storage material

    Indian Academy of Sciences (India)

    Aysel Kantürk Figen; Sabriye Pişkin

    2012-04-01

    The mechanism for the formation of sodium borohydride (NaBH4) was investigated for its ability to store hydrogen in the borosilicate glass–sodium (BSG–Na) solid system under low hydrogen pressure. BSG, which was prepared by melting borax with silica, was used as the starting material in the BSG–Na system that would be prepared to store hydrogen. It was observed that the mechanism for storing hydrogen in the BSG–Na solid system consisted of six steps and when the BSG–Na system was heated under a pressure of 4 atm, which was created through the use of hydrogen atmosphere, the storage of hydrogen occurred at nearly 480°C for approximate duration of 200 min, with the excellent yield (97%). In addition, the hydrogen storage capacity of the NaBH4 sample was measured using the Au–PS structure, which was designed as a mini-hydrogen cell. It was determined that the minimum amount of NaBH4 to generate the maximum volume of hydrogen gas was 12 mg/ml at 270 mV.

  17. 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.

  18. Performance evaluation of vitrified waste product based on barium-borosilicate matrix deployed for vitrification of sulphate bearing high level radioactive liquid waste

    International Nuclear Information System (INIS)

    Aqueous waste of various categories (viz., low, intermediate and high level depending on the concentration of radionuclides) is generated at different stages of the nuclear fuel cycle. Most of the radioactivity generated in entire nuclear fuel cycle is concentrated in high level radioactive liquid waste (HLW). Since the radioactivity of the waste is to be isolated from the human-environment for extended period of time, a three stage approach has been adopted for management of HLW. This involves (i) immobilization of waste oxides in stable and inert solid matrices, (ii) interim retrievable storage of conditioned waste packages under cooling and surveillance and (iii) deep underground disposal in suitable geological formulations. Composition of HLW depends on various factors like type of fuel and its cladding, off reactor cooling, reprocessing flow sheet etc. Compositional changes in HLW necessitate modification in glass formulations, so as to get the conditioned product of desired characteristics. This report describes the experimental studies and results obtained for performance evaluation of the vitrified waste product made from barium borosilicate glass matrix accommodating sulphate bearing chemically simulated HLW. Product characteristics like chemical durability, homogeneity, phase separation, thermal conductivity, impact strength etc have been evaluated and discussed in the report. (author)

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

    International Nuclear Information System (INIS)

    Highlights: • Na5Gd9F32 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 Na5Gd9F32 lattice. • Luminescent color could be tuned by controlling glass crystallization temperature. - Abstract: Lanthanide-activated cubic Na5Gd9F32 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 Na5Gd9F32 lattice was in situ formed without the requirement of long-range ionic diffusion. Impressively, such fabricated glass ceramic co-doped with Yb3+/Er3+ 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

  20. 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.

  1. Influence of zirconium on the structure of pristine and leached soda-lime borosilicate glasses: towards a quantitative approach by 17O MQMAS NMR

    International Nuclear Information System (INIS)

    17O MQMAS NMR was used to characterize the influence of zirconium on the structural organization of soda-lime borosilicate glasses. A new method of quantitative analysis of the 17O MQMAS spectra is presented, by a direct fit of the two-dimensional MQMAS spectrum which provides the resolution of all the structural groups in glasses containing up to five oxides. Additional data were also obtained from the quantitative deconvolution of the 11B MAS NMR spectra, with the help of the direct fit of MQMAS data as well. Excess of non-bridging oxygen is clearly identified in these glasses. Six-folded zirconium is preferentially compensated rather than the tetrahedral boron and calcium only partially compensate the tetrahedral boron. Alteration gels arising from glass leaching were probed by oxygen-17 supplied by the alteration solution. Most of the zirconium is inserted in the silicate network forming Si-O-Zr bonds with the same configuration in the glass and in the gel. During leaching, calcium clearly remains in the alteration gel, either near non-bridging oxygen or as a zirconium charge compensator. This quantitative approach applied to 17O MQMAS spectra demonstrates its potential for investigating the structure of increasingly complex glass and gel compositions. (authors)

  2. Luminescence Properties of Eu/Tm/Tb-doped Borosilicate Glass%Eu/Tm/Tb掺杂硼硅酸盐玻璃的发光性能

    Institute of Scientific and Technical Information of China (English)

    石冬梅; 赵营刚

    2016-01-01

    Eu/Tm/Tb-doped singly, doubly and triply borosilicate glasses were prepared using a conventional melting-quenching method. The luminescent properties of Eu/Tm/Tb-doped samples under the UV excitation were investigated in detail by measuring the excitation and emission spectra and calculating CIE chromaticity coordinates. The results show that the sharp emission peak centered at 459 nm originating from 1 D2→3 F4 of Tm3+ is observed, and the characteristic emission intensity centered at 437 nm ascribing to the broad peak of Eu2+, 589 nm( 5 D0→7 F1 ) and 612 nm( 5 D0→7 F2 ) of Eu3+ is reduced due to the energy transfer from Eu3+,Eu2+ to Tm3+ ion. Red, green and blue light can be observed in Eu/Tm/Tb-doped triply samples simultaneously under the excitation of 377 nm. The luminescent intensity and color of borosilicate glasses might be changed by adjusting Eu2 O3 content, and the sample with CIE chromaticity coordinates(0. 33, 0. 386 7)are obtained.%采用熔融淬冷法制备了性能优越的Eu/Tm/Tb单掺、双掺和三掺的硼硅酸盐玻璃。测试了样品的激发和发射光谱,计算了CIE色坐标,研究了紫外激发下Eu/Tm/Tb掺杂的硼硅酸盐玻璃的发光性能。结果表明:在361 nm激发下,随着Tm3+加入到Eu2O3掺杂的硼硅酸盐样品中,观察到Tm3+的459 nm(1D2→3F4)锐线特征发射峰,同时由于Eu3+,Eu2+→Tm3+的能量传递的存在降低了Eu2+的437 nm宽带峰及Eu3+的589 nm(5 D0→7 F1)和612 nm(5 D0→7 F2)的特征发射峰强度。在377 nm激发下,Eu/Tm/Tb三掺样品能够同时出现红、绿和蓝光。调节 Eu2O3的含量能有效改变发光玻璃的发光强度和颜色,最终得到色坐标为(0.33,0.3867)的发光玻璃。

  3. Effects of alpha, gamma, and alpha-recoil radiation on borosilicate glass containing Savannah River Plant defense high-level nuclear waste

    International Nuclear Information System (INIS)

    At the Savannah River Plant, the reference process for the immobilization of defense high-level waste (DHLW) for geologic storage is vitrification into borosilicate glass. During geologic storage for 106 y, the glass would be exposed to approx. 3 x 1010 rad of β radiation, approx. 1010 rad of γ radiation, and 1018 particles/g glass for both α and α-recoil radiation. This paper discusses tests of the effect of these radiations on the leachability and density of the glass. Even though the doses were large, no effect of the radiations was detected that reduced the effectiveness of the glass for long-term storage of DHLW even at doses corresponding to 106 years storage for the actual glass. For the tests, glass containing simulated DHLW was prepared from frit of the reference composition. Three methods were used to irradiate the glass: external irradiations with beams of approx. 200 keV Xe or Pb ions, internal irradiations with Cm-244 doped glass, and external irradiations with Co-60 γ rays. Results with both Xe and Pb ions indicate that a dose of 3 x 1013 ions/cm2 (simulating > 106 years storage) does not significantly increase the leachability of the glass in deionized water. Tests with Cm-244 doped glass show no increase in leach rate in water or brine up to a dose of 1018 α and α-recoils/g glass. Results of larger doses are being examined. The density of the Cm-244 doped glass has decreased by 1% at a dose of 1018 particles/g glass. With γ-radiation, the density has changed by 10 rad. Results of leach tests in deionized water and brine indicated that this very large dose of γ-radiation increased the leach rate by only 20%. Also, the leach rates are lower in brine

  4. 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. PMID:20544804

  5. 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)

  6. Liquid phase sintering of 20Bi(Zn0.5Ti0.5)O 3-80BaTiO3 dielectrics with bismuth-zinc-borate and bismuth borosilicate glasses

    Science.gov (United States)

    Shahin, David I.

    Dielectrics in the Bi(Zn0.5Ti0.5)O3-BaTiO 3 system (specifically 20BZT-80BT, in mol%) are promising candidates for high energy density capacitor applications due to broad temperature-dependent dielectric constant maxima and a relatively field-independent permittivity. Bulk samples require sintering temperatures of greater than 1180°C to reach useful densities. Due to incompatibility of Bi with low-pO2 processing, BZT-BT-based multilayer capacitors must utilize noble metal electrodes that resist oxidation during sintering. Sintering temperatures must be reduced to allow use of less expensive electrode materials (Cu, etc.). This work studies the reduced temperature sintering behavior and dielectric properties of BZT-BT sintered with 30Bi2O3-30ZnO-40B 2O3 and 50Bi2O3-25B2O 3-25SiO2 (mol%) liquid phase formers. Dielectrics sintered with 1v% borate additions and 5v% additions of either the borate or borosilicate achieved relative densities greater than 95% after sintering at 1000°C for four hours. All compositions retained the relaxor behavior exhibited by pure 20BZT-80BT. Increased borate additions led to greater dielectric constant reductions, while increased borosilicate additions yielded no clear trend in the dielectric constant reduction. Energy densities were estimated between 0.3-0.5 J/cm3; smaller glass additions typically led to larger energy densities. Dielectrics sintered with 1v% borate additions are of interest due to their high relative densities (approx. 96%) and energy densities of approximately 0.5 J/cm3 under 100kV/cm electric fields. Studies of BZT-BT/glass interfaces revealed the formation of crystalline interfacial layers less than 10 microns thick. The borate formed a bismuth titanate phase (likely Bi4Ti3O12) during heating to 700°C, whereas the borosilicate formed a barium silicate phase (likely BaSiO3) during processing to 800°C. Similar phases are expected to be present in the liquid phase sintered dielectrics and likely affect the BZT

  7. Synthesis and structural characterization of the new rare-earth borosilicates Pr{sub 3}BSi{sub 2}O{sub 10} and Tb{sub 3}BSi{sub 2}O{sub 10}

    Energy Technology Data Exchange (ETDEWEB)

    Braeuchle, Sebastian; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2015-07-01

    The rare-earth borosilicates RE{sub 3}BSi{sub 2}O{sub 10} (RE = Pr, Tb) were synthesized under high-temperature conditions of 1600 C in a radio frequency furnace from praseodymium oxide, terbium oxide, silicon dioxide, silicon nitride, boron trioxide, and boric acid. The structure determinations based on powder diffraction data revealed that both phases RE{sub 3}BSi{sub 2}O{sub 10} (RE = Pr, Tb) are isotypic to Gd{sub 3}BSi{sub 2}O{sub 10} [L. Chi, H. Chen, X. Lin, H. Zhuang, J. Huang, Jiegou Huaxue 1998, 17, 297]. The compounds crystallize in the orthorhombic space group Pbca (no. 61) with eight formula units and the lattice parameters a = 982.9(2), b = 714.2(2), c = 2314.4(4) pm, V = 1.6247(4) nm{sup 3}, R{sub p} = 0.0231, and R{sub wp} = 0.0354 (all data) for Pr{sub 3}BSi{sub 2}O{sub 10} and a = 960.5(5), b = 692.1(3), c = 2272.4(1) pm, V = 1.5106(2) nm{sup 3} for Tb{sub 3}BSi{sub 2}O{sub 10}. The lattice parameters of Tb{sub 3}BSi{sub 2}O{sub 10} could be determined, but a final refinement of the powder data has not proved satisfactory. The structure of Pr{sub 3}BSi{sub 2}O{sub 10} exhibits eight- (Pr1) and ninefold coordinated rare-earth cations (Pr2 and 3). Layers of ortho-silicate anions [SiO{sub 4}]{sup 4-} and borosilicate anions [BSiO{sub 6}]{sup 5-} are arranged alternatingly along the c axis and the RE cations are located in between.

  8. Erbium-doped borosilicate glasses containing various amounts of P2O5 and Al2O3: Influence of the silica content on the structure and thermal, physical, optical and luminescence properties

    International Nuclear Information System (INIS)

    Highlights: • Er3+ doped borosilicate glasses were processed with different compositions and characterizations. • An increase in the SiO2 content leads to a silicate-rich environment around the Er3+ site. • An increase in the SiO2 content decreases the Er3+ absorption cross-section at 980 nm. • Glasses with 60 mol% of SiO2 exhibit a stronger emission intensity at 1530 nm than glasses with x = 50. • Highest 1.5 μm emission intensity was achieved for the Al and P containing glass with 60 mol% of SiO2. - Abstract: The influence of the silica content on several properties of Er-doped borosilicate glasses in the presence of various amounts of P2O5 and Al2O3 has been investigated. The introduction of P2O5 and/or Al2O3 are responsible for structural modifications in the glass network through a charge-compensation mechanism related to the formation of negatively-charged PO4 and AlO4 groups or through the formation of AlPO4-like structural units. In this paper, we show that an increase in the SiO2 content leads to a silicate-rich environment around the Er3+ site, resulting in an increased dependence of the Er3+ ions optical and luminescence properties on the P2O5 and/or Al2O3 concentration. The highest emission intensity at 1.5 μm was achieved for the glass with an equal proportion of P and Al in the glass system with 60 mol% of SiO2

  9. 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)

    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 (R2+ = Sr2+, Ba2+) 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 R2+ cations on both glass structure and melt crystallization tendency during cooling, two glass series were prepared by replacing either Na+ or Ca2+ cations in the simplified glass by respectively (Li+, K+, Rb+, Cs+) or (Mg2+, Sr2+, Ba2+) cations. From these substitutions, it was established that alkali ions are preferentially involved in the charge compensation of (AlO4)- 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)

  10. Single-pulse laser ablation threshold of borosilicate, fused silica, sapphire, and soda-lime glass for pulse widths of 500  fs, 10  ps, 20  ns.

    Science.gov (United States)

    Nieto, Daniel; Arines, Justo; O'Connor, Gerard M; Flores-Arias, María Teresa

    2015-10-10

    In this work, we report a comparative study of the laser ablation threshold of borosilicate, fused silica, sapphire, and soda-lime glass as a function of the pulse width and for IR laser wavelengths. We determine the ablation threshold for three different pulse durations: τ=500  fs, 10 ps, and 20 ns. Experiments have been performed using a single laser pulse per shot in an ambient (air) environment. The results show a significant difference, of two orders of magnitude, between the group of ablation thresholds obtained for femtosecond, picosecond, and nanosecond pulses. This difference is reduced to 1 order of magnitude in the soda-lime substrate with tin impurities, pointing out the importance of the incubation effect. The morphology of the marks generated over the different glass materials by one single pulse of different pulse durations has been analyzed using a scanning electron microscope (FESEM ULTRA Plus). Our results are important for practical purposes, providing the ablation threshold data of four commonly used substrates at three different pulse durations in the infrared regime (1030-1064 nm) and complete data for increasing the understanding of the differences in the mechanism's leading ablation in the nanosecond, picosecond, and femtosecond regimes. PMID:26479792

  11. 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)

  12. Effects of alpha, gamma, and alpha-recoil radiation on borosilicate glass containing Savannah River Plant defense high-level nuclear waste. [Lead ions-250 keV; xenon ions-160 keV

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, N.E.

    1981-01-01

    At the Savannah River Plant, the reference process for the immobilization of defense high-level waste (DHLW) for geologic storage is vitrification into borosilicate glass. During geologic storage for 10/sup 6/ y, the glass would be exposed to approx. 3 x 10/sup 10/ rad of ..beta.. radiation, approx. 10/sup 10/ rad of ..gamma.. radiation, and 10/sup 18/ particles/g glass for both ..cap alpha.. and ..cap alpha..-recoil radiation. This paper discusses tests of the effect of these radiations on the leachability and density of the glass. Even though the doses were large, no effect of the radiations was detected that reduced the effectiveness of the glass for long-term storage of DHLW even at doses corresponding to 10/sup 6/ years storage for the actual glass. For the tests, glass containing simulated DHLW was prepared from frit of the reference composition. Three methods were used to irradiate the glass: external irradiations with beams of approx. 200 keV Xe or Pb ions, internal irradiations with Cm-244 doped glass, and external irradiations with Co-60 ..gamma.. rays. Results with both Xe and Pb ions indicate that a dose of 3 x 10/sup 13/ ions/cm/sup 2/ (simulating > 10/sup 6/ years storage) does not significantly increase the leachability of the glass in deionized water. Tests with Cm-244 doped glass show no increase in leach rate in water or brine up to a dose of 10/sup 18/ ..cap alpha.. and ..cap alpha..-recoils/g glass. Results of larger doses are being examined. The density of the Cm-244 doped glass has decreased by 1% at a dose of 10/sup 18/ particles/g glass. With ..gamma..-radiation, the density has changed by < 0.05% at a dose of 8.5 x 10/sup 10/ rad. Results of leach tests in deionized water and brine indicated that this very large dose of ..gamma..-radiation increased the leach rate by only 20%. Also, the leach rates are lower in brine.

  13. Erbium-doped borosilicate glasses containing various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3}: Influence of the silica content on the structure and thermal, physical, optical and luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Bourhis, Kevin [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy); Massera, Jonathan [Department of Electronics and Communications Engineering, Tampere University of Technology, Korkeakoulunkatu 3, FI-33720 Tampere (Finland); BioMediTech, Tampere (Finland); Petit, Laeticia, E-mail: laeticia.petit@nlight.net [Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku (Finland); nLIGHT Corporation, Sorronrinne 9, FI-08500 Lohja (Finland); Koponen, Joona [nLIGHT Corporation, Sorronrinne 9, FI-08500 Lohja (Finland); Fargues, Alexandre; Cardinal, Thierry [CNRS, Université de Bordeaux, ISM, 351 Cours 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); Ferraris, Monica [Politecnico di Torino, DISAT, Istituto di Ingegneria e Fisica dei Materiali, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)

    2015-10-15

    Highlights: • Er{sup 3+} doped borosilicate glasses were processed with different compositions and characterizations. • An increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site. • An increase in the SiO{sub 2} content decreases the Er{sup 3+} absorption cross-section at 980 nm. • Glasses with 60 mol% of SiO{sub 2} exhibit a stronger emission intensity at 1530 nm than glasses with x = 50. • Highest 1.5 μm emission intensity was achieved for the Al and P containing glass with 60 mol% of SiO{sub 2}. - Abstract: The influence of the silica content on several properties of Er-doped borosilicate glasses in the presence of various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} has been investigated. The introduction of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} are responsible for structural modifications in the glass network through a charge-compensation mechanism related to the formation of negatively-charged PO{sub 4} and AlO{sub 4} groups or through the formation of AlPO{sub 4}-like structural units. In this paper, we show that an increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site, resulting in an increased dependence of the Er{sup 3+} ions optical and luminescence properties on the P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} concentration. The highest emission intensity at 1.5 μm was achieved for the glass with an equal proportion of P and Al in the glass system with 60 mol% of SiO{sub 2}.

  14. Effect of ZnO and CaO on Alkali Borosilicate Glass Waste-form Immobilizing Simulated Mixed HLW%ZnO 和 CaO对模拟高放废液硅酸盐玻璃固化体性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    张华; N.C.Hyatt; J.R.Stevens; R.Hand

    2015-01-01

    针对有些高放废液含有较多Fe、Cr、Ni过渡金属元素,在玻璃固化工艺过程中易于形成晶体,导致熔融玻璃体的黏度增加、化学稳定性变差以及工艺过程中易出现出料口堵塞等问题,研究了废物包容量为15%和20%、添加ZnO (5.6%)和CaO (1.75%)的配方对形成的4种玻璃固化体的物理性能(密度、硬度、断裂韧性)、化学性能(产品一致性测试和蒸汽腐蚀测试)和结构(X射线衍射析晶分析、拉曼光谱分析)的影响。研究分析显示,提高废物包容量至20%以及添加ZnO和CaO均可促进硼硅酸盐玻璃固化体网络结构的稳定性和化学稳定性,并增强玻璃体的密度,提高硬度;但玻璃固化体的高温黏度升高,断裂韧性下降。%Since the transit metals ,such as Fe ,Cr and Ni ,contained in some kinds of mixed HLW ,can likely to form crystal ,increase the melt viscosity ,destroy the chemi‐cal durability and block the discharge port .T he results obtained from investigating four glass waste‐forms ,including the alkali borosilicate glass matrix and alkali borosilicate glass matrix doped with 5.6% ZnO and 1.75% CaO in base matrixes ,immobilizing the simulated mixed HLW with 15% and 20% waste loadings aiming to determinate the effect of ZnO on the alkali borosilicate glass chemical durability with waste loading increasing ,were presented in this paper .Glass samples were characterized with XRD and Raman spectroscopy .The chemical durability was investigated using the standard protocols PCT and VHT .The XRD analysis results show that spinel crystal appears and grows in glass samples at the waste loading in 20% without ZnO addition and waste loading in 15% and 20% added ZnO .T he Raman spectroscopy analysis results indicate that ZnO and CaO can enhance the glass network connective ,and the chemical durability test results display that the addition of ZnO and CaO can improve the short term

  15. Influence of (Na2O-Al2O3)/B2O3 on Viscosity and Thermal Properties of Silica-rich Borosilicate Glasses%(Na2O-Al2O3)/B2O3对高硼硅酸盐玻璃粘度和热学性能的影响

    Institute of Scientific and Technical Information of China (English)

    何峰; 平财明; 郑媛媛; 乔勇

    2013-01-01

    采用熔融冷却法制备了不同R’系数的高硼硅酸盐玻璃,其中R’=(Na2O-Al2O3)/B2O3.利用红外光谱、高温旋转粘度计和热膨胀仪等对玻璃的结构和性能进行表征.结果表明:高温段粘度-温度关系符合阿伦尼乌斯定律;R’值的增大导致非桥氧的增加,高温粘度和熔制温度呈显著降低.当R’>0.5时,热膨胀系数近似线性增大,玻璃化转变温度增大至590℃基本维持不变.R’值影响结构中的[BO3]与[BO4]的比例及硅氧网络的完整程度,从而决定高硼硅酸盐玻璃的性能.%Silica-rich sodium borosilicate glasses with varying R' values have been prepared using conventional melt quenching method,where R' represents the ratio of (Na2O-Al2O3) and B2O3.The structure and properties have been investigated by the FTIR spectra,rotating crucible viscometer and thermal expanse dilatometer.The results show that the viscosity dependence of temperature is accord with Arrhenius law in the high temperature range.The non-bridging oxygen increases due to the increase of R',which leads to obvious decease of high temperature viscosity and melting temperature.Thermal expanse coefficient increases linearly with R' when R' exceeds 0.5,and the glass transformation temperature increases to 590 ℃.The fraction of [BO3] and [BO4] and the integrity of Si-O network are controlled mainly by R',then decide properties of borosilicate glasses.

  16. Electrical conductivity and viscosity of borosilicate glasses and melts

    DEFF Research Database (Denmark)

    Ehrt, Doris; Keding, Ralf

    2009-01-01

    by impedance measurements in a wide temperature range (250 to 1450°C). The activation energies were calculated by Arrhenius plots in various temperature regions: below the glass transition temperature, Tg, above the melting point, Tl, and between Tg and Tl. Viscosity measurements were carried out...

  17. In-vitro bioactivity of zirconia doped borosilicate glasses

    International Nuclear Information System (INIS)

    Glass composition 31B2O3-20SiO2-24.5Na2O-(24.5-x) CaO-xZrO2 x=1,2,3,4,5 were prepared by melt-quenching Technique. The formation of hydroxyapatite layer on the surface of glasses after immersion in simulated body fluid (SBF) was explored through XRD, Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM-EDX) analyses. In this report, we observed that hydroxyapatite formation for 5days of immersion time. Also observed that with increasing the immersion time up to 15days, higher amount of hydroxyapatite layer formation on the surface of glasses. The varying composition of zirconia in glass samples influences shown by XRD, FTIR studies. The present results indicate that, in-vitro bioactivity of glasses decreased with increasing zirconia incorporation

  18. Chemical compatibility of HLW borosilicate glasses with actinides

    International Nuclear Information System (INIS)

    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 230C and 1150C. (orig.)

  19. Fracture during cooling of cast borosilicate glass containing nuclear wastes

    International Nuclear Information System (INIS)

    Procedures and techniques were evaluated to mitigate thermal stress fracture in waste glass as the glass cools after casting. The two principal causes of fracture identified in small-scale testing are internal thermal stresses arising from excessive thermal gradients when cooled too fast, and shear fracturing in the surface of the glass because the stainless steel canister shrinks faster than the glass on cooling. Acoustic emission and ceramographic techniques were used to outline an annealing schedule that requires at least three weeks of controlled cooling below 5500C to avoid excessive thermal gradients and corresponding stresses. Fracture arising from canister interactions cannot be relieved by slow cooling, but can be eliminated for stainless steel canisters by using ceramic paper, ceramic or graphite paste linings, or by choosing a canister material with a thermal expansion coefficient comparable to, or less than, that of the glass

  20. Modeling surface area to volume effects on borosilicate glass dissolution

    International Nuclear Information System (INIS)

    We simulated the reaction of SRL-131 glass with equilibrated J-13 water in order to investigate the effects of surface area to volume ratio (SA/V) on glass dissolution. We show that glass-fluid ion exchange causes solution pH to rise to progressively higher values as SA/V increases. Because the ion exchange is rapid relative to the duration of the glass dissolution experiment, the pH effect does not scale with (SA/V)*time. Experiments compared at the same (SA/V)*time value therefore have different pHs, with higher pHs at higher SA/V ratios. Both experimental data and our simulation results show similar trends of increasing reaction rate as a function of SA/V ratio when scaled to (SA/V)*time. Glasses which react in systems of differing SA/V ratio therefore follow different reaction paths and high SA/V ratios cannot be used to generate data which accurately scales to long time periods unless the ion exchange effect is taken into account. We suggest some simple test designs which enable more reliable high. SA/V accelerated tests

  1. Structural and optical properties of barium borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vishal; Pandey, O.P. [School of Physics and Materials and Science, Thapar University, Patiala 147004 (India); Singh, K., E-mail: kusingh@thapar.ed [School of Physics and Materials and Science, Thapar University, Patiala 147004 (India)

    2010-01-01

    The 40SiO{sub 2}-30BaO-20B{sub 2}O{sub 3}-10A{sub 2}O{sub 3} (A=Y, La, Al, Cr) glasses were synthesized by melt quenching at 1550 deg. C. Controlled crystallization was carried out to convert these glasses to corresponding glass ceramics. The amorphous nature of as prepared glasses was ascertained from XRD diffraction pattern. Fourier-transform infrared spectroscopy was done to find out the basic structural units in these glasses. The effect of intermediate oxides on optical properties was investigated using UV-Visible spectra.

  2. Structural and optical properties of barium borosilicate glasses

    International Nuclear Information System (INIS)

    The 40SiO2-30BaO-20B2O3-10A2O3 (A=Y, La, Al, Cr) glasses were synthesized by melt quenching at 1550 deg. C. Controlled crystallization was carried out to convert these glasses to corresponding glass ceramics. The amorphous nature of as prepared glasses was ascertained from XRD diffraction pattern. Fourier-transform infrared spectroscopy was done to find out the basic structural units in these glasses. The effect of intermediate oxides on optical properties was investigated using UV-Visible spectra.

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

    International Nuclear Information System (INIS)

    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. V2O5 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-CO2 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: V4+/Vtotal ranges from 8 to 35%, while Cr3+/Crtotal can range from 15 to 100% and even to population distributions including Cr2+. 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 V4+ populations increase after initial bubbling, but as bubbling time increases, V4+ populations drop to near the level of the parent glass, while Cr becomes more reduced to the point of having increasing Cr2+ populations.

  4. Ion Current Rectification Behavior at Novel Borosilicate Glass Capillaries

    Czech Academy of Sciences Publication Activity Database

    Silver, Barry Richard; Holub, Karel; Mareček, Vladimír

    Ústí nad Labem: BEST servis, 2012 - (Navrátil, T.; Fojta, M.), s. 120-124 ISBN 978-80-905221-0-7. [Moderní elektrochemické metody /32./. Jetřichovice (CZ), 21.05.2012-25.05.2012] Institutional support: RVO:61388955 Keywords : ion * rectification * impedance Subject RIV: CG - Electrochemistry

  5. IR study of Pb–Sr titanate borosilicate glasses

    Indian Academy of Sciences (India)

    C R Gautam; Devendra Kumar; Om Parkash

    2010-04-01

    The infrared spectra (IR) of various glass compositions in the glass system, [(PbSr1–)O.TiO2]– [2SiO2.B2O3]–[BaO.K2O]–[La2O3], were recorded over a continuous spectral range (400–4000 cm-1) 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 glasses. The vibrational modes of the borate network are seen to be mainly due to the asymmetric stretching relaxation of the B–O bond of trigonal BO3 units. More splitting is observed in strontium-rich composition.

  6. Separation of Th and U using borosilicate glasses

    International Nuclear Information System (INIS)

    Boroaluminosilicate glasses having B2O3 to Na2O ratio 0.23 and 9.8 were prepared by conventional melt-quench method and used as room temperature ion exchanger for the sorption of thorium from aqueous solutions. Various experimental conditions were optimized to achieve selective and maximum uptake of thorium. The studies were extended to synthetic mixtures of thorium and uranium, wherein thorium could be selectively removed in presence of 10 fold excess of uranium. Structural elucidation studies were carried out to understand the ion exchange property of glasses. It is seen that presence of linkages like Si-O- and B-O- in the glasses was responsible for the uptake of metal ions. It is seen that the uptake depends on pH of the solution, composition of glass and the initial concentration of thorium ion in solution. (author)

  7. Borosilicate glasses for the high activity waste vetrification

    International Nuclear Information System (INIS)

    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

  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. The incorporation of 1 wt % Pu in the glass did not adversely impact glass viscosity (as assessed using Hf surrogate) or glass durability. Finally, evaluation of DWPF glass pour samples that had Pu concentrations below the 897 g/m{sup 3} limit showed that Pu concentrations in the glass pour stream were close to targeted compositions in the melter feed indicating that Pu neither volatilized from the melt nor stratified in the melter when processed in the DWPF melter.

  9. A critical review of radiation effects on borosilicate glasses

    International Nuclear Information System (INIS)

    Most of the experimental values have been obtained by loading the glass with alpha emitters like Cm 244 and Pu 238. The data existing in literature on stored energy, and density variation are presented and discussed. Attention is given to the variation of the leaching rate due to the radiation effect. Samples loaded with alpha emitters have given data up to 0.17 dpa and such bombarded with heavy ions show large effects due to dose rate effects. A study on defect formation has shown that under electrons irradiation, formation of bubbles is possible. (DG)

  10. In-vitro bioactivity of zirconia doped borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Samudrala, Rajkumar; Azeem, P. Abdul, E-mail: rk.satyaswaroop@gmail.com, E-mail: drazeem2002@yahoo.com [Department of Physics, National Institute of Technology, Warangal-506004 (India)

    2015-06-24

    Glass composition 31B{sub 2}O{sub 3}-20SiO{sub 2}-24.5Na{sub 2}O-(24.5-x) CaO-xZrO{sub 2} x=1,2,3,4,5 were prepared by melt-quenching Technique. The formation of hydroxyapatite layer on the surface of glasses after immersion in simulated body fluid (SBF) was explored through XRD, Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM-EDX) analyses. In this report, we observed that hydroxyapatite formation for 5days of immersion time. Also observed that with increasing the immersion time up to 15days, higher amount of hydroxyapatite layer formation on the surface of glasses. The varying composition of zirconia in glass samples influences shown by XRD, FTIR studies. The present results indicate that, in-vitro bioactivity of glasses decreased with increasing zirconia incorporation.

  11. Volatility mechanisms of borosilicate glasses and molten glasses of nuclear interest structural effects

    International Nuclear Information System (INIS)

    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 SiO2-B2O3-Al2O3-αNa2O-(1-alpha)Li2O-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 BIII and BIV sites near 700 deg.C, and the change of coordination number BIV- BIII 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 NaBO2(g), LiBO2(g) and Na2(BO2)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 α=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 Na2O and Li2O, which maintains the total vapor pressure on a quasi-constant lever up to α=0.27. (author)

  12. Crack bridging and trapping in borosilicate matrix composites with distributed metal particles

    Czech Academy of Sciences Publication Activity Database

    Kotoul, M.; Dlouhý, Ivo; Vysloužil, T.

    Stockholm : Royal Institute of Technology (KTH), 2004, s. 1-5. [European Conference of Fracture. Advanced Fracture Mechanics for Life and Safety Asessments /15./. Stockholm (SE), 11.08.2004-13.08.2004] R&D Projects: GA ČR GA101/02/0683 Institutional research plan: CEZ:AV0Z2041904 Keywords : ceramic composites * toughening effect * modelling Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass

  13. Leach mechanisms of borosilicate glass Defense Waste Forms - effects of composition

    International Nuclear Information System (INIS)

    The study described below concerns the mechanisms which control the leaching of two Defense Wasteforms, viz. SRL TDS-131 glass and MCC Defense Waste Reference Glass. It is shown that both the leach mechanisms and the structure of the leached surface are strongly dependent not only on the composition of the leachant and the contact time between the leachant and the glass but also on the exact composition of the glass. The relatively minor differences in composition between the two glasses investigated here were observed to give rise to large differences in leach behavior, in particular upon prolonged contact with water, rather than to limited changes in leach rate alone

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Andreia A. S.; Soares, Roque S.; Lima, Maria M. A.; Monteiro, Regina C. C., E-mail: rcm@fct.unl.pt [Department of Materials Science, CENIMAT/I3N, Faculty of Sciences and Technology, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2014-01-28

    The glass transition and crystallization kinetics of a glass with a molar composition 60BaO-30B{sub 2}O{sub 3}-10SiO{sub 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{sub g}) and of the maximum crystallization temperature (T{sub p}) on the heating rate was used to determine the activation energy associated with the glass transition (E{sub g}), the activation energy for crystallization (E{sub c}), and the Avrami exponent (n). X-ray diffraction (XRD) revealed that barium borate (β-BaB{sub 2}O{sub 4}) was the first crystalline phase to be formed followed by the formation of barium silicate (Ba{sub 5}Si{sub 8}O{sub 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{sub 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.

  16. Molecular dynamics study of structural changes versus deposited energy dose in a sodium borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Bureau, G.; Delaye, J.M.; Peuget, S. [DEN/DTCD/SECM, CEA Marcoule, BP 17171, Bagnols-sur-Ceze cedex, 30207 (France); Calas, G. [IMPMC, 140 rue de Lourmel, Paris, 75015 (France)

    2008-07-01

    Assessing the long-term behavior of nuclear glass implies evaluating the impact of cumulative alpha decay induced by the minor actinides it contains. When subjected to alpha decay ({sup 244}Cm-doped glass specimens) or to external ion irradiation, some macroscopic properties vary appreciably with the dose. Above a given dose level, the properties do not evolve any more. To improve our understanding of these modifications, studies are carried out on simplified glass compositions (three oxides SiO{sub 2}, B{sub 2}O{sub 3}, Na{sub 2}O), modeled by molecular dynamics in which irradiation effects are simulated by accelerating uranium projectiles. Accumulation of displacements cascades have been performed up to 4.5*10{sup 20} keV/cm{sup 3} nuclear energy deposited in the glass. The density variations observed in actinide-doped materials is qualitatively reproduced. At high doses, the swelling tends to stabilize. Marples model is used to fit the glass swelling versus the deposited energy dose, giving the volume damaged per projectile. This volume approximates the cascade core volume, suggesting that the underlying mechanisms of volume expansion are contained in the cascade core and are thus related to the highest energy events: atom ejection and thermal quenching. On the contrary, the volumetric parameter of the Marples model applied to the other structural properties is related to a volume corresponding to the core + periphery of the cascades. (authors)

  17. Corrosion behaviour of the high level waste forms borosilicate glass and spent fuel in salt brines

    International Nuclear Information System (INIS)

    The objective of the first part of this work is to describe the extent to which Np, Pu, Am and Tc are mobilized from vitrified high-level radioactive waste into the near field of an HLW repository in a salt formation, when a hot and concentrated salt solution comes into contact with the glass. Waste form corrosion studies are conducted with a salt solution representing the composition of a fluid phase encountered in drill holes in the Gorleben salt dome. Test temperatures are determined by the designed maximum surface temperature of 200 deg. C for the vitrified waste in the Gorleben salt. The following results were obtained: 1. pH changes of the radioactive leachate are the same as in inactive leachates. 2. The time and temperature dependence of the reaction for the radioactive glass are in excellent agreement with that of the inactive glass. 3. Np, Pu, Am, and Tc have not been reimmobilized in secondary minerals. Hence, mobilization of these radionuclides is governed by the kinetics of glass dissolution. Pu oxidation states were analyzed and related to Pu concentrations. The second part is focused on the corrosion behaviour of spent fuel in contact with salt solution. For characterizing the potential chemical reactions of spent UO2 fuel during direct disposal in salt formations, corrosion tests were performed at various particle sizes with both high burnup spent fuel and unirradiated UO2. Studied effects include temperature, pH, radiolysis, oxidant concentration, surface to volume ratio (S/V) and the presence of container material. Results are applicable not only to salt media but also to others: (1) 90Sr data are indicative of matrix dissolution. (2) Except at high S/V ratios, spent fuel dissolution rates are proportional to surface area and are similar in both saline media and deionized water. (3) Dissolution rates of unirradiated UO2 are much lower and are proportional to oxidant concentration but almost independent of the nature of the oxidant. (4) It is likely that spent fuel alteration rates are controlled by oxidants produced by a-radiolysis. At high S/V ratios, alteration rates are lower, probably resulting from limitation of radiolytic oxidant generation. (5) In the presence of iron, reaction rates decrease by a factor of 3-4 and actinide concentrations by many orders of magnitude. (6) Pu and Am concentrations are controlled by (co-)precipitation phenomena. (author)

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

    International Nuclear Information System (INIS)

    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 SiO2-B2O3-Na2O-CaO-ZrO2. Two series of glasses were synthesized by substituting CaO for Na2O and ZrO2 for SiO2. 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)

  19. Methodology of leach testing of boro-silicate glasses in water

    International Nuclear Information System (INIS)

    The leaching rate is the principal parameter to be taken into account in the optimization of the conditioning glasses. It is also important for the analysis of the possible release rate of radioactive elements. In this context leaching tests must provide an answer to the release rate of radioactive nuclides under three different conditions: radioactive leaks in cooling pools (when asked by the management scheme) during engineering storage; release of radioactive elements when, due to a possible (even if highly improbable) accident, a large amount of water leaches the glass up to its complete dissolution; long term degradation of the conditioning barrier in the repository. To find a single test which complies to these different requirements does not seem probable. The task is aggravated by the complexity of the leaching mechanism

  20. Electrical conductivity and 11B NMR studies of sodium borosilicate glasses

    International Nuclear Information System (INIS)

    A large number of compositions within the SiO2-NaO2-B2O3 (SNB) ternary glass system were investigated by various complementary techniques. Impedance spectroscopy was used to determine the parameters related to sodium ion diffusion in the glass structure; high-field boron NMR measurements on a series of samples identified and quantified the boron coordination as a function of the composition; exhaustive DTA measurements gave the glass transition temperature for all the compositions studied. Based on these results we demonstrate that the activation energy of sodium ion diffusion is closely related to the boron coordination number and involves two types of structural motifs: one corresponding to the sodium associated to non-bridging oxygen atoms, and the other to sodium compensating B(IV) motif. We also show that simple DTA measurements of the glass transition temperature can be used to define structural domains within this ternary composition range. (authors)

  1. Use of borosilicate system for solidification of nuclear power plant wastes

    International Nuclear Information System (INIS)

    The system Na2O-B2O3-Al2O3-SiO2 was studied in detail with regard to its use for the solidification of medium-level radioactive wastes. By experiment, in a four-dimensional space the regions of composition were determined where hydrolytic resistance makes the system suitable for solidification. Three samples, corresponding to three experimental points in the four-dimensional space with different ratios of basic components Na2O-B2O3 were chosen in order to test other properties important for the technological processing of wastes. It was found that suitable fixation products may be prepared with a high waste content exceeding 40% w.w. related to Na2O and B2O3. It is moreover possible to replace Al2O3 in the given system with oxides of corrosion products and MnO2. Hydrolytic resistance of the studied products reaches the quality level of fixation products of high-level radioactive wastes. The values of viscosity of these vitrified products are suitable for heat processing and at a temperature of 1050 degC the low corrosion activity of the respective melts may be reckoned with. The crystallization ability was found to be negligible which guarantees stability of properties over a long storage period. The possibility of metastable segregation is also low. (B.S.)

  2. Borosilicate nuclear waste glass alteration kinetics theoretical basis for the kinetic law of nuclear glass alteration

    International Nuclear Information System (INIS)

    Work carried out since the early 1980's to predict the long-term behavior of nuclear containment glasses has revealed the inadequacy of existing models, notably in accounting for the fundamental mechanisms involved in some complex systems (e.g. glass-water-clay), inciting us to examine and discuss the theoretical basis for the hypotheses generally assumed in our models. This paper discusses the theoretical basis for the Aagaard-Helgeson law and its application to nuclear glasses. The contribution of other types of kinetic laws is also considered to describe the alteration kinetics of nuclear glasses. (authors)

  3. Chapter 1. Complex processing of borosilicate ores. 1.1. Properties of borate ores

    International Nuclear Information System (INIS)

    This article is devoted to properties of borate ores, including borax (mineral), boric acid (H3BO3), ulexite (mineral), kernite (mineral), hydrocarbocyte (mineral) Ca Mg(B3O4(OH)3)2·3H2O, datolite (mineral) Ca[B OH(Si-4)], and danburite.

  4. Effect of cerium oxide addition on electrical and physical properties of alkali borosilicate glasses

    International Nuclear Information System (INIS)

    The study of electrical conductivity, density and coefficient of thermal expansion (CTE) of Na2O:K2O:B2O3:SiO2:BaO glass samples with addition of cerium oxide has been carried out. It has been observed that the addition of cerium oxide affects the electrical conductivity, density and CTE. The results have been explained on the basis of the variation in number of bridging oxygens (BOs) and non-bridging oxygens (NBOs) present in the glass. In general, the glass with more NBOs has a weak network which exhibits higher electrical conductivity. The weakening of the network has been supported by the observed decrease in density and increase in CTE for the glasses.

  5. Experimental Study and Monte Carlo Modeling of Calcium Borosilicate Glasses Leaching

    International Nuclear Information System (INIS)

    During aqueous alteration of glass an alteration layer appears on the glass surface. The properties of this alteration layer are of great importance for understanding and predicting the long-term behavior of high-level radioactive waste glasses. Numerical modeling can be very useful for understanding the impact of the glass composition on its aqueous reactivity and long-term properties but it is quite difficult to model these complex glasses. In order to identify the effect of the calcium content on glass alteration, seven oxide glass compositions (57SiO2 17B2O3 (22-x)Na2OxCaO 4ZrO2; 0 < x < 11) were investigated and a Monte Carlo model was developed to describe their leaching behavior. The specimens were altered at constant temperature (T = 90 deg. C) at a glass-surface-area-to-solution-volume (SA/V) ratio of 15 cm-1 in a buffered solution (pH 9.2). Under these conditions all the variations observed in the leaching behavior are attributable to composition effects. Increasing the calcium content in the glass appears to be responsible for a sharp drop in the final leached boron fraction. In parallel with this experimental work, a Monte Carlo model was developed to investigate the effect of calcium content on the leaching behavior especially on the initial stage of alteration. Monte Carlo simulations performed with this model are in good agreement with the experimental results. The dependence of the alteration rate on the calcium content can be described by a quadratic function: fitting the simulated points gives a minimum alteration rate at about 7.7 mol% calcium. This value is consistent with the figure of 8.2 mol% obtained from the experimental work. The model was also used to investigate the role of calcium in the glass structure and it pointed out that calcium act preferentially as a network modifier rather than a charge compensator in this kind of glasses. (authors)

  6. A Microstructured Fiber with Defined Borosilicate Regions to Produce a Radial Micronozzle Array for Nanoelectrospray Ionization

    Science.gov (United States)

    Fu, Y.; Morency, S.; Bachus, K.; Simon, D.; Hutama, T.; Gibson, G. T. T.; Messaddeq, Y.; Oleschuk, R. D.

    2016-02-01

    This work highlights the possibility of using microstructured fibres with predefined doped regions to produce functional microstructures at a fibre facet with differential chemical etching. A specially designed silica microstructured fibre (MSF) that possesses specific boron-doped silica regions was fabricated for the purpose of generating a radial micronozzle array. The MSF was drawn from a preform comprising pure silica capillaries surrounded by boron-doped silica rods. Different etching rates of the boron-doped and silica regions at the fiber facet produces raised nozzles where the silica capillaries were placed. Fabrication parameters were explored in relation to the fidelity and protrusion length of the nozzle. Using etching alone, the nozzle protrusion length was limited, and the inner diameter of the channels in the array is expanded. However with the addition of a protective water counter flow, nozzle protrusion is increased to 60 μm with a limited increase in hole diameter. The radial micronozzle array generated nine individual electrosprays which were characterized using spray current measurements and related to theoretical prediction. Signal enhancement for the higher charge state ions for two peptides showed a substantial signal enhancement compared to conventional emitter technology.

  7. Long-term aqueous alteration kinetics of an alpha-doped SON68 borosilicate glass

    OpenAIRE

    TRIBET M.; ROLLAND Séverine; S. Peuget; Magnin, Magali; BROUDIC Véronique; JANSSEN ARNE; Wiss, Thierry; JEGOU C.; Toulhoat, Pierre

    2013-01-01

    The long-term behavior of nuclear glass subjected to alpha radiation by minor actinides must be investigated with a view to geological disposal. This study focuses on the effect of alpha radiation on the chemical reactivity of R7T7 glass with pure water, mainly on the residual alteration rate regime. A glass specimen doped with 0.85 wt% 239PuO2 (α emitter) is leached under static conditions in argon atmosphere at 90°C and at a high surface-area-to-volume ratio (S/V = 20 cm-1). The alteration ...

  8. Synthesis, IR, crystallization and dielectric study of (Pb, Sr)TiO3 borosilicate glass–ceramics

    Indian Academy of Sciences (India)

    C R Gautam; D Kumar; O Parkash; Prabhakar Singh

    2013-06-01

    Eleven glass compositions were prepared by melt and quench method with progressive substitution of SrO for PbO (0 ≤ ≤ 1.0) with a step-wise increment of 0.10 in the glass [(PbSr1−)OTiO2]–[(2SiO2B2O3)]–[BaO.K2O].Nb2O5 (mol percentage) system. The infrared spectra (IR) of various glass compositions in the above mentioned glass system was recorded over a continuous spectral range 400–4000 cm-1 to study their different oxides structure systematically. Differential thermal analysis (DTA) was recorded from room temperature (∼27 °C) to 1400 °C employing a heating rate of 10 °C/min to determine glass transition temperature, g and crystallization temperature, c. The melting temperature, m, of these glass compositions was found to be in the range 597–1060 °C depending on the composition under normal atmospheric conditions. g and m of glasses were found to increase with increasing SrO content. X-ray diffraction analysis of these glass–ceramic samples shows that major crystalline phase of the glass–ceramic sample with ≤ 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.

  9. Synthesis, IR, crystallization and dielectric study of (Pb, Sr)TiO3 borosilicate glass-ceramics

    International Nuclear Information System (INIS)

    Eleven glass compositions were prepared by melt and quench method with progressive substitution of SrO for PbO (0 ≤ x ≤ 1.0) with a step-wise increment of 0.10 in the glass ((PbxSr1-x)OTiO2)-((2SiO2B2O3))-(BaO.K2O).Nb2O5 (mol percentage) system. The infrared spectra (IR) of various glass compositions in the above mentioned glass system was recorded over a continuous spectral range 400-4000 cm-1 to study their different oxides structure systematically. Differential thermal analysis (DTA) was recorded from room temperature (∼27°C) to 1400°C employing a heating rate of 10°C/min to determine glass transition temperature, Tg and crystallization temperature, Tc. The melting temperature, Tm, of these glass compositions was found to be in the range 597-1060°C depending on the composition under normal atmospheric conditions. Tg and Tm of glasses were found to increase with increasing SrO content. X-ray diffraction analysis of these glass-ceramic samples shows that major crystalline 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. (author)

  10. Effect of focusing condition on molten area characteristics in micro-welding of borosilicate glass by picosecond pulsed laser

    Science.gov (United States)

    Nordin, I. H. W.; Okamoto, Y.; Okada, A.; Takekuni, T.; Sakagawa, T.

    2016-05-01

    The characteristics of the molten area are attributed not only by laser energy condition but also the focusing condition. In this study, a picosecond pulsed laser of 1064 nm in wavelength and 12.5 ps in pulse duration was used as a laser source for joining glass material. Influence of focusing condition on micro-welding of glasses was experimentally investigated by using an objective lens with and without spherical aberration correction, and its molten area was characterized. The usage of objective lens with spherical aberration correction led to a larger molten area inside the bulk material of glass even under the same pulse energy, which related to the efficient micro-welding of glass materials. In addition, an optical system with the spherical aberration correction led to a stable absorption of laser energy inside the bulk glass material, stabilizing the shape of molten area, which resulted in the reliable weld joint. On the other hand, breaking strength of the specimens with spherical aberration correction was higher than that without spherical aberration correction. Therefore, it is concluded that the focusing condition with spherical aberration correction led to the larger and stable molten area, which resulted in higher joining strength in micro-welding of glass materials.

  11. Coupling of microanalytical techniques to study the relationships between chemical durability and irradiation resistance of alumino-borosilicate glasses

    International Nuclear Information System (INIS)

    Safety assessment of a nuclear waste deposit is based on the chemical durability and irradiation resistance of the nuclear waste forms. It is well-known that the consequences of the impact of α, β and γ irradiation on glass integrity essentially affect the level of its recrystallized fraction and its initial dissolution rate. Complex alkali-borosilico-aluminate glasses were submitted to aqueous leaching tests at temperature ranging from 25 to 100 deg. C, from pH = 0 to pH = 12. Simple glasses containing one or two transition metal oxides have been synthesized. Some of them have been irradiated before being leached at 90 deg. C. Irradiation experiments have been performed with 150 keV Xe+ions mainly producing displacement cascades in the first hundreds of nanometers beneath the sample surfaces. The leached samples were then characterized by coupling performance techniques such as scanning electron microscopy (SEM), electron microprobe analysis (EMA), secondary ion mass spectrometry (SIMS) and ion beam analytical (IBA) methods: Rutherford backscattering and elastic recoil spectrometries (RBS and ERDA)

  12. Oxygen bubble development on a platinum electrode in borosilicate glass melt by the effect of alternating current

    Czech Academy of Sciences Publication Activity Database

    Matěj, J.; Jebavá, Marcela

    2014-01-01

    Roč. 58, č. 4 (2014), s. 249-259. ISSN 0862-5468 R&D Projects: GA TA ČR TA01010844 Institutional support: RVO:67985891 Keywords : glass melt * platinum electrode * alternating current * oxygen bubble Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.435, year: 2014 http://www.ceramics-silikaty.cz/2014/pdf/2014_04_249.pdf

  13. OXYGEN BUBBLE DEVELOPMENT ON A PLATINUM ELECTRODE IN BOROSILICATE GLASS MELT BY THE EFFECT OF ALTERNATING CURRENT

    Directory of Open Access Journals (Sweden)

    Jiri Matej

    2014-10-01

    or on alternating reduction and re-forming of oxidic layer on the electrode in the transition range, has been suggested. Start of bubble evolution at low alternating current density has also been observed in simple sodium-calcium-silicate glass melt. A relation between bubble release and platinum corrosion caused by reduced silicon has been suggested

  14. In-can hot pressing of borosilicate glass for the immobilization of high- and medium-level wastes

    International Nuclear Information System (INIS)

    The paper presents a method for the immobilization of different waste streams based in the uniaxial in-can hot pressing of a glass frit together with the waste oxides. The process reported herein offers engineering simplicity in combination with many technological advantages such as significant decrease in temperature, use of small pressure, improved homogeneity of the products, production in easily arrangeable and interchangeable units. Furthermore, the proposed method has also proved to be suitable for treating intermediate-level waste streams containing Zry-4 cladding fragments. 9 references, 2 figures, 3 tables

  15. Investigation of the oxidation states of Cu additive in colored borosilicate glasses by electron energy loss spectroscopy

    International Nuclear Information System (INIS)

    Three optically transparent colorful (red, green, and blue) glasses were synthesized by the sol-gel method. Nano-sized precipitates were found in scanning electron microscopy images. The precipitates were analyzed by transmission electron microscopy (TEM) and high resolution TEM. The measured lattice parameters of these precipitates were found to fit the metallic copper in red glass but deviate from single valenced Cu oxides in green and blue glasses. The chemistry of these nano-sized particles was confirmed by electron energy loss spectroscopy (EELS). By fitting the EELS spectra obtained from the precipitates with the linear combination of reference spectra from Cu reference compounds, the oxidation states of Cu in the precipitates have been derived. First principle calculations suggested that the Cu nano-particles, which are in the similar oxidation states as our measurement, would show green color in the visible light range

  16. Synthesis and photoluminescence properties of a novel reddish orange-emitting Sm3+-doped strontium borosilicate phosphor

    Science.gov (United States)

    Sun, Jianfeng; Ding, Debao; Sun, Jiayue

    2016-08-01

    Sr3-2xSmxNaxB2SiO8 phosphors were synthesized by the solid-state reactions. X-ray diffraction, diffuse reflection, photoluminescence excitation and emission, as well as fluorescence decay measurements were utilized to investigate the structural and spectral properties of the samples. The results indicated that Sr3-2xSmxNaxB2SiO8 phosphors could be efficiently excited by the near-ultraviolet light to realize a novel reddish orange luminescence corresponding to the characteristic transitions 4G5/2→6HJ (J = 5/2, 7/2, 9/2, 11/2) of Sm3+ ions, with a maximum intensity at 600 nm. Based on the theoretical calculation, the dipole-dipole interaction was dominantly involved concentration quenching of Sm3+ in the phosphors, and the critical transfer distance (Rc) was determined to be 13.59 Å. Furthermore, Judd-Ofelt analysis was applied to evaluate three phenomenological Judd-Ofelt intensity parameters (Ωλ, λ = 2, 4, 6), and in turn radiative properties such as radiative transition probabilities (AR), radiative lifetimes (τR) and fluorescence branching ratios (βR) for the excited 4G5/2 luminescent level of Sm3+ ions were determined. Upon 402 nm excitation, the composition-optimized Sr2.90Sm0.05Na0.05B2SiO8 exhibited the preferable photoluminescence intensity and CIE coordinates of (0.534, 0.448). These results suggest that the Sm3+-doped Sr3B2SiO8 phosphors are competitive as the reddish orange-emitting phosphor-converted materials for application in near-ultraviolet-pumped LEDs.

  17. 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.

  18. Modelling the dissolution of borosilicate glasses for radioactive waste disposal with the PHREEQE/GLASSOL code: theory and practice

    International Nuclear Information System (INIS)

    A model describing the corrosion kinetics of silicate glasses has been developed by Grambow in recent years. In this report, the theoretical background of the model is thoroughly discussed, and its practical use demonstrated. The main objectives were: 1) to test the validity of the basic assumptions on which the model relies, and 2) to assess whether it can be applied to the safety analysis of a Swiss final repository for high-level radioactive waste. Transition State Theory, a tool based on quantum mechanical principles, has been used by Grambow to derive a general kinetic equation for the corrosion of silicate glasses. This equation predicts successfully the observed dependence of the corrosion rate on the silicic acid concentration in solution according to a first order kinetics law. However, some parameters required by this equation are determined on the base of questionable assumptions. In particular, the simplistic surface complexation model used for the calculation of the free energy of the glass-water reaction yields, for the protonation of silicon on the glass surface, results which are not consistent with the experimental findings. Further, although the model predicts a unique value, common to all silicate glasses, for the activation energy of the rate-determining elementary reaction, leaching experiments conducted on a wide variety of glasses suggest that this quantity may vary by a factor 2. In its present form, the model is judged to be unsuitable for the safety analysis of the Swiss final repository. The reasons include: 1) the model neglects the potential effects of diffusive transport and silica sorption in a bentonite backfill on the glass corrosion kinetics, 2) the release of radionuclides can be only modelled assuming congruent dissolution, and 3) the magnitude of the final rates of corrosion, the parameter defining the maximal lifetime of the glass matrix, is still not known with sufficient precision. (author) figs., tabs., 27 refs

  19. Why neutron guides may end up breaking down? Some results on the macroscopic behaviour of alkali-borosilicate glass support plates under neutron irradiation

    International Nuclear Information System (INIS)

    In this paper we report on a first part of a study on the mechanisms leading to brittle fracture in neutron guides made of glass as structural element. Such devices are widely used to deliver thermal and cold neutron beams to experimental lines in most large neutron research facilities. We present results on macroscopic properties of samples of guide glass substrates which are subjected to neutron irradiation at relatively large fluences. The results show a striking dependence of some of the macroscopic properties such as density, shape or surface curvature upon the specific chemical composition of a given glass. The relevance of the present findings for the installation of either replacement guides at the existing facilities or for the deployment of instruments for ongoing projects such as the European Spallation Source is briefly discussed

  20. Effect of Zn- and Ca-oxides on the structure and chemical durability of simulant alkali borosilicate glasses for immobilisation of UK high level wastes

    International Nuclear Information System (INIS)

    Highlights: • Spinel crystallization incorporates ZnO from base glass, displacing Mg and Ni. • Raman spectroscopy demonstrates significant impact on glass structure by addition of ZnO to base glass. • Addition of ZnO reduces glass dissolution rate at early time periods (up to 28 days). - Abstract: Compositional modification of United Kingdom high level nuclear waste (HLW) glasses was investigated with the aim of understanding the impact of adopting a ZnO/CaO modified base glass on the vitrified product phase assemblage, glass structure, processing characteristics and dissolution kinetics. Crystalline spinel phases were identified in the vitrified products derived from the Na2O/Li2O and the ZnO/CaO modified base glass compositions; the volume fraction of the spinel crystallites increased with increasing waste loading from 15 to 20 wt%. The spinel composition was influenced by the base glass components; in the vitrified product obtained with the ZnO/CaO modified base glass, the spinel phase contained a greater proportion of Zn, with a nominal composition of (Zn0.60Ni0.20Mg0.20)(Cr1.37Fe0.63)O4. The addition of ZnO and CaO to the base glass was also found to significantly alter the glass structure, with changes identified in both borate and silicate glass networks using Raman spectroscopy. In particular, these glasses were characterised by a significantly higher Q3 species, which we attribute to Si–O–Zn linkages; addition of ZnO and CaO to the glass composition therefore enhanced glass network polymerisation. The increase in network polymerisation, and the presence of spinel crystallites, were found to increase the glass viscosity of the ZnO/CaO modified base glass; however, the viscosities were within the accepted range for nuclear waste glass processing. The ZnO/CaO modified glass compositions were observed to be significantly more durable than the Na2O/Li2O base glass up to 28 days, due to a combination of the enhanced network polymerisation and the formation of Ca/Si containing alteration layers

  1. LOW-TEMPERATURE SINTERED (ZnMg2SiO4 MICROWAVE CERAMICS WITH TiO2 ADDITION AND CALCIUM BOROSILICATE GLASS

    Directory of Open Access Journals (Sweden)

    BO LI

    2011-03-01

    Full Text Available The low-temperature sintered (ZnMg2SiO–TiO2 microwave ceramic using CaO–B2O3–SiO2 (CBS as a sintering aid has been developed. Microwave properties of (Zn1-xMgx2SiO4 base materials via sol-gel method were highly dependent on the Mg-substituted content. Further, effects of CBS and TiO2 additives on the crystal phases, microstructures and microwave characteristics of (ZnMg2SiO4 (ZMS ceramics were investigated. The results indicated that CBS glass could lower the firing temperature of ZMS dielectrics effectively from 1170 to 950°C due to the liquid-phase effect, and significantly improve the sintering behavior and microwave properties of ZMS ceramics. Moreover, ZMS–TiO2 ceramics showed the biphasic structure and the abnormal grain growth was suppressed by the pinning effect of second phase TiO2. Proper amount of TiO2 could tune the large negative temperature coefficient of resonant frequency (tf of ZMS system to a near zero value. (Zn0.8Mg0.22SiO4 codoped with 10 wt.% TiO2 and 3 wt.% CBS sintered at 950°C exhibits the dense microstructure and excellent microwave properties: εr = 9.5, Q·f = 16 600 GHz and tf = −9.6 ppm/°C.

  2. Effect of Zn- and Ca-oxides on the structure and chemical durability of simulant alkali borosilicate glasses for immobilisation of UK high level wastes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hua, E-mail: nzhangh@aliyun.com [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); China Institute of Atomic Energy, P.O. Box 275-93, 102413 Beijing (China); Corkhill, Claire L.; Heath, Paul G.; Hand, Russell J.; Stennett, Martin C. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Hyatt, Neil C., E-mail: n.c.hyatt@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2015-07-15

    Highlights: • Spinel crystallization incorporates ZnO from base glass, displacing Mg and Ni. • Raman spectroscopy demonstrates significant impact on glass structure by addition of ZnO to base glass. • Addition of ZnO reduces glass dissolution rate at early time periods (up to 28 days). - Abstract: Compositional modification of United Kingdom high level nuclear waste (HLW) glasses was investigated with the aim of understanding the impact of adopting a ZnO/CaO modified base glass on the vitrified product phase assemblage, glass structure, processing characteristics and dissolution kinetics. Crystalline spinel phases were identified in the vitrified products derived from the Na{sub 2}O/Li{sub 2}O and the ZnO/CaO modified base glass compositions; the volume fraction of the spinel crystallites increased with increasing waste loading from 15 to 20 wt%. The spinel composition was influenced by the base glass components; in the vitrified product obtained with the ZnO/CaO modified base glass, the spinel phase contained a greater proportion of Zn, with a nominal composition of (Zn{sub 0.60}Ni{sub 0.20}Mg{sub 0.20})(Cr{sub 1.37}Fe{sub 0.63})O{sub 4}. The addition of ZnO and CaO to the base glass was also found to significantly alter the glass structure, with changes identified in both borate and silicate glass networks using Raman spectroscopy. In particular, these glasses were characterised by a significantly higher Q{sup 3} species, which we attribute to Si–O–Zn linkages; addition of ZnO and CaO to the glass composition therefore enhanced glass network polymerisation. The increase in network polymerisation, and the presence of spinel crystallites, were found to increase the glass viscosity of the ZnO/CaO modified base glass; however, the viscosities were within the accepted range for nuclear waste glass processing. The ZnO/CaO modified glass compositions were observed to be significantly more durable than the Na{sub 2}O/Li{sub 2}O base glass up to 28 days, due to a combination of the enhanced network polymerisation and the formation of Ca/Si containing alteration layers.

  3. Phase separation and crystallization in soda-lime borosilicate glass enriched in MoO3 studied by in situ Raman spectroscopy at high temperature

    OpenAIRE

    Magnin, Magali; Schuller, Sophie; Caurant, Daniel; Majérus, Odile; De Ligny, Dominique; Advocat, Thierry

    2008-01-01

    Phase separation and crystallisation processes may arise in molten glass when the MoO3 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 SiO2-B2O3Na2O-CaO system, wi...

  4. Homogeneous glass processing region defined for a lanthanide borosilicate glass composition for the mobilization of plutonium using thorium as a surrogate

    International Nuclear Information System (INIS)

    A ternary diagram showing the homogeneous glass processing region of a base frit, rare earth oxide and thorium oxide has been developed for a residence temperature of 1475 C. Thorium oxide was used as a plutonium surrogate. All ThO2 glasses that were processed included a 1:1 mole ratio of Th to Gd. Gadolinium is added to the glass as a neutron absorber. Forty individual glass compositions were melted at 1475 C for 4 to 6 hours with periodic stirring. Two glasses (B-20-25 and B-25-25) were processed with a ThO2 loading of 25 weight percent (oxide) without amorphous phase separation or crystalline species detected by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM). These were processed with 55 weight percent frit, 20 weight percent rare earth oxides and 50 percent frit, 25 percent rare earth oxides. Crystalline species that formed outside of the homogeneous glass processing region due to solubility limits or insufficient processing temperature were identified. Amorphous phase separation was detected and examined by TEM at high ThO2 loadings (20 to 30 weight percent oxide). The base frit was able to dissolve up to 65 weight percent rare earth oxides when thorium oxide was not present. Durability testing will be performed on three glasses from three different regions of the homogeneous glass processing region. Product Consistency Test (PCT) results are pending and will be added to this document under a future revision

  5. Why neutron guides may end up breaking down? Some results on the macroscopic behaviour of alkali-borosilicate glass support plates under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Boffy, R.; Kreuz, M. [Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9 (France); Beaucour, J., E-mail: beaucour@ill.fr [Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9 (France); Köster, U. [Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9 (France); Bermejo, F.J. [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, Serrano 123, E-20886 Madrid (Spain)

    2015-09-01

    In this paper we report on a first part of a study on the mechanisms leading to brittle fracture in neutron guides made of glass as structural element. Such devices are widely used to deliver thermal and cold neutron beams to experimental lines in most large neutron research facilities. We present results on macroscopic properties of samples of guide glass substrates which are subjected to neutron irradiation at relatively large fluences. The results show a striking dependence of some of the macroscopic properties such as density, shape or surface curvature upon the specific chemical composition of a given glass. The relevance of the present findings for the installation of either replacement guides at the existing facilities or for the deployment of instruments for ongoing projects such as the European Spallation Source is briefly discussed.

  6. 硼硅酸盐生物玻璃的制备及其体外生物活性和降解性%PREPARATION OF BOROSILICATE GLASS AND THEIR BIOACTIVITY AND BIODEGRADABILITY IN VITRO

    Institute of Scientific and Technical Information of China (English)

    宁佳; 王德平; 黄文旵; 周萘; 姚爱华; 付海罗; 刘欣

    2006-01-01

    采用熔融法制备了NaO-CaO-SiO2-P2O5-B2O3玻璃,用质量损失分析、pH值测定和X射线衍射、电子显微镜以及电感耦合等离子体离子浓度分析法表征玻璃与稀K2HPO4溶液的类生物反应,研究了这类玻璃的生物活性和生物降解性.结果表明:当玻璃中B2O3/SiO2的摩尔比为3:1时,生物活性较好.随着B2O3与SiO2的摩尔比减小,玻璃的降解速度变慢,获得的羟基磷灰石结晶度较低.利用此特性可控制生物玻璃的降解速度,从而与骨细胞生长速度相匹配.因此,此类硼硅酸盐生物活性玻璃有望在硬组织工程支架材料中得到应用.

  7. 烧结助剂对硼硅钙微晶玻璃结构和介电性能的影响%EFFECTS OF SINTERING ADDITIVES ON MICROSTRUCTURE AND DIELECTRIC PROPERTIES OF CALCIUM BOROSILICATE GLASS-CERAMICS

    Institute of Scientific and Technical Information of China (English)

    吕安国; 王美娜; 丘泰; 周洪庆; 刘敏

    2007-01-01

    研究了烧结助剂P2O5和ZnO对CaO-B2O3-SiO2(CBS)玻璃粉末的助烧作用及其对材料的相组成、显微结构和介电性能的影响.结果表明:未添加烧结助剂在1000 ℃烧成的样品晶粒粗大(1~3 μm),且结构疏松.复合添加2%(质量分数,下同)P2O5和0.5%ZnO后,850℃烧成的CBS微晶玻璃中,包含有β-CaSiO3,α-SiO2和CaB2O4 3种晶相,晶粒发育细小均匀,粒径为0.5 μm左右,具有一定量的玻璃相,且结构致密.加烧结助剂制得的样品在10 MHz下,相对介电常数εr为6.38,介电损耗tanδ为0.001 8.加复合烧结助剂P2O5和ZnO有效地降低了CBS玻璃粉末的烧结温度(低于900 ℃),可实现银、铜电极共烧.烧结助剂的作用机理是P2O5促进了液相的生成,ZnO则具有提高液相的粘度,增大烧结温度范围,细化晶粒和防止样品变形的作用.

  8. 新型掺铒镥硼硅酸盐玻璃的制备和红外发光性质研究%Preparation and Optical Properties of Er3+ -Doped Lutetium Borosilicate Glasses

    Institute of Scientific and Technical Information of China (English)

    孙江亭; 吴昭君; 唐婉如; 高艳杰; 吕树臣

    2009-01-01

    用高温熔融法制备了成分为:Er2O3,Lu2O3,SiO2,B2O3和Na2O的新型玻璃体系,探索了该玻璃体系的成玻范围,发现该玻璃体系在(摩尔分数)SiO2:0~50%,Lu2O3:0~25%和B2O3:20%以上的范围内均可形成完全透明的玻璃,在Lu2O3:10%.SiO2:50%,B2O3:30%和B2O3:30%,SiO2:60%两个组分附近时玻璃轻微失透.除此以外,在其他组分实验上没有得到玻璃.利用McCumtber理论计算出了样品的吸收和受激发射截面,并从玻璃1.5 μm的吸收光谱出发拟合出了Judd-Ofelt参数Ωλ(2,4,6).结果表明,该玻璃体系具有较大的吸收和受激发射截面.差热分析的数据表明,该玻璃体系具有极好的热稳定性.因此,从1.5μm发射的增益带宽和热稳定性两个方面来考虑,本文所制备的镥硼硅酸盐玻璃体系是一种具有应用潜力的掺铒光纤放大器的基质材料.

  9. Synthesis and thermophysical property measurements on various types of glasses for nuclear waste immobilization

    International Nuclear Information System (INIS)

    Borosilicate glasses (BSG) are worldwide known host matrices for immobilization of radioactive High Level Waste (HLW). Different types of borosilicate glasses were prepared by changing the modifier concentrations and compositions to know the efficacy of the resulting glass in terms of glass formation, durability towards various waste elements, stability at higher temperatures, mobility of ionic species etc. towards nuclear applications. In this study BSG, Aluminium borosilicate glass (AlBSG), Barium borosilicate glass (BaBSG) and Lead borosilicate glasses (PbBSG) were prepared and characterised to confirm the glass formations. Percentage linear thermal expansion and glass transition temperatures were measured by dilatometric techniques

  10. Development of melt compositions for sulphate bearing high level waste

    International Nuclear Information System (INIS)

    The report deals with the development and characterization of vitreous matrices for sulphate bearing high level waste. Studies were conducted in sodium borosilicate and lead borosilicate systems with the introduction of CaO, BaO, MgO etc. Lead borosilicate system was found to be compatible with sulphate bearing high level wastes. Detailed product evaluation carried on selected formulations is also described. (author)

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

    International Nuclear Information System (INIS)

    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

  12. Comparison of glass and crystalline nuclear waste forms

    International Nuclear Information System (INIS)

    Nuclear waste forms may be divided into two broad categories: single phase glasses with minor crystalline components (e.g., borosilicate glasses) and crystalline waste forms, either single phase (e.g., monazite) or polyphase (e.g., SYNROC). This paper reviews the materials properties data that are available for each of these two types of waste forms. The principal data include: physical, thermal and mechanical properties, chemical durability; and radiation damage effects. Complete data are only available for borosilicate glasses and SYNROC; therefore, this comparison focuses on the performance assessment of borosilicate glass and SYNROC

  13. Materials Characterization Center workshop on the leaching mechanisms of nuclear waste forms, December 7-8, 1982, Thousand Oaks, CA. Summary report

    International Nuclear Information System (INIS)

    Each of the six laboratories involved in the 3-yr leaching mechanism program presented a progress report on borosilicate glass studies. Presentations were made on various techniques for characterizing leached surfaces and on in situ characterization of leaching surfaces

  14. Picosecond laser welding of similar and dissimilar materials.

    Science.gov (United States)

    Carter, Richard M; Chen, Jianyong; Shephard, Jonathan D; Thomson, Robert R; Hand, Duncan P

    2014-07-01

    We report picosecond laser welding of similar and dissimilar materials based on plasma formation induced by a tightly focused beam from a 1030 nm, 10 ps, 400 kHz laser system. Specifically, we demonstrate the welding of fused silica, borosilicate, and sapphire to a range of materials including borosilicate, fused silica, silicon, copper, aluminum, and stainless steel. Dissimilar material welding of glass to aluminum and stainless steel has not been previously reported. Analysis of the borosilicate-to-borosilicate weld strength compares well to those obtained using similar welding systems based on femtosecond lasers. There is, however, a strong requirement to prepare surfaces to a high (10-60 nm Ra) flatness to ensure a successful weld. PMID:25089985

  15. SUPERCONDUCTING OPEN-GRADIENT MAGNETIC SEPARATION FOR THE PRETREATMENT OF RADIOACTIVE OR MIXED WASTE VITRIFICATION FEEDS

    Science.gov (United States)

    Scientists need to gain a better understanding of the magnetic separation processes that can be used to separate deleterious constituents (crystalline, amorphous, and colloidal) in vitrification feed streams for borosilicate glass production without adding chemicals or generating...

  16. 40 CFR Appendix A-4 to Part 60 - Test Methods 6 through 10B

    Science.gov (United States)

    2010-07-01

    ... Maintenance Requirements) of 40 CFR part 60, subpart A (General Provisions). Specific uses of these test... medium-coarse glass frit and borosilicate or quartz glass wool packed in top (see Figure 6-1) to...

  17. Excimer laser-induced material modification to create nanometer high smooth patterns in glass using mask projection

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, Thomas; Zimmer, Klaus; Boehme, Rico; Ruthe, David [Leibniz-Institut fuer Oberflaechenmodifizierung e.V., Permoserstrasse 15, D-04318 Leipzig (Germany)

    2007-04-15

    Laser swelling of borosilicate and soda-lime glass is shown for wavelengths of 193 and 248 nm. Very smooth patterns up to 45 nm high were generated by KrF laser (248 nm) irradiation of borosilicate glass at a fluence of 1.5 J/cm{sup 2}. At 193 nm laser wavelength, lower heights (up to 13 nm) and lower swelling threshold fluences (0.1 J/cm{sup 2}) were observed due to higher material absorption. For the less absorbing soda-lime glass higher fluences than for the borosilicate glass are needed to establish elevated structures. Gratings in borosilicate glass with sub-micron periodicity demonstrate the high resolution of the method. The results can be explained by a thermo-physical model based on the change of the glass transition temperature due to fast cooling after the pulsed laser irradiation.

  18. Spent fuel from nuclear research reactors immobilized in sintered glass

    International Nuclear Information System (INIS)

    Different kinds of glasses, borosilicates, Iron borosilicates and Iron phosphates, were tested in order to determine its capability to immobilize calcined uranium silicide in a sintering process. Iron phosphate glass developed in our laboratory showed the best results in SEM analysis. Also its gravimetric leaching rate is less than 0.45 g.m-2 .day-1 for 7 and 10% loading which is lower than any previously studied for us. (author)

  19. An assessment of methods for immobilizing reprocessed radioactive waste

    International Nuclear Information System (INIS)

    Nuclear waste forms presently used for the disposal of high-level wastes and other potential waste forms under development were studied using information available in the literature and by visits to the laboratories. The following waste forms were considered: Borosilicate glass, high-silica glass, glassceramics, supercalcine ceramics, synroc ceramics, borosilicate glass beads in a metal matrix, supercalcine and synroc ceramics in a metal matrix and coated ceramics. The following conclusions have been reached: To date the best developed wasteform, both in terms of overall product quality and process development, is monolithic borosilicate glass. However, hydrothermal instability is a major concern. Borosilicate glass in metal matrix waste form has better properties than monolithic borosilicate glass waste form. The process has been proven on a pilot scale. Hence, it is considered very close to monolithic glass in terms of overall development. The product qualities of the other waste forms are better than borosilicate glass. However, process development for these alternative waste forms is still in a conceptual stage. The technological basis for processing ceramic waste forms exists in a well developed state. Nevertheless, adaptation of the technology to continuous hot-cell operation, although feasible, has not been demonstrated. In view of the product potential of ceramic waste forms it is felt that their development should be given emphasis at this time. (auth)

  20. Solubility of actinides and surrogates in nuclear glasses

    International Nuclear Information System (INIS)

    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% PuO2 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)

  1. Vitrification of sulphate bearing high level waste (HLW)

    International Nuclear Information System (INIS)

    The Indian strategy for the management of spent fuel is based on Reprocessing-Conditioning- Recycle (RCR) option. Reprocessing of spent fuel by the PUREX process leads to the generation of high-level radioactive liquid waste. Strategy for the management of high-level waste in India involves: a) Immobilization of HLW in borosilicate matrices b) Interim storage of vitrified HLW for a period of about 50 years c) Ultimate disposal of vitrified HLW in deep geological repository Borosilicate matrices have found wide acceptance for immobilization of high level wastes. Suitable glass compositions within the borosilicate family have been formulated and characterized for sulphate bearing high-level radioactive waste. Presence of sulphate in HLW, generated earlier, is on account of ferrous sulphamate as a reducing agent, added during partitioning stage of reprocessing. Solubility of sulphur in the form of sodium sulphate is very less (<1% wt) in normally deployed borosilicate melts for vitrification of HLW. The soluble alkali sulphate gets phase separated in the glass melt and its presence is not desirable since this phase is enriched with radio Cs and has high solubility in water. In addition, volatility of sulphates during glass formation is another area of concern. Attempts to address this problem were made and alternative glass forming systems based on lead and barium borosilicate systems were studied for immobilization of this sulphate bearing waste. (author)

  2. 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)

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

    International Nuclear Information System (INIS)

    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 (SiO2 :B2O3 :Na2O : MnO : TiO2) 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)

  4. Photoluminescence of X-ray irradiated CdSe nanocrystals embedded in dielectric matrices

    Energy Technology Data Exchange (ETDEWEB)

    Prymak, M.V.; Azhniuk, Yu.M.; Zvenigorodsky, V.V.; Krasilinets, V.M.; Gomonnai, A.V. [Institute of Electron Physics, Ukrainian National Academy of Sciences, Universytetska Str. 21, Uzhhorod 88017 (Ukraine); Rayevska, O.E.; Stroyuk, O.L. [L.V. Pysarzhevsky Institute of Physical Chemistry, Ukrainian National Academy of Sciences, Prospect Nauky 31, Kyiv 03028 (Ukraine); Zahn, D.R.T. [Semiconductor Physics, Chemnitz University of Technology, 09107 Chemnitz (Germany)

    2013-06-15

    The effect of X-ray irradiation (up to 3200 Gy) on the photoluminescence (PL) of CdSe nanocrystals embedded in polyacrylamide and borosilicate glass matrices is studied. In both cases no PL quenching is observed: for the polyacrylamide-embedded CdSe nanocrystals the PL intensity remains stable, while for the borosilicate glass-embedded nanocrystals it increases somewhat. The obtained PL behavior correlates well with the optical absorption data. This testifies to the radiation stability of the optical characteristics of CdSe nanocrystals in polyacrylamide and irradiation-induced charge transfer between the nanocrystals and the borosilicate glass. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Effects of neodymium and gadolinium on weathering resistance of ZnO-B2O3-SiO2 glass

    Institute of Scientific and Technical Information of China (English)

    李雄伟; 李梅; 王觅堂; 柳召刚; 胡艳宏; 田俊虎

    2014-01-01

    The ZnO-B2O3-SiO2 glass doped with Nd2O3 and Gd2O3 was prepared by high temperature melt cooling method. The standard sample of the zinc borosilicate glass was placed in the constant temperature and humidity chamber in order to simulate the atmospheric corrosion process. The surface of the weathered glass was analyzed by scanning electron microscope and energy disper-sive spectrometry and the filtrate was analyzed by inductively coupled plasma-atomic emission spectrometry. The results showed that humidity was the most important factor influencing weathering; the morphology of glass surface of altered layer and the product on the surface was observed; the corroding degree of the zinc borosilicate glass doped with Nd or Gd was significantly lighter than that of the base glass.Adding rare earth Nd or Gd in the zinc borosilicate glass could suppress Na, Zn, Si ion release in weathering.

  6. Processing summary report: Fabrication of cesium and strontium heat and radiation sources

    International Nuclear Information System (INIS)

    The Pacific Northwest Laboratory (PNL), has produced 30 isotopic heat sources (canisters) for the Federal Republic of Germany (FRG) to be used as part of a repository testing program in the Asse Salt Mine. PNL program work involved the filling, closure, and decontamination of the 30 canisters. The canisters were fabricated (filled) in three separate processing campaigns using the radioactive liquid-fed ceramic melter to produce a borosilicate glass. Within the borosilicate glass matrix radiochemical constituents (137Cs and 90Sr) were immobilized to yield a product with a predetermined decay heat and surface radiation exposure rate

  7. Gallium phosphide as a new material for anodically bonded atomic sensors

    Directory of Open Access Journals (Sweden)

    Nezih Dural

    2014-08-01

    Full Text Available Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.

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

    International Nuclear Information System (INIS)

    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. Volume changes in glass induced by an electron beam

    International Nuclear Information System (INIS)

    Three glasses (float, borosilicate float and Schott D263 glasses) were irradiated by 50 keV electron beams with doses within the range of 0.21–318.5 kC/m2. Volume changes induced by electron bombarding were monitored by means of Atomic Force Microscopy. Incubation doses, related to mobility of alkali ions, were measured. Low doses showed compaction of all glasses while higher doses revealed volume inflation, except for borosilicate float glass. Both surfaces of float glass were irradiated and significant differences between them were found

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

    International Nuclear Information System (INIS)

    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 Na2O - B2O3 - SiO2. 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.)

  11. Multi-phase glass-ceramics as a waste form for combined fission products: alkalis, alkaline earths, lanthanides, and transition metals

    International Nuclear Information System (INIS)

    In this study, multi-phase silicate-based glass-ceramics were investigated as an alternate waste form for immobilizing non-fissionable products from used nuclear fuel. Currently, borosilicate glass is the waste form selected for immobilization of this waste stream, however, the low thermal stability and solubility of MoO3 in borosilicate glass translates into a maximum waste loading in the range of 15-20 mass%. Glass-ceramics provide the opportunity to target durable crystalline phases, e.g., powellite, oxyapatite, celsian, and pollucite, that will incorporate MoO3 as well as other waste components such as lanthanides, alkalis, and alkaline earths at levels 2X the solubility limits of a single-phase glass. In addition a glass-ceramic could provide higher thermal stability, depending upon the properties of the crystalline and amorphous phases. Glass-ceramics were successfully synthesized at waste loadings of 42, 45, and 50 mass% with the following glass additives: B2O3, Al2O3, CaO and SiO2 by slow cooling form from a glass melt. Glass-ceramics were characterized in terms of phase assemblage, morphology, and thermal stability. The targeted phases: powellite and oxyapatite were observed in all of the compositions along with a lanthanide borosilicate, and cerianite. Results of this initial investigation of glass-ceramics show promise as a potential waste form to replace single-phase borosilicate glass.

  12. Damage radiation alpha effects in sintered waste form

    International Nuclear Information System (INIS)

    We have subjected the borosilicate glass to thermal neutron irradiation in a reactor, with an accumulated fluence equivalent to approximately E3, E4, E5, y E6 years of waste disposal. We considered the following potential effects of accumulated alpha decay: a) Changes in the density; b) Changes in the dissolution rates; c) Changes in the microstructure of the sintered glass. (author)

  13. Glasses Containing Iron (II, III) Oxides For Immobilization Of Radioactive Technetium

    International Nuclear Information System (INIS)

    Technetium-99 (Tc-99) has posed serious environmental threats as US Department of Energy's high-level waste. This work reports the vitrification of Re, as surrogate for Tc-99, by iron-borosilicate and iron-phosphate glasses, respectively. Iron-phosphate glasses can dissolve Re as high as ∼ 1.2 wt. %, which can become candidate waste forms for Tc-99 disposal, while borosilicate glasses can retain less than 0.1 wt. % of Re due to high melting temperature and long melting duration. Vitrification of Re as Tc-99's mimic was investigated using iron-borosilicate and iron-phosphate glasses. The retention of Re in borosilicate glasses was less than 0.1 wt. % and more than 99 wt. % of Re were volatilized due to high melting temperature and long melting duration. Because the retention of Re in iron-phosphate glasses is as high as 1.2 wt. % and the volatilization is reduced down to ∼50 wt. %, iron-phosphate glasses can be one of the glass waste form candidates for Tc (or Re) disposal. The investigations of chemical durability and leaching test of iron-phosphate glasses containing Re are now underway to test the performance of the waste form.

  14. Phase Stability Determinations of DWPF Waste Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Marra, S.L.

    1999-10-22

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. To fulfill this requirement, glass samples were heat treated at various times and temperatures. These results will provide guidance to the repository program about conditions to be avoided during shipping, handling and storage of DWPF canistered waste forms.

  15. Mechanical Strength and Broadband Transparency Improvement of Glass Wafers via Surface Nanostructures.

    Science.gov (United States)

    Kumar, Amarendra; Kashyap, Kunal; Hou, Max T; Yeh, J Andrew

    2016-01-01

    In this study, we mechanically strengthened a borosilicate glass wafer by doubling its bending strength and simultaneously enhancing its transparency using surface nanostructures for different applications including sensors, displays and panels. A fabrication method that combines dry and wet etching is used for surface nanostructure fabrication. Specifically, we improved the bending strength of plain borosilicate glass by 96% using these surface nanostructures on both sides. Besides bending strength improvement, a limited optical transmittance enhancement of 3% was also observed in the visible light wavelength region (400-800 nm). Both strength and transparency were improved by using surface nanostructures of 500 nm depth on both sides of the borosilicate glass without affecting its bulk properties or the glass manufacturing process. Moreover, we observed comparatively smaller fragments during the breaking of the nanostructured glass, which is indicative of strengthening. The range for the nanostructure depth is defined for different applications with which improvements of the strength and transparency of borosilicate glass substrate are obtained. PMID:27322276

  16. Estimation of FPs solubility in glass melt states by method of multi-phase chemical equilibrium calculation

    International Nuclear Information System (INIS)

    In order to study the segregation or phase-separation of fission products in alkaline borosilicate glasses, the experiments for MoO3 and RuO2 have been done. In this paper, the primary theoretical approach to the inhomogeneity has been attempted, based on multi-phase equilibrium theory

  17. Mechanisms of dissolution of radioactive waste storage glasses and cesium migration from a granite repository

    International Nuclear Information System (INIS)

    Experimental and theoretical data are used to compare the effect of three possible leach mechanisms for borosilicate glass waste buried in a granite host-rock on the release and subsequent migration of 135Cs. Protracted release episodes and variations of up to an order of magnitude in groundwater transport times and five orders in output concentrations are possible. 4 figures

  18. Radiation effects on transport and bubble formation in silicate glasses

    International Nuclear Information System (INIS)

    Advanced Electron Paramagnetic Resonance spectroscopy (pulsed EPR, time-resolved EPR, high-frequency EPR, ENDOR) has been used to structurally characterize metastable point defects in irradiated alkali borate, silicate, and borosilicate glasses and to study mobile interstitial H atoms. In addition, the yield of radiolytic oxygen has been determined by outgassing. Several mechanisms for the defect formation in oxide glasses have been established

  19. Understanding and Predicting the Properties of Complex Materials

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, John C.; Yue, Yuanzheng

    Predicting the properties of new materials prior to manufacturing is a topic attracting great industrial and scientific interest. Mechanical properties are currently of particular interest given the increasing demand for stronger, thinner, and more flexible materials in recent years. Property pre...... and viscosity can be quantitatively predicted for oxide network glasses of industrial interest, such as borates and borosilicates....

  20. Topological Approach for Predicting the Properties of Glasses

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, John C.; Yue, Yuanzheng

    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...

  1. Systems approach to nuclear waste glass development

    International Nuclear Information System (INIS)

    Development of a host solid for the immobilization of nuclear waste has focused on various vitreous wasteforms. The systems approach requires that parameters affecting product performance and processing be considered simultaneously. Application of the systems approach indicates that borosilicate glasses are, overall, the most suitable glasses for the immobilization of nuclear waste. Phosphate glasses are highly durable; but the glass melts are highly corrosive and the glasses have poor thermal stability and low solubility for many waste components. High-silica glasses have good chemical durability, thermal stability, and mechanical stability, but the associated high melting temperatures increase volatilization of hazardous species in the waste. Borosilicate glasses are chemically durable and are stable both thermally and mechanically. The borosilicate melts are generally less corrosive than commercial glasses, and the melt temperature miimizes excessive volatility of hazardous species. Optimization of borosilicate waste glass formulations has led to their acceptance as the reference nuclear wasteform in the United States, United Kingdom, Belgium, Germany, France, Sweden, Switzerland, and Japan

  2. 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: 1.163, year: 2014

  3. Mechanical Strength and Broadband Transparency Improvement of Glass Wafers via Surface Nanostructures

    Science.gov (United States)

    Kumar, Amarendra; Kashyap, Kunal; Hou, Max T.; Yeh, J. Andrew

    2016-01-01

    In this study, we mechanically strengthened a borosilicate glass wafer by doubling its bending strength and simultaneously enhancing its transparency using surface nanostructures for different applications including sensors, displays and panels. A fabrication method that combines dry and wet etching is used for surface nanostructure fabrication. Specifically, we improved the bending strength of plain borosilicate glass by 96% using these surface nanostructures on both sides. Besides bending strength improvement, a limited optical transmittance enhancement of 3% was also observed in the visible light wavelength region (400–800 nm). Both strength and transparency were improved by using surface nanostructures of 500 nm depth on both sides of the borosilicate glass without affecting its bulk properties or the glass manufacturing process. Moreover, we observed comparatively smaller fragments during the breaking of the nanostructured glass, which is indicative of strengthening. The range for the nanostructure depth is defined for different applications with which improvements of the strength and transparency of borosilicate glass substrate are obtained. PMID:27322276

  4. 40 CFR 60.291 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... glass made of soda-lime recipe, clear or colored, which is pressed and/or blown into bottles, jars... nonexperimental furnaces. Flat glass means glass made of soda-lime recipe and produced into continuous flat sheets...) Glass of borosilicate recipe. (2) Glass of soda-lime and lead recipes. (3) Glass of opal,......

  5. 40 CFR 60.296 - Test methods and procedures.

    Science.gov (United States)

    2010-07-01

    ... production rate correction =227 g/hr for container glass, pressed and blown (soda-lime and lead) glass, and pressed and blown (other than borosilicate, soda-lime, and lead) glass. =454 g/hr for pressed and blown... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for...

  6. Reactivity control rod for controlling reactor power distribution

    International Nuclear Information System (INIS)

    Since a cladding tube is situated at the outer side, it undergoes neutron irradiation in a reactor core and also undergoes compression force due to high pressure of reactor coolants to cause a creep phenomenon, and the diameter is reduced as it is used. Then, neutron absorbing rods as reactivity control rods for controlling the power distribution are constituted with a cladding tube, a spacer tube disposed at the central portion of the cladding tube and a borosilicate glass tube disposed between the cladding tube and the spacer tube. The gap between the borosilicate glass tube and the spacer tube is gradually changed so that the inner diameter of the borosilicate glass is increased as it comes closer to the lower end plug. The time of contact between the cladding tube and the spacer tube in the inside is delayed by the constitution of the borosilicate glass tube disposed in the cladding tube of the neutron absorbing rod as the reactivity control rod thereby capable of extending the integral working life time with no rupture of the cladding tube. (N.H.)

  7. Physical and chemical degradation behavior of sputtered aluminum doped zinc oxide layers for Cu(In,Ga)Se2 solar cells

    NARCIS (Netherlands)

    Theelen, M.; Boumans, T.; Stegeman, F.; Colberts, F.; Illiberi, A.; Berkum, J. van; Barreau, N.; Vroon, Z.; Zeman, M.

    2014-01-01

    Sputtered aluminum doped zinc oxide (ZnO:Al) layers on borosilicate glass were exposed to damp heat (85 C/85% relative humidity) for 2876 h to accelerate the physical and chemical degradation behavior. The ZnO:Al samples were characterized by electrical, compositional and optical measurements before

  8. Hafnium in peralkaline and peraluminous boro-aluminosilicate glass, and glass subcomponents: a solubility study

    International Nuclear Information System (INIS)

    A relationship between the solubility of hafnia (HfO2) and the host glass composition was explored by determining the solubility limits of HfO2 in peralkaline and peraluminous borosilicate glasses in the system SiO2-Al2O3-B2O3-Na2O, and in glasses in the system SiO2-Na2O-Al2O3 in air at 1450 C. The only Hf-bearing phase to crystallize in the peralkaline borosilicate melts is hafnia, while in the boron-free melts sodium-hafnium silicates crystallize. All peraluminous borosilicate melts crystallize hafnia, but the slightly peraluminous glasses also have sector-zoned hafnia crystals that contain Al and Si. The more peraluminous borosilicate glasses also crystallize a B-containing mullite. The general morphology of the hafnia crystals changes as peralkalinity (Na2O/(Na2O+Al2O3)) decreases, as expected in melts with increasing viscosity. In all of the glasses with Na2O > Al2O3, the solubility of hafnia is linearly and positively correlated with Na2O/(Na2O + Al2O3) or Na2O - Al2O3 (excess sodium), despite the presence of 5 to 16 mol% B2O3. The solubility of hafnia is higher in the sodium-aluminum borosilicate glasses than in the sodium-aluminosilicate glasses, suggesting that the boron is enhancing the effect that excess sodium has on the incorporation of Hf into the glass structure. The results of this solubility study are compared to other studies of high-valence cation solubility in B-free silicate melts. From this, for peralkaline B-bearing glasses, it is shown that, although the solubility limits are higher, the solution behavior of hafnia is the same as in B-free silicate melts previously studied. By comparison, also, it is shown that in peraluminous melts, there must be a different solution mechanism for hafnia: different than for peralkaline sodium-aluminum borosilicate glasses and different than for B-free silicate melts studied by others

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

    International Nuclear Information System (INIS)

    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

  10. Evidence for formation of Se molecular clusters during precipitation of CdSe1-xSx nanoparticles in glass

    International Nuclear Information System (INIS)

    While studying the effect of thermal treatment at 625-700 C on the formation of borosilicate glass-embedded CdSe or CdSe1-xSx nanocrystals, pronounced bands at 323 and 646 cm-1 were observed in the Raman spectra. They are assigned to Se2 clusters on the base of their frequency positions, widths, intensities, and resonance behavior. The precipitation of Se2 molecular clusters in borosilicate glass is shown to occur when the heat treatment temperature and/or duration are beyond the range, most suitable for the formation of CdSe or CdSe-rich CdSe1-xSx nanocrystals. (orig.)

  11. Geochemical and petrographic studies and the relationships to durability and leach resistance of vitrified products from the in situ vitrification process

    International Nuclear Information System (INIS)

    Soil and sludge contaminated with hazardous and radioactive materials from sites in the United States and Australia were vitrified using in situ vitrification. Some of the resulting products were subjected to detailed geochemical, leach and durability testing using a variety of analytical techniques. The leach resistance and durability performance was compared to that of vitrified high level waste with borosilicate composition. Particular attention was given to crystallization behavior, the effects of crystallization on residual melt chemistry and how crystallization influences the behavior of contaminant ions. The results of this work show that the vitrified material studied has superior chemical durability and leach resistance relative to typical borosilicate waste glasses. Crystallization behavior was variable depending upon melt chemistry and cooling history. Crystallization was not observed to adversely affect chemical durability or leach resistance

  12. Washing and caustic leaching of Hanford tank sludges: results of FY 1996 studies. Revision

    International Nuclear Information System (INIS)

    During the past few years, the primary mission at the US Department of Energy's Hanford Site has changed from producing plutonium to restoring the environment. Large volumes of high-level radioactive wastes (HLW), generated during past Pu production and other operations, are stored in underground tanks on site. The current plan for remediating the Hanford tank farms consists of waste retrieval, pretreatment, treatment (immobilization), and disposal. The HLW will be immobilized in a borosilicate glass matrix and then disposed of in a geologic repository. Because of the expected high cost of HLW vitrification and geologic disposal, pretreatment processes will be implemented to reduce the volume of borosilicate glass produced in disposing of the tank wastes. On this basis, a pretreatment plan is being developed. This report describes the sludge washing and caustic leaching test conducted to create a Hanford tank sludge pretreatment flowsheet

  13. Understanding the origin of the fracture toughness evolution of nuclear glasses under irradiation

    International Nuclear Information System (INIS)

    In the nuclear industry, complex borosilicate glasses are used for the confinement of fission products and long-life minor actinides. Under irradiations, the structure and the mechanical properties of these glasses evolve. In this work, atomistic and multi-scale simulations of three simplified borosilicate glasses were run to understand the origin of their fracture behavior change under irradiation. Under the radiation effects, elasticity decreases and plasticity increases. Fracture happens due to the formation and coalescence of nano-cavities. The structural modifications under the radiation effects lead to a delay of the coalescence and of the irradiated glass rupture. Several phenomena overlay to explain this behavior, especially the cavities distribution modifications, the sodium mobility, and the borate and silicate entities organization in the glassy network. Depending on the nature of the more important mechanism, the fracture toughness can increase or decrease under radiation. (author)

  14. Engineering of composite metallic microfibers towards development of plasmonic devices for sensing applications

    Science.gov (United States)

    Petropoulou, A.; Antonopoulos, G.; Bastock, P.; Craig, C.; Kakarantzas, G.; Hewak, D. W.; Zervas, M. N.; Riziotis, C.

    2016-03-01

    The paper discusses the analysis of tapered hybrid composite microfibers based on a metal-core and dielectric-cladding composite material system. Its advantages over the pure metal tips conventionally used, are the inherent enhanced environmental robustness due to inert borosilicate cladding and the capability of multiple excitation of the tapered nanowire through the length of the fiber due to the enabled total internal reflection at the borosilicate/air interface. Simulations through finite element method (FEM) have demonstrated an improved field enhancement at the tapered region of such microfibers. Furthermore, experimental results on tapering in copper based microfibers together with light coupling and propagation studies will be demonstrated revealing the potential for the development of plasmonic devices for sensing applications.

  15. Characterization of artificial spherical particles for DEM validation studies

    Institute of Scientific and Technical Information of China (English)

    Ignazio Cavarretta; Catherine O'Sullivan; Erdin Ibraim; Martin Lings; Simon Hamlin; David Muir Wood

    2012-01-01

    This paper describes a study in which advanced particle-scale characterization was carried out on spherical particles that can be used in experimental tests to validate discrete element method (DEM) simulations,Two types of particle,alkaline and borosilicate glass heads,made from two different materials,were considered.The particle shape,stiffness,contact friction properties and surface roughness were measured.The influences of hardness and roughness on the mechanical response of the particles were carefully considered.Compared to the alkaline beads,the borosilicate beads were more spherical and more uniform in size,and they exhibited mechanical characteristics closer to natural quartz sand.While only two material types were studied,the work has the broader implication as a methodology for selecting particles suitable for use in DEM studies and the key parameters that should be considered in the selection process are highlighted.

  16. IMPROVED BAR IMPACT TESTS USING A PHOTONIC DOPPLER VELOCIMETER

    Energy Technology Data Exchange (ETDEWEB)

    Bless, S J; Tolman, J; Levinson, S; Nguyen, J

    2009-08-24

    Bar impact tests, using the techniques described elsewhere in this symposium, were used to measure compressive and tensile strengths of borosilicate glass, soda lime glass, and a glass ceramic. The glass ceramic was 25% crystalline spinel, furnished by Corning Inc. There are two measures of compressive strength: the peak stress that can be transmitted in unconfined compression, and the 'steady state' strength. For borosilicate glass and soda lime glass, these values were similar, being about 1.8 and 1.5 GPa, respectively. The glass ceramic (25% spinel) was almost 50% stronger. Tensile failure in the glass and glass ceramic takes places via surface flaws, and thus tensile strength is an extrinsic, as opposed to intrinsic property.

  17. The role of troublesome components in plutonium vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hong; Vienna, J.D.; Peeler, D.K.; Hrma, P.; Schweiger, M.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-05-01

    One option for immobilizing surplus plutonium is vitrification in a borosilicate glass. Two advantages of the glass form are (1) high tolerance to feed variability and, (2) high solubility of some impurity components. The types of plutonium-containing materials in the United States inventory include: pits, metals, oxides, residues, scrap, compounds, and fuel. Many of them also contain high concentrations of carbon, chloride, fluoride, phosphate, sulfate, and chromium oxide. To vitrify plutonium-containing scrap and residues, it is critical to understand the impact of each component on glass processing and chemical durability of the final product. This paper addresses glass processing issues associated with these troublesome components. It covers solubility limits of chlorine, fluorine, phosphate, sulfate, and chromium oxide in several borosilicate based glasses, and the effect of each component on vitrification (volatility, phase segregation, crystallization, and melt viscosity). Techniques (formulation, pretreatment, removal, and/or dilution) to mitigate the effect of these troublesome components are suggested.

  18. Immobilization of Radioactive Rare Earth oxide Waste by Solid Phase Sintering

    International Nuclear Information System (INIS)

    In the pyroprocessing of spent nuclear fuels, LiCl-KCl waste salt containing radioactive rare earth chlorides are generated. The radioactive rare earth oxides are recovered by co-oxidative precipitation of rare earth elements. The powder phase of rare earth oxide waste must be immobilized to produce a monolithic wasteform suitable for storage and ultimate disposal. The immobilization of these waste developed in this study involves a solid state sintering of the waste with host borosilicate glass and zinc titanate based ceramic matrix (ZIT). And the rare-earth monazite which synthesised by reaction of ammonium di-hydrogen phosphate with the rare earth oxides waste, were immobilized with the borosilicate glass. It is shown that the developed ZIT ceramic wasteform is highly resistant the leaching process, high density and thermal conductivity.

  19. First principles process-product models for vitrification of nuclear waste: Relationship of glass composition to glass viscosity, resistivity, liquidus temperature, and durability

    International Nuclear Information System (INIS)

    Borosilicate glasses will be used in the USA and in Europe to immobilize radioactive high level liquid wastes (HLLW) for ultimate geologic disposal. Process and product quality models based on glass composition simplify the fabrication of the borosilicate glass while ensuring glass processability and quality. The process model for glass viscosity is based on a relationship between the glass composition and its structural polymerization. The relationship between glass viscosity and electrical resistivity is also shown to relate to glass polymerization. The process model for glass liquidus temperature calculates the solubility of the liquidus phases based on the free energies of formation of the precipitating species. The durability product quality model is based on the calculation of the thermodynamic hydration free energy from the glass composition

  20. Evaluation of technological properties of clay ceramics with galvanic sludge as raw material

    International Nuclear Information System (INIS)

    This work investigates the possibility to obtain conventional ceramic-based clay added with galvanic sludge, soda-lime and borosilicate glasses. Initially, increasing levels of galvanic sludge in clay were added at 2%, 5%, and 10%, and burned at 900oC, 1000oC, and 1100oC, respectively. Thereafter, the formulations were analyzed with the addition of 2% sludge and contents of 5%, 10%, and 15% for both glasses. These formulations were burned at 1100oC. The ceramic bodies were obtained by uniaxial pressing and characterized, after burning, to flexural strength, water absorption, and linear shrinkage. In addition, the immobilization of hazardous elements present in sludge was evaluated by leaching tests and solubilization. An improvement at the mechanical properties with the addition of glass, especially with the addition of borosilicate glass was observed. Moreover, leaching and solubilization tests showed that the increasing addition of glass led to a reduction of heavy metals

  1. Hydrogen generation by Rhodobacter spahaeroides O.U. 001: the effect of photo-bioreactor construction material

    International Nuclear Information System (INIS)

    Generation of hydrogen by purple, non-sulfur bacteria of Rhodobacter sphaeroides O.U.001 was tested in photo-bioreactors made of different materials. Reactors made of ordinary sodium-type glass, borosilicate glass (Pyrex) or polycarbonate were applied in the present study. The applied medium containing malic acid and sodium glutamate inoculated with 0.11 or 0.31 g dry wt. of Rhodobacater sphaeroides was illuminated with 5 or 17 klx. Simultaneous measurements of evolved hydrogen, biomass growth, and COD were performed. The concentration of carotenoids and bacterio-chlorophyll was tested. In all tests the highest yield of hydrogen was obtained applying sodium glass photo-bioreactors illuminated with of 5 klx. Application of borosilicate glass or polycarbonate reactors reduced the amount of evolved hydrogen by 75 %. The best yield of hydrogen (2.1 dm3 of H2 per dm3 of medium) was obtained after illumination with 5 klx. (authors)

  2. Application of atomic layer deposited microchannel plates to imaging photodetectors with high time resolution

    International Nuclear Information System (INIS)

    Novel microchannel plates have been constructed using borosilicate glass micro-capillary array substrates with 20 µm and 10 µm pores and coated with resistive, and secondary electron emissive, layers by atomic layer deposition. Microchannel plates in 33 mm, 50 mm and 20 cm square formats have been made and tested. Although their amplification, imaging, and timing properties are comparable to standard glass microchannel plates, the background rates and lifetime characteristics are considerably improved. Sealed tube detectors based on the Planacon tube, and a 25 mm cross delay line readout tube with a GaN(Mg) opaque photocathode deposited on borosilicate microchannel plates have been fabricated. Considerable progress has also been made with 20 cm microchannel plates for a 20 cm format sealed tube sensor with strip-line readout that is being developed for Cherenkov light detection

  3. Application of atomic layer deposited microchannel plates to imaging photodetectors with high time resolution

    Energy Technology Data Exchange (ETDEWEB)

    Siegmund, O.H.W., E-mail: ossy@ssl.berkeley.edu [Experimental Astrophysics Group, Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); McPhate, J.B.; Tremsin, A.S.; Vallerga, J.V.; Ertley, C.D.; Richner, N.J.; Gerard, T.M. [Experimental Astrophysics Group, Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720 (United States); Frisch, H.J. [University of Chicago, 5640 S. Ellis Ave., Chicago, Il 60637 (United States); Elam, J.W.; Mane, A.U.; Wagner, R.G. [Argonne National Laboratory, 9700 S. Cass Ave. Lemont, Il 60439 (United States); Minot, M.J.; O' Mahony, A.; Craven, C.A. [Incom Inc., 294 Southbridge Road, Charlton, MA, 01507 (United States)

    2015-07-01

    Novel microchannel plates have been constructed using borosilicate glass micro-capillary array substrates with 20 µm and 10 µm pores and coated with resistive, and secondary electron emissive, layers by atomic layer deposition. Microchannel plates in 33 mm, 50 mm and 20 cm square formats have been made and tested. Although their amplification, imaging, and timing properties are comparable to standard glass microchannel plates, the background rates and lifetime characteristics are considerably improved. Sealed tube detectors based on the Planacon tube, and a 25 mm cross delay line readout tube with a GaN(Mg) opaque photocathode deposited on borosilicate microchannel plates have been fabricated. Considerable progress has also been made with 20 cm microchannel plates for a 20 cm format sealed tube sensor with strip-line readout that is being developed for Cherenkov light detection.

  4. Feasibility Study for Preparation and Use of Glass Grains as an Alternative to Glass Nodules for Vitrification of Nuclear Waste

    International Nuclear Information System (INIS)

    High level nuclear liquid waste (HLW) is immobilized using borosilicate glass matrix. Presently joule heated ceramic melter is being employed for vitrification of HLW in India. Preformed nodules of base glass are fed to melter along with liquid waste in predetermined ratio. In order to reduce the cost incurred for production of glass nodules of base glass, an alternative option of using glass grains was evaluated for its preparation and its suitability for the melter operation. (author)

  5. Glasses and Glass-Ceramic Components from Inorganic Waste and Novel Processing

    OpenAIRE

    Ponsot, Inès

    2015-01-01

    Thanks to European environmental rules and regulations establishment, waste recycling has become a more and more relevant problematic. For manufacturing plants, especially those producing hazardous wastes, expenses linked to waste production have drastically increased over the last decades. In the proposed work, various hazardous and non-hazardous wastes, among: soda-lime and borosilicate glass cullet, cathode ray tubes glass, exhausted lime from fume abatement systems residues, sludge and sl...

  6. ガラスの相分離を利用した都市ゴミ溶融スラグのマテリアルリサイクル

    OpenAIRE

    今岡, 卓也; 崎田, 真一; 難波, 徳郎; 三浦, 嘉也

    2007-01-01

    A novel recycling process of municipal waste slags obtaining Fe-free colorless materials was developed by using a phase separation of borosilicate glass. B(2)O(3) was added to a simulated waste slag to promote the phase separation. The slag glasses were heat-treated above glass transition temperatures, from which phase separation was successfully induced. The phase-separated slag glasses were still colored in black due to Fe ions, and after soaking in acid, they were successfully bleached, ob...

  7. Testing and evaluation of the properties of various potential materials for immobilizing high activity waste. First annual report (1977)

    International Nuclear Information System (INIS)

    Four borosilicate glasses and one Celsian glass ceramic were tested under strictly identical conditions. This report presents the results of the following test: (a) Leach testing of samples, in the as cast state, annealed at 8000C for up to 100 days; (b) Grain titration test of hydrolytic resistance (DIN 12111); (c) Examination of the glass structure and its changes due to thermal effects, differential thermal analysis, x ray diffraction analysis, scanning electron microscopy, microprobe analysis

  8. Development of glass ceramics for the incorporation of fission products

    International Nuclear Information System (INIS)

    Spontaneous devitrification of fission-product-containing borosilicate glasses can be avoided by controlled crystallization after melting. Glass ceramics have been developed from a vitrified simulated waste and further improvement of product properties was achieved. In particular perovskite, h-celsian, diopside and eucryptite glass ceramics were prepared. These contained leach resistant host phases which exhibited considerable enrichment of long-lived fission products. All products showed increased impact resistance, but the thermal expansion was only slightly improved

  9. Multi-phase glass-ceramics as a waste form for combined fission products: alkalis, alkaline earths, lanthanides, and transition metals

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.; Tang, Ming; Kossoy, Anna

    2012-04-01

    In this study, multi-phase silicate-based glass-ceramics were investigated as an alternate waste form for immobilizing non-fissionable products from used nuclear fuel. Currently, borosilicate glass is the waste form selected for immobilization of this waste stream, however, the low thermal stability and solubility of MoO{sub 3} in borosilicate glass translates into a maximum waste loading in the range of 15-20 mass%. Glass-ceramics provide the opportunity to target durable crystalline phases, e.g., powellite, oxyapatite, celsian, and pollucite, that will incorporate MoO{sub 3} as well as other waste components such as lanthanides, alkalis, and alkaline earths at levels 2X the solubility limits of a single-phase glass. In addition a glass-ceramic could provide higher thermal stability, depending upon the properties of the crystalline and amorphous phases. Glass-ceramics were successfully synthesized at waste loadings of 42, 45, and 50 mass% with the following glass additives: B{sub 2}O{sub 3}, Al{sub 2}O{sub 3}, CaO and SiO{sub 2} by slow cooling form from a glass melt. Glass-ceramics were characterized in terms of phase assemblage, morphology, and thermal stability. The targeted phases: powellite and oxyapatite were observed in all of the compositions along with a lanthanide borosilicate, and cerianite. Results of this initial investigation of glass-ceramics show promise as a potential waste form to replace single-phase borosilicate glass.

  10. Boron nitride nanotubes as a reinforcement for brittle matrices

    Czech Academy of Sciences Publication Activity Database

    Tatarko, Peter; Grasso, S.; Porwal, H.; Saggar, Richa; Chlup, Zdeněk; Dlouhý, Ivo; Reece, M.J.

    2014-01-01

    Roč. 34, č. 14 (2014), s. 3339-3349. ISSN 0955-2219 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 EU Projects: European Commission(XE) 264526 - GLACERCO Institutional support: RVO:68081723 Keywords : Amorphous borosilicate glass * Boron nitride nanotubes * Composite * Toughening mechanisms * Scratch resistance Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass Impact factor: 2.947, year: 2014

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 SiO2-B2O3-R2O (R = Li, Na, K, Cs), SiO2-B2O3-BaO and V2O5-B2O3-BaO systems. These compositions allowed us to study the influence of the nature of network-modifying ions (Li+, Na+, K+, Cs+ or Ba2+) 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. INVESTIGATION OF BIOFILM FORMATION IN COAGULASE-NEGATIVE STAPHYLOCOCCI ISOLATED FROM PLATELET CONCENTRATE BAGS

    OpenAIRE

    Rosiéli MARTINI; Hörner, Rosmari; Rampelotto, Roberta Filipini; Litiérri Razia Litiérri GARZON; Melise Silveira NUNES; TEIXEIRA, Mayza Dalcin; GRAICHEN, Daniel Ângelo Sganzerla

    2016-01-01

    Platelet Concentrates (PCs) are the blood components with the highest rate of bacterial contamination, and coagulase-negative staphylococci (CoNS) are the most frequently isolated contaminants. This study investigated the biofilm formation of 16 contaminated units out of 691 PCs tested by phenotypic and genotypic methods. Adhesion in Borosilicate Tube (ABT) and Congo Red Agar (CRA) tests were used to assess the presence of biofilm. The presence of icaADC genes was assessed by means of the Pol...

  14. Note: Anodic bonding with cooling of heat-sensitive areas

    DEFF Research Database (Denmark)

    Vesborg, Peter Christian Kjærgaard; Olsen, Jakob Lind; Henriksen, Toke Riishøj;

    2010-01-01

    Anodic bonding of silicon to glass always involves heating the glass and device to high temperatures so that cations become mobile in the electric field. We present a simple way of bonding thin silicon samples to borosilicate glass by means of heating from the glass side while locally cooling heat......-sensitive areas from the silicon side. Despite the high thermal conductivity of silicon, this method allows a strong anodic bond to form just millimeters away from areas essentially at room temperature....

  15. Characterization and photocatalytic treatability of red water from Brazilian TNT industry

    Energy Technology Data Exchange (ETDEWEB)

    Ludwichk, Raquel [Department of Chemistry, Postgraduate Programme in Technology of Chemical and Biochemical Processes, Federal Technological University of Paraná, Pato Branco, PR (Brazil); Helferich, Oliver Karil; Kist, Cristiane Patrícia [Academic Department of Chemistry and Biology, Post graduation in Environmental Science and Technology Federal Technological University of Paraná, Curitiba, PR (Brazil); Lopes, Aline Chitto; Cavasotto, Thiago [Department of Chemistry, Postgraduate Programme in Technology of Chemical and Biochemical Processes, Federal Technological University of Paraná, Pato Branco, PR (Brazil); Silva, Davi Costa [Academic Department of Chemistry and Biology, Post graduation in Environmental Science and Technology Federal Technological University of Paraná, Curitiba, PR (Brazil); Barreto-Rodrigues, Marcio, E-mail: marciorodrigues@utfpr.edu.br [Department of Chemistry, Postgraduate Programme in Technology of Chemical and Biochemical Processes, Federal Technological University of Paraná, Pato Branco, PR (Brazil); Academic Department of Chemistry and Biology, Post graduation in Environmental Science and Technology Federal Technological University of Paraná, Curitiba, PR (Brazil)

    2015-08-15

    Highlights: • The red water effluent has high levels of COD, color and acute toxicity. • The compounds 2-methyl-1, 3-dinitrobenzene, 1-methyl-2, 4-dinitrobenzene and 1-methyl-3, 5-dinitrobenzene were identified. • A nanostructured TiO{sub 2}-borosilicate glass was obtained and characterized. • The photocatalytic treatment removes all color 32% of the organic matter content of the effluent. • The borosilicate-glass-TiO{sub 2} system degrades all content of identified nitroaromatic compounds. - Abstract: The current study aims to characterize and evaluate the photocatalytic treatability of the “red water” effluent from a Brazilian TNT production industry. Analyses were performed using physical, chemical, spectroscopic and chromatographic assays, which demonstrated that the effluent presented a significant pollution potential, mainly due to COD, BOD, solids and to the high concentration of nitroaromatic compounds such as 1,3,5-trinitrobenzene, 1-methyl-2,4-dinitrobenzene, 2-methyl-1,3-dinitrobenzene, 2,4,6-trinitrotoluene-3,5-dinitro-p-toluidine and 2-methyl-3,5-dinitro-benzoamine. By a modified sol-gel and a dip-coating technique, it was possible to obtain a TiO{sub 2} film on borosilicate glass substrate which functional composition and microstructure were characterized by infrared spectroscopy and scanning electron microscopy. The evaluation of the photocatalytic treatability using borosilicate-glass-TiO{sub 2} demonstrated high degradation efficiency. In this context, a reduction of 32 and 100% for COD and nitroaromatic compounds, respectively, was observed. Although the proposed photocatalytic process has found difficulties in reducing the content of organic matter and effluent color in the red water, its potential for degrading refractory chemical compounds such as the nitroaromatic ones enables it to be used as tertiary treatment.

  16. The Silicon-To-Silicon Anodic Bonding Using Sputter Deposited Intermediate Glass Layer

    OpenAIRE

    TIWARI, R; Chandra, S.

    2011-01-01

    Glass-to-silicon anodic bonding is an attractive process for packaging of microelectronics devices and Micro-electro-mechanical Systems (MEMS). Silicon to silicon anodic bonding can also be accomplished by incorporating an intermediate glass layer. In the present work, silicon-to-silicon anodic bonding has been studied with an intermediate borosilicate glass layer deposited by RF magnetron sputtering process. The bonding was carried out at low dc voltage of about 48 V at 400 °C. Surface rough...

  17. Underwater current leakage between encapsulated NiChrome tracks: Implications for strain-gauges and other implantable devices

    OpenAIRE

    Vanhoestenberghe, A.; Bickerton, S.; Taylor, S. J. G.; Donaldson, N. D. N.

    2014-01-01

    We present the results of experiments aimed at identifying a suitable polymer for the encapsulation of thin-film strain gauges for underwater applications (with a view of using it in an instrumented bone fusion nail). The leakage currents across grooves cut (using a laser) in thin films of NiChrome over borosilicate glass were studied for encapsulated samples, immersed in water at 37 °C. The selected encapsulants were five silicone rubbers (of both medical and engineering grades), produced by...

  18. High-Level Waste System Process Interface Description

    Energy Technology Data Exchange (ETDEWEB)

    d' Entremont, P.D.

    1999-01-14

    The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment.

  19. Laser-induced damage of multilayer coated optical components

    International Nuclear Information System (INIS)

    A number of optics having high quality and high damage threshold were developed. The damage threshold of borosilicate crown glass has been considerably improved. The surface roughness dependence of the laser-induced surface damage of optical glasses and the laser-induced damage of high resolution coating were found for the first time. These optical technologies meet the GEKKO XII Upgrade fluence requirements. (author)

  20. Laser-induced damage of multilayer coated optical components

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Kunio (Osaka Inst. of Tech. (Japan)); Yoshida, Hidetsugu; Nakatsuka, Masahiro; Jitsuno, Takahisa; Namba, Yoshiharu; Sasaki, Takatomo; Kanabe, Tadashi; Yamanaka, Tatsuhiko; Nakai, Sadao

    1992-11-01

    A number of optics having high quality and high damage threshold were developed. The damage threshold of borosilicate crown glass has been considerably improved. The surface roughness dependence of the laser-induced surface damage of optical glasses and the laser-induced damage of high resolution coating were found for the first time. These optical technologies meet the GEKKO XII Upgrade fluence requirements. (author).

  1. Production of aromatic compounds containing nitrogen during high level radioactive waste processing

    International Nuclear Information System (INIS)

    The Savannah River Site Defense Waste Processing Facility will use a slurry-fed melter to immobilize high-level radioactive waste in borosilicate glass for permanent storage. During the melter feed operation, some nitrogen-containing organic species are generated due to the nitrite in the sludge and the organic by-products in the aqueous product. The chemistry involved is summarized in this paper

  2. Space-selective laser joining of dissimilar transparent materials using femtosecond laser pulses

    International Nuclear Information System (INIS)

    We report on the joining of dissimilar transparent materials based on localized melting and resolidification of the materials only around the focal volume due to nonlinear absorption of focused femtosecond laser pulses. We demonstrate the joining of borosilicate glass and fused silica, whose coefficients of thermal expansion are different. The joint strength and the transmittance through joint volume were investigated by varying the translation velocity of the sample and the pulse energy of the irradiated laser pulses

  3. Nucleate boiling from smooth and rough surfaces - Part 1: Fabrication and characterization of an optically transparent heater-sensor substrate with controlled surface roughness

    OpenAIRE

    McHale, John P.; Garimella, Suresh V.

    2013-01-01

    The effect of surface roughness on nucleate boiling heat transfer is not clearly understood. This study is devised to conduct detailed heat transfer and bubble measurements during boiling on a heater surface with controlled roughness. This first of two companion papers discusses details of the fabrication, construction, and operation of the experimental facility. Test pieces are fabricated from 50.8 mm x 50.8 mm x 3.18 mm borosilicate glass squares that are roughened by abrading with diamond ...

  4. Long term corrosion of glasses in salt brines

    OpenAIRE

    Roggendorf, Hans; Schmidt, Helmut K.

    1989-01-01

    Borosilicate glasses are supposed to be a suitable matrix for the fixation of calcined radioactive wastes. For the safety assessment of the disposal of these glasses in geological formations like carnallite or rock salt, their chemical durability in saturated salt brines has been investigated. Temperatures up to 200° C, pressures up to 130 bar, and corrosion times up to 5 years were applied. Special attention was given to the long term corrosion which is mainly characterized by the saturation...

  5. Luminescence of powdered uranium glasses

    Science.gov (United States)

    Eubanks, A. G.; Mcgarrity, J. M.; Silverman, J.

    1974-01-01

    Measurement of cathodoluminescence and photoluminescence efficiencies in powdered borosilicate glasses having different particle size and different uranium content. Excitation with 100 to 350 keV electrons and with 253.7 nm light was found to produce identical absolute radiant exitance spectra in powdered samples. The most efficient glass was one containing 29.4 wt% B2O3, 58.8 wt% SiO2, 9.8 wt% Na2O and 2.0 wt% UO2.

  6. High-Level Waste System Process Interface Description

    International Nuclear Information System (INIS)

    The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment

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

    International Nuclear Information System (INIS)

    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

  8. Comparison of Magnetic Separation and Flotation Results for Beneficiation of Emet Colemanite Ores

    OpenAIRE

    Ozkan, S. G.

    2001-01-01

    Colemanite (2CaO 3B2O3 5H2O) is one of the commercially preferable borates for many industries, such as agricultural, metallurgical, nuclear and production of fibreglass, borosilicate glasses, soaps, detergents, fire retardants, enamels and frits, used directly or after being transformed to boric acid (H3BO3). This paper aims mainly to investigate the practical floatability of colemanite from the Emet deposits of Turkey using a conventional collector and to compare the concentration results w...

  9. Characterization and photocatalytic treatability of red water from Brazilian TNT industry

    International Nuclear Information System (INIS)

    Highlights: • The red water effluent has high levels of COD, color and acute toxicity. • The compounds 2-methyl-1, 3-dinitrobenzene, 1-methyl-2, 4-dinitrobenzene and 1-methyl-3, 5-dinitrobenzene were identified. • A nanostructured TiO2-borosilicate glass was obtained and characterized. • The photocatalytic treatment removes all color 32% of the organic matter content of the effluent. • The borosilicate-glass-TiO2 system degrades all content of identified nitroaromatic compounds. - Abstract: The current study aims to characterize and evaluate the photocatalytic treatability of the “red water” effluent from a Brazilian TNT production industry. Analyses were performed using physical, chemical, spectroscopic and chromatographic assays, which demonstrated that the effluent presented a significant pollution potential, mainly due to COD, BOD, solids and to the high concentration of nitroaromatic compounds such as 1,3,5-trinitrobenzene, 1-methyl-2,4-dinitrobenzene, 2-methyl-1,3-dinitrobenzene, 2,4,6-trinitrotoluene-3,5-dinitro-p-toluidine and 2-methyl-3,5-dinitro-benzoamine. By a modified sol-gel and a dip-coating technique, it was possible to obtain a TiO2 film on borosilicate glass substrate which functional composition and microstructure were characterized by infrared spectroscopy and scanning electron microscopy. The evaluation of the photocatalytic treatability using borosilicate-glass-TiO2 demonstrated high degradation efficiency. In this context, a reduction of 32 and 100% for COD and nitroaromatic compounds, respectively, was observed. Although the proposed photocatalytic process has found difficulties in reducing the content of organic matter and effluent color in the red water, its potential for degrading refractory chemical compounds such as the nitroaromatic ones enables it to be used as tertiary treatment

  10. Brine chemistry effects on the durability of a simulated nuclear waste glass

    International Nuclear Information System (INIS)

    The effects of various solution chemistry parameters on the alteration and leaching characteristics of a copper borosilicate simulated waste glass have been determined under hydrothermal conditions. Results are presented which demonstrate that leachant salinity, volume/glass surface area ratio, pH, cation content, and dissolved SiO2 concentration effects are important. A brief explanation of these results is given which is based on ion exchange and solution saturation equilibria

  11. Fluidized bed calcination experience with simulated commercial high-level nuclear waste

    International Nuclear Information System (INIS)

    Development and testing of a pilot-scale fluidized bed calciner (1-2 MTU/day) are described. Simulated high-level liquid waste compositions representing those most likely to be generated by commercial nuclear fuel reprocessors were calcined prior to conversion to borosilicate glass forms. A new, much improved operating technique, continuous inert-bed operation (CIB), is described. 38 figures, 16 tables

  12. Final report, Task 2: alternative waste management options, Nuclear Fuel Services, Inc., high level waste

    International Nuclear Information System (INIS)

    Of the alternatives considered for disposal of the high-level waste in tanks 8D2 and 8D4, the following process is recommended: homogenization of the contents of tank 8D2, centrifugation of the sludge and supernate, mixing of the 8D4 acid waste with the centrifuged sludge, and converting the mixture to a borosilicate glass using the Hanford spray calciner/in-can melter

  13. Feasibility study for removal of sulphate from HLW prior to its immobilisation

    International Nuclear Information System (INIS)

    Sulphate removal from HLW can improve the waste loading significantly during vitrification using barium borosilicate glass matrix. This paper describes the experimental works carried out to see the feasibility of sulphate removal from HLW by precipitation method using barium nitrate. Various parameters like optimization of stoichiometric amount of barium, extent of sulphate removal, partitioning of radionuclide and feasibility of sludge fixation in cement matrix etc were also studied. (author)

  14. TEM investigation of a ceramic waste form for immobilization of process salts generated during electrometallurgical treatment of spent nuclear fuel

    International Nuclear Information System (INIS)

    Transmission electron microscopy (TEM) examination is presented of the microstructure of a ceramic waste form developed at Argonne National Lab - West for immobilization of actinides and fission products present in an electrorefiner salt. The material is produced by occluding the salt in zeolite granules, followed by hot isostatic pressing of the occluded zeolite in a mixture with a borosilicate glass. The paper presents results from a cold surrogate ceramic waste form, as well as 239Pu and 238Pu loaded samples

  15. Femtosecond laser direct written diffractive optical elements and their integration in oxide glass

    Science.gov (United States)

    Choi, Jiyeon; Richardson, Martin

    2009-02-01

    Femtosecond laser direct writing was applied to fabricate 3D diffractive optical elements in oxide glass. Here we report our initial results. We describe the consequences of fabricating Fresnel Zone Plates (FZPs) with various femtosecond laser parameters. Single or multiple layers of laser written FZPs were produced in borosilicate glasses. We are investigating the diffraction efficiencies as a function of laser and writing parameters such as pulse energy, writing speed and repetition rate.

  16. Comparison of (α,n) thick-target neutron yields and spectra from ORIGEN-S and SOURCES

    International Nuclear Information System (INIS)

    Both ORIGEN-S and SOURCES generate thick-target neutron yields and energy spectra from (α, n) reactions in homogeneous material containing alpha-emitting and (α,n) target elements by simulating reaction physics, using alpha-emission energy spectra, elemental stopping cross sections, (α, n) target elements by simulating reaction physics, using alpha-emission energy spectra, elemental stopping cross sections, (α, n) cross sections for target nuclei, and branching fractions to product-nuclide energy levels. This methodology results in accurate yield and spectra. ORIGEN-S has two options for calculating yields and spectra. The UO2 option (default) estimates yields and spectra assuming the input alpha emitters to be infinitely dilute in UO2. The borosilicate-glass option estimates yields from the total input material composition and generates spectra purportedly representative of spectra generated by 238Pu, 241Am, 242Cm, and 244Cm infinitely dilute in borosilicate glass, even if none of these four alpha emitters are present in the input material composition. Because yields from the borosilicate-glass option in ORIGEN-S are based on entire input material composition and are reasonably accurate, the same is often assumed to be true for spectra. The input/output functionality of the borosilicate-glass option, along with ambiguity in ORIGEN-S documentation, gives the incorrect impression that spectra representative of input compositions are generated. This impression is reinforced by wide usage of the SCALE code system and its ORIGEN-S module and their sponsorship by the US Nuclear Regulatory Commission

  17. Investigation of Design Parameters in Ultrasound Reactors

    OpenAIRE

    Jordens, Jeroen; Degrève, Jan; Braeken, Leen; Van Gerven, Tom

    2012-01-01

    The cavitational activity of a tubular sonoreactor was simulated and related to the chemical reaction rate in order to study the effect of different design parameters. The conversion was improved with a factor 10 by optimization of the reactor diameter. Further improvement of the conversion with 20% was achieved by shifting the transducers apart. When the reactor diameter is in the millimeter scale, stainless steel and borosilicate glass walls very well resemble sound-hard walls. The impact o...

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

    International Nuclear Information System (INIS)

    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)

  19. The integrated melter off-gas treatment systems at the West Valley Demonstration Project

    International Nuclear Information System (INIS)

    The West Valley Demonstration project was established by an act of Congress in 1980 to solidify the high level radioactive liquid wastes produced from operation of the Western New York Nuclear Services Center from 1966 to 1972. The waste will be solidified as borosilicate glass. This report describes the functions, the controlling design criteria, and the resulting design of the melter off-gas treatment systems

  20. Solubility of actinide surrogates in nuclear glasses

    International Nuclear Information System (INIS)

    This paper discusses the results of a study of actinide surrogates in a nuclear borosilicate glass to understand the effect of processing conditions (temperature and oxidizing versus reducing conditions) on the solubility limits of these elements. The incorporation of cerium oxide, hafnium oxide, and neodymium oxide in this borosilicate glass was investigated. Cerium is a possible surrogate for tetravalent and trivalent actinides, hafnium for tetravalent actinides, and neodymium for trivalent actinides. The material homogeneity was studied by optical, scanning electron microscopy. Cerium LIII XANES spectroscopy showed that the Ce3+/Cetotal ratio increased from about 0.5 to 0.9 as the processing temperature increased from 1100 to 1400 deg. C. Cerium LIII XANES spectroscopy also confirmed that the increased Ce solubility in glasses melted under reducing conditions was due to complete reduction of all the cerium in the glass. The most significant results pointed out in the current study are that the solubility limits of the actinide surrogates increases with the processing temperature and that Ce3+ is shown to be more soluble than Ce4+ in this borosilicate glass

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-30

    Pyroprocessing is a reprocessing 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 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. 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)

  3. Wettability measurement under high P-T conditions using X-ray imaging with application to the brine-supercritical CO2 system

    Science.gov (United States)

    Chaudhary, Kuldeep; Guiltinan, Eric J.; Cardenas, M. Bayani; Maisano, Jessica A.; Ketcham, Richard A.; Bennett, Philip C.

    2015-09-01

    We present a new method for measuring wettability or contact angle of minerals at reservoir pressure-temperature conditions using high-resolution X-ray computed tomography (HRXCT) and radiography. In this method, a capillary or a narrow slot is constructed from a mineral or a rock sample of interest wherein two fluids are allowed to form an interface that is imaged using X-rays. After some validation measurements at room pressure-temperature conditions, we illustrate this method by measuring the contact angle of CO2-brine on quartz, muscovite, shale, borosilicate glass, polytetrafluoroethylene (PTFE or Teflon), and polyether ether ketone (PEEK) surfaces at 60-71°C and 13.8-22.8 MPa. At reservoir conditions, PTFE and PEEK surfaces were found to be CO2-wet with contact angles of 140° and 127°, respectively. Quartz and muscovite were found to be water-wet with contact angles of 26° and 58°, respectively, under similar conditions. Borosilicate glass-air-brine at room conditions showed strong water-wet characteristics with a contact angle of 9°, whereas borosilicate glass-CO2-brine at 13.8 MPa and 60°C showed a decrease in its water-wetness with contact angle of 54°. This method provides a new application for X-ray imaging and an alternative to other methods.

  4. Annual progress report to Battelle Pacific Northwest National Laboratories on prediction of phase separation of simulated nuclear waste glasses

    International Nuclear Information System (INIS)

    The objective of this research is to predict the immiscibility boundaries of multi-component borosilicate glasses, on which many nuclear waste glass compositions are based. The method used is similar to the prediction method of immiscibility boundaries of multi-component silicate glass systems successfully made earlier and is based upon the superposition of immiscibility boundaries of simple systems using an appropriate parameter. This method is possible because many immiscibility boundaries have similar shapes and can be scaled by a parameter. In the alkali and alkaline earth binary silicate systems, for example, the critical temperature and compositions were scaled using the Debye-Hueckel theory. In the present study on borosilicate systems, first, immiscibility boundaries of various binary alkali and alkaline borate glass systems (e.g. BaO-B2O3) were examined and their critical temperatures were evaluated in terms of Debye-Hueckel theory. The mixing effects of two alkali and alkaline-earth borate systems on the critical temperature were also explored. Next immiscibility boundaries of ternary borosilicate glasses (e.g. Na2O-SiO2-B2O3, K2O-SiO2-B2O3, Rb2O-SiO2-B2O3, and Cs2O-SiO2-B2O3) were examined. Their mixing effects are currently under investigation

  5. Testing and evaluation of solidified high-level waste forms

    International Nuclear Information System (INIS)

    The report describes research by several laboratories on the behaviour, in aqueous and salt environments, of borosilicate glass ceramics proposed for the solidification of nuclear wastes by the European Community. Results were obtained on inactive simulates, doped materials, and on borosilicate glass containing real radioactive waste. The influence of many important parameters were studied: leaching mode, nature of the leachant, pH, pressure, temperature, duration of the treatment, etc. The results of tests lasting for as little as a few hours or for as long as several hundred days, at temperatures up to 2000C or under pressures up to 200 bars, are presented. Numerous analytical techniques (ESCA, EMP, IRR, SEM, etc.) were used to determine the structure and the chemical composition of the altered layer developed by hydration at the glass surface. Information is also given on physical properties of the borosilicate glass: crystallization phase separation, alpha-irradiation stability, mechanical and thermal stability, etc. Finally, preliminary results on the structure and composition of hollandite ceramics are given

  6. Performance testing of waste forms in a tuff environment

    International Nuclear Information System (INIS)

    This paper describes experimental work conducted to establish the chemical composition of water which will have reacted with Topopah Spring Member tuff prior to contact with waste packages. The experimental program to determine the behavior of spent fuel and borosilicate glass in the presence of this water is then described. Preliminary results of experiments using spent fuel segments with defects in the Zircaloy cladding are presented. Some results from parametric testing of a borosilicate glass with tuff and 304L stainless steel are also discussed. Experiments conducted using Topopah Spring tuff and J-13 well water have been conducted to provide an estimate of the post-emplacement environment for waste packages in a repository at Yucca Mountain. The results show that emplacement of waste packages should cause only small changes in the water chemistry and rock mineralogy. The changes in environment should not have any detrimental effects on the performance of metal barriers or waste forms. The NNWSI waste form testing program has provided preliminary results related to the release rate of radionuclides from the waste package. Those results indicate that release rates from both spent fuel and borosilicate glass should be below 1 part in 105 per year. Future testing will be directed toward making release rate testing more closely relevant to site specific conditions. 17 references, 7 figures

  7. Application of PCT to the EBR II ceramic waste form

    International Nuclear Information System (INIS)

    We are evaluating the use of the Product Consistency Test (PCT) developed to monitor the consistency of borosilicate glass waste forms for application to the multiphase ceramic waste form (CWF) that will be used to immobilize waste salts generated during the electrometallurgical conditioning of spent sodium-bonded nuclear fuel from the Experimental Breeder Reactor No. 2 (EBR II). The CWF is a multiphase waste form comprised of about 70% sodalite, 25% borosilicate glass binder, and small amounts of halite and oxide inclusions. It must be qualified for disposal as a non-standard high-level waste (HLW) form. One of the requirements in the DOE Waste Acceptance System Requirements Document (WASRD) for HLW waste forms is that the consistency of the waste forms be monitored.[1] Use of the PCT is being considered for the CWF because of the similarities of the dissolution behaviors of both the sodalite and glass binder phases in the CWF to borosilicate HLW glasses. This paper provides (1) a summary of the approach taken in selecting a consistency test for CWF production and (2) results of tests conducted to measure the precision and sensitivity of the PCT conducted with simulated CWF

  8. Environmental assessment: waste-form selection for SRP high-level waste

    International Nuclear Information System (INIS)

    DOE has recently decided to construct and operate a Defense Waste Processing Facility (DWPF) at the Savannah River Plant (SRP) to immobilize the high-level radioactive waste generated and stored pending disposal in a federal geologic repository. In the immobilization process the high-activity fraction of the SRP high-level waste is mixed with glass frit to form the feed for the melter. The glass is cast from an electric-heated, ceramic-lined melter into canisters. Crystalline ceramic, the leading alternative to borosilicate glass, also appears to be an acceptable form for immobilizing the SRP high-level waste. Both are expected to meet regulations and repository acceptance criteria. The assessment also shows that the environmental effects of disposing of SRP high-level waste as a crystalline ceramic form would not differ significantly from the projected effects for disposal of the borosilicate glass form. A comprehensive evaluation program led to the recommendation of borosilicate glass as the preferred waste form. 10 figures, 19 tables

  9. Development, evaluation, and selection of candidate high-level waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Bernadzikowski, T A; Allender, J S; Gordon, D E; Gould, Jr, T H

    1982-01-01

    The seven candidate waste forms, evaluated as potential media for the immobilization and gelogic disposal of high-level nuclear wastes were borosilicate glass, SYNROC, tailored ceramic, high-silica glass, FUETAP concrete, coated sol-gel particles, and glass marbles in a lead matrix. The evaluation, completed on August 1, 1981, combined preliminary waste form evaluations conducted at Department of Energy (DOE) defense waste-sites and at independent laboratories, peer review assessments, a product performance evaluation, and a processability analysis. Based on the combined results of these four inputs, two of the seven forms, borosilicate glass and a titanate-based ceramic, SYNROC, were selected as the reference and alternative forms, respectively, for continued development and evaluation in the National HLW Program. The borosilicate glass and ceramic forms were further compared during FY-1982 on the basis of risk assessments, cost comparisons, properties comparisons, and conformance with proposed regulatory and repository criteria. Both the glass and ceramic forms are viable candidates for use at DOE defense HLW sites; they are also candidates for immobilization of commercial reprocessing wastes. This paper describes the waste form screening process, discusses each of the four major inputs considered in the selection of the two forms in 1981, and presents a brief summary of the comparisons of the two forms during 1982 and the selection process to determine the final form for SRP defense HLW.

  10. Glass viscosity calculation based on a global statistical modeling approach

    International Nuclear Information System (INIS)

    A global statistical glass viscosity model was developed for predicting the complete viscosity curve, based on more than 2200 composition-property data of silicate glasses from the scientific literature, including soda-lime-silica container and float glasses, TV panel glasses, borosilicate fiber wool and E type glasses, low expansion borosilicate glasses, glasses for nuclear waste vitrification, lead crystal glasses, binary alkali silicates, and various further compositions from over half a century. It is shown that within a measurement series from a specific laboratory the reported viscosity values are often over-estimated at higher temperatures due to alkali and boron oxide evaporation during the measurement and glass preparation, including data by Lakatos et al. (1972) and the recently published High temperature glass melt property database for process modeling by Seward et al. (2005). Similarly, in the glass transition range many experimental data of borosilicate glasses are reported too high due to phase separation effects. The developed global model corrects those errors. The model standard error was 9-17 C, with R2 = 0.985-0.989. The prediction 95% confidence interval for glass in mass production largely depends on the glass composition of interest, the composition uncertainty, and the viscosity level. New insights in the mixed-alkali effect are provided

  11. Glass viscosity calculation based on a global statistical modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    Fluegel, Alex

    2007-02-01

    A global statistical glass viscosity model was developed for predicting the complete viscosity curve, based on more than 2200 composition-property data of silicate glasses from the scientific literature, including soda-lime-silica container and float glasses, TV panel glasses, borosilicate fiber wool and E type glasses, low expansion borosilicate glasses, glasses for nuclear waste vitrification, lead crystal glasses, binary alkali silicates, and various further compositions from over half a century. It is shown that within a measurement series from a specific laboratory the reported viscosity values are often over-estimated at higher temperatures due to alkali and boron oxide evaporation during the measurement and glass preparation, including data by Lakatos et al. (1972) and the recently published High temperature glass melt property database for process modeling by Seward et al. (2005). Similarly, in the glass transition range many experimental data of borosilicate glasses are reported too high due to phase separation effects. The developed global model corrects those errors. The model standard error was 9-17°C, with R^2 = 0.985-0.989. The prediction 95% confidence interval for glass in mass production largely depends on the glass composition of interest, the composition uncertainty, and the viscosity level. New insights in the mixed-alkali effect are provided.

  12. 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. PMID:24261406

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

    International Nuclear Information System (INIS)

    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 r0, 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)

  14. Silica based gel as a potential waste form for high level waste from fuel reprocessing

    International Nuclear Information System (INIS)

    To assess the feasibility of safe disposal of high-level radioactive waste as synthetic clay, or material that would react with ground water to form clay, experiments have been carried out to determine the hydrothermal crystallisation and leaching behaviour of silica based gels fired at 900 deg C. Crystallisation rates at a pressure of 500 bars and at temperatures below 400 deg C are negligible and this more or less precludes pre-disposal production of synthetic clay on the scale required. Leaching experiments suggest that the leach rates of Cs from gels by distilled water are higher than those of boro-silicate glasses and SYNROC at the lower temperatures that would be preferred for geological storage. However, amounts of bulk dissolution of gels may be lower than those of boro-silicate glasses. The initial leaching behaviour of gels might be considerably improved by hot compaction at 900 to 1000 deg C. Consideration of likely waste form dissolution behaviour in a repository environment suggests that gels of appropriate composition might perform as well as, or better than, boro-silicate glasses. A novel hypothetical plant is described that could produce the gel waste form on the scale required on a more or less continuous basis. (author)

  15. High level radioactive waste glass production and product description

    International Nuclear Information System (INIS)

    This report examines borosilicate glass as a means of immobilizing high-level radioactive wastes. Borosilicate glass will encapsulate most of the defense and some of the commercial HLW in the US. The resulting waste forms must meet the requirements of the WA-SRD and the WAPS, which include a short term PCT durability test. The waste form producer must report the composition(s) of the borosilicate waste glass(es) produced but can choose the composition(s) to meet site-specific requirements. Although the waste form composition is the primary determinant of durability, the redox state of the glass; the existence, content, and composition of crystals; and the presence of glass-in-glass phase separation can affect durability. The waste glass should be formulated to avoid phase separation regions. The ultimate result of this effort will be a waste form which is much more stable and potentially less mobile than the liquid high level radioactive waste is currently

  16. Automated radiosynthesis of [18F]ciprofloxacin

    International Nuclear Information System (INIS)

    We transferred the previously published manual synthesis of [18F]ciprofloxacin (decay-corrected RCY: 5.5±1.0%) to an automated synthesis module (TRACERlabTM FXFDG, GE Healthcare) and observed a strong decrease in RCY (0.4±0.4%). When replacing the standard 15-mL glassy carbon reactor of the synthesis module with a 3-mL V-shaped borosilicate glass reactor a considerable improvement in RCY was observed. [18F]Ciprofloxacin was obtained in a RCY of 2.7±1.4% (n=23) with a specific activity at EOS of 1.4±0.5 GBq/µmol in a synthesis time of 160 min. - Highlights: • Automated synthesis of [18F]ciprofloxacin in a TRACERlabTM FXFDG (GE Healthcare) synthesis module was developed. • Dependence of radiochemical yield on reactor type was observed. • 3-mL V-shaped borosilicate glass reactor gave higher radiochemical yield as compared with standard 15-mL glassy carbon reactor. • V-shaped borosilicate glass reactor might also give higher radiochemical yield for other [18F]radiotracers than [18F]ciprofloxacin

  17. Optical and structural properties of ZnO-PbO-B2O3 and ZnO-PbO-B2O3-SiO2 glasses

    International Nuclear Information System (INIS)

    Borate and borosilicate glasses with compositions of xZnO-2xPbO-(1-3x)B2O3 and xZnO-2xPbO-1/2(1-3x)B2O3-1/2(1-3x)SiO2 with x varying from 0.1 to 0.26 mole fraction were prepared by the conventional melt quench technique. Optical and structural properties have been determined by using ultraviolet-visible (UV/vis) and Fourier transform infrared (FTIR) spectroscopic techniques. Decreases in the band gap from 3.57 to 2.62 eV for borate glasses and from 3.00 to 2.35 eV for borosilicate glasses with an increase in the metal oxide content is observed. The density and molar volume has also been measured. Increases in density from 3.994 to 6.339 g cm-3 for borate and from 4.221 to 6.548 g cm-3 for borosilicate glasses are observed with an increase in metal oxide (PbO, ZnO or PbO+ZnO) content. Changes in the atomic structure with composition are observed due to the formation of BO4- units

  18. Structural Roles of Boron and Silicon in the CaO-SiO2-B2O3 Glasses Using FTIR, Raman, and NMR Spectroscopy

    Science.gov (United States)

    Sun, Yongqi; Zhang, Zuotai

    2015-08-01

    The present paper provided not only a deep insight of network structures of borosilicate glasses but also a basic linkage between the network structures and the viscous flow behaviors of many borosilicate melts. The structures of a ternary system of CaO-SiO2-B2O3 were characterized using Fourier transformation infrared (FTIR), Raman, and magic angular spinning nuclear magnetic resonance spectroscopy. The results of FTIR and Raman spectra complementally verified that the main Si-related units were SiO4 tetrahedral with zero, one, two, and three bridging oxygens [Q0(Si), Q1(Si), Q2(Si), and Q3(Si)]; the added B2O3 leaded to an increase of Q3(Si) at the cost of Q0(Si) and Q2(Si), and therefore an increasing degree of polymerization (DOP) was induced. Additionally, the 11B NMR spectra demonstrated that the dominant B-related groups were BO3 trigonal and BO4 tetrahedral, while an increasing B2O3 content facilitated the existence of BO4 tetrahedral. Moreover, there was a competitive effect between the enhanced DOP and the presence of BO3 trigonal and BO4 tetrahedral in the networks, which therefore resulted in a decreasing viscosity of borosilicate melts in numerous studies.

  19. Extended Development Work to Validate a HLW Calcine Waste Form via INL's Cold Crucible Induction Melter

    International Nuclear Information System (INIS)

    To accomplish calcine treatment objectives, the Idaho Clean-up Project contractor, CWI, has chosen to immobilize the calcine in a glass-ceramic via the use of a Hot-Isostatic-Press (HIP); a treatment selection formally documented in a 2010 Record of Decision (ROD). Even though the HIP process may prove suitable for the calcine as specified in the ROD and validated in a number of past value engineering sessions, DOE is evaluating back-up treatment methods for the calcine as a result of the technical, schedule, and cost risk associated with the HIPing process. Consequently DOE HQ has requested DOE ID to make INL's bench-scale cold-crucible induction melter (CCIM) available for investigating its viability as a process alternate to calcine treatment. The waste form is the key component of immobilization of radioactive waste. Providing a solid, stable, and durable material that can be easily be stored is the rationale for immobilization of radioactive waste material in glass, ceramic, or glass-ceramics. Ceramic waste forms offer an alternative to traditional borosilicate glass waste forms. Ceramics can usually accommodate higher waste loadings than borosilicate glass, leading to smaller intermediate and long-term storage facilities. Many ceramic phases are known to possess superior chemical durability as compared to borosilicate glass. However, ceramics are generally multiphase systems containing many minor phase that make characterization and prediction of performance within a repository challenging. Additionally, the technologies employed in ceramic manufacture are typically more complex and expensive. Thus, many have proposed using glass-ceramics as compromise between in the more inexpensive, easier to characterize glass waste forms and the more durable ceramic waste forms. Glass-ceramics have several advantages over traditional borosilicate glasses as a waste form. Borosilicate glasses can inadvertently devitrify, leading to a less durable product that could crack

  20. Reaction of Inconel 690 and 693 in Iron Phosphate Melts: Alternative Glasses for Waste Vitrification

    International Nuclear Information System (INIS)

    The corrosion resistance of candidate materials used for the electrodes (Inconel 690 and 693) and the melt contact refractory (Monofrax K-3) in a Joule Heated Melter (JHM) has been investigated at the University of Missouri-Rolla (UMR) during the period from June 1, 2004 to August 31, 2005. This work was supported by the U.S. Department of Energy (DOE) Office of Biological and Environmental Research (DE-FG02-04ER63831). The unusual properties and characteristics of iron phosphate glasses, as viewed from the standpoint of alternative glasses for vitrifying nuclear and hazardous wastes which contain components that make them poorly suited for vitrification in borosilicate glass, were recently discovered at UMR. The expanding national and international interest in iron phosphate glasses for waste vitrification stems from their rapid melting and chemical homogenization which results in higher furnace output, their high waste loading that varies from 32 wt% up to 75 wt% for the Hanford LAW and HLW, respectively, and the outstanding chemical durability of the iron phosphate wasteforms which meets all present DOE requirements (PCT and VHT). The higher waste loading in iron phosphate glasses, compared to the baseline borosilicate glass, can reduce the time and cost of vitrification considerably since a much smaller mass of glass will be produced, for example, about 43% less glass when the LAW at Hanford is vitrified in an iron phosphate glass according to PNNL estimates. In view of the promising performance of iron phosphate glasses, information is needed for how to best melt these glasses on the scale needed for practical use. Melting iron phosphate glasses in a JHM is considered the preferred method at this time because its design could be nearly identical to the JHM now used to melt borosilicate glasses at the Defense Waste Processing Facility (DWPF), Westinghouse Savannah River Co. Therefore, it is important to have information for the corrosion of candidate electrode

  1. Characterization of Fast-Scan Cyclic Voltammetric Electrodes Using Paraffin as an Effective Sealant with In Vitro and In Vivo Applications.

    Directory of Open Access Journals (Sweden)

    Eric S Ramsson

    Full Text Available Fast-scan cyclic voltammetry (FSCV is a powerful technique for measuring sub-second changes in neurotransmitter levels. A great time-limiting factor in the use of FSCV is the production of high-quality recording electrodes; common recording electrodes consist of cylindrical carbon fiber encased in borosilicate glass. When the borosilicate is heated and pulled, the molten glass ideally forms a tight seal around the carbon fiber cylinder. It is often difficult, however, to guarantee a perfect seal between the glass and carbon. Indeed, much of the time spent creating electrodes is in an effort to find a good seal. Even though epoxy resins can be useful in this regard, they are irreversible (seals are permanent, wasteful (epoxy cannot be reused once hardener is added, hazardous (hardeners are often caustic, and require curing. Herein we characterize paraffin as an electrode sealant for FSCV microelectrodes. Paraffin boasts the advantages of near-immediate curing times, simplicity in use, long shelf-life and stable waterproof seals capable of withstanding extended cycling. Borosilicate electrode tips were left intact or broken and dipped in paraffin embedding wax. Excess wax was removed from the carbon surface with xyelenes or by repeated cycling at an extended waveform (-0.4 to 1.4V, 400 V/s, 60 Hz. Then, the waveform was switched to a standard waveform (-0.4 to 1.3V, 400 V/s, 10 Hz and cycled until stable. Wax-sealing does not inhibit electrode sensitivity, as electrodes detected linear changes in dopamine before and after wax (then xylenes exposure. Paraffin seals are intact after 11 days of implantation in the mouse, and still capable of measuring transient changes in in vivo dopamine. From this it is clear that paraffin wax is an effective sealant for FSCV electrodes that provides a convenient substitute to epoxy sealants.

  2. Characterization of Fast-Scan Cyclic Voltammetric Electrodes Using Paraffin as an Effective Sealant with In Vitro and In Vivo Applications.

    Science.gov (United States)

    Ramsson, Eric S; Cholger, Daniel; Dionise, Albert; Poirier, Nicholas; Andrus, Avery; Curtiss, Randi

    2015-01-01

    Fast-scan cyclic voltammetry (FSCV) is a powerful technique for measuring sub-second changes in neurotransmitter levels. A great time-limiting factor in the use of FSCV is the production of high-quality recording electrodes; common recording electrodes consist of cylindrical carbon fiber encased in borosilicate glass. When the borosilicate is heated and pulled, the molten glass ideally forms a tight seal around the carbon fiber cylinder. It is often difficult, however, to guarantee a perfect seal between the glass and carbon. Indeed, much of the time spent creating electrodes is in an effort to find a good seal. Even though epoxy resins can be useful in this regard, they are irreversible (seals are permanent), wasteful (epoxy cannot be reused once hardener is added), hazardous (hardeners are often caustic), and require curing. Herein we characterize paraffin as an electrode sealant for FSCV microelectrodes. Paraffin boasts the advantages of near-immediate curing times, simplicity in use, long shelf-life and stable waterproof seals capable of withstanding extended cycling. Borosilicate electrode tips were left intact or broken and dipped in paraffin embedding wax. Excess wax was removed from the carbon surface with xyelenes or by repeated cycling at an extended waveform (-0.4 to 1.4V, 400 V/s, 60 Hz). Then, the waveform was switched to a standard waveform (-0.4 to 1.3V, 400 V/s, 10 Hz) and cycled until stable. Wax-sealing does not inhibit electrode sensitivity, as electrodes detected linear changes in dopamine before and after wax (then xylenes) exposure. Paraffin seals are intact after 11 days of implantation in the mouse, and still capable of measuring transient changes in in vivo dopamine. From this it is clear that paraffin wax is an effective sealant for FSCV electrodes that provides a convenient substitute to epoxy sealants. PMID:26505195

  3. Electrical conductivity of oxides from molten state to glassy. Effect on the incorporation of RuO{sub 2} particles; Conductivite electrique des verres et fontes d'oxides. Effets de l'incorporation de particules RuO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Simonnet, C

    2004-07-01

    This study concerns the electrical conductivity of oxides from molten state to glassy state and, in particular, the effect of the incorporation of RuO{sub 2} particles in the context of vitrification of radioactive waste. The material of interest in the nuclear field is basically a viscous or vitreous borosilicate containing a dispersion of RuO{sub 2} microcrystals. A very simple model of this heterogeneous material has been studied in particular (SiO{sub 2}, B{sub 2}O{sub 3}, Na{sub 2}O, RuO{sub 2}). An original method of impedance measurement in the liquid at high temperature yields reliable electrical conductivity values over a temperature range covering the liquid and vitreous phases of the borosilicates studied. In the borosilicate matrix, alkaline transport is mainly responsible for the ionic conduction. The temperature dependence of the conductivity may thus be represented by an equation combining a VFT law and an Arrhenius law to represent the electrical conductivity above and below T{sub g}. Beyond a critical volume fraction V{sub c} {approx} 0.01 of RuO{sub 2}, an electronic contribution is added to the ionic contribution of the matrix and the electrical conductivity increases significantly with the RuO{sub 2} content. This effect is described in terms of electrical percolation of the particle network. An electronic mechanism by tunnel transfer between particles is demonstrated. A mathematical model is developed to describe this mechanism in the solid composite. Beyond T{sub g}, conduction by the tunnel effect persists and the partial solubilization of RuO{sub 2} appears to be mainly responsible for the significant increase in electronic conductivity with the temperature. (author)

  4. Immobilization of Uranium Silicide in Sintered Iron-Phosphate Glass

    International Nuclear Information System (INIS)

    This work is a continuation of a previous one performed in vitrification of uranium silicide in borosilicate and iron-silicate glasses, by sintering.We present the results obtained with an iron-phosphate glass developed at our laboratory and we compare this results with those obtained with the above mentioned glasses. The main objective was to develop a method as simple as possible, so as to get a monolithic glass block with the appropriate properties to be disposed in a deep geological repository.The thermal transformation of the uranium silicide was characterized by DTA/TG analysis and X-ray diffraction.We determined the evolution of the crystalline phases and the change in weight.Calcined uranium silicide was mixed with natural U3O8, the amount of U3O8 was calculated to simulate an isotopic dilution of 4%.This material was mixed with powdered iron-phosphate glass (in wt.%: 64,9 P2O5; 22,7 Fe2O3; 8,1 Al2O3; 4,3 Na2O) in different proportions (in wt%): 7%, 10% y 15%.The powders were pressed and sintered at temperatures between 585 y 670 °C. Samples of the sintered pellet were prepared for the lixiviation tests (MCC-1P: monolithic samples; deionised water; 90° C; 7, 14 and 28 days).The samples showed a quite good durability (0,6 g.m-2.day-1), similar to borosilicate glasses.The microstructure of the glass samples showed that the uranium particles are much better integrated to the glass matrix in the iron-phosphate glasses than in the borosilicate or iron-silicate glasses.We can conclude that the sintered product obtained could be a good alternative for the immobilization of nuclear wastes with high content of uranium, as the ones arising from the conditioning of research reactors spent fuels

  5. Vitrification of spent mordenite molecular sieves

    International Nuclear Information System (INIS)

    Vitrification of cesium loaded inorganic ion exchangers (mordenite type molecular sieves/zeolite AR-1) was studied empolying borosilicate glass systems. Direct vitrification of aluminosilicates is rather difficult mainly on account of volatility of cesium at processing temperatures of 1100 degC-1300 degC. In the borosilicate glass system, oxides of lead, sodium and zinc along with boric oxide were employed as major glass formers. Homogeneous glass matrix was obtained incorporating simulated composition of mordenite along with oxides of sodium, lead and boron at the processing temperature of 950 degC. The waste oxide loading up to 50% on dry weight basis was incorporated in this glass formulation. Partial replacement of PbO by TeO2, Bi2O3 and CaF2 resulted in lowering of the processing temperature and also increasing homogeneity of matrix. Based on these results, a glass matrix was prepared with actual cesium AR-1 molecular sieves with processing temperature limited to 925 degC. Powdered samples of glass matrix were subjected to leaching as per ASTM-1285 Product Consistency Test in high purity water at 90 degC for 28 days. The normalised cesium leach rate of this glass was found to be 3.92 x 10-6 g/cm2/day, which is comparable to sodium borosilicate glass matrices currently in use for immobilisation of high level waste. The molecular sieves are also amenable to immobilization in cement matrix. As expected, there is substantial volume reduction by factor 3 in vitrification compared to their immobilization in cementious matrices. Also the quantity of cesium leached from vitrified product was nearly 10,000 times lower compared to cement based matrix. Vitrification of mordenite molecular sieves would lead to high capacity utilisation of zeolite AR-1 for the treatment of low and intennediate levelliquid effluents. (author)

  6. Directly laser-written integrated photonics devices including diffractive optical elements

    Science.gov (United States)

    Choi, Jiyeon; Ramme, Mark; Richardson, Martin

    2016-08-01

    Femtosecond laser-written integrated devices involving Fresnel Zone Plates (FZPs) and waveguide arrays are demonstrated as built-in optical couplers. These structures were fabricated in borosilicate glass using a direct laser writing technique. The optical properties of these integrated photonic structures were investigated using CW lasers and high-resolution CCDs. For a single FZP coupled to a single waveguide, the overall coupling efficiency was 9%. A multiplexed optical coupler composed of three FZP layers was demonstrated to couple three waveguides simultaneously in a waveguide array. Structures of this type can be used as platforms for multichannel waveguide coupling elements or as microfluidic sensors that require higher light collecting efficiency.

  7. Aqueous corrosion of silicate glasses. Analogy between volcanic glasses and the French nuclear waste glass R7T7

    International Nuclear Information System (INIS)

    The behaviour of borosilicate glasses upon aqueous corrosion is controlled for long periods of time (>10,000 years) by processes which are not directly accessible by means of laboratory experiments. The analogical approach consists here to compare leaching performances between the french nuclear waste glass R7T7 and natural volcanic glasses, basaltic and rhyolitic ones. The three glasses were leached in the same conditions; open system, 90 deg C, initial pH of 9.7. Basaltic and R7T7 glasses having the same kinetic of dissolution, the basaltic glass was chosen as the best analogue. (author). refs., figs., tabs

  8. The role of ceramics, cement and glass in the immobilization of radioactive wastes

    International Nuclear Information System (INIS)

    A brief account is given of the constitution and origin of nuclear waste. The immobilization of wastes is discussed: borosilicate glasses are considered as possible matrices; ceramic forms are dealt with in more detail. The principles of the use of ceramics are explained, with examples of different ceramic structures; cements are mentioned as being suitable for wet, medium- to low-active wastes. The effects of radiation on cement, ceramic and glass waste forms are indicated. The account concludes with 'summary and future progress'. (U.K.)

  9. ガラスの分相現象を利用した高炉水砕スラグの再資源化技術の開発

    OpenAIRE

    崎田, 真一; 三上, 修平; 難波, 徳郎; 三浦, 嘉也

    2007-01-01

    A novel recycling process of blast furnace slag was developed in order to obtain colorless silica-rich solids by using phase separation of borosilicate glass. B(2)O(3) was added to blast furnace slag to promote the phase separation. The slag glasses were heat-treated above glass transition temperatures. The slag glass prepared from blast furnace slag gelled after the heat treatment and the subsequent three types of acid treatment. The ratios of SiO(2) component in the gels were 40 – 60mass%. ...

  10. ガラスの分相現象を利用した高炉水砕スラグの再資源化技術の開発

    OpenAIRE

    崎田, 真一; 三上, 修平; 難波, 徳郎; 三浦, 嘉也

    2007-01-01

    A novel recycling process of blast furnace slag was developed in order to obtain colorless silica-rich solids by using phase separation of borosilicate glass. B(2)O(3) was added to blast furnace slag to promote the phase separation. The slag glasses were heat-treated above glass transition temperatures. The slag glass prepared from blast furnace slag gelled after the heat treatment and the subsequent three types of acid treatment. The ratios of SiO(2) component in the gels were 40 - 60mass%. ...

  11. Investigation on technetium species in ground water and migration through caly columns

    International Nuclear Information System (INIS)

    Speciation of technetium in ground water has been studied for understanding the migration behaviour of this radionuclide in deep geological formations. A combination of free-liquid electromigration, ion exchange, solvent extraction, coprecipitation and dialysis methods has been applied. Both oxic and anoxic conditions have been employed. Systems studied include leaching of sodium borosilicate glass spiked with 99Tc and sup(95m)Tc followed by its passage through glauconitic sand columns, and dialysis of TcO2 with ground water, sodium chloride, and humic acid solutions. Results indicate the presence of the pertechnetate, TcO4-, ion as the dominating species. (author)

  12. Leaching from irradiated nuclear fuel by direct disposal

    International Nuclear Information System (INIS)

    To evaluate the radiological hazards of storing irradiated fuel in geological formations the literature of leaching irradiated LWR fuel in water has been studied. There seems to have been made very few relevant experimental studies. Leach tests are being performed at Batelle-Northwest, Richland, US and some of the results have been published. These results and conclusions are summarized and discussed. The relative leachability of the elements decrease in the order of Cs gt Sb gt Sr + Y gt Pu gt Cm. The cesium based periodic leach rate for irradiated fuel fragments are similar to the based leach rate for borosilicate glass containing radioactive waste. (author)

  13. A High-Precision Micropipette Sensor for Cellular-Level Real-Time Thermal Characterization

    OpenAIRE

    Wonseok Chang; Donsik Kim; Ramesh Shrestha; Tae-Youl Choi

    2011-01-01

    We report herein development of a novel glass micropipette thermal sensor fabricated in a cost-effective manner, which is capable of measuring steady thermal fluctuation at spatial resolution of ~2 µm with an accuracy of ±0.01 °C. We produced and tested various micrometer-sized sensors, ranging from 2 µm to 30 µm. The sensor comprises unleaded low-melting-point solder alloy (Sn-based) as a core metal inside a pulled borosilicate glass pipette and a thin film of nickel coating outside, creatin...

  14. Dissolution of vitrified wastes in a high-pH calcium-rich solution

    Science.gov (United States)

    Utton, C. A.; Hand, R. J.; Bingham, P. A.; Hyatt, N. C.; Swanton, S. W.; Williams, S. J.

    2013-04-01

    The current baseline for the conditioning of most UK intermediate-level radioactive waste (ILW) is immobilisation using cement. However, vitrification of some UK ILW is being considered as an alternative. One option for the disposal of the resulting vitrified ILW would be to place it in a geological disposal facility in a high-pH environment with cemented ILW and a cement-based backfill. Therefore, the potential effects of such a high pH (˜12.5), calcium-rich cement-based environment on the dissolution behaviour of simulant ILW glasses have been studied using the product consistency test (PCT). Three non-radioactive waste compositions were assessed: a laboratory simulant ILW vitrified in a borosilicate glass and two full-scale simulant vitrified products (a slag containing simulant plutonium-contaminated material and Magnox sludge; and a glass containing clinoptilolite). Powdered samples were leached in saturated Ca(OH)2 solutions for up to 42 days at temperatures between 30 and 90 °C. In general the rates of dissolution were lower than expected at such a high pH compared to studies in the literature under alkaline conditions. In contrast to the typical dissolution behaviour of high level waste (HLW) glasses, dissolution of the simulant borosilicate ILW glass was initially slow, followed by a period of faster boron and alkali metal release. The saturation/residual regime was not reached within experimental timescales. The rate of dissolution during the period of faster release increased with increasing temperature; the activation energy for this stage of dissolution was calculated to be 47 ± 2 kJ mol-1 based on boron release. The two full-scale simulant glasses, which contained negligible boric oxide, exhibited conventional static dissolution profiles, and entered the residual rate regime after 7-14 days at 50 °C. The greater durability of the full-scale simulants is thought to be due to the greater content of network-forming oxides in these glasses compared to

  15. Effect of compressive stress inducing a band gap narrowing on the photoinduced activities of sol-gel TiO2 films

    OpenAIRE

    Ghazzal, Mohamed N.; Chaoui, N.; Genet, Michel; Gaigneaux, Eric M.; Robert, D.

    2011-01-01

    TiO2 thin films grown on different kinds of substrates were obtained by sol–gel process. X-ray diffraction revealed that the TiO2 lattice parameter c decreased continuously, indicating a continuous variation in the compressive stress, a negligible compressive stress of the film grown onto Soda-Lime Glass (SLG), medium compressive stress of the film grown onto BoroSilicate Glass (BSG) and large compressive stress of the film deposited onto the Quartz Substrate (QS). UV–Vis absorbance spectra e...

  16. Hanford Waste Vitrification Program process development: Melt testing subtask, pilot-scale ceramic melter experiment, run summary

    International Nuclear Information System (INIS)

    Hanford Waste Vitrification Program (HWVP) activities for FY 1985 have included engineering and pilot-scale melter experiments HWVP-11/HBCM-85-1 and HWVP-12/PSCM-22. Major objectives designated by HWVP fo these tests were to evaluate the processing characteristics of the current HWVP melter feed during actual melter operation and establish the product quality of HW-39 borosilicate glass. The current melter feed, defined during FY 85, consists of reference feed (HWVP-RF) and glass-forming chemicals added as frit

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

    International Nuclear Information System (INIS)

    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

  18. Graphite fiber reinforced glass matrix composites for aerospace applications

    Science.gov (United States)

    Prewo, K. M.; Bacon, J. F.; Dicus, D. L.

    1979-01-01

    The graphite fiber reinforced glass matrix composite system is described. Although this composite is not yet a mature material, it possesses low density, attractive mechanical properties at elevated temperatures, and good environmental stability. Properties are reported for a borosilicate glass matrix unidirectionally reinforced with 60 volume percent HMS graphite fiber. The flexural strength and fatigue characteristics at room and elevated temperature, resistance to thermal cycling and continuous high temperature oxidation, and thermal expansion characteristics of the composite are reported. The properties of this new composite are compared to those of advanced resin and metal matrix composites showing that graphite fiber reinforced glass matrix composites are attractive for aerospace applications.

  19. Low-loss waveguides fabricated in BK7 glass by high repetition rate femtosecond fiber laser

    International Nuclear Information System (INIS)

    For the first time femtosecond-laser writing has inscribed low-loss optical waveguides in Schott BK7 glass, a commercially important type of borosilicate widely used in optical applications. The use of a variable repetition rate laser enabled the identification of a narrow processing window at 1 MHz repetition rate with optimal waveguides exhibiting propagation losses of 0.3 dB/cm and efficient mode matching to standard optical fibers at a 1550 nm wavelength. The waveguides were characterized by complementary phase contrast and optical transmission microscopy, identifying a micrometer-sized guiding region within a larger complex structure of both positive and negative refractive index variations

  20. Reference commercial high-level waste glass and canister definition

    International Nuclear Information System (INIS)

    This report presents technical data and performance characteristics of a high-level waste glass and canister intended for use in the design of a complete waste encapsulation package suitable for disposal in a geologic repository. The borosilicate glass contained in the stainless steel canister represents the probable type of high-level waste product that will be produced in a commercial nuclear-fuel reprocessing plant. Development history is summarized for high-level liquid waste compositions, waste glass composition and characteristics, and canister design. The decay histories of the fission products and actinides (plus daughters) calculated by the ORIGEN-II code are presented

  1. Performance of a large-scale melter off-gas system utilizing simulated SRP DWPF waste

    International Nuclear Information System (INIS)

    The Department of Energy and the DuPont Company have begun construction of a Defense Waste Processing Facility to immobilize radioactive waste now stored as liquids at the Department of Energy's Savannah River Plant. The immobilization process solidifies waste sludge by vitrification into a leach-resistant borosilicate glass. Development of the process has been the responsibility of the Savannah River Laboratory. As part of the development, two large-scale glass melter systems have been designed and operated with simulated waste. Experimental data from these operations show that process requirements will be met. 6 references, 8 figures, 4 tables

  2. Observation of tunable optical filtering in photosensitive composite structures containing liquid crystals.

    Science.gov (United States)

    Gilardi, Giovanni; De Sio, Luciano; Beccherelli, Romeo; Asquini, Rita; d'Alessandro, Antonio; Umeton, Cesare

    2011-12-15

    We report on the investigation and characterization of an optically tunable filtering effect, observed in a waveguide grating made of alternated strips of photocurable polymer and a mixture of azo-dye-doped liquid crystal. The grating is sandwiched between two borosilicate glasses, one of which includes an ion-exchanged channel waveguide, which confines the optical signal to be filtered. Exposure to a low power visible light beam modifies the azo-dye molecular configuration, thus allowing the filtered wavelength to be tuned over a 6.6 nm range. Simulations of the filtering response are well described with our experimental findings. PMID:22179873

  3. High efficiency tantalum-based ceramic composite structures

    Science.gov (United States)

    Stewart, David A. (Inventor); Leiser, Daniel B. (Inventor); DiFiore, Robert R. (Inventor); Katvala, Victor W. (Inventor)

    2010-01-01

    Tantalum-based ceramics are suitable for use in thermal protection systems. These composite structures have high efficiency surfaces (low catalytic efficiency and high emittance), thereby reducing heat flux to a spacecraft during planetary re-entry. These ceramics contain tantalum disilicide, molybdenum disilicide and borosilicate glass. The components are milled, along with a processing aid, then applied to a surface of a porous substrate, such as a fibrous silica or carbon substrate. Following application, the coating is then sintered on the substrate. The composite structure is substantially impervious to hot gas penetration and capable of surviving high heat fluxes at temperatures approaching 3000.degree. F. and above.

  4. Comparison of spray pyrolyzed FTO, ATO and ITO coatings for flat and bent glass substrates

    OpenAIRE

    Bisht, Harish; Aegerter, Michel A.; Mehrtens, Andre; Eun, H.-T.

    1999-01-01

    Transparent conductive FTO, ATO and ITO films were synthesized by spray pyrolysis technique on flat 12x12 cm borosilicate glass substrates at 500-550°C and investigated with respect to their electrical and optical properties. The resistivity of sprayed ITO films decreases with the thickness down to 3.0x10-4 Ω cm (300 nm). The optical transmission in the visible range is 80% and the near IR reflection up to 96% for thicknesses larger than 300 nm. A reducing treatment at 400°C in forming g...

  5. Optical devices in adverse environments; Proceedings of the Meeting, Cannes, France, Nov. 19, 20, 1987

    Science.gov (United States)

    Greenwell, Roger A.

    Recent advances in the design of fiber-optic devices, test equipment, optical sensors, and lasers for operation in hostile environments are discussed in reviews and reports. Topics examined include radiation effects on optical fibers, the effect of H2 treatment and water content on the recovery of undoped core fibers after pulsed and continuous irradiation, the NATO test program for optical fibers and components, alpha-irradiation damage to borosilicate glasses, high-reliability optical components for undersea light-wave systems, the behavior of Si optoelectronic components under gamma irradiation, optical devices and sensors of special-purpose fibers, and a fiber-optic microprobe for interferometric measurements in generators.

  6. Design of the Apache-Point Observatory 3.5-METER Telescope - Part Two - Deformation Analysis of the Primary Mirror

    Science.gov (United States)

    Siegmund, W. A.; Mannery, E. J.; Radochia, J.; Gillett, P. E.

    1986-01-01

    The authors have calculated the deflection of the surface of a 3.5 meter diameter borosilicate mirror using the finite element method. The mirror is a 0.46 m thick honeycomb structure with 25 mm thick face plates and 13 mm ribs. The cell spacing is 0.192 m and is regular except near the inner and outer perimeters. Axial support for the mirror will be provided by 48 air pistons. The effects of thickness variations in fabrication of the mirror are presented and are small for the magnitudes of the variations expected. Several thermal load cases are described.

  7. SRAT/SME Vessel

    International Nuclear Information System (INIS)

    The Defense Waste Processing Facility (DWPF), at the Savannah River Site (SRS), is processing and immobilizing the radioactive high level waste sludge slurry at SRS into a durable borosilicate glass for final geological disposal. Each time a new batch of radioactive sludge is to be processed by the DWPF, the process flow sheet is to be tested and demonstrated to ensure an acceptable melter feed and glass can be made. These demonstrations are completed in the Shielded Cells Facility in the Savannah River National Laboratory at SRS

  8. Large-scale optical diffraction tomography for inspection of optical plastic lenses

    CERN Document Server

    Kim, Kyoohyun; Park, YongKeun

    2015-01-01

    Herein is presented an optical diffraction tomography (ODT) technique for measuring 3-D refractive index (RI) maps of optical plastic lenses. A Mach-Zehnder interferometer was used to measure multiple complex optical fields of a plastic lens immersed in RI matching oil, at various rotational orientations. From this, ODT was used to reconstruct a 3-D RI distribution of the plastic lens with unprecedented RI sensitivity (dn = 4.21 x 10^-5) and high resolution (12.8 um). As a demonstration, 3-D RI distributions of a 2-mm-diameter borosilicate sphere and a 5-mm-diameter plastic lens

  9. Strategy for product composition control in the Hanford Waste Vitrification Plant

    International Nuclear Information System (INIS)

    The Hanford Waste Vitrification Plant (HWVP) will immobilize transuranic and high-level radioactive waste in borosilicate glass. The major objective of the Process/Product Model Development (PPMD) cost account of the Pacific Northwest Laboratory HWVP Technology Development (PHTD) Project is the development of a system for guiding control of feed slurry composition (which affects glass properties) and for checking and documenting product quality. This document lays out the broad structure of HWVP's product composition control system, discusses five major algorithms and technical issues relevant to this system, and sketches the path of development and testing

  10. Structural evaluation of candidate space shuttle thermal protection systems

    Science.gov (United States)

    Burns, A. B.

    1972-01-01

    The characteristics and development of a lightweight reusable thermal protection system for the space shuttle are discussed. The test articles consisted of metallic substrates with upper surfaces covered with all-silica, reusable, surface insulation material. The material is processed in the form of tiles. The external surfaces of the tiles are provided with a coating system which consists of a borosilicate coating with a silicon carbide emittance agent and impregnation with a hydrophobic agent. The finished tiles are attached to the metal substrate by adhesive bonding. Charts and graphs of the properties of the material are provided.

  11. Polycrystalline silicon for thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, R.; Kuehnle, J.; Werner, J.H. [Max-Planck-Inst. fuer Festkoerperforschung, Stuttgart (Germany); Oelting, S. [ANTEC GmbH, Kelkheim (Germany); Albrecht, M.; Strunk, H.P. [Univ. Erlangen (Germany). Inst. fuer Werkstoffwissenschaften; Herz, K.; Powalla, M. [Zentrum fuer Sonnenenergie und Wasserstofforschung, Stuttgart (Germany)

    1994-12-31

    The authors report on the characterization of epitaxial Si on Si substrates grown at temperatures around 450 C as one prerequisite for crystalline Si deposition on low temperature resistant foreign substrates and describe two novel approaches aimed to produce large grained seedling films for subsequent polycrystalline Si deposition on glass substrates. A modified solution growth process at temperatures around 600--650 C produces polycrystalline Si seeding films with grains laterally extending several 100 {micro}m on borosilicate glass substrates. In a second approach, the authors use polycrystalline {beta}-FeSi{sub 2} films as a seed for Si deposition.

  12. Pilot production & commercialization of LAPPD™

    International Nuclear Information System (INIS)

    We present a progress update on plans to establish pilot production and commercialization of Large Area (400 cm2) Picosecond Photodetector (LAPPD™). Steps being taken to commercialize this MCP and LAPPD™ technology and begin tile pilot production are presented including (1) the manufacture of 203 mm×203 mm borosilicate glass capillary arrays (GCAs), (2) optimization of MCP performance and creation of an ALD coating facility to manufacture MCPs and (3) design, construction and commissioning of UHV tile integration and sealing facility to produce LAPPDs. Taken together these plans provide a “pathway toward commercialization”

  13. Low energy ion transmission through a conical insulating capillary with macroscopic dimensions

    International Nuclear Information System (INIS)

    Transmission of 1 keV single charged nitrogen ions through a macroscopic tapered borosilicate glass capillary is studied theoretically and experimentally. Measured time trend of the transmission for different low beam intensities are given. They are compared to realistic microscopic calculation that allows simulating the transmission of charged particles through a conical capillary with macroscopic dimensions. We show clear evidence that a low energy ion beam with intensities in the pA range can be transmitted and focused through tapered macroscopic insulator capillaries

  14. Câmaras climáticas para o envelhecimento acelerado: ação de microambientes sobre bens culturais Environmental chambers for the accelerated ageing: effect of microclimates on cultural heritage

    Directory of Open Access Journals (Sweden)

    Renato Inhasz Paiva

    2010-01-01

    Full Text Available Environmental chambers were designed for the accelerated ageing of materials used in artistic artifacts to study the synergistic action of temperature, humidity, UV and visible radiation and gaseous pollutants. Two inox-steel/PTFE compartments are kept under controlled temperature and relative humidity, whose values are transmitted to a PC, which stores, plots in real time and continuously feedback heating and humidifying devices through logical signals. A borosilicate, or quartz, window allows the irradiation inside the chamber from an external source. A flow of purified air purges the chamber and conveys selected pollutants from an external source. Each independent compartment works under either stationary or cyclic conditions.

  15. Inhomogeneity and microstructure in e-beam evaporated ZrO2 films

    International Nuclear Information System (INIS)

    In this paper thin films of zirconium dioxide are deposited by e-beam evaporation on optically polished borosilicate crown glass. Two different oxygen partial pressures in the chamber are used. The optical properties of the films are characterized by ellipsometry. The influence of oxygen stoichiometry on the composition and microstructure of the material is investigated by polycrystalline X-ray diffraction for different film thicknesses. The films are found to be inhomogeneous, and a composition gradient (i.e. amorphous ↔ tetragonal ↔ monoclinic) is observed from the substrate to the surface. The oxygen partial pressure influences the growth of the films

  16. Melting Hanford LAW into Iron-Phosphate Glass in a CCIM

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Sharna Rossberg

    2011-09-01

    A vitrification test has been conducted using the cold crucible induction melter (CCIM) test system at the Idaho National Laboratory. The test was conducted to demonstrate the vitrification of a Hanford low activity waste (LAW) that contains relatively large amounts of sulfate and sodium, compared to other radioactive Hanford waste streams. The high sulfate content limits the potential loading of this waste stream in conventional borosilicate glass, so this test demonstrated how this waste stream could be vitrified in an iron-phosphate glass that can tolerate higher levels of sulfate.

  17. 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.

  18. A large-area microstrip-gas-counter for X-ray astronomy

    Science.gov (United States)

    Ramsey, B. D.; Apple, J. A.; Austin, R. A.; Dietz, K. L.; Minamitani, T.; Kolodziejczak, J. J.; Weisskopf, M. C.

    1996-02-01

    We have developed a large-area coded-mask telescope for hard-X-ray astronomy. The heart of the instrument is an imaging microstrip-gas-counter of active area 30 cm × 30 cm and filled with 2 × 105 Pa of xenon + 2% isobutylene. Fabricated on a single sheet of borosilicate glass, 1 mm thick, the microstrip features fine anodes (10 μm) and interleaved cathodes from which the position sensing is derived. Rear pickup electrodes provide the second coordinate. Full details of the instrument and its performance are presented. A first flight, from a high-altitude balloon, is scheduled for the Spring of 1977.

  19. Glass matrix composites. I - Graphite fiber reinforced glass

    Science.gov (United States)

    Prewo, K. M.; Bacon, J. F.

    1978-01-01

    An experimental program is described in which graphite fibers of Hercules HMS and HTS, Thornel 300, and Celanese DG-12 were used to reinforce, both uniaxially and biaxially, borosilicate pyrex glass. Composite flexural strength distribution, strength as a function of test temperature, fracture toughness and oxidative stability were determined and shown to be primarily a function of fiber type and the quality of fiber-matrix bond formed during composite fabrication. It is demonstrated that the graphite fiber reinforced glass system offers unique possibilities as a high performance structural material.

  20. Hanford Waste Vitrification Plant full-scale feed preparation testing with water and process simulant slurries

    International Nuclear Information System (INIS)

    The Hanford Waste Vitrification Plant was intended to convert selected, pretreated defense high-level waste and transuranic waste from the Hanford Site into a borosilicate glass. A full-scale testing program was conducted with nonradioactive waste simulants to develop information for process and equipment design of the feed-preparation system. The equipment systems tested included the Slurry Receipt and Adjustment Tank, Slurry Mix Evaporator, and Melter-Feed Tank. The areas of data generation included heat transfer (boiling, heating, and cooling), slurry mixing, slurry pumping and transport, slurry sampling, and process chemistry. 13 refs., 129 figs., 68 tabs

  1. Hanford Waste Vitrification Plant full-scale feed preparation testing with water and process simulant slurries

    Energy Technology Data Exchange (ETDEWEB)

    Gaskill, J.R.; Larson, D.E.; Abrigo, G.P. [and others

    1996-03-01

    The Hanford Waste Vitrification Plant was intended to convert selected, pretreated defense high-level waste and transuranic waste from the Hanford Site into a borosilicate glass. A full-scale testing program was conducted with nonradioactive waste simulants to develop information for process and equipment design of the feed-preparation system. The equipment systems tested included the Slurry Receipt and Adjustment Tank, Slurry Mix Evaporator, and Melter-Feed Tank. The areas of data generation included heat transfer (boiling, heating, and cooling), slurry mixing, slurry pumping and transport, slurry sampling, and process chemistry. 13 refs., 129 figs., 68 tabs.

  2. Immobilization of Pu-containing wastes into glass and ceramics: Results of US-Russia collaboration

    Science.gov (United States)

    Anderson, E. B.; Aloy, A. S.; Burakov, B. E.; Jardine, L. J.

    2000-07-01

    This continuing collaboration between the V.G. Khlopin Radium Institute (KRI) in St. Petersberg, Russia, and Lawrence Livermore National Laboratory (LLNL) in the United States was initiated in 1997. The collaboration is focused on plutonium immobilization to support the disposition of excess weapons plutonium in the US and Russia. Our work consists primarily of laboratory-scale experiments and studies of borosilicate and phosphate Pu-doped glasses and zircon/zirconia, mono-zirconia, and pyrochlore ceramics. The results were used to compare and evaluate the use of these various materials in Pu immobilization.

  3. Raman signature modification induced by copper nanoparticles in silicate glass

    OpenAIRE

    Colomban, Philippe; D. Screiber, Henry

    2005-01-01

    Composite materials formed by metal nanoclusters embedded in glasses/glazes have been produced for centuries (Roman hematinum and Renaissance alassonti, Coptic lustre-painted glass and Islamic lustre ceramics). Comparisons were drawn from Raman analyses of alkali borosilicate glasses coloured by copper as “blue” Cu2+ (peak absorption at 750 nm), as “colourless” Cu+, and as “opaque red” Cu0 (peak absorptions at ~420 and 570 nm). In particular, Raman analyses of copper-ruby glasses containing C...

  4. Spin-polarized lithium diffusion in a glass hot-vapor cell

    Science.gov (United States)

    Ishikawa, Kiyoshi

    2016-08-01

    We report diffusion coefficients of optically pumped lithium atoms in helium buffer gas. The free-induction decay and the spin-echo signals of ground-state atoms were optically detected in an external magnetic field with the addition of field gradient. Lithium hot vapor was produced in a borosilicate-glass cell at a temperature between 290 and 360°C. The simple setup using the glass cells enabled lithium atomic spectroscopy in a similar way to other alkali-metal atoms and study of the collisional properties of lithium atoms in a hot-vapor phase.

  5. Influence of Composition of Sm2O3-Containing Rare Earth Glass on Its Absorption Spectrum

    Institute of Scientific and Technical Information of China (English)

    Zhang Qitu; Wang Tingwei; Meng Xianfeng; Shan Xiaobing; Xu Zhongzi

    2005-01-01

    Borosilicate glass with high rare earth content was fabricated by traditional method. The influence of glass compositions and rare earth content on absorption spectra was examined and discussed. With increasing Sm2O3 content, the intensity of characteristic absorption peak is increased and the absorption peak is broadened. With increasing of the ratios of SiO2/B2O3 and Al2O3/SiO2, the broadening degree of absorption peak is increased. The experimental results provide basis for making special optical glasses which have the characteristics of high absorption for special wavelength laser and high transparence for visible light.

  6. Fiscal Year 2010 Summary Report on the Epsilon-Metal Phase as a Waste Form for 99 Tc

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Crum, Jarrod V.; Buck, Edgar C.; Riley, Brian J.; Zumhoff, Mac R.

    2010-09-30

    Epsilon metal (ε-metal) is generated in nuclear fuel during irradiation. This metal consists of Pd, Ru, Rh, Mo, and some Te. These accumulate at the UO2 grain boundaries as small (ca 5 µm) particles. These metals have limited solubility in the acid used to dissolve fuel during reprocessing and in typical borosilicate glass. These must be treated separately to improve overall waste loading in glass. This low solubility and their survival in 2 Gy-old natural reactors led us to investigate them as a waste form for the immobilization of 99Tc and 107Pd, two very long-lived isotopes.

  7. Preliminary evaluation of alternative forms for immobilization of Savannah River Plant high-level waste. [Eleven alternative solid forms

    Energy Technology Data Exchange (ETDEWEB)

    Stone, J.A.; Goforth, S.T. Jr.; Smith, P.K.

    1979-12-01

    An evaluation of available information on eleven alternative solid forms for immobilization of SRP high-level waste has been completed. Based on the assessment of both product and process characteristics, four forms were selected for more detailed evaluation: (1) borosilicate glass made in the reference process, (2) a high-silica glass made from a porous glass matrix, (3) crystalline ceramics such as supercalcine or SYNROC, and (4) ceramics coated with an impervious barrier. The assessment includes a discussion of product and process characteristics for each of the eleven forms, a cross comparison of these characteristics for the forms, and the bases for selecting the most promising forms for further study.

  8. An international initiative on long-term behavior of high-level nuclear waste glass

    Directory of Open Access Journals (Sweden)

    S. Gin

    2013-06-01

    Full Text Available Nations using borosilicate glass as an immobilization material for radioactive waste have reinforced the importance of scientific collaboration to obtain a consensus on the mechanisms controlling the long-term dissolution rate of glass. This goal is deemed to be crucial for the development of reliable performance assessment models for geological disposal. The collaborating laboratories all conduct fundamental and/or applied research using modern materials science techniques. This paper briefly reviews the radioactive waste vitrification programs of the six participant nations and summarizes the current state of glass corrosion science, emphasizing the common scientific needs and justifications for on-going initiatives.

  9. SEM/EDS analysis of boron in waste glasses with ultrathin window detector and digital pulse processor

    International Nuclear Information System (INIS)

    Analysis of boron in waste glasses and in the reaction products that form during the reaction of glass is important for understanding the reaction kinetics and mechanism of glass corrosion. Two borosilicate waste glasses (1.55 and 3.47 wt% B) have been analyzed by SEM/EDS. The 1.55 wt% is the lowest B concentration detected with EDS. However, the B peaks severely overlap with the C peaks due to the carbon films used for conductive layers, but this problem can be solved by subtracting the C peaks, and possibly even lower B content could be detected by EDS with the digital pulse processor

  10. Actinide speciation in glass leach-layers: An EXAFS study

    International Nuclear Information System (INIS)

    Uranium L3 X-ray absorption data were obtained from two borosilicate glasses, which are considered as models for radioactive wasteforms, both before and after leaching. Surface sensitivity to uranium speciation was attained by a novel application of simultaneous fluorescence and electron-yield detection. Changes in speciation are clearly discernible, from U(VI) in the bulk to (UO2)2+-uranyl in the leach layer. The leach-layer uranium concentration variations with leaching times are also determined from the data

  11. The relationship between glass viscosity and composition: A first principles model for vitrification of nuclear waste

    International Nuclear Information System (INIS)

    The Defense Waste Processing Facility will incorporate high-level liquid waste into borosilicate glass for stabilization and permanent disposal in a geologic repository. The viscosity of the melt determines the rate of melting of the raw feed, the rate of gas bubble release due to foaming and fining, the rate of homogenization, and thus, the quality of the glass produced. The viscosity of the glass is in turn, a function of both glass composition and temperature. A model describing the viscosity dependence on composition, temperature, and glass structure (bonding) has been derived for glasses ranging from pure frits to frit plus 35 wt % simulated waste. 17 refs., 37 figs

  12. Property Data for Simulated Americium/Curium Glasses

    International Nuclear Information System (INIS)

    The authors studied the properties of mixed lanthanide-alumino-borosilicate glasses. Fifty-five glasses were designed to augment a previous, Phase I, study by systematically varying the composition of Ln2O3 and the concentrations of Ln2O3, SiO2, B2O3, Al2O3, and SrO in glass. These glasses were designed and fabricated at the Savannah River Technology Center and tested at the Pacific Northwest National Laboratory. The properties measured include the high-temperature viscosity (η) as a function of temperature (T) and the liquidus temperature (TL) of Phase II test glasses

  13. Patch electrode glass composition affects ion channel currents.

    OpenAIRE

    Furman, R E; Tanaka, J C

    1988-01-01

    The influence of patch electrode glass composition on macroscopic IV relations in inside-out patches of the cGMP-activated ion channel from rod photoreceptors was examined for a soda lime glass, a Kovar sealing glass, a borosilicate glass, and several soft lead glasses. In several glasses the shape or magnitude of the currents changed as the concentration of EGTA or EDTA was increased from 200 microM to 10 mM. The changes in IV response suggest that, at low concentrations of chelator, divalen...

  14. 2.4. The kinetics of hydrochloric-acid decomposition of calcined concentrate of boron raw material of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Present article is devoted to kinetics of hydrochloric-acid decomposition of calcined concentrate of boron raw material of Ak-Arkhar Deposit. The experimental data of dependence of hydrochloric-acid decomposition of calcined boron raw material for boron oxide extraction on temperature (20-80 deg C) and process duration (15-60 min) were considered. It was defined that at temperature increasing the boron oxide extraction from borosilicate raw material increases from 24.1 till 86.8%. The constants of decomposition rate of boron raw material were calculated.

  15. Vitrification experience and projects in France

    International Nuclear Information System (INIS)

    Research on the vitrification of concentrated fission product solutions has been conducted in France for over a quarter of a century. This work has resulted in the formulation of a series of borosilicate glasses applicable to the high level wastes produced at the Marcoule and La Hague reprocessing plants. The properties of these nuclear glasses permit interim storage and future long-term disposal under safe conditions. A continuous vitrification process has also been developed and implemented on an industrial scale at Marcoule since 1978; a larger facility will begin operation at La Hague in late 1986

  16. Thermal expansion uniformity of materials for large telescope mirrors

    Science.gov (United States)

    Jacobs, S. F.; Shough, D.; Connors, C.

    1984-01-01

    Uniformity of thermal expansion has been measured for fused quartz and borosilicate glass. The variation of expansion coefficient for three melts of TO8E was 5 x 10 to the -9th/K over a temperature range of 300 to 100 K and was found to vary linearly with position in the melt. This spatial gradient averaged 3.5 x 10 to the -11th/K-cm. The room-temperature thermal expansivity variation of Duran (Tempax) glass was about 27 x 10 to the -9th/K, while that of E6 glass was about 52 x 10 to the -9th/K.

  17. Response of large optical mirrors to thermal distributions

    Science.gov (United States)

    Pearson, E.; Stepp, L.

    1987-01-01

    FEM has been used to predict the optical surface distortions that can be expected in the lightweight honeycomb structure cast-borosilicate glass mirrors being contemplated for use in the National New Technology Telescope; this material has a relatively high coefficient of thermal expansion. Temperature patterns were described by a least-squares fit to a polynomial expression which was then used to predict nodal temperatures of the model. The individual terms of the polynomial describe such temperature patterns as linear-diametral and radial gradients.

  18. Fabrication of computer-generated holograms using femtosecond laser direct writing.

    Science.gov (United States)

    Berlich, René; Richter, Daniel; Richardson, Martin; Nolte, Stefan

    2016-04-15

    We demonstrate a single-step fabrication method for computer-generated holograms based on femtosecond laser direct writing. Therefore, a tightly arranged longitudinal waveguide array is directly inscribed into a transparent material. By tailoring the individual waveguide length, the phase profile of an incident laser beam can be arbitrarily adapted. The approach is verified in common borosilicate glass by inscribing a designed phase hologram, which forms the desired intensity pattern in its far field. The resulting performance is analyzed, and the potential as well as limitations of the method are discussed. PMID:27082336

  19. Transparent glass coatings incorporated with upconversion nanocrystals by laser cladding method

    International Nuclear Information System (INIS)

    To develop β-NaYF4 as bulk luminescence material, transparent glass coatings incorporated with β-NaYF4:20%Yb3+,2%Er3+ nanocrystals were fabricated by laser cladding method for the first time. The composite films on quartz glasses were characterized by optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM), which showed that β-NaYF4 nanocrystals were introduced into the borosilicate glass and formed to glass composites with highly efficient upconversion (UC) luminescence. It is highly promising to achieve the preparation of crystals-glass composites through this novel method.

  20. Nanogratings formation in multicomponent silicate glasses

    Science.gov (United States)

    Lancry, M.; Zimmerman, F.; Desmarchelier, R.; Tian, J.; Brisset, F.; Nolte, S.; Poumellec, B.

    2016-03-01

    We demonstrate the formation of porous nanogratings in various oxide glasses including TiO2-doped silica, GeO2 and alumino-borosilicate by near-IR femtosecond laser radiation. ULE and GeO2 glasses exhibit similar birefringence to pure silica, whereas Borofloat 33 reveals twice weaker amplitude. Using quantitative birefringence measurements, small-angle X-ray scattering and scanning electron microscopy, we correlate birefringence and porous nanolayers formation according to laser repetition rate and glass composition. We show that heat accumulation is a crucial parameter limiting the glass decomposition and thus nanogratings formation.

  1. Quarterly Progress Report Research And Development Activities Waste Fixation Program October Through December 1976

    International Nuclear Information System (INIS)

    Research and development activities of the Waste Fixation Program for October through December 1976 are described in this report. The objective of this program is to develop processes to convert high-level radioactive liquid waste (HLLW) to solid forms that are demonstrated to be physically, chemically, and radiolytically stable and inert. The scope of this program encompasses plans to make available a flexible advancing technology for the solidification of radioactive waste. Early technology will produce borosilicate glass by in-can melting and continuous electric melters. Multibarrier waste forms will be developed for future application

  2. Pilot production & commercialization of LAPPD{sup ™}

    Energy Technology Data Exchange (ETDEWEB)

    Minot, Michael J., E-mail: mjm@incomusa.com [Incom Inc, 294 Southbridge Road, Charlton, MA 01507 (United States); Bennis, Daniel C.; Bond, Justin L.; Craven, Christopher A.; O' Mahony, Aileen; Renaud, Joseph M.; Stochaj, Michael E. [Incom Inc, 294 Southbridge Road, Charlton, MA 01507 (United States); Elam, Jeffrey W.; Mane, Anil U.; Demarteau, Marcellinus W.; Wagner, Robert G. [Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL 60439-4814 (United States); McPhate, Jason B.; Helmut Siegmund, Oswald [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Elagin, Andrey; Frisch, Henry J.; Northrop, Richard; Wetstein, Matthew J. [University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637 (United States)

    2015-07-01

    We present a progress update on plans to establish pilot production and commercialization of Large Area (400 cm{sup 2}) Picosecond Photodetector (LAPPD{sup ™}). Steps being taken to commercialize this MCP and LAPPD{sup ™} technology and begin tile pilot production are presented including (1) the manufacture of 203 mm×203 mm borosilicate glass capillary arrays (GCAs), (2) optimization of MCP performance and creation of an ALD coating facility to manufacture MCPs and (3) design, construction and commissioning of UHV tile integration and sealing facility to produce LAPPDs. Taken together these plans provide a “pathway toward commercialization”.

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

    International Nuclear Information System (INIS)

    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

  4. Preliminary evaluation of alternative forms for immobilization of Savannah River Plant high-level waste

    International Nuclear Information System (INIS)

    An evaluation of available information on eleven alternative solid forms for immobilization of SRP high-level waste has been completed. Based on the assessment of both product and process characteristics, four forms were selected for more detailed evaluation: (1) borosilicate glass made in the reference process, (2) a high-silica glass made from a porous glass matrix, (3) crystalline ceramics such as supercalcine or SYNROC, and (4) ceramics coated with an impervious barrier. The assessment includes a discussion of product and process characteristics for each of the eleven forms, a cross comparison of these characteristics for the forms, and the bases for selecting the most promising forms for further study

  5. Small-scale, joule-heated melting of Savannah River Plant waste glass. I. Factors affecting large-scale vitrification tests

    International Nuclear Information System (INIS)

    A promising method of immobilizing SRP radioactive waste solids is incorporation in borosilicate glass. In the reference vitrification process, called joule-heated melting, a mixture of glass frit and calcined waste is heated by passage of an electric current. Two problems observed in large-scale tests are foaming and formation of an insoluble slag. A small joule-heated melter was designed and built to study problems such as these. This report describes the melter, identifies factors involved in foaming and slag formation, and proposes ways to overcome these problems

  6. The vitrification of high-level wastes in France: from the Lab to industrial plants

    International Nuclear Information System (INIS)

    Research in the area of vitrifying concentrated fission product solutions began in France in the 1950s. Vitrification processes were developed along with suitable materials, notably borosilicate glasses. The primary objective of glass investigations is to determine and assess the alteration phenomena that occur during ultimate storage in a geological repository. With the development of glass fabrication processes, a continuous vitrification technique has been implemented in three vitrification units, associated with the three French reprocessing plants; the units were commissioned in 1978, 1989 and 1992. (author). 1 fig., 5 tabs., 37 refs

  7. Vitrification of high level waste surrogate from Savannah River Plant (USA) at industrial scale plant with cold crucible

    International Nuclear Information System (INIS)

    Paper describes the experiment efforts to vitrify frit-320 containing sludge when oxide content in a glass was up to 50% using the cold crucible equipped commercial plant. Paper presents the estimated chemical composition of the frit-320 containing glass, % by mass: 8 Li2O, 8 B2O3, 12 Na2O, 72 SiO2. According to the X-ray phase analysis and the electron microscopy data, the products represents a borosilicate matrix containing up to 15% of magnetite quality spinel as to the crystalline phase volume. The procedure is the most efficient one when large crucibles are used

  8. Ion implantation induced microstructural damage in a nuclear waste glass

    International Nuclear Information System (INIS)

    Borosilicate glasses are presently the matrix accepted worldwide to solidify high-level radioactive waste from reprocessing fuel elements of nuclear power stations. The glass will experience radiation damage from alpha particles and their associated alpha-recoil atoms, from beta particles (electrons) and from gamma rays. From the viewpoint of the wasteform stability, the most serious radiation effects are expected to be phase separation, pore and/or bubble formation and micro fracturing. These types of microstructural damage may significantly increase the leachability of the primary waste-storage material. (authors). 3 figs., 7 refs

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

    International Nuclear Information System (INIS)

    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)

  10. Studies of material issues, science and technology for immobilization of sulphate bearing high level radioactive liquid waste

    International Nuclear Information System (INIS)

    High level radioactive liquid waste (HL) generated during reprocessing of spent fuel contains most of radioactivity present in the entire nuclear fuel cycle. The composition of HLW is site specific and largely depends on off reactor cooling of spent nuclear fuel, its type and burn up, and chemistry of reprocessing flow sheet. Development of matrices for conditioning of HLW to ensure isolation of radioactivity from human environment for extended period of time is a scientific and technological challenge. Sodium borosilicate glass formulations adopted worldwide for immobilization of waste is not suitable for sulphate bearing HLW, because of its low solubility in such glass. Various compositions based on different glass formulations were made with simulated waste to examine compatibility with waste oxide and containing around 10% sulphate. Vitrified waste product obtained from barium borosilicate glass matrix were extensively evaluated for its characteristic properties like homogeneity, glass transition temperature, thermal conductivity and impact strength etc. using appropriate techniques. Properties like melt viscosity, pour temperature were also determined. It is found that SB44 glass composition (SiO2+B2O3=50.5wt%, Na2O+BaO=28.5wt%) can be safely loaded with 21 wt% waste oxide without any phase separation. The other product qualities of SB-44 glass were also found to be at par with internationally adopted glass matrices. This formulation has been successfully implemented in plant scale for immobilization of sulphate bearing HLW. (author)

  11. Characteristics of high-level radioactive waste forms for their disposal

    International Nuclear Information System (INIS)

    In order to develop a deep geological repository for a high-level radioactive waste coming from reprocessing of spent nuclear fuels discharged from our domestic nuclear power plants, the the required characteristics of waste form are dependent upon a solidifying medium and the amount of waste loading in the medium. And so, by the comparative analysis of the characteristics of various waste forms developed up to the present, a suitable medium is recommended.The overall characteristics of the latter is much better than those of the former, but the change of the properties due to an amorphysation by radiation exposure and its thermal expansion has not been clearly identified yet. And its process has not been commercialized. However, the overall properties of the borosilicate glass waste forms are acceptable for their disposal, their production cost is reasonable and their processes have already been commercialized. And plenty informations of their characteristics and operational experiences have been accumulated. Consequently, it is recommended that a suitable medium solidifying the HLW is a borosilicate glass and its composition for the identification of a reference waste form would be based on the glass frit of R7T7

  12. The precision of product consistency tests conducted with a glass-bonded ceramic waste form

    International Nuclear Information System (INIS)

    The product consistency test (PCT) that is used for qualification of borosilicate high-level radioactive waste (HLW) glasses for disposal can be used for the same purpose in the qualification of the glass-bonded sodalite ceramic waste form (CWF). The CWF was developed to immobilize radioactive salt wastes generated during the electrometallurgical treatment of spent sodium-bonded nuclear fuels. An interlaboratory study was conducted to measure the precision of PCTs conducted with the CWF for comparison with the precision of PCTs conducted with HLW glasses. The six independent sets of triplicate PCT results generated in the study were used to calculate the intralaboratory and interlaboratory consistency based on the concentrations of Al, B, Na, and Si in the test solutions. The results indicate that PCTs can be conducted as precisely with the CWF as with HLW glasses. For example, the values of the reproducibility standard deviation for Al, B, Na, and Si were 1.36, 0.347, 3.40, and 2.97 mg/l for PCT with CWF. These values are within the range of values measured for borosilicate glasses, including reference HLW glasses

  13. Characteristics of porous zirconia coated with hydroxyapatite as human bones

    Indian Academy of Sciences (India)

    V V Narulkar; S Prakash; K Chandra

    2007-08-01

    Since hydroxyapatite has excellent biocompatibility and bone bonding ability, porous hydroxyapatite ceramics have been intensively studied. However, porous hydroxyapatite bodies are mechanically weak and brittle, which makes shaping and implantation difficult. One way to solve this problem is to introduce a strong porous network onto which hydroxyapatite coating is applied. In this study, porous zirconia and alumina-added zirconia ceramics were prepared by ceramic slurry infiltration of expanded polystyrene bead compacts, followed by firing at 1500°C. Then slurry of hydroxyapatite–borosilicate glass mixed powder was used to coat the porous ceramics, followed by firing at 1200°C. The porous structures without the coating had high porosities of 51–69%, high pore interconnectivity, and sufficiently large pore window sizes (300–500 m). The porous ceramics had compressive strengths of 5.3∼36.8 MPa, favourably comparable to the mechanical properties of cancellous bones. In addition, porous hydroxyapatite surface was formed on the top of the composite coating, whereas a borosilicate glass layer was found on the interface. Thus, porous zirconia-based ceramics were modified with a bioactive composite coating for biomedical applications.

  14. Radioactive waste forms for the future

    International Nuclear Information System (INIS)

    This volume presents a compilation of important information on the full range of radioactive waste forms that have been developed, or at least suggested, for the incorporation of high-level nuclear waste. Many of the results were published in the 'gray literature' of final reports of national laboratories or in various, generally less available, proceedings volumes. This is the first publication to draw information on nuclear waste forms for high-level wastes togehter into a single volume. A detailed presentation is given on the properties and performance of non-crystalline waste forms (borosilicate glass, sintered glass, sintered glass, and lead-iron phosphate glass), and crystalline waste forms (Synroc, tailored ceramics, TiO2-ceramic matrix, glass-ceramics and concrete). A chapter on Novel waste forms reviews a number of methods that warrant further development because of their potential superior performance and unique applications. The final chapter includes a tabulated comparison of important waste form properties and an extended discussion on the corrosion process and radiation damage effects for each waste form. Of particular interest is a performance assessment of nuclear waste borosilicate glass and the crystalline ceramic Synroc. This is the first detailed attempt to compare these two important waste forms on the basis of their materials properties. The discussion emphasizes the difficulties in making such a comparison and details the types of data that are required. (author). refs.; figs.; tabs

  15. Studies on long term leaching behaviour of vitrified waste product containing sulphate bearing high level radioactive waste

    International Nuclear Information System (INIS)

    Borosilicate glass system is adopted in India and world-wide as a matrix for immobilization of high level radioactive liquid waste (HLW). Sulphate bearing HLW is generated during reprocessing of spent fuel from research reactors at BARC, Trombay. The presently stored HLW at Trombay contains uranium, sodium and sulphate in addition to fission products, corrosion products and small amount of other actinides. Presence of sulphate in HLW is attributed to the usage of ferrous sulphamate as a reducing agent in earlier reprocessing flow sheets for valency adjustment of plutonium during partitioning stage. A barium borosilicate based glass matrix is developed for vitrification of sulphate bearing HLW. Assessment of long term chemical durability is one of the critical aspects for evaluation of conditioned products from containment and environmental protection point of view. Chemical durability of waste form is evaluated by studying the leaching behaviour of the conditioned product. Leaching, being the only pathway through which radionuclide can migrate to human environment, is one of the most important properties of vitrified waste product which depends on various factors like composition of waste, glass matrix, type of test method, flow rate, composition of leachant, effect of radiation etc. The present paper reports the details of leaching studies of the glass products made with chemically simulated waste. Efforts were also made to understand the mechanism of leaching and to study the alteration layer formed on the leached surface of the glass products. (author)

  16. Characterization of projected DWPF glasses heat treated to simulate canister centerline cooling

    International Nuclear Information System (INIS)

    Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). Eventually these canistered waste forms will be sent to a geologic repository for final disposal. In order to assure acceptability by the repository, the Department of Energy has defined requirements which DWPF canistered waste forms must meet. These requirements are the Waste Acceptance Product Specifications (WAPS). The WAPS require DWPF to identify the crystalline phases expected to be present in the final glass product. Knowledge of the thermal history of the borosilicate glass during filling and cooldown of the canister is necessary to determine the amount and type of crystalline phases present in the final glass product. Glass samples of seven projected DWPF compositions were cooled following the same temperature profile as that of glass at the centerline of the full scale DWPF canister. The glasses were characterized by X-ray diffraction and scanning electron microscopy to identify the crystalline phases present. The volume percents of each crystalline phase present were determined by quantitative x-ray diffraction. The Product Consistency Test (PCT) was used to determine the durability of the heat treated glasses

  17. Characterization of atmospheric pressure microplasma produced from argon and a mixture of argon–ethylenediamine

    International Nuclear Information System (INIS)

    A non-thermal atmospheric pressure microplasma generated from pure argon (Ar) and a mixture of argon–ethylenediamine vapors (Ar/EDA) has been characterized in this study. A sinusoidal power supply operating at 30 kHz was used to excite microplasma in a rectangular borosilicate glass capillary (4×0.4 mm2). The monomer EDA was mixed with Ar in order to perform plasma polymerization inside the microchannel. The analyses were made by measuring spectroscopic and electrical parameters of the discharge. The effects of EDA mixing on plasma parameters such as electron, excitation and rotational temperatures during the process of surface coating of the microchannel were investigated. These parameters play an important role in the deposition process. The plasma temperatures estimated through spectroscopic measurement were found in the sequence Te>Texc>Tvib>Trot, which indicated the non-thermal characteristics of the proposed DBD microplasma. The parameters of the Ar discharge were also numerically computed using plasma simulations. The numerical predictions of electron temperature (2D simulations) and electron density (3D simulations) were found to be in close agreement to those estimated through experiments. - Highlights: • An atmospheric pressure microplasma was generated in a borosilicate glass capillary. • A pure argon and a mixture of argon–ethylenediamine plasmas were characterized. • Characterization was performed by emission spectrometry and electrical measurements. • Plasma parameters were also predicted by numerical simulations. • The sequence of estimated plasma temperatures indicated its non-thermal behaviour

  18. Vitrification of high-level liquid wastes

    International Nuclear Information System (INIS)

    High-level radioactive liquid wastes produced in the fuel elements reprocessing require, for their disposal, a preliminary treatment by which, through a series of engineering barriers, the dispersion into the biosphere is delayed by 10 000 years. Four groups of compounds are distinguished among a great variety of final products and methods of elaboration. From these, the borosilicate glasses were chosen. Vitrification experiences were made at a laboratory scale with simulated radioactive wastes, employing different compositions of borosilicate glass. The installations are described. A series of tests were carried out on four basic formulae using always the same methodology, consisting of a dry mixture of the vitreous matrix's products and a dry simulated mixture. Several quality tests of the glasses were made 1: Behaviour in leaching following the DIN 12 111 standard; 2: Mechanical resistance; parameters related with the facility of the different glasses for increasing their surface were studied; 3: Degree of devitrification: it is shown that devitrification turns the glasses containing radioactive wastes easily leachable. From all the glasses tested, the composition SiO2, Al2O3, B2O3, Na2O, CaO shows the best retention characteristics. (M.E.L.)

  19. Characteristics of high-level radioactive waste forms for their disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Soo; Chun, Kwan Sik; Kang, Chul Hyung

    2000-12-01

    In order to develop a deep geological repository for a high-level radioactive waste coming from reprocessing of spent nuclear fuels discharged from our domestic nuclear power plants, the the required characteristics of waste form are dependent upon a solidifying medium and the amount of waste loading in the medium. And so, by the comparative analysis of the characteristics of various waste forms developed up to the present, a suitable medium is recommended.The overall characteristics of the latter is much better than those of the former, but the change of the properties due to an amorphysation by radiation exposure and its thermal expansion has not been clearly identified yet. And its process has not been commercialized. However, the overall properties of the borosilicate glass waste forms are acceptable for their disposal, their production cost is reasonable and their processes have already been commercialized. And plenty informations of their characteristics and operational experiences have been accumulated. Consequently, it is recommended that a suitable medium solidifying the HLW is a borosilicate glass and its composition for the identification of a reference waste form would be based on the glass frit of R7T7.

  20. Performance assessment of the direct disposal in unsaturated tuff or spent nuclear fuel and high-level waste owned by USDOE: Volume 2, Methodology and results

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, R.P. [ed.

    1995-03-01

    This assessment studied the performance of high-level radioactive waste and spent nuclear fuel in a hypothetical repository in unsaturated tuff. The results of this 10-month study are intended to help guide the Office of Environment Management of the US Department of Energy (DOE) on how to prepare its wastes for eventual permanent disposal. The waste forms comprised spent fuel and high-level waste currently stored at the Idaho National Engineering Laboratory (INEL) and the Hanford reservations. About 700 metric tons heavy metal (MTHM) of the waste under study is stored at INEL, including graphite spent nuclear fuel, highly enriched uranium spent fuel, low enriched uranium spent fuel, and calcined high-level waste. About 2100 MTHM of weapons production fuel, currently stored on the Hanford reservation, was also included. The behavior of the waste was analyzed by waste form and also as a group of waste forms in the hypothetical tuff repository. When the waste forms were studied together, the repository was assumed also to contain about 9200 MTHM high-level waste in borosilicate glass from three DOE sites. The addition of the borosilicate glass, which has already been proposed as a final waste form, brought the total to about 12,000 MTHM.

  1. Equations for predicting release rates for waste packages in unsaturated tuff

    International Nuclear Information System (INIS)

    Nuclear waste will be placed in the potential repository at Yucca Mountain in waste packages. Spent fuel assemblies or consolidated fuel rods and borosilicate glass in steel pour canisters will be enclosed in sealed containers. The waste package consists of the waste form, the cladding on spent fuel or the defense-waste pour canister, and the outside container. Current design calls for the waste packages to be surrounded by an air gap. Although the waste package is generally not seen as the primary barrier for nuclear waste isolation it must in fact meet specific regulatory requirements: substantially complete requirement and release-rate from the engineered barrier system [USNRC 1983]. This report gives derivations of equations for predicting releases rates. We consider the release of three types of species: solubility-limited species, species released congruent with solid-solid alteration of spent-fuel matrix or borosilicate glass, and readily soluble species from the fuel-cladding gap, gas plenum, and readily accessible grain boundaries. We develop analytic expressions for the release rates of individual constituents from each of these mechanisms. For a given species and for given parameters, the mechanism that results in the lowest predicted release rate is to be adopted as the rate-controlling mechanism for that species. Some of the equations are newly derived for this report, others are restated from earlier work. Release rates have been calculated for key radionuclides in a companion report. 11 refs., 7 figs

  2. Research and development activities: high-level waste immobilization program. Quarterly progress report, January-March 1979

    Energy Technology Data Exchange (ETDEWEB)

    McElroy, J.L.; Mendel, J.E.; Bonner, W.F.; Henry, M.H.

    1979-11-01

    Liquid waste, made from zirconium-clad UO/sub 2/ power reactor fuel with an average burnup of 25,000 MWd/MT, was converted to glass by the in-can melting process. An intrinsic-gamma melt-level detection system was tested during the NWVP demonstrations; results showed that if a sufficient number of collimators are used the system will track the melt surface with a precision of 1 in. during the filling of cans with waste glass. The two canisters filled in the NWVP are both 8 in. in diameter and contain borosilicate glass of very similar compositions. One canister contains 116 kg of glass that generated 0.38 kW of self-heat when produced; the other contains 145 kg of glass, and generates 1.01 kW. Spray calcination of simulated Savannah River Plant liquid waste at a rate of 400 L/h was demonstrated in the 36-in.-dia. calciner. Five waste forms are being compared: concrete-containing waste calcine, sintered waste glass, glass-ceramic, Synroc B (a crystalline assemblage of titanates), and borosilicate waste glass (composition 76-68). Results of initial tests indicate that the reaction rate of carbon with water, previously found to be very low, may be increased in a radiation field.

  3. The role of chemical reaction in waste-form performance

    International Nuclear Information System (INIS)

    The dissolution rate of waste solids in a geologic repository is a complex function of waste form geometry, chemical raction rate, exterior flow field, and chemical environment. We present here an analysis to determine the stady-state mass transfer rate, over the entire range of flow conditions relevant to geologic disposal of nuclear waste. The equations for steady-state mass transfer with a chemical-reaction-rate boundary condition are solved by three different mathematical techniques which supplement each other. This theory is illustrated with laboratory leach data for borosilicate-glass and a spherical spent-fuel waste form under typical repository conditions. For borosilicate glass waste in the temperature range of 57/degree/C to 250/degree/C, dissolution rate in a repository is determined for a wide range of chemical reaction rates and for Peclet numbers from zero to well over 100, far beyond any Peclet values expected in a repository. Spent-fuel dissolution in a repository is also investigated, based on the limited leach data now available. 10 refs., 4 figs., 1 tab

  4. Application of cold crucible melting to NPP waste conditioning using basaltic rocks

    International Nuclear Information System (INIS)

    Cold crucible inductive melting (CCIM) is one of the most promising technologies for treatment of various inorganic and organic radioactive wastes. This technology was successfully applied for vitrification of NPP operational wastes produced at Russian RBMK and WWER reactors. These wastes with high concentration of sodium nitrate were vitrified with borosilicate glass formers and high leach resistant and mechanically strong glasses were produced. To reduce a cost of the process boron-containing additives may be substituted by local basaltic rocks. Such rocks contain major silicon, aluminium, iron oxides and minor sodium, potassium, calcium, manganese and other oxides and may be used as effective and inexpensive glass forming additives to NNP waste salts. Lab-scale tests using a cold crucible energized from 10 kW high frequency (5.28 MHz) generator were conducted. Glasses and glass-crystalline materials obtained had low leach rates of alkali elements, boron, and silicon being very similar to leach rates from HLW borosilicate glasses (PCT test). (author)

  5. In-can melting process and equipment development from 1974 to 1978

    Energy Technology Data Exchange (ETDEWEB)

    Blair, H. Thomas

    1979-08-01

    Both the defense HLLW stores in tanks presently and the HLLW from proposed reprocessing of commercial LWR fuel can be vitrified as borosilicate glass in containers made of 300-series stainless steel by the ICM (in-can melting) process. Melting rates of 50 kg/h in 12-in.-dia cans and 117 kg/h in 28-in.-dia cans can be achieved in the ICM by using the rising-level charging method and internal heat-transfer plate assemblies in the cans. The ICM process can be monitored and remotely controlled without the aid of instrumentation attached to the waste can. The ICM process is compatible with both heated-wall spray calciners and fluidized-bed calciners. The ICM process causes residual tensile stresses as high as the yield strength in vitrified product containers made of 300-series stainless steel. Spall due to oxidation of the exterior of the can during an ICM process can be prevented by using an inert cover gas, by putting a protective coating on the can surface, or by using an oxidation-resistant alloy. Processing problems are minimized and product quality is improved when the complete can is located inside the furnace chamber by setting it on the hearth. A maximum of 24 kW and an average of 15 kW is required per 15-in.-high furnace zone to melt waste borosilicate glass at a rate of 117 kg/h in a 28-in.-dia ICM.

  6. In-can melting process and equipment development from 1974 to 1978

    International Nuclear Information System (INIS)

    Both the defense HLLW stores in tanks presently and the HLLW from proposed reprocessing of commercial LWR fuel can be vitrified as borosilicate glass in containers made of 300-series stainless steel by the ICM (in-can melting) process. Melting rates of 50 kg/h in 12-in.-dia cans and 117 kg/h in 28-in.-dia cans can be achieved in the ICM by using the rising-level charging method and internal heat-transfer plate assemblies in the cans. The ICM process can be monitored and remotely controlled without the aid of instrumentation attached to the waste can. The ICM process is compatible with both heated-wall spray calciners and fluidized-bed calciners. The ICM process causes residual tensile stresses as high as the yield strength in vitrified product containers made of 300-series stainless steel. Spall due to oxidation of the exterior of the can during an ICM process can be prevented by using an inert cover gas, by putting a protective coating on the can surface, or by using an oxidation-resistant alloy. Processing problems are minimized and product quality is improved when the complete can is located inside the furnace chamber by setting it on the hearth. A maximum of 24 kW and an average of 15 kW is required per 15-in.-high furnace zone to melt waste borosilicate glass at a rate of 117 kg/h in a 28-in.-dia ICM

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

    International Nuclear Information System (INIS)

    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 10500C. 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 1000C 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 2000C. (author)

  8. Up- and down-conversion luminescence in the oxyfluoride glass ceramics containing Ba2+1.5xYb1−xF7:Tb3+ nanocrystals

    International Nuclear Information System (INIS)

    Transparent oxyfluoride borosilicate glass ceramics containing Ba2+1.5xYb1−xF7:Tb3+ nanocrystals were successfully prepared by a melt-quenching method with subsequent heat treatment. The precipitated crystalline phase in the glass matrix changed gradually from BaF2 to Ba2+1.5xYb1−xF7 with the increase of YbF3 content, which was confirmed by the results of XRD, HRTEM and EDX measurements. The ultraviolet and visible up-conversion and near-infrared quantum cutting down-conversion emissions were observed and interpreted. These materials could be used to modify the solar spectrum and enhance the silicon solar cell efficiency by the up-conversion and down-conversion luminescence of Tb3+–Yb3+ couples in the oxyfluoride borosilicate glass ceramics. -- Highlights: ► Oxyfluoride glass ceramics containing Ba2+1.5xYb1−xF7:Tb nanocrystals were prepared. ► The precipitated crystal phase changed from BaF2 to Ba2+1.5xYb1−xF7. ► Strong up-conversion and down-conversion emissions were observed and interpreted.

  9. Up- and down-conversion luminescence in the oxyfluoride glass ceramics containing Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}:Tb{sup 3+} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Fengxia [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Zhao, Shilong, E-mail: shilong_zhao@hotmail.com [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Jia, Guohua; Huang, Lihui; Deng, Degang; Wang, Huanping [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China); Xu, Shiqing, E-mail: sxucjlu@hotmail.com [College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018 (China)

    2012-11-15

    Transparent oxyfluoride borosilicate glass ceramics containing Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}:Tb{sup 3+} nanocrystals were successfully prepared by a melt-quenching method with subsequent heat treatment. The precipitated crystalline phase in the glass matrix changed gradually from BaF{sub 2} to Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7} with the increase of YbF{sub 3} content, which was confirmed by the results of XRD, HRTEM and EDX measurements. The ultraviolet and visible up-conversion and near-infrared quantum cutting down-conversion emissions were observed and interpreted. These materials could be used to modify the solar spectrum and enhance the silicon solar cell efficiency by the up-conversion and down-conversion luminescence of Tb{sup 3+}-Yb{sup 3+} couples in the oxyfluoride borosilicate glass ceramics. -- Highlights: Black-Right-Pointing-Pointer Oxyfluoride glass ceramics containing Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}:Tb nanocrystals were prepared. Black-Right-Pointing-Pointer The precipitated crystal phase changed from BaF{sub 2} to Ba{sub 2+1.5x}Yb{sub 1-x}F{sub 7}. Black-Right-Pointing-Pointer Strong up-conversion and down-conversion emissions were observed and interpreted.

  10. Studies of the beam finding and targeting accuracy of the CAS-LIBB single-particle microbeam

    Institute of Scientific and Technical Information of China (English)

    Wang Xiao-Hua; Wu Li-Jun; Wang Shao-Hu; Yu Zeng-Liang; Wang Xu-Fei; Hu Zhi-Wen; Cheng Lian-Yun; Zhang Jun; Zhan Fu-Ru; Li Jun; Chen Bin; Xu Ming-Liang

    2005-01-01

    A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering (LIBB), Chinese Academy of Sciences (CAS). The system was designed to deliver a defined number of hydrogen ions produced by a Van de Graaff accelerator, in an energy range of 2.0-3.0MeV, into an area smaller than the nuclei of individual living cells grown on thin plastic films. The beam is collimated by a borosilicate glass capillary that forms the beam-line exit. An computer integrated control program is developed to recognize the cells and to target them one by one for irradiation.Experiments for finding (capturing and recognizing) the microbeam position in the microscope imaging system and measuring the overall targeting accuracy of the facility are presented in this article. When a borosilicate glass capillary with 5μm inner diameter and 980μm length is used as the microbeam collimator, the overall targeting accuracy is that 91% aimed pit clusters are located within 2.4μm radius, and 98% are within 3.6μm radius.

  11. Description of processes for the immobilization of selected transuranic wastes

    International Nuclear Information System (INIS)

    Processed sludge and incinerator-ash wastes contaminated with transuranic (TRU) elements may require immobilization to prevent the release of these elements to the environment. As part of the TRU Waste Immobilization Program sponsored by the Department of Energy (DOE), the Pacific Northwest Laboratory is developing applicable waste-form and processing technology that may meet this need. This report defines and describes processes that are capable of immobilizing a selected TRU waste-stream consisting of a blend of three parts process sludge and one part incinerator ash. These selected waste streams are based on the compositions and generation rates of the waste processing and incineration facility at the Rocky Flats Plant. The specific waste forms that could be produced by the described processes include: in-can melted borosilicate-glass monolith; joule-heated melter borosilicate-glass monolith or marble; joule-heated melter aluminosilicate-glass monolith or marble; joule-heated melter basaltic-glass monolith or marble; joule-heated melter glass-ceramic monolith; cast-cement monolith; pressed-cement pellet; and cold-pressed sintered-ceramic pellet

  12. The DWPF: Results of full scale qualification runs leading to radioactive operations

    International Nuclear Information System (INIS)

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site in Aiken, SC will immobilize high-level radioactive liquid waste, currently stored in underground carbon steel tanks, in borosilicate glass. The radioactive waste is transferred to the DWPF in two forms: precipitate slurry and sludge slurry. The radioactive waste is pretreated and then combined with a borosilicate glass frit in the DWPF. This homogeneous slurry is fed to a Joule-heated melter which operates at approximately 1150 degrees C. The glass is poured into stainless steel canisters for eventual disposal in a geologic repository. The DWPF product (i.e. the canistered waste form) must comply with the Waste Acceptance Product Specifications (WAPS) in order to be acceptable for disposal. The DWPF has completed Waste Qualification Runs which demonstrate the facility's ability to comply with the waste acceptance specifications. During the Waste Qualification Runs seventy-one canisters of simulated waste glass were produced in preparation for Radioactive Operations. These canisters of simulated waste glass were produced during five production campaigns which also exercised the facility prior to beginning Radioactive Operations. The results of the Waste Qualification Runs are presented

  13. Initial demonstration of the vitrification of nuclear waste sludge containing an organic Cs-loaded ion exchange resin

    International Nuclear Information System (INIS)

    When immobilizing into borosilicate glass the radionuclides in the caustic high-level radioactive wastes stored in the USA, the soluble fission product Cs-137 has to be removed from supernates of the wastes. In the current processes zeolites or an organic precipitant will be used to remove the Cs. These solids are then treated further and mixed with the radioactive sludges and vitrified into a borosilicate glass. This paper describes the vitrification of a mixture resulting from using a new process to remove Cs from the caustic supernate. An organic ion exchange resin is used. This resin was then mixed with sludge andfrit and vitrified. Using an organic ion exchange resin rather than zeolite or the organic precipitant has certain advantages. Some of these are discussed in the paper. Results in the paper indicate that a mixture of the resin, sludge and frit can be successfully vitrified in a joule-heated, slurry fed melter. The redox state of the glass is lowered by the presence of the resin in the feed, but the glass is still suitable as a canistered wasteform for radioactive waste glass

  14. Nepheline structural and chemical dependence on melt composition

    Energy Technology Data Exchange (ETDEWEB)

    Marcial, José; Crum, Jarrod; Neill, Owen; McCloy, John

    2016-02-01

    Nepheline crystallizes upon slow-cooling in some melts concentrated in Na2O and Al2O3, which can result in a residual glass phase of low chemical durability. Nepheline can incorporate many components often found in high-level waste radioactive borosilicate glass, including glass network ions (e.g., Si, Al, Fe), alkali metals (e.g., Cs, K, Na, and possibly Li), alkaline-earth metals (e.g., Ba, Sr, Ca, Mg), and transition metals (e.g., Mn, and possibly Cr, Zn, Ni). When crystallized from melts of different compositions, nepheline chemistry varies as a function of starting glass composition. Five simulated high level nuclear waste borosilicate glasses shown to crystallize large fractions of nepheline on slow cooling, were selected for study. These melts constituted a range of Al2O3, B2O3, CaO, Na2O, K2O, Fe2O3, and SiO2 compositions. Compositional analyses of nepheline crystals in glass by electron probe micro-analysis (EPMA) indicate that boron is unlikely to be present in any significant concentration, if at all, in nepheline. Also, several models are presented for calculating the fraction of vacancies in the nepheline structure.

  15. Laboratory measurements of seismic attenuation in partially saturated rocks

    Science.gov (United States)

    Chapman, Samuel; Tisato, Nicola; Quintal, Beatriz; Holliger, Klaus

    2014-05-01

    Laboratory measurements of seismic attenuation and transient pore fluid pressure are performed on partially saturated Berea sandstone and synthetic borosilicate samples. Various degrees of water (liquid) and nitrogen (gas) saturation are considered. These measurements are carried out at room temperature and under confining pressures varying from ambient conditions up to 25 MPa. The cylindrical samples are 25 cm long and have a diameter of 7.6 cm. In the context of the experimental setup, the solid frames of both the Berea sandstone and the borosilicate samples can be considered homogenous, which in turn allows for isolating and exploring the effects of partial saturation on seismic attenuation. We employ the sub-resonance method, which is based on the application of a time-harmonic vertical stress to the top of the sample and the measurement of the thus resulting strain. For any given frequency, the attenuation is then inferred as the tangent of the phase shift between the applied stress and the observed strain. Using five equally spaced sensors along the central axis of the cylindrical sample, we measure the transient fluid pressure induced by the application of a step-function-type vertical stress to the top of the sample. Both the sensors and the sample are sealed off with the regard to the confining environment. Together with the numerical results from corresponding compressibility tests based on the quasi-static poroelastic equations, these transient fluid pressure measurements are then used to assist the interpretation of the seismic attenuation measurements.

  16. Photolysis of oxyfluorfen in aqueous methanol.

    Science.gov (United States)

    Chakraborty, Subhasish K; Chakraborty, Savitri; Bhattacharyya, Anjan; Chowdhury, Ashim

    2013-01-01

    Photolysis of oxyfluorfen, an herbicide of the nitrodiphenyl ether class, was studied in aqueous methanol under UV and sunlight. UV irradiation was carried out in a borosilicate glass photoreactor (containing 250 ppm oxyfluorfen in 50% aqueous methanol) equipped with a quartz filter and 125 watt mercury lamp (maximum output 254 nm) at 25 ± 1°C. Sunlight irradiation was conducted at 28 ± 1°C in borosilicate Erlenmeyer flasks containing 250 ppm oxyfluorfen in 50% aqueous methanol. The samples from both the irradiated conditions were withdrawn at a definite time interval and extracted to measure oxyfluorfen content by gas chromatography-flame ionization detector for rate study. The half-life values were 20 hours and 2.7 days under UV and sunlight exposure, respectively. Photolysis of oxyfluorfen yielded 13 photoproducts of which three were characterized by infrared spectrophotometer and (1)H NMR and (13)C NMR spectroscopy. The rest of the photoproducts were identified by gas chromatography-mass spectrometry (GC-MS) and thin layer chromatography (TLC). An ionization potential 70 eV was used for electron impact-mass spectrometry (EI-MS) and methane was used as reagent gas for chemical ionization-mass spectrometry (CI-MS). Two of the photoproducts were also synthesized for comparison. The main phototransformation pathways of oxyfluorfen involved nitro reduction, dechlorination, and hydrolysis as well as nucleophiles displacement reaction. PMID:23998303

  17. Survey of Potential Glass Compositions for the Immobilisation of the UK's Separated Plutonium Stocks

    International Nuclear Information System (INIS)

    The Nuclear Decommissioning Authority (NDA) has taken over ownership of the majority of the UK's separated civil plutonium stocks, which are expected to exceed 100 metric tons by 2010. Studies to technically underpin options development for the disposition of these stocks, for example by immobilization or re-use as fuel, are being carried out by Nexia Solutions on behalf of NDA. Three classes of immobilization matrices have been selected for investigation by means of previous studies and stakeholder dialogue: ceramic or crystalline waste-forms, storage MOx, and vitreous or glass-based waste-forms. This paper describes the preliminary inactive experimental program for the vitrification option, with results from a wide range of glass compositions along with conclusions on their potential use for plutonium immobilization. Following review, four glass systems were selected for preliminary investigation: borosilicate, lanthanide borosilicate, aluminosilicate and phosphate glasses. A broad survey of glass properties was completed in order to allow meaningful evaluation, e.g. glass formulation, waste loading, chemical durability, thermal properties, and viscosity. The program was divided into two parts, with silicate and phosphate glasses being investigated by Nexia Solutions and the Immobilisation Science Laboratory (ISL) at the University of Sheffield respectively. (authors)

  18. Plutonium doping of SYNROC-D

    International Nuclear Information System (INIS)

    The purpose of this work was to perform an experimental simulation of the radiation effects that SYNROC-D (a ceramic waste form and the alternate to borosilicate glass for US defense high-level nuclear waste) will experience during the first million years of storage. Technology was developed for doping SYNROC-D with 238Pu and performing external gamma irradiation to simulate both actinide and fission product decay. The doping technique was tested using both Ce and U as stand-ins to simulate the +3 and +4 oxidation states of Pu, respectively. Samples were characterized by ceramography, density measurements, x-ray diffraction, scanning electron microscope-energy dispersive x-ray analysis, electron microprobe, scanning transmission electron microscope, gamma ray spectrometry, and leaching; equipment was fabricated for dilatation measurements. An early decision by the Department of Energy (DOE) to select borosilicate glass and terminate SYNROC-D development prevented doping with 238Pu or external gamma irradiation. However, a sample was doped with 239Pu in order to study the Pu distribution, and characterization of this sample was completed. Although conclusive proof was not developed, all indications from this work are that Pu will go into the zirconolite and perovskite phases in SYNROC-D, favoring perovskite under the redox conditions prevailing in a graphite die. Technology development and results of Ce, U, and 239Pu doping studies are described in this report

  19. Phase stability effects on the corrosion behavior of the metal barrier candidate materials for the nuclear waste management program

    International Nuclear Information System (INIS)

    Six candidate materials are currently under consideration by the Nuclear Waste Management Program (NWMP) at Lawrence Livermore National Laboratory as potential metal barrier materials for high-level nuclear waste storage. The waste package, which must meet the Nuclear Regulatory Commission licensing requirements for the Nevada Nuclear Waste Storage Investigations Project (NNWSI), will contain spent fuel from civilian nuclear power plants PWR and BWR fuel assemblies, commercial high level waste (CHLW) in the form of borosilicate glass containing commercial spent fuel reprocessing wastes and defense high level waste (DHLW) contained in borosilicate glass. The waste package is being designed for emplacement in the unsaturated zone above the water table at the Yucca Mountain site in Nevada. This location should result in a slightly oxidizing repository environment. The Metal Barrier Selection and Testing Task is responsible for the selection of the materials to be employed in the waste package container. The candidate materials include three iron to nickel-based austenitic materials and three copper-based alloy materials. The austenitic materials are AISI 304L stainless steel, AISI 316L stainless steel and alloy 825. The copper-based alloy materials are CDA 102 (OFHC copper), CDA 613 (Cu-7Al) and CDA 715 (Cu-30Ni). The selection of the final metal barrier material is dependent upon the expected behavior of these materials in the repository environment

  20. Washing and caustic leaching of Hanford tank sludges: Results of FY 1995 studies

    International Nuclear Information System (INIS)

    During the past few years, the primary mission at the US Department of Energy's Hanford Site has changed from producing plutonium to environmental restoration. Large volumes of high-level radioactive wastes (HLW), generated during past Pu production and other operations, are stored in underground tanks on site. The current plan for remediating the Hanford tank farms consists of waste retrieval, pretreatment, treatment (immobilization), and disposal. The HLW will be immobilized in a borosilicate glass matrix; the resulting glass canisters will then be disposed of in a geologic repository. Because of the expected high cost of HLW immobilization and disposal, pretreatment processes will be implemented to reduce the volume of borosilicate glass produced in processing the tank wastes. This document describes sludge washing and caustic leaching tests conducted in FY 1995 at the Pacific Northwest Laboratory (PNL) at the request of Westinghouse Hanford Company. These tests were performed using sludges from seven Hanford waste tanks -- B-111, BX-107, C-103, S-104, SY-103, T-104, and T-111. The primary and secondary types of waste stored in each of these tanks are given in Table 1. 1. The data collected in this effort will be used to support the March 1998 Tri-Party Agreement decision on the extent of pretreatment to be performed on the Hanford tank sludges (Ecology, EPA, and DOE 1994)

  1. Oxidation of SiC/BN/SiC Composites in Reduced Oxygen Partial Pressures

    Science.gov (United States)

    Opila, Elizabeth J.; Boyd, Meredith

    2010-01-01

    SiC fiber-reinforced SiC composites with a BN interphase are proposed for use as leading edge structures of hypersonic vehicles. The durability of these materials under hypersonic flight conditions is therefore of interest. Thermogravimetric analysis was used to characterize the oxidation kinetics of both the constituent fibers and composite coupons at four temperatures: 816, 1149, 1343, and 1538 C (1500, 2100, 2450, and 2800 F) and in oxygen partial pressures between 5% and 0.1% (balance argon) at 1 atm total pressure. One edge of the coupons was ground off so the effects of oxygen ingress into the composite could be monitored by post-test SEM and EDS. Additional characterization of the oxidation products was conducted by XPS and TOF-SIMS. Under most conditions, the BN oxidized rapidly, leading to the formation of borosilicate glass. Rapid initial oxidation followed by volatilization of boria lead to protective oxide formation and further oxidation was slow. At 1538C in 5% oxygen, both the fibers and coupons exhibited borosilicate glass formation and bubbling. At 1538C in 0.1% oxygen, active oxidation of both the fibers and the composites was observed leading to rapid SiC degradation. BN oxidation at 1538C in 0.1% oxygen was not significant.

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

    International Nuclear Information System (INIS)

    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 129I, 85Kr and 14C. (author). 104 refs., 9 tabs., 5 figs

  3. High-efficiency thin-film cadmium telluride photovoltaic cells. Annual technical report, January 20, 1996--January 19, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A D; Bohn, R G; Contreras-Puente, G [Univ. of Toledo, OH (United States)

    1997-08-01

    The University of Toledo photovoltaics group has been instrumental in developing rf sputtering for CDs/CdTe thin-film solar cells. During the third phase of the present contract our work focussed on efforts to determine factors which limit the efficiency in our {open_quotes}all-sputtered{close_quotes} thin-film CdTe solar cells on soda-lime glass. We find that our all-sputtered cells, which are deposited at substantially lower temperature than those by sublimation or vapor deposition, require less aggressive CdCl{sub 2} treatments than do other deposition techniques and this is presumably related to CDs/CdTe interdiffusion. The CDs/CdTe interdiffusion process has been studied by several methods, including photoluminescence and capacitance-voltage measurements. Furthermore, we have deposited special thin bilayer films on quartz and borosilicate glass. Interdiffusion in these thin bilayers have been probed by Rutherford backscattering, with collaborators at Case Western Reserve University, and grazing incidence x-ray scattering (GIXS), with collaborators at the University at Buffalo and Brookhaven National Lab. Also, in order better to understand the properties of the ternary alloy material, we used laser physical vapor deposition to prepare a series of CdS{sub x}Te{sub 1-x} films on borosilicate glass. The composition of the alloy films was determined by wavelength dispersive x-ray spectroscopy at NREL. These films are currently being investigated by us and other groups at NREL and IEC.

  4. Radioactive waste forms: A review and comparison

    International Nuclear Information System (INIS)

    Borosilicate glass is, at present, the waste form of choice for most countries and for most compositions. The selection of borosilicate glass is based mainly on an anticipated ease of processing (glass frit and the waste are mixed, melted at relatively low temperatures, and poured into canisters), the fact that the technology is well demonstrated for actual (radioactive) waste, and finally the assumption that the glass as an aperiodic solid will easily accommodate wide variation in waste stream compositions which are extremely complex and varied. There are, however, alternative waste forms which may be single or polyphase crystalline ceramics. Principal ceramic nuclear waste forms include: Synroc, tailored ceramics (= supercalcine), TiO2-matrix ceramics, glass ceramics, monazite, synthetic ''basalt'', cementitious materials, and FUETAP concrete. In addition, there are a number of ''novel'' ceramic waste forms which have been developed to only the most preliminary stages (e.g., crichtonite and cesium-Titanates), and there are several multi-barrier strategies which encapsulate one ceramic waste form in another. Finally, in recent years, spent fuel has become an important waste form. Finally, in recent years, spent fuel has become an important waste form. This paper will briefly describe the importance and types of ceramic waste forms that have been developed and review their advantages and disadvantages. (author). 9 refs

  5. Damage on fused silica optics caused by laser ablation of surface-bound microparticles.

    Science.gov (United States)

    Raman, Rajesh N; Demos, Stavros G; Shen, Nan; Feigenbaum, Eyal; Negres, Raluca A; Elhadj, Selim; Rubenchik, Alexander M; Matthews, Manyalibo J

    2016-02-01

    High peak power laser systems are vulnerable to performance degradation due to particulate contamination on optical surfaces. In this work, we show using model contaminant particles that their optical properties decisively determine the nature of the optical damage. Borosilicate particles with low intrinsic optical absorption undergo ablation initiating in their sub-surface, leading to brittle fragmentation, distributed plasma formation, material dispersal and ultimately can lead to micro-fractures in the substrate optical surface. In contrast, energy coupling into metallic particles is highly localized near the particle-substrate interface leading to the formation of a confined plasma and subsequent etching of the substrate surface, accompanied by particle ejection driven by the recoil momentum of the ablation plume. While the tendency to create fractured surface pitting from borosilicate is stochastic, the smooth ablation pits created by metal particles is deterministic, with pit depths scaling linearly with laser fluence. A simple model is employed which predicts ~3x electric field intensity enhancement from surface-bound fragments. In addition, our results suggest that the amount of energy deposited in metal particles is at least twice that in transparent particles. PMID:26906835

  6. Corrosion Testing of Monofrax K-3 Refractory in Defense Waste Processing Facility (DWPF) Alternate Reductant Feeds

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jantzen, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-06

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) uses a combination of reductants and oxidants while converting high level waste (HLW) to a borosilicate waste form. A reducing flowsheet is maintained to retain radionuclides in their reduced oxidation states which promotes their incorporation into borosilicate glass. For the last 20 years of processing, the DWPF has used formic acid as the main reductant and nitric acid as the main oxidant. During reaction in the Chemical Process Cell (CPC), formate and formic acid release measurably significant H2 gas which requires monitoring of certain vessel’s vapor spaces. A switch to a nitric acid-glycolic acid (NG) flowsheet from the nitric-formic (NF) flowsheet is desired as the NG flowsheet releases considerably less H2 gas upon decomposition. This would greatly simplify DWPF processing from a safety standpoint as close monitoring of the H2 gas concentration could become less critical. In terms of the waste glass melter vapor space flammability, the switch from the NF flowsheet to the NG flowsheet showed a reduction of H2 gas production from the vitrification process as well. Due to the positive impact of the switch to glycolic acid determined on the flammability issues, evaluation of the other impacts of glycolic acid on the facility must be examined.

  7. Low helium permeation cells for atomic microsystems technology.

    Science.gov (United States)

    Dellis, Argyrios T; Shah, Vishal; Donley, Elizabeth A; Knappe, Svenja; Kitching, John

    2016-06-15

    Laser spectroscopy of atoms confined in vapor cells can be strongly affected by the presence of background gases. A significant source of vacuum contamination is the permeation of gases such as helium (He) through the walls of the cell. Aluminosilicate glass (ASG) is a material with a helium permeation rate that is many orders of magnitude lower than borosilicate glass, which is commonly used for cell fabrication. We have identified a suitable source of ASG that is fabricated in wafer form and can be anodically bonded to silicon. We have fabricated chip-scale alkali vapor cells using this glass for the windows and we have measured the helium permeation rate using the pressure shift of the hyperfine clock transition. We demonstrate micro fabricated cells with He permeation rates at least three orders of magnitude lower than that of cells made with borosilicate glass at room temperature. Such cells may be useful in compact vapor-cell atomic clocks and as a micro fabricated platform suitable for the generation of cold atom samples. PMID:27304286

  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. SON68 glass dissolution driven by magnesium silicate precipitation

    International Nuclear Information System (INIS)

    Experimental results are reported on the effect of magnesium silicate precipitation on the mechanisms and rate of borosilicate glass dissolution. Leaching experiments with SON68 glass, a borosilicate containing no Mg, were carried out in initially deionized water at 50 °C with a glass-surface-area-to-solution-volume ratio of 20,000 m−1. After 29 days of alteration the experimental conditions were modified by the addition of Mg to trigger the precipitation of Mg-silicate. Additional experiments were conducted to investigate the importance of other parameters such as pH or dissolved silica on the mechanisms of precipitation of Mg-silicates and their consequences on the glass dissolution rate. Mg-silicates precipitate immediately after Mg is added. The amount of altered glass increases with the quantity of added Mg, and is smaller when silicon is added in solution. A time lag is observed between the addition of magnesium and the resumption of glass alteration because silicon is first provided by partial dissolution of the previously formed alteration gel. It is shown that nucleation does not limit Mg-silicate precipitation. A pH above 8 is necessary for the phase to precipitate under the investigated experimental conditions. On the other hand the glass alteration kinetics limits the precipitation if the magnesium is supplied in solution at a non-limiting rate

  10. Performance assessment of the direct disposal in unsaturated tuff or spent nuclear fuel and high-level waste owned by USDOE: Volume 2, Methodology and results

    International Nuclear Information System (INIS)

    This assessment studied the performance of high-level radioactive waste and spent nuclear fuel in a hypothetical repository in unsaturated tuff. The results of this 10-month study are intended to help guide the Office of Environment Management of the US Department of Energy (DOE) on how to prepare its wastes for eventual permanent disposal. The waste forms comprised spent fuel and high-level waste currently stored at the Idaho National Engineering Laboratory (INEL) and the Hanford reservations. About 700 metric tons heavy metal (MTHM) of the waste under study is stored at INEL, including graphite spent nuclear fuel, highly enriched uranium spent fuel, low enriched uranium spent fuel, and calcined high-level waste. About 2100 MTHM of weapons production fuel, currently stored on the Hanford reservation, was also included. The behavior of the waste was analyzed by waste form and also as a group of waste forms in the hypothetical tuff repository. When the waste forms were studied together, the repository was assumed also to contain about 9200 MTHM high-level waste in borosilicate glass from three DOE sites. The addition of the borosilicate glass, which has already been proposed as a final waste form, brought the total to about 12,000 MTHM

  11. Radioactive demonstration of DWPF product control strategy

    International Nuclear Information System (INIS)

    The Defense Waste Processing Facility at the Savannah River Site (SRS) will vitrify high-level nuclear waste into borosilicate glass. The waste will be mixed with properly formulated glass-making frit and fed to a melter at 1150 degrees C. Process reliability and product quality are ensured by proper control of the melter feed composition. The effectiveness of the product and process control strategies that will be utilized by the Defense Waste Processing Facility (DWPF) was demonstrated during a campaign in the Shielded Cells Facility of the Savannah River Technology Center (SRTC). The remotely operated process included the preparation of the melter feed, vitrification in a slurry-fed 1/100th scale melter an analysis of the glass product both for its composition an durability. The campaign processed approximately 10 kg (on a dry basis) of radioactive sludge from Tank 51. This sludge is representative of the first batch of sludge that will be sent to the DWPF for immobilization into borosilicate glass. Additions to the sludge were made based on calculations using the Product Composition Control System (PCCS). Analysis of the glass produced during the campaign showed that a durable glass was produced with a composition very close to that predicted using the PCCS. 10 refs., 4 tabs

  12. Growth and properties of CdS/CdTe heterojunctions on soda lime glass substrates

    International Nuclear Information System (INIS)

    Polycrystalline thin films of CdTe grown on glass/SnO2/CdS substrates are studied using X-ray diffraction, atomic force microscopy, and time resolved photoluminescence decay techniques. CdS films were deposited by chemical solution. CdTe films were grown by close-spaced sublimation at substrate temperatures between 475--625 degree C. CdTe thin films deposited at temperatures higher than 525 degree C show preferential orientation in the left-angle 111 right-angle direction. The Grain size of the films increases with substrate temperature and the films are faceted for all the temperatures. The PL decay constant increases with substrate temperature up to 575 degree C for as-deposited films on soda-lime substrates. Films on borosilicate substrates show an increase up to the highest temperature used (625 degree C). There is systematic increase in the PL decay constant after CdCl2 heat treatment, and the range of values is 1--1.5 nsec for soda-lime samples and 1--2 nsec for borosilicate samples

  13. Nanoscale topographic changes on sterilized glass surfaces affect cell adhesion and spreading.

    Science.gov (United States)

    Wittenburg, Gretel; Lauer, Günter; Oswald, Steffen; Labudde, Dirk; Franz, Clemens M

    2014-08-01

    Producing sterile glass surfaces is of great importance for a wide range of laboratory and medical applications, including in vitro cell culture and tissue engineering. However, sterilization may change the surface properties of glass and thereby affect its use for medical applications, for instance as a substrate for culturing cells. To investigate potential effects of sterilization on glass surface topography, borosilicate glass coverslips were left untreated or subjected to several common sterilization procedures, including low-temperature plasma gas, gamma irradiation and steam. Imaging by atomic force microscopy demonstrated that the surface of untreated borosilicate coverslips features a complex landscape of microislands ranging from 1000 to 3000 nm in diameter and 1 to 3 nm in height. Steam treatment completely removes these microislands, producing a nanosmooth glass surface. In contrast, plasma treatment partially degrades the microisland structure, while gamma irradiation has no effect on microisland topography. To test for possible effects of the nanotopographic structures on cell adhesion, human gingival fibroblasts were seeded on untreated or sterilized glass surfaces. Analyzing fibroblast adhesion 3, 6, and 24 h after cell seeding revealed significant differences in cell attachment and spreading depending on the sterilization method applied. Furthermore, single-cell force spectroscopy revealed a connection between the nanotopographic landscape of glass and the formation of cellular adhesion forces, indicating that fibroblasts generally adhere weakly to nanosmooth but strongly to nanorough glass surfaces. Nanotopographic changes induced by different sterilization methods may therefore need to be considered when preparing sterile glass surfaces for cell culture or biomedical applications. PMID:24027204

  14. Management of cesium loaded AMP- Part I preparation of 137Cesium concentrate and cementation of secondary wastes

    International Nuclear Information System (INIS)

    Separation of 137cesium from High Level Waste can be achieved by use of composite-AMP, an engineered form of Ammonium Molybdo-Phosphate(AMP). Direct vitrification of cesium loaded composite AMP in borosilicate glass matrix leads to separation of water soluble molybdate phase. A proposed process describes two different routes of selective separation of molybdates and phosphate to obtain solutions of cesium concentrates. Elution of 137Cesium from composite-AMP by decomposing it under flow conditions using saturated barium hydroxide was investigated. This method leaves molybdate and phosphate embedded in the column but only 70% of total cesium loaded on column could be eluted. Alternatively composite-AMP was dissolved in sodium hydroxide and precipitation of barium molybdate-phosphate from the resultant solution, using barium nitrate was investigated by batch methods. The precipitation technique gave over 99.9% of 137Cesium activity in solutions, free of molybdates and phosphates, which is ideally suited for immobilization in borosilicate glass matrix. Detailed studies were carried out to immobilize secondary waste of 137Cesium contaminated barium molybdate-phosphate precipitates in the slag cement matrix using vermiculite and bentonite as admixtures. The cumulative fraction of 137Cs leached from the cement matrix blocks was 0.05 in 140 days while the 137Cs leach rate was 0.001 gm/cm2/d. (author)

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

    International Nuclear Information System (INIS)

    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 (SiO2-B2O3-Na2O (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)

  16. Radiation problems associated with Skylab

    Science.gov (United States)

    Braly, J. E.; Heaton, T. R.

    1972-01-01

    Radiation tests were conducted on the various types of Skylab film to establish the total radiation dosages compatible with an acceptable level of film fogging, and on the S190 borosilicate window to establish radiation limits for an acceptable darkening level. The results verified that most of the films would be unusable when returned to earth, and that the borosilicate window would be darkened beyond allowable limit, unless additional protection was provided. The operational solutions to these problems involve protecting the film with five film vaults and protecting the window with a radiation shield. The largest vault is made of aluminum and weighs over 2000 lb (its thickest compartment wall is 3.4 in.). The window radiation shield is a light honeycomb structure which is swung away for limited astronaut viewing or when the S190 experiment is in operation. Although the shield is light weight, it is heavy enough to stop the large number of low energy electrons making up a major part of the external environment and which are potentially damaging to the window. A brief description is given of the Skylab mission and some of the associated experiments. The radiation environment the spacecraft will encounter is discussed.

  17. 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

  18. Planar patch-clamp force microscopy on living cells

    Energy Technology Data Exchange (ETDEWEB)

    Pamir, Evren [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany); George, Michael; Fertig, Niels [Nanion Technologies GmbH, Erzgiessereistr. 4, 80335 Munich (Germany); Benoit, Martin [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany)], E-mail: martin.benoit@physik.uni-muenchen.de

    2008-05-15

    Here we report a new combination of the patch-clamp technique with the atomic force microscope (AFM). A planar patch-clamp chip microstructured from borosilicate glass was used as a support for mechanical probing of living cells. The setup not only allows for immobilizing even a non-adherent cell for measurements of its mechanical properties, but also for simultaneously measuring the electrophysiological properties of a single cell. As a proof of principle experiment we measured the voltage-induced membrane movement of HEK293 and Jurkat cells in the whole-cell voltage clamp configuration. The results of these measurements are in good agreement with previous studies. By using the planar patch-clamp chip for immobilization, the AFM not only can image non-adhering cells, but also gets easily access to an electrophysiologically controlled cellular probe at low vibrational noise.

  19. Reevaluation of Vitrified High-Level Waste Form Criteria for Potential Cost Savings at the Defense Waste Processing Facility - 13598

    International Nuclear Information System (INIS)

    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 durable borosilicate glass since 1996. Currently the DWPF has poured over 3,500 canisters, all of which are compliant with the U. S. Department of Energy's (DOE) Waste Acceptance Product Specifications for Vitrified High-Level Waste Forms (WAPS) and therefore ready to be shipped to a federal geologic repository for permanent disposal. Due to DOE petitioning to withdraw the Yucca Mountain License Application (LA) from the Nuclear Regulatory Commission (NRC) in 2010 and thus no clear disposal path for SRS canistered waste forms, there are opportunities for cost savings with future canister production at DWPF and other DOE producer sites by reevaluating high-level waste form requirements and compliance strategies and reducing/eliminating those that will not negatively impact the quality of the canistered waste form. (authors)

  20. Atomic layer deposition and characterization of biocompatible hydroxyapatite thin films

    International Nuclear Information System (INIS)

    Atomic layer deposition (ALD) was used to produce hydroxyapatite from Ca(thd)2 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) and (CH3O)3PO onto Si(100) and Corning (0211). Film crystallinity, stoichiometry, possible impurities and surface morphology were determined. The as-deposited films contained significant amounts of carbonate impurities however, annealing at moist N2 flow reduced the carbonate content even at 400 oC. The as-deposited Ca-P-O films were amorphous but rapid thermal annealing promoted the formation of the hydroxyapatite phase. Mouse MC 3T3-E1 cells were used for the cell culture experiments. According to the bioactivity studies cell proliferation was enhanced on as-deposited ALD-grown Ca-P-O films and greatly enhanced on films annealed at 500 oC in comparison with reference cells on borosilicate glass or cell culture polystyrene.