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1

Effects of deposited nuclear and electronic energy on the hardness of R7T7-type containment glass  

NASA Astrophysics Data System (ADS)

The effects of elastic and inelastic interactions induced by cumulative alpha decay on the hardness of R7T7-type nuclear containment glass were investigated on actinide-doped glass specimens and by external irradiation of inactive glass by light and heavy ions. Vickers microindentation and nanoindentation hardness measurements showed that in the deposited energy range investigated (below 3 × 1022 keV/cm3) inelastic effects have no influence on the plastic response of the glass. Conversely, identical hardness variations versus the nuclear energy deposited in the material were observed on curium-doped glass and on glass irradiated by ion bombardment. The observed hardness variation stabilized after the deposited energy reached about 3 × 1020 keVnucl/cm3. These findings indicate that the change in the plastic response of the glass is a consequence of ballistic effects.

Peuget, S.; Noël, P.-Y.; Loubet, J.-L.; Pavan, S.; Nivet, P.; Chenet, A.

2006-05-01

2

Use of orthophosphate complexing agents to investigate mechanisms limiting the alteration kinetics of French SON 68 nuclear glass  

Microsoft Academic Search

This investigation was carried out to assess the protective properties of the alteration film that develops during aqueous alteration of the French SON 68 (R7T7-type) nuclear glass, notably by examining the behavior of some network-forming cations in the presence of complexing anions. Glass alteration was studied here in the presence of orthophosphate ions. Comparisons were established between two series of

S Gin; C Jégou; E Vernaz

2000-01-01

3

Long-term safety of radioactive waste disposal: Retention of Pu, Am, Np and Tc in the corrosion of COGEMA glass R7T7 in salt solutions. Final report.  

National Technical Information Service (NTIS)

For performance assessment of high-level radioactive waste disposal in salt formations, corrosion tests were carried out, using high active R7T7-type glass containing reprocessing waste, produced by CEA Marcoule. The objective of this investigation was to...

B. Grambow W. Lutze L. Kahl H. Geckeis E. Bohnert

1996-01-01

4

Nuclear Waste Glass Composition Limitations.  

National Technical Information Service (NTIS)

This paper discusses the primary considerations involved in nuclear waste glass composition development, explains why the maximum content of certain elements in those glasses is limited, and suggests some possible improvements in reprocessing and waste ma...

L. A. Chick J. L. Swanson D. S. Goldman

1984-01-01

5

Nuclear waste glass corrosion mechanisms  

Microsoft Academic Search

Dissolution of nuclear waste glass occurs by corrosion mechanisms similar to those of other solids, e.g., metallurgical and mineralogic systems. Metallurgical phenomena such as active corrosion, passivation and immunity have been observed to be a function of the glass composition and the solution pH. Hydration thermodynamics was used to quantify the role of glass composition and its effect on the

Jantzen

1987-01-01

6

Glasses for nuclear waste immobilization  

Microsoft Academic Search

Vitrification of nuclear wastes is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting waste form. Vitrification is a mature technology and has been used for high level nuclear waste (HLW) immobilisation for more than 40 years in France, Germany and

M. I. Ojovan; O. G. Batyukhnova

2007-01-01

7

Crystallization during processing of nuclear waste glass  

SciTech Connect

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glassmaking are reviewed.

Hrma, Pavel R.

2010-12-01

8

GLASS FIBERS IN NUCLEAR REACTOR TECHNOLOGY  

Microsoft Academic Search

A novel technique of incorporating fissionable and fertile material, ; homogeneously dispersed, in mineral or glass fibers, appears to have definite ; advantages for use in nuclear reactor fuel elements. To date, incorporation of ; 10% uranium-235 oxide by weight has been readily achieved. Radiation stability ; studies were made of these fibers, examining the effect of fiber diameter, ;

P. Harteck; S. Dondes; J. W. Michener

1958-01-01

9

Glass produced by underground nuclear explosions. [Rainier  

SciTech Connect

Detonation of an underground nuclear explosive produces a strong shock wave which propagates spherically outward, vaporizing the explosive and nearby rock and melting, the surrounding rock. The vaporized material expands adiabatically, forming a cavity. As the energy is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is quenched by fractured rock fragments falling from above as the cavity collapses. Measurements indicate that about 740 tonnes of rock and/or soil are melted for every kiloton (10/sup 12/ calories) of explosive energy, or about 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with explosive debris. The appearance ranges from white pumice to dense, dark lava. The bulk composition and color vary with the amount of explosive iron incorporated into the glass. The refractory explosion products are mixed with the solidified melt, although the degree of mixing is variable. Electron microprobe studies of glasses produced by Rainier in welded tuff have produced the following results: glasses are dehydrated relative to the host media, glasses are extremely heterogeneous on a 20 ..mu..m scale, a ubiquitous feature is the presence of dark marble-cake regions in the glass, which were locally enriched in iron and may be related to the debris, optically amorphous regions provide evidence of shock melting, only limited major element redistribution and homogenization occur within the cavity.

Schwartz, L.; Piwinskii, A.; Ryerson, F.; Tewes, H.; Beiriger, W.

1983-01-01

10

Nuclear Waste Glasses: Continuous Melting and Bulk Vitrification  

Microsoft Academic Search

This contribution addresses various aspects of nuclear waste vitrification. Composition of nuclear wastes varies in the number of components and their composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee that the glass is easily made and resists environmental degradation. Glass

Pavel R. Hrma; Albert A. Kruger

2009-01-01

11

NUCLEAR WASTE GLASSES CONTINUOUS MELTING AND BULK VITRIFICAITON  

Microsoft Academic Search

This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes have a variety of components and composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee the glass can be easily made and resist environmental degradation. Glass formulation is facilitated by

Pavel R. Hrma; Albert A. Kruger

2008-01-01

12

Thermodynamic model of natural, medieval and nuclear waste glass durability  

SciTech Connect

A thermodynamic model of glass durability based on hydration of structural units has been applied to natural glass, medieval window glasses, and glasses containing nuclear waste. The relative durability predicted from the calculated thermodynamics correlates directly with the experimentally observed release of structural silicon in the leaching solution in short-term laboratory tests. By choosing natural glasses and ancient glasses whose long-term performance is known, and which bracket the durability of waste glasses, the long-term stability of nuclear waste glasses can be interpolated among these materials. The current Savannah River defense waste glass formulation is as durable as natural basalt from the Hanford Reservation (10/sup 6/ years old). The thermodynamic hydration energy is shown to be related to the bond energetics of the glass. 69 references, 2 figures, 1 table.

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

1983-01-01

13

Observations of Nuclear Explosive Melt Glass Textures and Surface Areas  

Microsoft Academic Search

This memo report summarizes our current knowledge of the appearance of melt glass formed and subsequently deposited in the subsurface after an underground nuclear test. We have collected archived pictures and melt glass samples from a variety of underground nuclear tests that were conducted at the Nevada Test Site (NTS) during the U.S. nuclear testing program. The purpose of our

A B Kersting; D K Smith

2006-01-01

14

Hydration process of nuclear-waste glass: an interim report  

SciTech Connect

Aging of simulated nuclear waste glass by contact with a controlled-temperature, humid atmosphere results in the formation of a double hydration layer penetrating the glass, as well as the formation of minerals on the glass surface. The hydration process can be described by Arrhenius behavior between 120 and 240/sup 0/C. Results suggest that simulated aging reactions are necessary for demonstrating that nuclear waste forms can meet projected Nuclear Regulatory Commission regulations. 16 figures, 4 tables.

Bates, J.K.; Jardine, L.J.; Steindler, M.J.

1982-07-01

15

Nuclear waste glass leaching in a simulated granite repository  

Microsoft Academic Search

Burial experiments of three Savannah River Laboratory (SRL) and three Swedish alkali borosilicate (ABS) simulated nuclear waste glasses were conducted to evaluate the resistance of these glasses to ground water attack under repository-like conditions. Glass samples were buried in the boreholes at a depth of about 350 meters below the surface in the Stripa granite at either ambient mine temperature

Zhu

1987-01-01

16

Nuclear waste glass Product Consistency Test (PCT), Version 3. 0  

Microsoft Academic Search

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs

C. M. Jantzen; N. E. Bibler

1990-01-01

17

Nuclear waste glass product consistency test (PCT), Version 5. 0  

Microsoft Academic Search

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs

C. M. Jantzen; N. E. Bibler; D. C. Beam; W. G. Ramsey; B. J. Waters

1992-01-01

18

Electron beam irradiation effects in Trombay nuclear waste glass  

NASA Astrophysics Data System (ADS)

Electron beam irradiated nuclear waste glasses were studied by EPR, positron annihilation spectroscopy and IR techniques. Formation of boron-oxygen and silicon based hole centers along with E ? centers were observed in the glass after irradiation. Increase in the free volume size and fraction was observed in the irradiated glasses. EPR spin counting technique was employed to evaluate the defect concentration in the glasses after irradiation.

Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Dutta, D.; Pujari, P. K.; Kaushik, C. P.; Kshirsagar, R. J.; Tomar, B. S.; Godbole, S. V.

2011-10-01

19

Spectroscopic investigation of U, Np and Th in nuclear glasses  

NASA Astrophysics Data System (ADS)

Vitrification of high-level radioactive waste in borosilicate glasses is currently used on an industrial scale in several countries. The fundamental properties of the waste forms are their chemical and mechanical durability against the forcing conditions represented by chemical alteration or internal/external irradiation. The waste immobilized in glass is composed of over 30 different nuclear fission and activation products, as well as minor actinides. The oxidation state and local atomic coordination of long-lived radionuclides are important parameters to understand the long-term evolution of the glass. We present an overview of the local structure around actinides in glasses similar to the French nuclear glass. X-Ray absorption spectroscopy has been used to probe the local environment around uranium, neptunium and thorium in these glasses. It is combined with with UV-visible spectroscopy, used to get selective information on the surrounding of U(IV), U(V) and U(VI) in glasses. Our spectroscopic data show that U, Np and Th occur in nuclear glasses in a peculiar surrounding showing significant differences with the crystal chemistry of these elements in crystalline compounds. Element speciation may be used as a pertinent parameter to follow the long-term stability of nuclear glasses, either under irradiation or during the alteration of the glass.

Calas, G.; Galoisy, L. V.; Petit-Maire, D.

2011-12-01

20

Nuclear Waste Glasses: Beautiful Simplicity of Complex Systems  

SciTech Connect

The behavior of glasses with a large number of components, such as waste glasses, is not more complex than the behavior of simple glasses. On the contrary, the presence of many components restricts the composition region of these glasses in a way that allows approximating composition-property relationships by linear functions. This has far-reaching practical consequences for formulating nuclear waste glasses. On the other hand, processing high-level and low-activity waste glasses presents various problems, such as crystallization, foaming, and salt segre-gation in the melter. The need to decrease the settling of solids in the melter to an acceptable level and to maximize the rate of melting presents major challenges to processing technology. However, the most important property of the glass product is its chemical durability, a somewhat vague concept in lieu of the assessment of the glass resistance to aqueous attack while the radioactivity decays over tens of thousands of years.

Hrma, Pavel R.

2009-01-01

21

Basalt glass: an analogue for the evaluation of the long-term stability of nuclear waste form borosilicate glasses  

Microsoft Academic Search

The long-term stability of nuclear waste form borosilicate glasses can be evaluated by understanding the processes that effect the long-term alteration of glass and by comparing laboratory alteration of synthetic basalt and borosilicate glasses with the observed stability of naturally occurring basaltic glasses in diverse geologic environments. This paper presents detailed electron microprobe analyses of naturally altered basaltic glasses (with

C. D. Byers; M. J. Jercinovic; R. C. Ewing; K. Keil

1984-01-01

22

Redox reaction and foaming in nuclear waste glass melting  

Microsoft Academic Search

This document was prepared by Pacific Northwest Laboratory (PNL) and is an attempt to analyze and estimate the effects of feed composition variables and reducing agent variables on the expected chemistry of reactions occurring in the cold cap and in the glass melt in the nuclear waste glass Slurry-fed, joule-heated melters as they might affect foaming during the glass-making process.

Ryan

1995-01-01

23

Control of Nepheline Crystallization in Nuclear Waste Glass  

SciTech Connect

Glass frits with a high B{sub 2}O{sub 3} concentration have been designed which, when combined with high-alumina concentration nuclear waste streams, will form glasses with durabilities that are acceptable for repository disposal and predictable using a free energy of hydration model. Two glasses with nepheline discriminator values closest to 0.62 showed significant differences in normalized boron release between the quenched and heat treated versions of each glass. X-ray diffraction confirmed that nepheline crystallized in the glass with the lowest nepheline discriminator value, and nepheline may also exist in the second glass as small nanocrystals. The high-B{sub 2}O{sub 3} frit was successful in producing simulated waste glasses with no detectable nepheline crystallization at waste loadings of up to 45 wt%. The melt rate of this frit was also considerably better than other frits with increased concentrations of Na{sub 2}O.

Fox, Kevin

2008-07-01

24

Statistical process control of glass manufactured for nuclear waste disposal  

Microsoft Academic Search

Construction of the nation's first, and the world's largest, facility to immobilize high-level nuclear waste has recently been completed at the Savannah River Site (SRS) in Aiken, SC. Liquid, high-level nuclear waste that has accumulated from over 35 years of reprocessing of nuclear fuels for national defense purposes will be immobilized in durable borosilicate glass in the SRS Defense Waste

C. M. Jantzen; K. G. Brown

1993-01-01

25

Iron Phosphate Glasses: An Alternative for Vitrifying Certain Nuclear Wastes  

SciTech Connect

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

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

2004-12-28

26

Structural control of the stability of nuclear waste glasses  

NASA Astrophysics Data System (ADS)

Vitrification of liquid high-level radioactive waste in borosilicate glasses has received a great attention in several countries. The fundamental properties of the waste forms are their chemical and mechanical durability. We present an overview of the local structure of inactive analogs of the French nuclear glass, using structural information obtained by a combination of X-ray absorption Fine Structure (XAFS) and Wide Angle X-ray Scattering (WAXS). We will first contrast several classes of elements, such as Zr, Mo or Zn, which give nuclear glasses peculiar positive or adverse properties for the industrial process: enhanced chemical stability, phase separation, crystal nucleation and separation. These properties may be rationalized using Pauling rules, familiar to Mineralogists, as other properties are correctly modelled in simplified glass compositions using molecular dynamics. We will also point out the importance of the melt-to-glass transition and the consequence of the glass structural properties on the resistance of glassy matrices to irradiation. Glass alteration affects the long-term stability of the glass. It is characterized by an amorphous (glass)-amorphous (gel) transformation. Depending on alteration conditions, alteration layers may have or not a protective character, which will influence radionuclide retention over time. We will present the structural modification of the surface chemistry of the glass monoliths during short-term experiments and the evolution towards a gel, which forms progressively at the expense of the glass. The protective character of the gel, observed during glass leaching under near-saturated conditions, will be rationalized by its structural properties.

Calas, G.; Galoisy, L.; Cormier, L.; Bergeron, B.; Jollivet, P.

2009-05-01

27

Melting of foaming batches: Nuclear waste glass  

SciTech Connect

A simple model is presented for the rate of melting of a batch blanket in an electric glassmelting furnace. The melting process is assumed to be jointly controlled by the heat transfer from the pool of molten glass and the batch-to-glass conversion kinetics. Factors affecting the melting rate in the conversion-controlled regime are discussed. Attention is paid to gas evolution from redox reactions in waste glass batches and component accumulation within the blanket. It is suggested that the high rate of the blanket-free melting in a mechanically agitated furnace is made possible by increasing the rate of melt surface renewal. 27 refs.

Hrma, P.

1990-10-01

28

Impact of nuclear dipoles on polarization echoes in glasses  

Microsoft Academic Search

A few years ago surprising magnetic field effects were found in non- magnetic glasses at low temperatures (approx 10 mK). It has since been established that this effect can be attributed to the tunnelling motion of particles carrying nuclear quadrupole moments. The magnetic field effect saturates when the nuclear Zeeman energy becomes larger than the quadrupole splitting. For glycerol this

M. Bazrafshan; G. Fickenscher; M. v. Schickfus; A. Fleischmann; C. Enss

2007-01-01

29

Hydrogen speciation in hydrated layers on nuclear waste glass  

SciTech Connect

The hydration of an outer layer on nuclear waste glasses is known to occur during leaching, but the actual speciation of hydrogen (as water or hydroxyl groups) in these layers has not been determined. As part of the Nevada Nuclear Waste Storage Investigations Project, we have used infrared spectroscopy to determine hydrogen speciations in three nuclear waste glass compositions (SRL-131 & 165, and PNL 76-68), which were leached at 90{sup 0}C (all glasses) or hydrated in a vapor-saturated atmosphere at 202{sup 0}C (SRL-131 only). Hydroxyl groups were found in the surface layers of all the glasses. Molecular water was found in the surface of SRL-131 and PNL 76-68 glasses that had been leached for several months in deionized water, and in the vapor-hydrated sample. The water/hydroxyl ratio increases with increasing reaction time; molecular water makes up most of the hydrogen in the thick reaction layers on vapor-phase hydrated glass while only hydroxyl occurs in the least reacted samples. Using the known molar absorptivities of water and hydroxyl in silica-rich glass the vapor-phase layer contained 4.8 moles/liter of molecular water, and 0.6 moles water in the form hydroxyl. A 15 {mu}m layer on SRL-131 glass formed by leaching at 90{sup 0}C contained a total of 4.9 moles/liter of water, 2/3 of which was as hydroxyl. The unreacted bulk glass contains about 0.018 moles/liter water, all as hydroxyl. The amount of hydrogen added to the SRL-131 glass was about 70% of the original Na + Li content, not the 300% that would result from alkali=hydronium ion interdiffusion. If all the hydrogen is then assumed to be added as the result of alkali-H{sup +} interdiffusion, the molecular water observed may have formed from condensation of the original hydroxyl groups.

Aines, R.D.; Weed, H.C.; Bates, J.K.

1987-01-15

30

Nuclear waste under glass, further discussion  

Microsoft Academic Search

J. J. Crovisier and J. Honnorez [1988] discuss an article by W. W. Maggs, ``Mg May Protect Waste Under Glass'' [Maggs, 1988] summarizing work by A. Barkatt (Catholic University, Washington, D.C.), B. P. Glass (University of Delaware, Newark), and S. Alterescu and J. A. O'Keefe (NASA\\/GSFC, Greenbelt, Md.). We found that seawater is orders of magnitude less corrosive t h

J. A. O'Keefe; A. Barkatt; B. P. Glass; S. Alterescu

1988-01-01

31

NUCLEAR WASTE GLASSES CONTINUOUS MELTING AND BULK VITRIFICAITON  

SciTech Connect

This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes have a variety of components and composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee the glass can be easily made and resist environmental degradation. Glass formulation is facilitated by developing property-composition models, and the strategy of model development and application is reviewed. However, the large variability of waste compositions presents numerous additional challenges: insoluble solids and molten salts may segregate; foam may hinder heat transfer and slow down the process; molten salts may accumulate in container refractory walls; the glass on cooling may precipitate crystalline phases. These problems need targeted exploratory research. Examples of specific problems and their possible solutions are discussed.

KRUGER AA; HRMA PR

2008-03-24

32

Nuclear Waste Glasses: Continuous Melting and Bulk Vitrification  

SciTech Connect

This contribution addresses various aspects of nuclear waste vitrification. Nuclear wastes have a variety of components and composition ranges. For each waste composition, the glass must be formulated to possess acceptable processing and product behavior defined in terms of physical and chemical properties that guarantee that the glass can be easily made and resist environmental degradation. Glass formulation is facilitated by developing property-composition models, and the strategy of model development and application is reviewed. However, the large variability of waste compositions presents numerous additional challenges: insoluble solids and molten salts may segregate; foam may hinder heat transfer and slow down the process; molten salts may accumulate in container refractory walls; on cooling, the glass may precipitate crystalline phases. These problems need targeted exploratory research. Examples of specific problems and their possible solutions are discussed.

Hrma, Pavel R.; Kruger, Albert A.

2008-02-25

33

Nuclear waste glass product consistency test (PCT), Version 5. 0  

SciTech Connect

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached.

Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

1992-06-01

34

Nuclear waste glass Product Consistency Test (PCT), Version 3. 0  

SciTech Connect

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Product Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples.

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

1990-11-01

35

Stained glasses under the nuclear microprobe: A window into history  

NASA Astrophysics Data System (ADS)

Stained glass fragments from the 15th, 16th and 20th centuries, belonging to Mosteiro de Santa Maria da Vitória, Batalha (Portugal), were characterised non-destructively in a nuclear microprobe. The work aimed at finding the composition of the glasses and glass paintings and relating these with the corresponding production periods. The elemental compositions of the glass fragments were obtained by means of scanning micro-beam Particle Induced X-ray Emission (?-PIXE) spectrometry in selected cross-sections. These were complemented by micro X-Ray fluorescence spectrometry. Characterisation of colour was performed by optical absorption spectroscopy in the UV-vis range, while the corrosion products were identified by optical microscopy and ?-FTIR (Fourier Transform Infra Red) spectroscopy in combination with the data generated by ?-PIXE. Nuclear microprobe analysis allowed unveiling the compositions and structures, in particular of glass paintings and corrosion products. While it is not surprising that Fe, Cu and Pb were the main elements identified in the grisaille paintings of all studied periods, as well as Ag and Cu found in the glasses decorated with yellow silver painting, their distribution gave important clues on the materials and techniques used to manufacture these stained glasses. Furthermore, it allowed establishing a definite relation between the compositions found and the periods of production, with the added bonus of correctly reassigning the manufacturing period of some samples.

Vilarigues, M.; Fernandes, P.; Alves, L. C.; da Silva, R. C.

2009-06-01

36

Effect of lead species on the durability of simulated nuclear waste glass  

Microsoft Academic Search

It has been shown that the incorporation of lead metal into the corrosion environment reduces the leaching rate of nuclear waste glasses. The present study evaluated the effects of lead metal, oxides, alloys, glasses and soluble species on the corrosion rate of a waste glass. The inherent durability of nuclear waste glasses comes from the about due to the insoluble

Kuchinski

1987-01-01

37

Leach tests at Savannah River Laboratory for radioactive and nonradioactive nuclear waste glasses  

Microsoft Academic Search

The high-level nuclear wastes currently stored at Savannah River Plant as caustic slurries will be immobilized into borosilicate glass. To characterize the glass resulting from this vitrification process, the Savannah River Laboratory (SRL) has developed and performed a variety of leach tests on both radioactive glass containing actual nuclear waste and nonradioactive glass containing simulated waste. These leach tests range

N. E. Bibler; C. M. Jantzen

1989-01-01

38

Weathered basalt glass: a natural analogue for the effects of reaction progress on nuclear waste glass alteration  

Microsoft Academic Search

Empirical data from natural occurrences of basalt glass are interpreted by a model which has been developed to describe the reaction progress of the corrosion of nuclear waste form borosilicate glass. A description of the basalt glass\\/water reaction model is included. Implications are that there are similarities and differences in the phases that form in nature as compared with those

B. Grambow; M. J. Jercinovic; R. C. Ewing; C. D. Byers

1986-01-01

39

IRON PHOSPHATE GLASSES: AN ALTERNATIVE FOR VITRIFYING CERTAIN NUCLEAR WASTES  

Microsoft Academic Search

During the past year, iron phosphate glasses containing the following three types of nuclear waste, as recommended by the Tank Focus Area (TFA) group, have been investigated. (1) a high sodium\\/sulfate Hanford Low-Activity Waste (LAW) (2) a High Chrome Waste (HCW) at Hanford, and (3) a Sodium Bearing Waste (SBW) at Idaho National Engineering and Environmental Laboratory (INEEL) Over three

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

2003-01-01

40

The Role of Biofilm on the Alteration of Glasses: Example of Basaltic and Nuclear Glasses  

NASA Astrophysics Data System (ADS)

It is generally accepted that alterations of rocks and anthropogenic products are not exclusively driven by the interaction with water or mineral aqueous solutions. Organic compounds as well as microorganisms are important in mineral degradation processes, together with secondary mineralization. However, the exact role of biofilms in these processes remains unclear. In our study we tested two materials, a tholeiitic basaltic glass and the reference French nuclear glass SON68 17 LIDC2A2Z1. Experiments were carried out for 19 weeks using a modified soxhlet's device at 25°C. We developed a specific growth medium which allows both the growth of Pseudomonas bacterium and a precise measurement, using ICP-MS, of trace elements solubilized from the two glass materials. The thickness of biofilms, analyzed by confocal laser microscopy was 40?m for both materials. These biofilms are able to efficiently trap most of the glass constituents, some of them being potentially toxic. They also form a protective barrier at the solid/solution interface. Alteration rates were determined at the end of the experiments. The basaltic glass deteriorated with a rate of 18.3 10-4g.m-2.d-1 in biotic conditions and 29.8 10-4g.m-2.d-1 in the sterile system. The nuclear glass had a dissolution rate of 17.6 10^{- 4}g.m-2.d-1 in the biotic experiment and 25.0 10-4g.m-2.d-1in the sterile medium.

Aouad, G.; Crovisier, J.; Meyer, J.; Stille, P.; Damidot, D.; Hutchens, E.; Vuilleumier, S.; Geoffroy, V.

2006-12-01

41

Processing glass pyrochlore composites for nuclear waste encapsulation  

NASA Astrophysics Data System (ADS)

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

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

2005-05-01

42

Role of Self-Irradiation in Corrosion of Nuclear Waste Glasses  

SciTech Connect

The effect of self irradiation on corrosion mechanisms of nuclear waste glasses is examined. Self irradiation is shown to have a strong impact on corrosion of nuclear waste glasses under conditions where hydrolytic dissolution is suppressed and the corrosion is controlled solely by diffusion-controlled ion exchange. In contrast glasses corroding via hydrolytic reactions are affected only slightly by self irradiation. (authors)

Ojovan, M. I. [Immobilisation Science Laboratory, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD (United Kingdom); Lee, W. E. [Department of Materials, Imperial College London South Kensington campus, London, SW7 2AZ (United Kingdom)

2006-07-01

43

Role of Self-Irradiation in Corrosion of Nuclear Waste Glasses  

Microsoft Academic Search

The effect of self irradiation on corrosion mechanisms of nuclear waste glasses is examined. Self irradiation is shown to have a strong impact on corrosion of nuclear waste glasses under conditions where hydrolytic dissolution is suppressed and the corrosion is controlled solely by diffusion-controlled ion exchange. In contrast glasses corroding via hydrolytic reactions are affected only slightly by self irradiation.

M. I. Ojovan; W. E. Lee

2006-01-01

44

MILLIMETER-WAVE MONITORING OF NUCLEAR WASTE GLASS MELTS - AN OVERVIEW  

EPA Science Inventory

Molten glass characteristics of temperature, resistivity, and viscosity can be monitored reliably in the high temperature and chemically corrosive environment of nuclear waste glass melters using millimeter-wave sensor technology. Millimeter-waves are ideally suited for such meas...

45

Fluorine in silicate glasses: A multinuclear nuclear magnetic resonance study  

SciTech Connect

Anhydrous nepheline, jadeite, and albite glasses doped with F as well as hydrous F-containing haplogranitic glasses were investigated using {sup 19}F combined rotation and multiple-pulse spectroscopy; {sup 19}F {yields} {sup 29}Si cross-polarization/magic angle spinning (MAS); and high-power {sup 19}F decoupled {sup 29}Si, {sup 23}Na, and {sup 27}Al MAS nuclear magnetic resonance methods. Fluorine preferentially coordinates with Al to form octahedral AlF{sub 6}{sup 3{minus}} complexes in all glasses studied. In addition, F anions bridging two Al cations, units containing octahedral Al coordinated by both O and F, or tetrahedral Al-F complexes might be present. The presence of Si-F bonds cannot be entirely ruled out but appears unlikely on the basis of the {sup 19}F {yields} {sup 29}Si CP/MAS spectra. There is no evidence for any significant coordination of F with alkalis in the glasses studied. Over the range of F contents studied (up to 5 wt.%), there seems to be hardly any dependence of F speciation on the concentration of F in the samples. The spectroscopic results explain the decrease of the viscosity of silicate melts with increasing F content by removal of Al from bridging AlO{sub 4}-units due to complexing with F, which causes depolymerization of the melt. The same mechanism can account for the shift of the eutectic point in the haplogranite system to more feldspar-rich compositions with increasing F content, and for the peraluminous composition of most F-rich granites. Liquid immiscibility in F-rich granitic melts might be caused by formation of (Na,K){sub 3}AlF{sub 6} units in the melt with little or no interaction with the silicate component. The presence of F in granitic melts might increase the solubility of high field strength cations by making nonbridging O atoms available which form complexes with these cations.

Schaller, T.; Dingwell, D.B.; Keppler, H.; Merwin, L.; Sebald, A. (Univ. Bayreuth (West Germany)); Knoeller, W. (Bruker Analytische Messtechnik, Rheinstetten (West Germany))

1992-02-01

46

Nuclear waste glass product consistency test (PCT): Version 7.0. Revision 3  

Microsoft Academic Search

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Product Specifications (WAPS), the durability of the glass needs

C. M. Jantzen; N. E. Bibler; D. C. Beam; W. G. Ramsey

1994-01-01

47

Nuclear waste glass product consistency test (PCT), Version 5.0. Revision 2  

Microsoft Academic Search

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs

C. M. Jantzen; N. E. Bibler; D. C. Beam; W. G. Ramsey; B. J. Waters

1992-01-01

48

Redox of Simulated Nuclear Waste Glass Forming Melts  

Microsoft Academic Search

Glasses are found in most reduction-oxidation (redox) items that are used everyday; from automobiles to planes. With stability of most glasses, they are being used to store hazardous waste materials. Many elements have different oxidation states and are found in multiple states in glasses. Redox of glasses has significant effect on processing of waste glass melts in melters as well

Sara C. Vick; S. K. Sundaram

2001-01-01

49

Development of glass vitrification at SRL as a waste treatment technique for nuclear weapon components  

SciTech Connect

This report discusses the development of vitrification for the waste treatment of nuclear weapons components at the Savannah River Site. Preliminary testing of surrogate nuclear weapon electronic waste shows that glass vitrification is a viable, robust treatment method.

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

1991-12-31

50

Development of glass vitrification at SRL as a waste treatment technique for nuclear weapon components  

SciTech Connect

This report discusses the development of vitrification for the waste treatment of nuclear weapons components at the Savannah River Site. Preliminary testing of surrogate nuclear weapon electronic waste shows that glass vitrification is a viable, robust treatment method.

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

1991-01-01

51

Final technical report: Effects of water on properties of the simulated nuclear waste glasses  

SciTech Connect

For isolation of nuclear wastes through the vitrification process, waste slurry is mixed with borosilicate based glass and remelted at high temperature. During these processes, water can enter into the final waste glass. It is known that water in silica and silicate glasses changes various glass properties, such as chemical durability, viscosity and electrical conductivity. These properties are very important for processing and assuring the quality and safety controls of the waste glasses. The objective of this project was to investigate the effect of water in the simulated nuclear waste glasses on various glass properties, including chemical durability, glass transition temperature, liquidus temperature, viscosity and electrical conductivity. This report summarizes the results of this investigation conducted at Rensselaer during the past one year.

Li, H.; Tomozawa, M.

1996-02-01

52

Ion-beam analysis of implanted simulated nuclear-waste glasses  

Microsoft Academic Search

Pb-ion implantation, used as a means of simulating ..cap alpha..-recoil nuclei damage in nuclear waste glasses, introduces damage which affects the leach rates of the glasses. Rutherford backscattering and elastic recoil detection has been used to profile near-surface elemental compositions in leached Pb-implanted glasses. Data are given for borosilicate glasses from Savannah River Laboratories (SRP), Pacific Northwest Laboratories (PNL), the

G. W. Arnold; J. C. Petit

1982-01-01

53

Stabilizing Glass Bonded Waste Forms Containing Fission Products Separated from Spent Nuclear Fuel  

Microsoft Academic Search

A model has been developed to represent the stresses developed when a molten, glass-bonded brittle cylinder (used to store nuclear material) is cooled from high temperature to working temperature. Large diameter solid cylinders are formed by heating glass or glass-bonded mixtures (mixed with nuclear waste) to high temperature (915°C). These cylinders must be cooled as the final step in preparing

Kenneth J. Bateman; Charles W. Solbrig

2008-01-01

54

IRON PHOSPHATE GLASSES: AN ALTERNATIVE FOR VITRIFYING CERTAIN NUCLEAR WASTES  

SciTech Connect

During the past year, iron phosphate glasses containing the following three types of nuclear waste, as recommended by the Tank Focus Area (TFA) group, have been investigated. (1) a high sodium/sulfate Hanford Low-Activity Waste (LAW) (2) a High Chrome Waste (HCW) at Hanford, and (3) a Sodium Bearing Waste (SBW) at Idaho National Engineering and Environmental Laboratory (INEEL) Over three hundred trial melts, ranging in size from 50 g to more than 10 kg, have been evaluated. The experimental work consisted of (1) evaluating the melting behavior and characteristics, (2) measurement of the viscosity and electrical conductivity of promising melts over their melting range, (3) determining the chemical durability by the PCT and VHT methods of both glassy and partially crystallized iron phosphate wasteforms, (4) determining the solubility limit for chrome oxide in selected iron phosphate melts, (5) examining the feasibility of melting iron phosphate glasses by Cold Crucible Induction melting (CCIM), Hot Crucible Induction Melting (HCIM), and Microwave Melting, (6) and measuring the corrosion of Inconel 690 and 693, potential electrode materials, in an iron phosphate melt. In the past year, the results of the above experimental work have been described in eight technical papers and reports that have been submitted for publication.

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

2003-06-13

55

Gadolinium Borosilicate Glass-Bonded Gd-Silicate Apatite: A Glass-Ceramic Nuclear Waste Form for Actinides  

SciTech Connect

A Gd-rich crystalline phase precipitated in a sodium gadolinium alumino-borosilicate glass during synthesis. The glass has a chemical composition of 45.39-31.13 wt% Gd2O3, 28.80-34.04 wt% SiO2, 10.75-14.02 wt% Na2O, 4.30-5.89 wt% Al2O3, and 10.75-14.91 wt% B2O3. Backscattered electron images revealed that the crystals are hexagonal, elongated, acicular, prismatic, skeletal or dendritic, tens of mm in size, some reaching 200 mm 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.

Zhao, Donggao (Michigan, Univ Of - Ann Arbor); Li, Liyu (BATTELLE (PACIFIC NW LAB)); Davis, Linda L. (ASSOC WESTERN UNIVERSITY); Weber, William J. (BATTELLE (PACIFIC NW LAB)); Ewing, Rodney C. (Michigan, Univ Of - Ann Arbor); KP Hart and GR Lumpkin

2001-01-01

56

Leaching of Devitrified Glass Containing Simulated SRP Nuclear Waste  

Microsoft Academic Search

Time-temperature transformation curves have been determined for SRL-165 and SRL-131 waste glasses for all potential waste compositions. SRL-165 glasses, which contain less alkali, exhibit less complex devitrification and higher overall durability than SRL-131 waste glasses. Devitrification was found to have less effect on the durability of waste glasses than changes in composition. Non-uniform dissolution at the glass leached layer interface

Carol M. Jantzen; Dennis F. Bickford

1984-01-01

57

Leaching behavior of glass ceramic nuclear waste forms  

NASA Astrophysics Data System (ADS)

Glass ceramic waste forms were investigated as alternatives to borosilicate glasses for the immobilization of high-level radioactive waste. Three glass ceramic systems were investigated, including basalt, celsian, and fresnoite, each containing 20 wt percent simulated high-level waste calcine. Static leach tests were performed on seven glass ceramic materials and one parent glass (before recrystallization). Samples were leached at 90 C for 3 to 28 days in deionized water and silicate water. The results, expressed in normalized elemental mass loss, show comparable releases from celsian and fresnoite glass ceramics. Basalt glass ceramics demonstrated the lowest normalized elemental losses with a nominal release less than 2 grams per square meter when leached in polypropylene containers. The releases from basalt glass ceramics when leached in silicate water were nearly identical with those in deionized water. The overall leachability of celsian and fresnoite glass ceramics was improved when silicate water was used as the leachant.

Lokken, R. O.

1981-11-01

58

Chemical Durability of Zinc Borosilicate Nuclear Waste Glass.  

National Technical Information Service (NTIS)

Chemical durability is of primary concern when evaluating the safety of waste glass. For this reason, testing the leachability of waste glasses is a fundamental part of their development and characterization. The leachability is also very much a function ...

J. H. Westsik J. E. Mendel

1977-01-01

59

ALKALI/ AKALINE-EARTH CONTENT EFFECTS ON PROPERTIES OF HIGH-ALUMINA NUCLEAR WASTE GLASSES  

SciTech Connect

A series of high alumina (>20 mass %) borosilicate glasses have been made and characterized based on the assumption that the primary modifier cation field strength plays a significant role in mediating glass structure of nuclear waste glasses. Any crystallization upon quenching or after heat treatment at 950 °C for 24 hours was identified and quantified by X-ray diffraction. Particular note was take of any aluminosilicates formed, such as those in the nepheline group (MAlSiO4 where M=K, Na, Li), as these remove multiple glass-formers from the network upon crystallization. The relative roles of potassium, sodium, lithium, calcium, and magnesium on glass structure and crystallization in high alumina glasses were explored using Raman and infrared vibrational spectroscopy. Strong evidence was found for the importance of 4 membered rings in glasses with 10 mol % alkaline earths (Ca, Mg).

McCloy, John S.; Rodriguez, Carmen P.; Windisch, Charles F.; Leslie, Clifford J.; Schweiger, Michael J.; Riley, Brian J.; Vienna, John D.

2010-10-01

60

Product Consistency Durability Test for SRP (Savannah River Plant) Nuclear Waste Glass.  

National Technical Information Service (NTIS)

Beginning in 1990, Savannah River Plant (SRP) will be converting its high-level nuclear waste to a borosilicate glass. To ensure that this glass will be acceptable for permanent storage in a federal repository, SRP must demonstrate that the durability of ...

N. E. Bibler C. M. Jantzen

1988-01-01

61

Ion-Beam Analysis of Implanted Simulated Nuclear-Waste Glasses.  

National Technical Information Service (NTIS)

Pb-ion implantation, used as a means of simulating alpha -recoil nuclei damage in nuclear waste glasses, introduces damage which affects the leach rates of the glasses. Rutherford backscattering and elastic recoil detection has been used to profile near-s...

G. W. Arnold J. C. Petit

1982-01-01

62

Design and Test of the Borosilicate Glass Burnable Poison Rod for Qinshan Nuclear Power Plant Core.  

National Technical Information Service (NTIS)

Material for the burnable poison of Qinshan Nuclear Power Plant core is GG-17 borosilicate glass. The chemical composition and physico-chemical properties of GG-17 is very close to Pyrex-7740 glass used by Westinghouse. It is expected from the results of ...

J. Huang H. Sun

1988-01-01

63

ASSESSMENT OF NEPHELINE PRECIPITATION IN NUCLEAR WASTE GLASS VIA THERMOCHEMICAL MODELING  

EPA Science Inventory

A thermochemical representation of the Na-Al-Si-B-O system relevant for nuclear waste glass has been developed based on the associate species approach for the glass solution phase. Thermochemical data were assessed and associate species data determined for binary and ternary sub...

64

Electrical power supply and controls for a remotely operated glass melter for nuclear waste  

Microsoft Academic Search

An electrical power supply, controls and instruments used for a joule heated glass melter for nuclear waste are discussed. Remotely replaceable interconnection wiring assemblies for power, controls and instruments are also described.

Haideri

1985-01-01

65

Electrical Power Supply and Controls for a Remotely Operated Glass Melter for Nuclear Waste  

Microsoft Academic Search

An electrical power supply and the controls and instruments used for a joule-heated glass melter for nuclear waste are discussed. Remotely replaceable interconnection wiring assemblies for the power, controls, and instruments are also described.

Abdul Q. Haideri

1986-01-01

66

Physical and Chemical Characteristics of Lead-Iron Phosphate Nuclear Waste Glasses.  

National Technical Information Service (NTIS)

Experimental determinations of the properties of lead-iron phosphate glasses pertinent to their application to the problem of permanently disposing of high-level nuclear wastes have been carried out. These investigations included studies of the compositio...

B. C. Sales L. A. Boatner

1985-01-01

67

Ion-beam analysis of implanted simulated nuclear-waste glasses  

SciTech Connect

Pb-ion implantation, used as a means of simulating ..cap alpha..-recoil nuclei damage in nuclear waste glasses, introduces damage which affects the leach rates of the glasses. Rutherford backscattering and elastic recoil detection has been used to profile near-surface elemental compositions in leached Pb-implanted glasses. Data are given for borosilicate glasses from Savannah River Laboratories (SRP), Pacific Northwest Laboratories (PNL), the French Marcoule Laboratories, and for CFS 7740 (Pyrex). The data show wide variability in the degree of hydration and near-surface compositional changes attained as a function of Pb-ion fluence. 11 figures.

Arnold, G.W.; Petit, J.C.

1982-01-01

68

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

SciTech Connect

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.

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

1996-02-01

69

Physical and chemical characteristics of lead-iron phosphate nuclear waste glasses  

SciTech Connect

Experimental determinations of the properties of lead-iron phosphate glasses pertinent to their application to the problem of permanently disposing of high-level nuclear wastes have been carried out. These investigations included studies of the composition and physical properties of nuclear waste glasses (NWG), as well as the effect of preparation conditions. Lead-iron phosphate nuclear waste glasses were prepared by dissolving simulated US defense wastes or simulated commercial power reactor wastes in molten lead-iron phosphate melts at temperatures between 900 and 1050/sup 0/C. The measured physical and chemical properties of the nuclear waste glasses formed by cooling these melts and annealing included the following: (1) aqueous corrosion resistance as a function of the solution pH, solution temperature, and glass composition, (2) glass density, (3) thermal expansion coefficient, (4) glass transition temperature and softening point, (5) heat capacity, (6) critical cooling rate, (7) temperature for the maximum crystallization rate, (8) relative solubility of waste oxides in the glass melt, (9) reactions between the molten glass and the melting crucible (Pt, ZrO/sub 2/, Al/sub 2/O/sub 3/), and (10 studies of possible metal cannister materials. Experimental results for the lead-iron phosphate NWG are compared to available data for borosilicate NWG. Relative to borosilicate NWG, the lead-iron phosphate glasses have several distinct advantages which include a much lower aqueous corrosion rate, a lower preparation temperature, and the ability to immobilize many types of commercial and defense-related high-level radioactive wastes. 34 refs., 18 figs., 10 tabs.

Sales, B.C.; Boatner, L.A.

1985-05-01

70

Effect of alpha radiation on the leaching behaviour of nuclear glass  

NASA Astrophysics Data System (ADS)

The behaviour of nuclear glass subjected to the stress loading expected in a repository must be investigated to demonstrate that it is capable of durably confining radioactive elements. Because of the minor actinides (Np, Am, Cm) contained in the glass, alpha radiation is one of the stresses that could affect the glass properties. This study focuses on the effect of alpha radiation on the chemical reactivity of R7T7 glass with pure water. Various glass samples doped with 237Np, 238Pu, 239Pu, 241Am or 244Cm were fabricated in the CEA facilities at Marcoule. The content of each actinide was adjusted to cover a range of alpha activity varying from 105 to 1011 Bq g-1 and a range of alpha decay doses up to 4 × 1018 g-1. Inactive glass samples were also subjected to multiple-energy external irradiation by heavy ions to simulate the impact of alpha damage. The initial glass alteration rates, which reflect the chemical reactivity between the glass matrix and pure water, were determined by standard Soxhlet tests together with analysis of the leaching solution by ICP-AES. Comparing the glass leaching rates is indicative of the impact of alpha radiation. The experimental data show that neither the alpha activity nor the alpha decay dose has a significant impact on the initial alteration rate of R7T7 glass.

Peuget, S.; Broudic, V.; Jégou, C.; Frugier, P.; Roudil, D.; Deschanels, X.; Rabiller, H.; Noel, P. Y.

2007-05-01

71

THE IMPACT OF KINETICS ON NEPHELINE FORMATION IN NUCLEAR WASTE GLASSES  

SciTech Connect

Sixteen glass compositions were selected to study the potential impacts of the kinetics of nepheline formation in high-level nuclear waste (HLW) glass. The chosen compositions encompassed a relatively large nepheline discriminator (ND) range, 0.40-0.66, and included a relatively broad range, and amount of, constituents including high aluminum and high boron concentrations. All glasses were fabricated in the laboratory and subsequently exposed to six different cooling treatments. The cooling treatments consisted of three 'stepped' profiles and their corresponding 'smooth' profiles. Included in the cooling treatment was the Defense Waste Processing Facility (DWPF) canister centerline cooling (CCC) profile in addition to a 'faster' and a 'slower' total cooling line. After quenching and heat treating, x-ray diffraction confirmed the type and amount of any resultant crystallization. The target compositions were shown to be consistent with the measured compositions. Two quenched glasses and several treated glasses exhibited minor amounts of spinel and spinel-like phases. Nepheline was not observed in any of the quenched glasses but was observed in many of the treated glasses. The amount of nepheline ranged from approximately 2wt% to 30wt% for samples cooled over shorter times and longer times respectively. Differences were observed in the amount of nepheline crystallization after smooth and stepped cooling and increased with total cooling time. In some glasses, nepheline crystallization appeared to be directly proportional to total cooling time while the total amount of nepheline crystallization varied, suggesting that the nepheline crystallization rate was independent of (or at least faster than) cooling rate but, varied depending on the glass composition. On the contrary, in another glass, nepheline crystallization appeared to be inversely proportional to cooling rate. The high alumina glasses, predicted to form nepheline according to the ND, did not precipitate nepheline. Additionally, analysis from different regions of treated glasses indicated that nepheline nucleation and growth occurs at the glass/crucible and glass/atmosphere interfaces. Furthermore, the measured amount of non-nepheline phases appeared independent of the sampling region. It is postulated that crucible-scale methods used to heat treat HLW glass, such as the CCC method, artificially induce nepheline formation in the glass. The results of this study suggest nepheline kinetics can vary significantly depending on glass composition and, more importantly, glasses fabricated using current DWPF conditions are potentially susceptible to the impact of nepheline kinetics. This report summarizes the supporting research and provides the basis for continued research on nepheline kinetics and its effects on HLW glasses.

Amoroso, J.

2011-03-07

72

Low leach rate glasses for immobilization of nuclear wastes  

SciTech Connect

Improved defense and commercial waste glass have about one order of magnitude lower leach rates at 90/sup 0/C in static deionized water than reference glasses. This durability difference diminishes as the leaching temperature is raised, but at repository temperature less than 150/sup 0/C, the improved compositions would have considerable advantages over reference glases. At the melting temperatures necessary for most of the high-durability glasses, volatility was found to be higher than that experienced in processing current reference glases. Higher volatilities might be compensated for by specific design of the off-gas system for improved off-gas treatment and volatile materials recovery. 6 figures, 2 tables.

Chick, L.A.; Buckwalter, C.Q.

1980-10-01

73

Overview of chemical modeling of nuclear waste glass dissolution  

SciTech Connect

Glass dissolution takes place through metal leaching and hydration of the glass surface accompanied by development of alternation layers of varying crystallinity. The reaction which controls the long-term glass dissolution rate appears to be surface layer dissolution. This reaction is reversible because the buildup of dissolved species in solution slows the dissolution rate due to a decreased dissolution affinity. Glass dissolution rates are therefore highly dependent on silica concentrations in solution because silica is the major component of the alteration layer. Chemical modeling of glass dissolution using reaction path computer codes has successfully been applied to short term experimental tests and used to predict long-term repository performance. Current problems and limitations of the models include a poorly defined long-term glass dissolution mechanism, the use of model parameters determined from the same experiments that the model is used to predict, and the lack of sufficient validation of key assumptions in the modeling approach. Work is in progress that addresses these issues. 41 refs., 7 figs., 2 tabs.

Bourcier, W.L.

1991-02-01

74

Surface-layer formation on a nuclear-waste glass  

SciTech Connect

Surface layers are a common feature of leached surfaces of borosilicate waste glasses. The question of whether these layers can protect the glass against further attack by decreasing the leach rate is still a subject of controversy. The present study investigates the effects of layer formation on leaching kinetics of a borosilicate waste glass containing 20 wt % LWR-type simulated waste oxides: (1) surface layer formation on the borosilicate waste glass in a closed system can be divided in a sequence of overlapping processes. The formation of amorphous phases on the glass surface is observed first, followed by crystalline phase formation, with new phases still appearing after one year in NaCl solution; (2) the complexity of the kinetics is reflected in the variation of concentration of different elements in solution; (3) the overall leaching process varies as a function of time with t/sup n/ and n < 0.3. This reflects that the process cannot be described in terms of either diffusion (n = 0.5) or linear dissolution (n = 1), or a combination of both; and (4) though the details of the process are not yet understood, it is possible to extract a parameter, n, to describe the total mass release from the glass in the longer term in NaCl solution if leaching data are measured for at least one year.

Lutze, W.; Malow, G.; Rabe, H.; Headley, T.J.

1982-01-01

75

Progress toward bridging from atomistic to continuum modeling to predict nuclear waste glass dissolution.  

SciTech Connect

This report summarizes research performed for the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Subcontinuum and Upscaling Task. The work conducted focused on developing a roadmap to include molecular scale, mechanistic information in continuum-scale models of nuclear waste glass dissolution. This information is derived from molecular-scale modeling efforts that are validated through comparison with experimental data. In addition to developing a master plan to incorporate a subcontinuum mechanistic understanding of glass dissolution into continuum models, methods were developed to generate constitutive dissolution rate expressions from quantum calculations, force field models were selected to generate multicomponent glass structures and gel layers, classical molecular modeling was used to study diffusion through nanopores analogous to those in the interfacial gel layer, and a micro-continuum model (K{mu}C) was developed to study coupled diffusion and reaction at the glass-gel-solution interface.

Zapol, Peter (Argonne National Laboratory, Argonne, IL); Bourg, Ian (Lawrence Berkeley National Laboratories, Berkeley, CA); Criscenti, Louise Jacqueline; Steefel, Carl I. (Lawrence Berkeley National Laboratories, Berkeley, CA); Schultz, Peter Andrew

2011-10-01

76

Nuclear waste glass product consistency test (PCT), Version 5.0. Revision 2  

SciTech Connect

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF), poured into stainless steel canisters, and eventually disposed of in a geologic repository. In order to comply with the Waste Acceptance Preliminary Specifications (WAPS), the durability of the glass needs to be measured during production to assure its long term stability and radionuclide release properties. A durability test, designated the Produce Consistency Test (PCT), was developed for DWPF glass in order to meet the WAPS requirements. The response of the PCT procedure was based on extensive testing with glasses of widely different compositions. The PCT was determined to be very reproducible, to yield reliable results rapidly, and to be easily performed in shielded cell facilities with radioactive samples. Version 5.0 of the PCT procedure is attached.

Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.; Waters, B.J.

1992-06-01

77

The Structural Role of Zr within Alkali Borosilicate Glasses for Nuclear Waste Immobilisation  

SciTech Connect

Zirconium is a key constituent element of High Level nuclear Waste (HLW) glasses, occurring both as a fission product and a fuel cladding component. As part of a wider research program aimed at optimizing the solubility of zirconium in HLW glasses, we have investigated the structural chemistry of zirconium in such materials using X-ray Absorption Spectroscopy (XAS). Zirconium K-edge XAS data were acquired from several inactive simulant and simplified waste glass compositions, including a specimen of blended Magnox/UO{sub 2} fuel waste glass. These data demonstrate that zirconium is immobilized as (octahedral) six-fold coordinate ZrO{sub 6} species in these glasses, with a Zr-O contact distance of 2.09 {angstrom}. The next nearest neighbors of the Zr species are Si at 3.42 {angstrom} and possibly Na at 3.44 {angstrom}, no next nearest neighbor Zr could be resolved.

A Connelly; N Hyatt; K Travis; R Hand; E Maddrell; R Short

2011-12-31

78

Iron Phosphate Glasses for Vitrifying DOE High Priority Nuclear Wastes  

SciTech Connect

Iron phosphate glasses have been studied as an alternative glass for vitrifying Department of Energy (DOE) high priority wastes. The high priority wastes were the Low Activity Waste (LAW) and the High Level Waste (HLW) with high chrome content stored at Hanford, WA, and the Sodium Bearing Waste (SBW) stored at the Idaho National Engineering and Environmental Laboratory. These wastes were recommended by Tanks Focus Area since they were expected to require special attention when vitrified in borosilicate glasses. All three of these wastes have been successfully vitrified in iron phosphate glasses at waste loadings ranging from a low of 32 wt% for the high sulfate LAW to 40 wt% for the SBW to a high of 75 wt% for the high chrome HLW. In addition to these desirable high waste loadings, the iron phosphate glasses were easily melted, typically between 950 and 1200 C, in less than 4 hours in commercial refractory oxide containers. It is noteworthy that the chemical durability of both glassy and deliberately crystallized iron phosphate wasteforms not only met, but significantly exceeded, all current DOE chemical durability requirements as measured by the Product Consistency Test (PCT) and Vapor Hydration Test (VHT). The high waste loading, low melting temperature, rapid furnace throughput (short melting time) and their outstanding chemical durability could significantly accelerate the clean up effort and reduce the time and cost of vitrifying these high priority wastes.

Kim, C.W.; Day, D.E.

2004-03-29

79

Characteristics of colloids generated during the corrosion of nuclear waste glasses in groundwater  

Microsoft Academic Search

Aqueous colloidal suspensions were generated by reacting nuclear waste glasses with groundwater at 90°C at different ratios of the glass surface area to solution volume (S\\/V). The colloids have been characterized in terms of size, charge, identity, and stability with respect to salt concentration, pH, and time, by examination using dynamic light scattering, electrophoretic mobility, and transmission electron microscopy. The

X. Feng; E. C. Buck; C. Mertz; J. K. Bates; J. C. Cunnane; D. Chaiko

1993-01-01

80

Reaction of reference commercial nuclear waste glasses during gamma irradiation in a saturated tuff environment  

Microsoft Academic Search

The effects of gamma irradiation on groundwater and the reaction between groundwater and glass have been investigated at radiation exposure rates of 2 x 10⁵ , 1 x 10³ , and 0 R\\/h. These experiments, which bound the conditions that may occur in a high-level nuclear waste repository located in tuff, have been performed using the actinide-containing glasses ATM-1c and

John K. Bates; William L. Ebert; Donald F. Fischer; Thomas J. Gerding

1988-01-01

81

Measurement of leaching from simulated nuclear-waste glass using radiotracers  

SciTech Connect

The use of radiotracer spiking as a method of measuring the leaching from simulated nuclear-waste glass is shown to give results comparable with other analytical detection methods. The leaching behavior of /sup 85/Sr, /sup 106/Ru, /sup 133/Ba, /sup 137/Cs, /sup 141/Ce, /sup 152/Eu, and other isotopes is measured for several defense waste glasses. These tests show that radiotracer spiking is a sensitive, multielement technique that can provide leaching data, for actual waste elements, that are difficult to obtain by other methods. Additionally, a detailed procedure is described that allows spiked glass to be prepared with a suitable distribution of radionuclides.

Bates, J.K.; Jardine, L.J.; Steindler, M.J.

1982-09-01

82

AN APPROACH TO THERMOCHEMICAL MODELING OF NUCLEAR WASTE GLASS  

EPA Science Inventory

This initial work is aimed at developing a basic understanding of the phase equilibria and solid solution behavior of the constituents of waste glass. Current, experimentally determined values are less than desirable since they depend on measurement of the leach rate under non-r...

83

The role of natural glasses as analogues in projecting the long-term alteration of high-level nuclear waste glasses: Part 1  

SciTech Connect

The common observation of glasses persisting in natural environments for long periods of time (up to tens of millions of years) provides compelling evidence that these materials can be kinetically stable in a variety of subsurface environments. This paper reviews how natural and historical synthesized glasses can be employed as natural analogues for understanding and projecting the long-term alteration of high-level nuclear waste glasses. The corrosion of basaltic glass results in many of the same alteration features found in laboratory testing of the corrosion of high-level radioactive waste glasses. Evidence has also been found indicating similarities in the rate controlling processes, such as the effects of silica concentration on corrosion in groundwater and in laboratory leachates. Naturally altered rhyolitic glasses and tektites provide additional evidence that can be used to constrain estimates of long-term waste glass alteration. When reacted under conditions where water is plentiful, the corrosion for these glasses is dominated by network hydrolysis, while the corrosion is dominated by molecular water diffusion and secondary mineral formation under conditions where water contact is intermittent or where water is relatively scarce. Synthesized glasses that have been naturally altered result in alkali-depleted alteration features that are similar to those found for natural glasses and for nuclear waste glasses. The characteristics of these alteration features appear to be dependent on the alteration conditions which affect the dominant reaction processes during weathering. In all cases, care must be taken to ensure that the information being provided by natural analogues is related to nuclear waste glass corrosion in a clear and meaningful way.

Mazer, J.J.

1993-12-31

84

The connectivity of silicon sites in silicate glasses, as determined by two-dimensional 29Si nuclear magnetic resonance spectroscopy  

Microsoft Academic Search

The application of two-dimensional silicon-29 homonuclear shift correlated magic angle spinning nuclear magnetic resonance (COSY MAS NMR) spectroscopy to silicate glasses prepared using silica isotopically enriched in silicon-29 is reported. Two sodium silicate glass compositions and a sodium phospho-silicate glass were examined. The results suggest that a substantial proportion of the four coordinate silicate sites in sodium silicate glasses (Q2\\/Q3

Christopher T. G. KNIGHT; R. J. KIRKPATRICK; Eric OLDFIELD

1990-01-01

85

Lead-iron phosphate glass as a containment medium for the disposal of high-level nuclear wastes  

DOEpatents

Disclosed are lead-iron phosphate glasses containing a high level of Fe/sub 2/O/sub 3/ for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste

Boatner, L.A.; Sales, B.C.

1984-04-11

86

IRON PHOSPHATE GLASSES: AN ALTERNATIVE FOR VITRIFYING CERTAIN NUCLEAR WASTES  

Microsoft Academic Search

The U.S. Department of Energy (DOE) Environmental Management Science Program (EMSP) has funded research on iron phosphate glasses at the University of Missouri-Rolla (UMR) for the period from September 15, 1996 to September 30, 2004 (DE-FG07-96ER45618). The final report for the initial period from September 15, 1996 to September 14, 2000 (project number 55110) has been submitted previously and can

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

2004-01-01

87

Determination of the Fe sup 2+ /Fe sup 3+ ratio in nuclear waste glasses  

SciTech Connect

This paper reports on the Fe{sup 2 +}/Fe{sup 3 +} ratios of 47 simulated nuclear waste glass samples with ratios varying from 0.01 (oxidized) to 1.6 (reduced) determined by wet-chemical and Mossbauer spectral analyses. The wet-chemical method involved the spectrophotometric determination of Fe{sup 2 +} and total iron using remote spectroscopy with fiber optic chemical sensing. Interferences from other species present in these glasses were examined and alternative analytical techniques were investigated. Results of wet-chemical and Mossbauer spectral analysis were comparable; however, the wet-chemical method is probably preferable for the analysis of highly radioactive glasses until such glasses have been shown to have satisfactory Mossbauer spectra.

Hunter, R.T.; Edge, M.; Kalivretenos, A.; Brewer, K.M.; Brock, N.A.; Hawkes, A.E.; Fanning, J.C. (Clemson Univ., SC (United States). Dept. of Chemistry)

1989-06-01

88

Comprehensive data base of high-level nuclear waste glasses: September 1987 status report: Volume 1, Discussion and glass durability data  

SciTech Connect

The Materials Characterization Center (MCC) at Pacific Northwest Laboratory is assembling a comprehensive data base (CDB) of experimental data collected for high-level nuclear waste package components. Data collected throughout the world are included in the data base; current emphasis is on waste glasses and their properties. The goal is to provide a data base of properties and compositions and an analysis of dominant property trends as a function of composition. This data base is a resource that nuclear waste producers, disposers, and regulators can use to compare properties of a particular high-level nuclear waste glass product with the properties of other glasses of similar compositions. Researchers may use the data base to guide experimental tests to fill gaps in the available knowledge or to refine empirical models. The data are incorporated into a computerized data base that will allow the data to be extracted based on, for example, glass composition or test duration. 3 figs.

Kindle, C.H.; Kreiter, M.R.

1987-12-01

89

ANNUAL PROGRESS REPORT. IRON PHOSPHATE GLASSES: AN ALTERNATIVE FOR VITRIFYING CERTAIN NUCLEAR WASTES  

EPA Science Inventory

A high priority has been given to investigating the vitrification of three specific nuclear wastes in iron phosphate glasses (IPG). These wastes, which were recommended by the Tank Focus Area (TFA) group of Hanford, are poorly suited for vitrification in the currently DOE-approve...

90

The use of ``self heating`` ceramics as crucibles for microwave melting metals and nuclear waste glass  

SciTech Connect

Silicon carbide (SiC) crucibles were used to melt aluminum and copper in conventional and tuned microwave cavities at a microwave frequency of 2450 MHz. SiC crucibles were also used to vitrify and homogenize mixtures of nuclear waste and glass frit.

Sturcken, E.F.

1990-12-31

91

The use of self heating'' ceramics as crucibles for microwave melting metals and nuclear waste glass  

SciTech Connect

Silicon carbide (SiC) crucibles were used to melt aluminum and copper in conventional and tuned microwave cavities at a microwave frequency of 2450 MHz. SiC crucibles were also used to vitrify and homogenize mixtures of nuclear waste and glass frit.

Sturcken, E.F.

1990-01-01

92

Oxidation state of multivalent elements in high-level nuclear waste glass  

SciTech Connect

Nuclear waste contains many different elements that have more than one oxidation state. When the nuclear waste is treated by vitrification, the behavior of the element in the melter and resulting glass product depends on the stable oxidation state. The stable oxidation state in any medium can be calculated from the standard potential in that medium. Consequently, the standard potential of multi-valent elements has been measured in many silicate-melts, including ones relevant to nuclear waste treatment. In this study, the relationship between the standard potential in molten nuclear waste glass and the standard potential in water will be quantified so that the standard potential of elements that have not been measured in glass can be estimated. The regression equation was found to have an R{sup 2} statistic of 0.96 or 0.83 depending on the number of electrons transferred in the reaction. The Nernst equation was then used to calculate the oxidation state of other relevant multi-valent elements in nuclear waste glass from these standard potentials and the measured ferrous to ferric iron ratio. The calculated oxidation states were consistent with all oxidation state measurements available. The calculated oxidation states were used to rationalize the behavior of many of the multi-valent elements. For instance, chromium increases glass crystallization because it is in the trivalent-state, iodine volatilises from the melter because it is in the volatile zero-valent state, and the leaching behavior of arsenic is driven by its oxidation state. Thus, these thermodynamic calculations explain the behavior of many trace elements during the vitrification process. (authors)

Reynolds, J.G. [Washington Group International, Richland, WA (United States)

2007-07-01

93

Crystallization of neodymium-rich phases in silicate glasses developed for nuclear waste immobilization  

NASA Astrophysics Data System (ADS)

Glass-ceramics containing neodymium-rich crystalline phases can be obtained by crystallization of silicate glasses (nucleation + crystal growth heat treatments) or by controlled cooling of melts. Such materials could be envisaged as durable matrices for conditioning minor actinides- and Pu-rich nuclear wastes if the partitioning ratio of the wastes between crystalline phase and residual glass is high (principle of double containment barrier). In radioactive waste forms, Nd would be partially substituted by actinides and neutron absorbers (Gd). In this work, two silicate glass compositions leading to efficient nucleation and crystallization of either zirconolite (Ca1-xNdxZrTi2-xAlxO7, x < 1) or apatite (Ca2Nd8Si6O26) in their bulk were studied as potential waste forms. The effect of the method used to prepare glass-ceramics (controlled cooling from the melt or nucleation + crystal growth from the glass) on both the microstructure and the structure of the neodymium-rich crystalline phase was studied. The highest number of zirconolite or apatite crystals in the bulk was obtained using the nucleation + crystal growth method. However, the percentage of neodymium incorporated in zirconolite crystals remained too small to make realistic the use of such materials for the conditioning of actinides in comparison with more durable bulk ceramics.

Caurant, D.; Majerus, O.; Loiseau, P.; Bardez, I.; Baffier, N.; Dussossoy, J. L.

2006-08-01

94

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

SciTech Connect

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.

Cunnane, J.C.; Bates, J.K.; Ebert, W.L.; Feng, X.; Mazer, J.J.; Wronkiewicz, D.J. (Argonne National Lab., IL (United States)); Sproull, J. (Westinghouse Savannah River Co., Aiken, SC (United States)); Bourcier, W.L. (Lawrence Livermore National Lab., CA (United States)); McGrail, B.P. (Battelle Pacific Northwest Lab., Richland, WA (United States))

1992-01-01

95

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

SciTech Connect

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.

Cunnane, J.C.; Bates, J.K.; Ebert, W.L.; Feng, X.; Mazer, J.J.; Wronkiewicz, D.J. [Argonne National Lab., IL (United States); Sproull, J. [Westinghouse Savannah River Co., Aiken, SC (United States); Bourcier, W.L. [Lawrence Livermore National Lab., CA (United States); McGrail, B.P. [Battelle Pacific Northwest Lab., Richland, WA (United States)

1992-12-01

96

THERMOCHEMICAL MODELS FOR NUCLEAR WASTE GLASS SUBSYSTEMS - MGO-CAO AND MGO-AL2O3  

EPA Science Inventory

A relatively simple model, the associate species model, is being applied to nuclear waste glass compositions in order to accurately predict behavior and thermodynamic activities in the material. In the model, the glass is treated as a supercooled liquid, with the liquid species ...

97

An alternative host matrix based on iron phosphate glasses for the vitrification of specialized nuclear waste forms. 1998 annual progress report  

Microsoft Academic Search

'Certain high level wastes (HLW) in the US contain components such as phosphates, heavy metals, and halides which make them poorly suited for disposal in borosilicate glasses. Iron phosphate glasses appear to be a technically feasible alternative to borosilicate glasses for vitrifying these HLWs. The iron phosphate glasses mentioned above and their nuclear wasteforms are relatively new, so little is

D. E. Day; C. S. Ray; G. K. Marasinghe; M. Karabulut; X. Fang

1998-01-01

98

Molecular-Scale Mechanisms Governing Alteration of Nuclear Waste Glasses, as Seen Around Zr and Fe: a Surface XAS-Study  

Microsoft Academic Search

Glass alteration is of major importance for the long-term behavior of waste matrices, but amorphous (glass)- amorphous (gel) structural transformations created by glass alteration are difficult to describe with conventional techniques. These alteration layers develop with time at the surface of high-level nuclear waste glasses. Depending on alteration conditions, they may have a protective character, which will contribute to higher

L. Galoisy; G. Calas; E. Pelegrin

2006-01-01

99

Vitrification of borate waste from nuclear power plant using coal fly ash. (I) Glass formulation development  

Microsoft Academic Search

Borate waste, which is the main liquid waste from daily operation of PWR nuclear power plants, contains a large amount of Na and B. The coal fly ash is a by-product of the coal combustion power plants. The high content of SiO2 and Al2O3 of coal fly ash makes it a desirable glass network former additive; therefore, using the coal

Jiawei Sheng

2001-01-01

100

Nepheline Crystallization in Nuclear Waste Glasses: Progress toward acceptance of high-alumina formulations  

SciTech Connect

We have critically compiled and analyzed historical data for investigating the quantity of nepheline (NaAlSiO4) precipitation as a function of composition in simulated nuclear waste glasses. To understand composition we used two primary methods: 1) investigating the Al2O3-SiO2-Na2O ternary with filtering for different B2O3 levels and 2) creating a quadrant system consisting of compositions reduced to two metric numbers. These metrics are 1) the nepheline discriminator (ND) which depends only on the SiO2 content by weight normalized to the total weight of the Al2O3-SiO2-Na2O sub-mixture and 2) the optical basicity (OB) which contains contributions from all constituents in the glass. Nepheline precipitation is expected to be suppressed at high SiO2 levels (ND >0.62) or at low basicities (OB <0.55 to 0.57). Changes in sodium aluminosilicate glass OB due to additions of CaO and B2O3 correlate with observed effects on nepheline formation. We propose that additional composition space is available for formulating high-waste-loading, high-Al¬2O3 nuclear waste glasses when Na2O levels are less than ~0.125 (normalized by weight on the Al2O3-SiO2-Na2O sub-mixture). However, this compositional space is considerably extended to higher Na2O levels when adding >5 wt% B2O3. The OB concept can help further refine regions of nepheline-free glass formation.

McCloy, John S.; Schweiger, Michael J.; Rodriguez, Carmen P.; Vienna, John D.

2011-09-01

101

Raman Spectra, Structural Units and Durability of Nuclear Waste Glasses With Variations in Composition and Crystallization: Implications for Intermediate Order in the Glass Network  

SciTech Connect

The Raman spectra of nuclear waste glasses are composed of large variations in half-width and intensity for the commonly observed bridging (Q0) and nonbridging (Q1 to Q4) bands in silicate structures. With increase in waste concentration in a boroaluminosilicate melt, the bands of quenched glasses are distinctly localized with half-width and intensity indicative of increase in atomic order. Since the nuclear waste glasses contain disparate components, and since the bands depart from the typical random network, a systematic study for the origin of these bands as a function of composition and crystallization was undertaken. From a comparative study of Raman spectra of boroaluminosilicate glasses containing Na2O-ZrO2, Na2O-MgO, MgO-Na2O-ZrO2, Na2O-CaO-ZrO2, Na2O-CaO, and Na2O-MgO-CaF2 component sets and orthosilicate crystals of zircon and forsterite, intermediate order is inferred. An edge-sharing polyhedral structural unit is proposed to account for narrow bandwidth and high intensity for Q2 antisymmetric modes, and decreased leaching of sodium with ZrO2 concentration in glass. The intense Q4 band in nuclear waste glass is similar to the intertetrahedral antisymmetric modes in forsterite. The Raman spectra of zircon contains intratetrahedral quartz-like peaks and intertetrahedral non-bridging silicate peaks. The quartz-like peaks nearly vanish in the background of forsterite spectrum. This difference between the Raman spectra of the two orthosilicate crystals presumably results from their biaxial and uniaxial effects on polarizability ellipsoids. The results also reveal formation of 604, 956 and 961 cm-1 defect bands with composition and crystallization.

Raman, Swaminathan Venkat

2002-11-01

102

Nuclear Magnetic Resonance Studies of Binary and Ternary Oxide Glass Systems Using BORON-11 and Silicon -29  

NASA Astrophysics Data System (ADS)

The Si('29) nuclear magnetic resonance spectra for glasses and polycrystalline materials in the potassium silicate system have been observed. An anisotropic chemical shift is present in these materials and the first ever detections of these shifts are presented. Resultant NMR lineshapes for materials at selected compositions are correlated with the structural groupings proposed as present in both glasses and crystalline materials. The B('11) NMR spectra in several zinc borate crystalline compounds and glasses have been used to study the structures present in these materials. The NMR spectra in conjunction with computer-generated spectra were used to make structural inferences for these materials. Correlations are made between the structures found using NMR and the crystalline structures proposed in the literature for these materials. Zinc borate glasses spanning the reported glass formation range were studied and values for N(,4) in the glasses are given. The NMR spectra for B('11) in glasses of the Li(,2)O -TeO(,2)-B(,2)O(,3) and TeO(,2)-B(,2)O(,3)-Al(,2)O(,3) systems were secured and used to study the behavior of N(,4), the fraction of boron atoms in four-coordination, as a function of glass composition. The appearance of non-zero values for N(,4) in the TeO(,2)-B(,2)O(,3)-Al(,2)O(,3) glasses and the enhancement of N(,4) in the Li(,2)O-TeO(,2)-B(,2)O(,3) glasses above that obtained for the binary Li(,2)O-B(,2)O(,3) glass system indicates that the TeO(,2) in the glasses contributes to the formation of four-coordinated boron atoms. A mechanism which accounts for the N(,4) behavior is presented. Relations describing the behavior of N(,4) for the binary TeO(,2)-B(,2)O(,3) system are inferred from the results secured.

Harris, Isaac Anthony, Jr.

103

DIADDHEM set-up: New IBA facility for studying the helium behavior in nuclear glasses  

NASA Astrophysics Data System (ADS)

The immobilization of fission products and minor actinides by vitrification is the reference process for industrial management of high-level radioactive wastes generated from spent fuel reprocessing. The glassy matrix is subjected to radiation damage and radiogenic helium generation due to the alpha decays of minor actinides. A specific experimental study has been conducted to better understand the behavior of helium and its diffusion mechanisms in the borosilicate glass. Helium production is simulated by external irradiation with 3He+ ions at a concentration (2 × 1015 He cm-2) equivalent to the one obtained after 1000 years of glass storage. He diffusion coefficients as function of temperature are extracted from the evolution of the depth profiles after annealing. The 3He(d, ?) 1H Nuclear Reaction Analysis (NRA) technique is successfully used for in situ low-temperature measurements of depth profiles. Its high depth resolution allows detecting helium mobility at a temperature as low as 250 K and the presence of a trapped helium fraction. The good agreement of our first values of diffusion coefficients with the literature data highlights the relevance of the implantation technique in the study of helium diffusion mechanisms in borosilicate glasses.

Chamssedine, F.; Sauvage, T.; Peuget, S.

2010-06-01

104

A two-dimensional deuterium nuclear magnetic resonance study of molecular reorientation in sugar\\/water glasses  

Microsoft Academic Search

Two-dimensional nuclear magnetic resonance time domain analysis of the stimulated echo experiment is used to study the molecular reorientation of deuterated glucose molecules in a glucose\\/water glass at about 15 °C above the glass transition. By measuring both the cos-cos and sin-sin two-time single particle correlation functions it is shown that the reorientation is isotropic, which enables the determination of

Andrew M. Wachner; Kenneth R. Jeffrey

1999-01-01

105

Identification of a Secondary Crystallized Phase formed during Nuclear Glasses Leaching - Effect of the Leached Glass Composition  

NASA Astrophysics Data System (ADS)

Silicate glass leaching in a unrenewed aqueous solution leads to gel formation at the glass water interface. This amorphous hydrated layer sometimes behaves like a diffusion barrier: the glass alteration rate decreases according to an inverse square root of time equation. In the case of Mg-containing glasses, the alteration rate usually remains quasi constant and seems to be controlled by the growth of secondary crystallized phases. These phases consume elements from solution. They can sustain gel dissolution inducing a decrease of its passivating properties. Long-term behaviour modelling of Mg-containing glasses designed for the confinement of fission products (AVM glasses, Atelier de vitrification de Marcoule, France) first requires a precise identification of these Mg-rich phases. Experimental investigations were performed on several glass samples using X-ray diffraction (XRD), 27Al and 29Si MAS NMR and elemental chemical analysis. Aluminous hectorite Na0.45(Mg2.28Li0.11Al0.39Fe0.06M0.16)(Si3.21Al0.79)O10(OH)2, with M being a divalent cation, was identified. 25 glasses were required for a full representation in term variations of AVM glasses composition range. Their residual alteration rates were proved to significantly depend on glass composition since a one order of magnitude difference was measured between the less and the most altered glasses. Nevertheless, the same crystallized phase was evidenced whatever the glass composition and whatever the initial composition of the solution (pure water or Mg-rich groundwater). Only a shift of the (060) peak between 1.521 and 1.530 Å was evidenced. It can be attributed to slight composition variations. Relations between the glass magnesium fraction, the amount of precipitated hectorite, the residual rate, and the measured pH are not obvious. However, hectorite precipitation was proved to depend on pH, being favoured between pH50°C 9 and 9.5. Moreover, the higher the amount of precipitated hectorite, the lower the solution pH. Self regulation of hectorite precipitation evidences that all mechanisms involved are strongly interdependent.

Thien, Bruno; Godon, Nicole; Frugier, Pierre; Gin, Stéphane; Ayral, André

2010-05-01

106

(6)Li, (7)Li Nuclear Magnetic Resonance Investigation of Lithium Coordination in Binary Phosphate Glasses  

SciTech Connect

{sup 6}Li and {sup 7}Li solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy has been used to investigate the local coordination environment of lithium in a series of xLi{sub 2}O {center_dot} (1-x)P{sub 2}O{sub 5} glasses, where 0.05 {le} x {le} 0.55. Both the {sup 6}Li and {sup 7}Li show chemical shift variations with changes in the Li{sub 2}O concentration, but the observed {sup 6}Li NMR chemical shifts closely approximate the true isotropic chemical shift and can provide a measure of the lithium bonding environment. The {sup 6}Li NMR results indicate that in this series of lithium phosphate glasses the Li atoms have an average coordination between four and five. The results for the metaphosphate glass agree with the coordination number and range of chemical shifts observed for crystalline LiPO{sub 3}. An increase in the {sup 6}Li NMR chemical shift with increasing Li{sub 2}O content was observed for the entire concentration range investigated, correlating with increased cross-linking of the phosphate tetrahedral network by O-Li-O bridges. The {sup 6}Li chemical shifts were also observed to vary monotonically through the anomalous glass transition temperature (T{sub g}) minimum. This continuous chemical shift variation shows that abrupt changes in the Li coordination environment do not occur as the Li{sub 2}O concentration is increased, and such abrupt changes can not be used to explain the T{sub g} minimum.

Alam, T.M.; Boyle, T.J.; Brow, R.K.; Conzone, S.

1999-02-08

107

Characterization of borate glasses by W-band pulse electron-nuclear double resonance spectroscopy.  

PubMed

(100-x) mol % B(2)O(3) x mol % Me(2)O (Me = Li,Na,K) glasses, exposed to gamma-(60)Co irradiation to produce paramagnetic states, were characterized by W-band (95 GHz) pulse electron-nuclear double resonance (ENDOR) spectroscopy in order to characterize local structures occurring in the range of compositions between x=16 and x=25 at which the "boron oxide" anomaly occurs. The high resolution of nuclear frequencies allowed resolving the (7)Li and (11)B ENDOR lines. In the samples with x=16 and x=20 glasses, (11)B hyperfine couplings of 16, 24, and 36 MHz were observed and attributed to the tetraborate, triborate, and boron oxygen hole center (BOHC) structures, respectively. The x=25 samples showed hyperfine couplings of 15 MHz for the tetraborate and 36 MHz for BOHC. Density functional theory (DFT) calculations predicted for these structures negative hyperfine couplings, which were confirmed by W-band ENDOR. This suggests that a spin polarization mechanism accounts for the negative hyperfine structure splitting. PMID:19045204

Kordas, George; Goldfarb, Daniella

2008-10-21

108

Crystallization in simulated glasses from Hanford high-level nuclear waste composition range.  

National Technical Information Service (NTIS)

Glass crystallization was investigated as part of a property-composition relationship study of Hanford waste glasses. Non-radioactive glass samples were heated in a gradient furnace over a wide range of temperatures. The liquidus temperature was measured,...

D. S. Kim P. Hrma D. E. Smith M. J. Schweiger

1993-01-01

109

Radiation effects in moist-air systems and the influence of radiolytic product formation on nuclear waste glass corrosion  

SciTech Connect

Ionizing radiation may affect the performance of glass in an unsaturated repository site by interacting with air, water vapor, or liquid water to produce a variety of radiolytic products. Tests were conducted to examine the effects of radiolysis under high gas/liquid ratios. Results indicate that nitrate is the predominant radiolytic product produced following both gamma and alpha radiation exposure, with lesser amounts of nitrite and carboxylic acids. The formation of nitrogen acids during exposure to long-lived, alpha-particle-emitting transuranic elements indicates that these acids may play a role in influencing nuclear waste form reactions in a long-term unsaturated disposal scenario. Experiments were also conducted with samples that simulate the composition of Savannah River Plant nuclear waste glasses. Radiolytic product formation in batch tests (340 m{sup {minus}1}, 90 C) resulted in a small increase in the release rates of many glass components, such as alkali and alkaline earth elements, although silicon and uranium release rates were slightly reduced indicating an overall beneficial effect of radiation on waste form stability. The radiolytic acids increased the rate of ion exchange between the glass and the thin film of condensate, resulting in accelerated corrosion rates for the glass. The paragenetic sequence of alteration phases formed on both the irradiated and nonirradiated glass samples reacted in the vapor hydration tests matches closely with those developed during volcanic glass alteration in naturally occurring saline-alkaline lake systems. This correspondence suggests that the high temperatures used in these tests have not changed the underlying glass reaction mechanism relate to that which controls glass reactions under ambient surficial conditions.

Wronkiewicz, D.J.; Bates, J.K.; Buck, E.C.; Hoh, J.C.; Emery, J.W. [Argonne National Lab., IL (United States). Chemical Technology Div.; Wang, L.M. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Geology

1997-07-01

110

Devitrification and subsequent effects on the leach behavior of a simulated borosilicate nuclear waste glass  

SciTech Connect

The effects of various heat treatments on the devitrification and subsequent leach behavior of a simulated alkali-borosilicate nuclear waste glass containing trace levels of Cs, Sr, and U are examined. Samples were held at 500, 525, 550, and 575/sup 0/C for 1, 2, 4, and 10 days and then air cooled. The volume percent of the crystalline phase was determined by a statistical point-count of petrographic thin sections for 2 samples, and by normalized x-ray diffraction for the remainder of the samples. Samples from each heat treatment scheduled were corroded in static-leach tests. Post-heat-treatment and post-corrosion samples were examined by optical microscopy, scanning electron microscopy-energy dispersive spectroscopy, electron spectroscopy for chemical analysis (x-ray photoelectron spectroscopy). and fourier-transformed infrared reflection spectroscopy (FTIRRS), and results were correlated with the crystalline volume and solution data. Leach behavior degrades with increasing crystalline volume fraction by as much as 40 x. Devitrification is not observed below 525/sup 0/C and appears to be more time-sensitive than temperature-sensitive, range within the range of treatments studied. The principal crystalline phases identified by x-ray diffraction and FTIRRS are solid solution variations of acmite, augite, and aegirine. The range of solid solution variation is fairly large and is likely due to the limited diffusion rates at the heat treatment temperatures and glass inhomogenity prior to heat treatment.

Spilman, D.B.; Hench, L.L.; Clark, D.E.

1986-01-01

111

Chemical Decomposition of High-Level Nuclear Waste Storage/Disposal Glasses Under Irradiation  

SciTech Connect

The objective of this project is to employ the technique of electron spin resonance (ESR), in conjunction with other experimental methods, to study radiation-induced decomposition of vitreous compositions proposed for immobilization/disposal of high-level nuclear wastes (HLW) or excess weapons plutonium. ESR is capable of identifying, even at the parts-per-million level, displaced atoms, ruptured bonds, and free radicals created by radiation in such glassy forms. For example, one of the scientific goals is to search for ESR-detectable superoxide (O2 -) and ozonide (O3 -) ions, which could be precursors of radiation-induced oxygen gas bubbles reported by other investigators via the disproportionation reaction, 2O2 - : O2 2- + O2. The fundamental understandings obtained in this study will enable reliable predictions of the long-term effects of a and B decays of the immobilized radionuclides on the chemical integrity of HLW glasses.

Griscom, David L.

1999-06-01

112

Comprehensive data base of high-level nuclear waste glasses: September 1987 status report: Volume 2, Additional appendices  

SciTech Connect

The Materials Characterization Center (MCC) is assembling a comprehensive data base (CDB) of experimental data collected for high-level nuclear waste package components. The status of the CDB is summarized in Volume I of this report. Volume II contains appendices that present data from the data base and an evaluation of glass durability models applied to the data base.

Kindle, C.H.; Kreiter, M.R.

1987-12-01

113

MASBAL: A computer program for predicting the composition of nuclear waste glass produced by a slurry-fed ceramic melter  

SciTech Connect

This report is a user's manual for the MASBAL computer program. MASBAL's objectives are to predict the composition of nuclear waste glass produced by a slurry-fed ceramic melter based on a knowledge of process conditions; to generate simulated data that can be used to estimate the uncertainty in the predicted glass composition as a function of process uncertainties; and to generate simulated data that can be used to provide a measure of the inherent variability in the glass composition as a function of the inherent variability in the feed composition. These three capabilities are important to nuclear waste glass producers because there are constraints on the range of compositions that can be processed in a ceramic melter and on the range of compositions that will be acceptable for disposal in a geologic repository. MASBAL was developed specifically to simulate the operation of the West Valley Component Test system, a commercial-scale ceramic melter system that will process high-level nuclear wastes currently stored in underground tanks at the site of the Western New York Nuclear Services Center (near West Valley, New York). The program is flexible enough, however, to simulate any slurry-fed ceramic melter system. 4 refs., 16 figs., 5 tabs.

Reimus, P.W.

1987-07-01

114

Iron Phosphate Glasses: An Alternative for Vitrifying Certain Nuclear Wastes. (Report for June 16, 2002 to June 15, 2003).  

National Technical Information Service (NTIS)

During the past year, iron phosphate glasses containing the following three types of nuclear waste, as recommended by the Tank Focus Area (TFA) group, have been investigated. (1) a high sodium/sulfate Hanford Low-Activity Waste (LAW) (2) a High Chrome Was...

C. S. Ray C. W. Kim D. Zhu D. E. Day

2003-01-01

115

The dual effect of Mg on the long-term alteration rate of AVM nuclear waste glasses  

NASA Astrophysics Data System (ADS)

Inactive Mg-containing nuclear waste glasses simulating actual HLW glasses produced at the AVM facility since 1995 (Marcoule, France), were leached in aqueous solution in order to assess their long term behaviour. The focus was on the effect of Mg. Our findings show that the distribution of Mg between the gel and the secondary crystalline phases strongly influences the glass dissolution rate.The glasses were leached in initially pure water (T = 50 °C, surface/volume ratio (S/V) = 55 cm-1) with and without addition of Mg2+ in the solution. "Mg-free" AVM glasses were also leached in initially pure water (50 °C, 200 cm-1) with and without addition of Mg2+ in the solution. Accurate identification of Mg-smectite secondary phases and gel composition calculations enable us to explain the different observed behaviours.Glass AVM 10 was the less altered glass in pure water. Its gel is more protective than the other probably because it is mainly balanced by Mg2+. The addition of Mg2+ in the solution triggers the precipitation of smectite (not observed in pure water experiments), which consumes silicon from the gel, leading finally to a significant increase of the glass alteration.We also focused on the AVM 6 glass which was the most altered glass in pure water of available AVM glasses. Contrary to AVM 10, the gel of AVM 6 is mainly balanced by Na+. The addition of Mg2+ in the solution allows the replacement of Na by Mg within the gel. This reaction clearly improves the gel properties and allows the rate to decrease more rapidly, in spite of the precipitation of smectite (also observed in pure water experiments).Finally, the two glasses were altered in synthetic groundwater (SGW) with a high Mg-Ca content. As expected from the previous observations, AVM 10 was insensitive to the presence of alkaline earths in the leaching solution whereas AVM 6 glass exhibited a lower rate than in pure water thanks to the incorporation of Mg and Ca within the gel.

Thien, Bruno M. J.; Godon, Nicole; Ballestero, Anthony; Gin, Stéphane; Ayral, André

2012-08-01

116

The determination of the Fe sup 2+ /Fe sup 3+ ratio in simulated nuclear waste glass by ion chromatography  

SciTech Connect

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass in the Defense Waste Processing Facility (DWPF). In this facility, control of the oxidation/reduction (redox) equilibrium in the glass melter is critical for processing of the nuclear waste. Therefore, the development of a rapid and reliable analytical method for the determination of the redox equilibrium is of considerable interest. Redox has been determined by measuring the ratio of ferrous to ferric ions in the glass melt. Two analytical techniques for glass redox measurement have been investigated for the DWPF: Mossbauer Spectroscopy which may be subject to interferences from the radiation in actual waste, and a rapid and simple chemical dissolution/spectrophotometric technique. Comparisons of these techniques have been made at several laboratories including Clemson University. In the study attached, the determination of the redox ratio by Ion Chromatography (IC) was investigated as a potential new technology. Clemson University performed IC analyses on the same glasses as previously examined by wet chemical and Mossbauer techniques. Results from all three techniques were highly correlated and IC was reported to be a promising new technology for redox measurement. 19 refs., 19 figs., 5 tabs.

Jantzen, C.M.

1990-10-01

117

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

SciTech Connect

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.

Jantzen, C.M.

1990-12-31

118

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

SciTech Connect

540The 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.

Jantzen, C.M.

1990-01-01

119

Transmission electron microscopy of simulated DWPF high level nuclear waste glasses following gamma irradiation.  

National Technical Information Service (NTIS)

In the near future the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will begin stabilizing high-level radioactive waste using borosilicate glass. The molten waste glass will be poured into stainless steel canisters which, afte...

J. C. Marra N. E. Bibler J. R. Harbour M. H. Tosten

1994-01-01

120

Effects of temperature and radiation on the nuclear waste glass product consistency leach test.  

National Technical Information Service (NTIS)

Previous leach studies carried out with monolithic glass samples have shown that glass dissolution rates increase with increasing temperature and may or may not increase on exposure to external gamma radiolysis. In this study we have investigated the effe...

C. L. Crawford N. E. Bibler

1993-01-01

121

Cerium, uranium, and plutonium behavior in glass-bonded sodalite, a ceramic nuclear waste form.  

SciTech Connect

Glass-bonded sodalite is being developed as a ceramic waste form (CWF) to immobilize radioactive fission products, actinides, and salt residues from electrometallurgical treatment of spent nuclear reactor fuel. The CWF consists of about 75 mass % sodalite, 25 mass % glass, and small amounts of other phases. This paper presents some results and interpretation of physical measurements to characterize the CWF structure, and dissolution tests to measure the release of matrix components and radionuclides from the waste form. Tests have been carried out with specimens of the CWF that contain rare earths at concentrations similar to those expected in the waste form. Parallel tests have been carried out on specimens that have uranium or plutonium as well as the rare earths at concentrations similar to those expected in the waste forms; in these specimens UCl{sub 3} forms UO{sub 2} and PuCl{sub 3} forms PuO{sub 2}. The normalized releases of rare earths in dissolution tests were found to be much lower than those of matrix elements (B, Si, Al, Na). When there is no uranium in the CWF, the release of cerium is two to ten times lower than the release of the other rare earths. The low release of cerium may be due to its tetravalent state in uranium-free CWF. However, when there is uranium in the CWF, the release of cerium is similar to that of the other rare earths. This trivalent behavior of cerium is attributed to charge transfer or covalent interactions among cerium, uranium, and oxygen in (U,Ce)O{sub 2}.

Lewis, M. A.; Lexa, D.; Morss, L. R.; Richmann, M. K.

1999-09-03

122

Transmission electron microscopy of simulated DWPF high level nuclear waste glasses following gamma irradiation  

Microsoft Academic Search

In the near future the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will begin stabilizing high-level radioactive waste using borosilicate glass. The molten waste glass will be poured into stainless steel canisters which, after cooling, will be sealed shut to produce the canistered waste forms. Following interim storage at SRS, the glass-filled canisters will be shipped

J. C. Marra; N. E. Bibler; J. R. Harbour; M. H. Tosten

1994-01-01

123

Quantitative fluid inclusion gas analysis of airburst, nuclear, impact and fulgurite glasses  

Microsoft Academic Search

We present quantitative fluid inclusion gas analysis on a suite of violently-formed glasses. We used the incremental crush mass spectrometry method (Norman & Blamey, 2001) to analyze eight pieces of Libyan Desert Glass (LDG). As potential analogues we also analyzed trinitite, three impact crater glasses, and three fulgurites. The 'clear' LDG has the lowest CO content and O\\/Ar ratios are

John Parnell; Horton E. Newsom; Nigel J. F. Blamey; Mark Bruce Elrick Boslough

2010-01-01

124

Research investigation on dense scintillation glass for use in total absorption nuclear cascade detectors. Final report  

Microsoft Academic Search

Three approaches to the development of a high-density scintillation ; glass were investigated. They include the increase of density of glass systems ; containlng cerium---the only systems which were known to show scintillation, the ; testing of a novel silicate glass system containlng significant concentrations of ; silver produced by ion exchange and never tested previously, and the hot pressing

Hensler

1973-01-01

125

INCORPORATION OF MONO SODIUM TITANATE AND CRYSTALLINE SILICOTITANATE FEEDS IN HIGH LEVEL NUCLEAR WASTE GLASS  

SciTech Connect

Four series of glass compositions were selected, fabricated, and characterized as part of a study to determine the impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. All of the glasses studied were considerably more durable than the benchmark Environmental Assessment (EA) glass. The measured Product Consistency Test (PCT) responses were compared with the predicted values from the current DWPF durability model. One of the KT01-series and two of the KT03-series glasses had measured PCT responses that were outside the lower bound of the durability model. All of the KT04 glasses had durabilities that were predictable regardless of heat treatment or compositional view. In general, the measured viscosity values of the KT01, KT03, and KT04-series glasses are well predicted by the current DWPF viscosity model. The results of liquidus temperature (T{sub L}) measurements for the KT01-series glasses were mixed with regard to the predictability of the T{sub L} for each glass. All of the measured T{sub L} values were higher than the model predicted values, although most fell within the 95% confidence intervals. Overall, the results of this study show a reasonable ability to incorporate the anticipated SCIX streams into DWPF-type glass compositions with TiO{sub 2} concentrations of 4-5 wt % in glass.

Fox, K.; Johnson, F.; Edwards, T.

2010-11-23

126

Hydrolysis of R7T7 nuclear waste glass in dilute media: mechanisms and rate as a function of pH.  

National Technical Information Service (NTIS)

R7T7 nuclear waste glass dissolution in highly dilute aqueous media under static conditions at 90(sup 0)C occurs according to two different mechanisms depending on the solution acidity. In acid media (pH 4.8 and 5.5), preferential extraction of glass netw...

T. Advocat E. Vernaz H. Charpentier J. L. Crovisier G. Ehret

1990-01-01

127

Characterization by nuclear and spectrophotometric analysis of near-surface modifications of glass implanted with heavy ions  

Microsoft Academic Search

A soda-lime-silica glass was irradiated by different heavy ions (N,Ne, Ar, and Kr) with energies chosen in order to obtain the same penetration depth. The near-surface sodium depletion layer, characterized by nuclear analysis and infrared reflectance spectrophotometry (IRRS), is deeper than the implanted-ion range and grows with increasing incident-ion mass at the same dose and current density. By using reflectance

PIETRO POLATO; PAOLO MAZZOLDI; ANGELO BOSCOLO BOSCOLETTO

1987-01-01

128

IMPACT OF URANIUM AND THORIUM ON HIGH TIO2 CONCENTRATION NUCLEAR WASTE GLASSES  

SciTech Connect

This study focused on the potential impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. MST from the Salt Waste Processing Facility (SWPF) is also considered in the study. The KT08-series of glasses was designed to evaluate any impacts of the inclusion of uranium and thorium in glasses containing the SCIX components. All but one of the study glasses were found to be amorphous by X-ray diffraction (XRD). One of the slowly cooled glasses contained a small amount of trevorite, which is typically found in DWPF-type glasses and had no practical impact on the durability of the glass. The measured Product Consistency Test (PCT) responses for the study glasses and the viscosities of the glasses were well predicted by the current DWPF models. No unexpected issues were encountered when uranium and thorium were added to the glasses with SCIX components.

Fox, K.; Edwards, T.

2012-01-11

129

Microanalysis of colloids and suspended particles from nuclear waste glass alteration  

Microsoft Academic Search

Fully radioactive and non-radioactive Savannah River Laboratory (SRL) borosilicate glasses were reacted with water under static conditions at glass surface area to leachant volume (S\\/V) ratios of 340 m?1, 2000 m?1, and 20?000 m?1 for times varying from several days to several years at 90°C. A radioactive SRL 200 glass was also reacted under intermittent flow conditions at 90°C. Colloidal

Edgar C Buck; John K Bates

1999-01-01

130

Effects of temperature and radiation on the nuclear waste glass product consistency leach test  

SciTech Connect

Previous leach studies carried out with monolithic glass samples have shown that glass dissolution rates increase with increasing temperature and may or may not increase on exposure to external gamma radiolysis. In this study we have investigated the effects of temperature (70--1200{degrees}C) and radiation on the dissolution of simulated radioactive waste glasses using the Product Consistency Test (PCT). The PCT is a seven day, crushed glass leach test in deionized water that is carried out at 9OO{degrees}C. To date our results indicate no significant effect of external Co--60 gamma radiation when testing various simulated waste glasses at 90{degrees}C in a wellinsulated compartment within a Gammacell 220 irradiation unit. The temperature dependence for glass dissolution clearly exhibits Arrheniustype behavior for two of the three glasses tested. For the third glass the dissolution decreases at the higher temperatures, probably due to saturation effects. Actual radioactive waste glasses will be investigated later as part of this study.

Crawford, C.L.; Bibler, N.E.

1993-04-01

131

Effects of temperature and radiation on the nuclear waste glass product consistency leach test  

SciTech Connect

Previous leach studies carried out with monolithic glass samples have shown that glass dissolution rates increase with increasing temperature and may or may not increase on exposure to external gamma radiolysis. In this study we have investigated the effects of temperature (70--1200[degrees]C) and radiation on the dissolution of simulated radioactive waste glasses using the Product Consistency Test (PCT). The PCT is a seven day, crushed glass leach test in deionized water that is carried out at 9OO[degrees]C. To date our results indicate no significant effect of external Co--60 gamma radiation when testing various simulated waste glasses at 90[degrees]C in a wellinsulated compartment within a Gammacell 220 irradiation unit. The temperature dependence for glass dissolution clearly exhibits Arrheniustype behavior for two of the three glasses tested. For the third glass the dissolution decreases at the higher temperatures, probably due to saturation effects. Actual radioactive waste glasses will be investigated later as part of this study.

Crawford, C.L.; Bibler, N.E.

1993-01-01

132

Chemical decomposition of high-level nuclear waste storage/disposal glasses under irradiation. 1998 annual progress report  

SciTech Connect

'The objective of this project is to employ the technique of electron spin resonance (ESR), in conjunction with other experimental methods, to study radiation-induced decomposition of vitreous compositions proposed for immobilization/disposal of high-level nuclear wastes (HLW) or excess weapons plutonium. ESR is capable of identifying, even at the parts-per-million level, displaced atoms, ruptured bonds, and free radicals created by radiation in such glassy forms. For example, one of the scientific goals is to determine whether ESR-detectable superoxide (O{sub 2}{sup -}) and ozonide (O{sub 3}{sup -}) ions are precursors of radiation-induced oxygen gas bubbles reported by other investigators. The fundamental understandings obtained in this study will enable reliable predictions of the long-term effects of and decays of the immobilized radionuclides on HLW glasses. This report represents the results of an 18-month effort performed under a 3-year research award. Four categories of materials were studied: (1) several actual and proposed HLW glass compositions fabricated at Savannah River Technology Center (SRTC), samples of which had been irradiated to a dose of 30 MGy (1 Gy = 100 rad) to simulate decay effects, (2) several high-iron phosphate glasses fabricated at the University of Missouri-Rolla (UMR), (3) one other model HLW glass and several simulated natural glasses which had been implanted with 160-keV He{sup +} ions to simulate-decay damage, and (4) an actual geological glass damaged by decays of trace amounts of contained {sup 238}U and {sup 232}Th over a period of 65 Myears. Among the category-1 materials were two samples of Defense Waste Processing Facility (DWPF) borosilicate glasses modeling compositions currently being used to vitrify HLW at SRTC. The ESR spectra recorded for the unirradiated DWPF-glass simulants were attributable to Fe 3{sup +} ions. The 30-MGy irradiation was found to change the Fe{sup 3+} concentration of these glasses by a statistically insignificant factor (0.987 \\261 0.050) and not to create measurable numbers of other defects.'

Griscom, D.L.; Merzbacher, C.I.

1998-06-01

133

CRYSTALLIZATION IN MULTICOMPONENT GLASSES  

SciTech Connect

In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

KRUGER AA; HRMA PR

2009-10-08

134

The reaction of synthetic nuclear waste glass in steam and hydrothermal solution  

SciTech Connect

Glass monoliths of the WVCM 44, WVCM 50, SRL 165, and SRL 202 compositions were reacted in steam and in hydrothermal liquid at 200{degree}C. The glass reaction resulted in the formation of leached surface layers in both environments. The reaction in steam proceeds at a very low rate until precipitates form, after which the glass reaction proceeds at a greater rate. Precipitates were formed on all glass types reacted in steam. The assemblage of phases formed was unique to each glass type, but several precipitates were common to all glasses, including analcime, gyrolite, and weeksite. Reaction in steam occurs in a thin layer of condensed water which becomes saturated with respect to the observed phases after only a few days of reaction. The reaction in steam is accelerated relative to reaction in hydrothermal liquid in the sense that secondary phases from after a shorter reaction time, that is, after less glass has reacted, because of the smaller effective leachant volume present in the steam environment. A knowledge of the secondary phases which form and their influence on the glass reaction rate is crucial to the modeling effort of the repository program. 9 refs., 3 figs., 2 tabs.

Ebert, W.L.; Bates, J.K.

1989-12-31

135

Flow model for the kinetics of dissolution of nuclear waste glasses  

Microsoft Academic Search

A model has been developed to give reliable long-term predictions for the rate of material loss from radioactive waste solids and glasses exposed to aqueous environments. The model takes into full account the effects of the interaction of the glass with the medium over the entire range of flow\\/dilution conditions expected in geological repositories. These effects include an increase in

P. B. Macedo; A. Barkatt; J. H. Simmons

1982-01-01

136

Induction glass melting under conditioning highly- and moderately active nuclear wastes  

Microsoft Academic Search

The most reliable method of HLW stabilization is vitrification. To be solidified radioactive waste as a solution of salts of different humidities or mixed oxides are pre-mixed with glass-formers need to produce glass, fed to be concentrated and then into a melter. The paper discusses the results of the work to vitrify liquid HLW by a two stage process using

Y. B. Petrov; D. B. Lopukh; A. M. Lyubomirov

1993-01-01

137

Residual internal stress in partially crystallized photothermorefractive glass: Evaluation by nuclear magnetic resonance spectroscopy and first principles calculations  

NASA Astrophysics Data System (ADS)

In some circumstances, the mechanical and optical properties of multiphase brittle materials strongly depend on the level of residual micromechanical stresses that arise upon cooling due to thermal and elastic mismatch between the constituent phases. Here we study the residual internal stress in a partially crystallized oxyfluoride glass, best known as photothermorefractive (PTR) glass. This material is composed of a glass matrix with embedded nanosize sodium fluoride (NaF) crystals. Using both the Selsing model and solid-state nuclear magnetic resonance in combination with first principles calculations we found that the crystals are under a tensile stress field of approximately 610-800 MPa. For this stress level the estimated critical crystal diameter for spontaneous cracking is about 2300-1900 nm, which greatly exceeds the observed diameters of 7-35 nm. Hence no spontaneous cracking is expected for the PTR glasses. First principles calculations indicate that the stress induced change of the refractive index of the NaF crystals is about -0.08%, which agrees with the observed refractive index changes.

Zwanziger, J. W.; Werner-Zwanziger, U.; Zanotto, E. D.; Rotari, E.; Glebova, L. N.; Glebov, L. B.; Schneider, J. F.

2006-04-01

138

Simultaneous nuclear reaction analyses of boron and phosphorus in thin borophosphosilicate glass films using /(?,p) reactions  

NASA Astrophysics Data System (ADS)

A method combining /(?,p) nuclear reaction analysis (NRA) and ellipsometry has been developed for measuring the boron and phosphorus content of borophosphosilicate glass (BPSG) used for interlevel dielectrics in integrated circuits. Yields from the 31P(?,p0)34S (Q=0.63 MeV) and 10B(?,p0)13C (Q=4.06 MeV) reactions are coupled with ellipsometry thickness measurements to determine the average atomic percent of B and P in the film. We have determined that 6.0 MeV incident ?'s with a detector angle of 135 deg and about 100 ?m of Mylar range foil are optimum for our system. The yield for the 10B(?,p0)13C reaction is quite constant in our energy range of interest (~5.8-6 MeV) but the yield for the 31P(?,p0)34S is not. Consequently, a simple conversion from ``standard'' BPSG reference samples (independently quantified by ICP mass spectrometry) is adequate to calculate a film's %B content. The %P calculation is more complex, involving a three-dimensional fit of the P yield data and measured film thickness to the film %P content. This fit is based upon yield data from a matrix of standard film samples. The technique is sensitive to 0.1% with an accuracy of /+/-3-/+/-10% depending on the sample. This measurement method is now used routinely at Sandia National Laboratories in support of our fabrication process lines.

Walsh, D. S.; Doyle, B. L.

2000-03-01

139

A review of literature pertaining to the leaching and sorption of radionuclides associated with nuclear explosive melt glasses  

SciTech Connect

For the purposes of groundwater characterization, environmental remediation and health risk assessment, the mechanism and rate by which radionuclides bound within nuclear device melt glass are manifest in Nevada Test Site groundwaters must be known. Exchange between radionuclides and groundwater is dominated by the kinetics of leaching and the resultant sorption of derivative nuclides by minerals along the flow-path. In this context, a survey of the report literature has been conducted to review work related to these subjects. This report provides a representative, although not exhaustive, summary of the literature; because of the specialized nature of nuclear melt glass, emphasis was given to the report literature available from Lawrence Livermore and Los Alamos National Laboratories, the Department of Energy and its predecessor agencies and pertinent contractors. Where data is corroborated in journal literature, those references are also included. Before the risk to ground waters is estimated with any accuracy, recommendations for continued future work integrate systematic characterization of melt glass with leaching studies of these heterogeneous matrices.

Smith, D.K.

1993-05-01

140

An International Initiative on Long-Term Behavior of High-Level Nuclear Waste Glass  

SciTech Connect

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 longterm 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.

Gin, Stephane [French Atomic Energy Commission (CEA); Abdelouas, Abdesselam [SUBATECH Laboratory (France); Criscenti, Louise J [Sandia National Laboratory (SNL); Ebert, William L [Argonne National Laboratory (ANL); Ferrand, K [Belgian Nuclear Research Centre, SCK-CEN; Geisler, T [Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany; Harrison, Michael T [National Nuclear Laboratory (NNL); Inagaki, Y [Kyushu University, Japan; Mitsui, S [Japan Atomic Energy Agency (JAEA); Mueller, K T [Pacific Northwest National Laboratory (PNNL); Marra, James C [Savannah River National Laboratory (SRNL), Aiken, S.C.; Pantano, Carlo G [Pennsylvania State University, State College, PA; Pierce, Eric M [ORNL; Ryan, Joseph V [Pacific Northwest National Laboratory (PNNL); Schofield, J M [AMEC, Harwell Oxford Didcot Oxfordshire, United Kingdom; Steefel, Carl I [Lawrence Berkeley National Laboratory (LBNL); Vienna, John D. [Pacific Northwest National Laboratory (PNNL)

2013-01-01

141

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

SciTech Connect

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-B{sub 2}O{sub 3}) 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. Na{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}, K{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}, Rb{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}, and Cs{sub 2}O-SiO{sub 2}-B{sub 2}O{sub 3}) were examined. Their mixing effects are currently under investigation.

Sung, Y.M.; Tomozawa, M.

1996-02-01

142

Alteration of glass and crystalline ceramic nuclear waste forms under hydrothermal conditions  

Microsoft Academic Search

Alteration of borosilicate glass, sintered ceramic, glass-ceramic, and supercalcine ceramic was studied under hydrothermal conditions of 100\\/degree\\/, 200\\/degree\\/, or 220\\/degree\\/C and 300\\/degree\\/C for 28 days under a confining pressure of 30 MPa. Results show that the chemical composition of the waste, in addition to its form, plays an important role in keeping the hazardous nuclides out of solution during waste-form

N. Sasaki; S. Komarneni; R. Roy

1982-01-01

143

Development of Vitrification Process and Glass Formulation for Nuclear Waste Conditioning  

SciTech Connect

The vitrification of high-level waste is the internationally recognized standard to minimize the impact to the environment resulting from waste disposal as well as to minimize the volume of conditioned waste to be disposed of. COGEMA has been vitrifying high-level waste industrially for over 20 years and is currently operating three commercial vitrification facilities based on a hot metal crucible technology, with outstanding records of safety, reliability and product quality. To further increase the performance of vitrification facilities, CEA and COGEMA have been developing the cold crucible melter technology since the beginning of the 1980s. This type of melter is characterized by a virtually unlimited equipment service life and a great flexibility in dealing with various types of waste and allowing development of high temperature matrices. In complement of and in parallel with the vitrification process, a glass formulation methodology has been developed by the CEA in order to tailor matrices for the wastes to be conditioned while providing the best adaptation to the processing technology. The development of a glass formulation is a trade-off between material properties and qualities, technical feasibility, and disposal safety criteria. It involves non-radioactive and radioactive laboratories in order to achieve a comprehensive matrix qualification. Several glasses and glass ceramics have thus been studied by the CEA to be compliant with industrial needs and waste characteristics: glasses or other matrices for a large spectrum of fission products, or for high contents of specifics elements such as sodium, phosphate, iron, molybdenum, or actinides. New glasses or glass-ceramics designed to minimize the final wasteform volume for solutions produced during the reprocessing of high burnup fuels or to treat legacy wastes are now under development and take benefit from the latest CEA hot-laboratories and technology development. The paper presents the CEA state-of-the-art in developing matrices or glasses and provides several examples.

Petitjean, V.; Fillet, C.; Boen, R.; Veyer, C.; Flament, T.

2002-02-26

144

Liquidus Temperature Measurements for Modeling Oxide Glass Systems Relevant to Nuclear Waste Vitrification  

SciTech Connect

Liquidus temperatures TL have been measured and primary phases have been determined for 42 (from an initial test matrix of 60) compositions within the Al2O3-B2O3-CaO-Na2O-SiO2 glass forming network. These data have been used to test TL calculations and primary phase predictions obtained using a modified associate species model (ASM). This paper highlights the strong linear correlations between composition and TL for glasses within the same primary phase fields, the strengths of the ASM in determining TL and phase for glasses observed to precipitate nepheline, and weaknesses of the ASM in predicting phase information and TL for calcia- and boria-rich glasses. TL has also been measured for glasses using two baseline compositions from the five-component network that have been individually doped with Fe2O3, Li2O, NiO, ZrO2, Cr2O3, ZnO, and MnO. These additional oxide glasses are intended for use as benchmark data for testing the model as more oxides are included.

Hanni, Jonathan; Pressly, Eric D.; Crum, Jarrod V.; Minister, Kevin B.; Tran, Diana N.; Hrma, Pavel R.; Vienna, John D.

2005-12-01

145

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

National Technical Information Service (NTIS)

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...

C. M. Jantzen

1991-01-01

146

Characterization by nuclear and spectrophotometric analysis of near-surface modifications of glass implanted with heavy ions  

SciTech Connect

A soda-lime-silica glass was irradiated by different heavy ions (N,Ne, Ar, and Kr) with energies chosen in order to obtain the same penetration depth. The near-surface sodium depletion layer, characterized by nuclear analysis and infrared reflectance spectrophotometry (IRRS), is deeper than the implanted-ion range and grows with increasing incident-ion mass at the same dose and current density. By using reflectance spectrophotometry in the solar range, the formation of a near-surface perturbed layer having a modified refractive index as compared to the bulk and a thickness comparable to the sodium depletion layer was confirmed.

Polato, P.; Mazzoldi, P.; Boscoletto, A.B.

1987-10-01

147

Site symmetry in binary and ternary tin silicate glasses—29Si and 119Sn nuclear magnetic resonance  

Microsoft Academic Search

29Si and 119Sn nuclear magnetic resonance (NMR) spectroscopy has been performed on binary xSnO(100 ? x)SiO2 and ternary xR2O(50 ? x)SnO50SiO2 glasses (R = Li,Na,K,Rb for the 29Si NMR and R = Na for 119Sn NMR). The spectra obtained have been fitted to obtain the spectral parameters. The variation of these parameters as a function of composition has been compared

D Holland; A P Howes; R Dupree; J A Johnson; C E Johnson

2003-01-01

148

Site symmetry in binary and ternary tin silicate glasses29Si and 119Sn nuclear magnetic resonance  

Microsoft Academic Search

29Si and 119Sn nuclear magnetic resonance (NMR) spectroscopy has been performed on binary xSnO(100 - x)SiO2 and ternary xR2O(50 - x)SnO50SiO2 glasses (R = Li,Na,K,Rb for the 29Si NMR and R = Na for 119Sn NMR). The spectra obtained have been fitted to obtain the spectral parameters. The variation of these parameters as a function of composition has been compared

D. Holland; A. P. Howes; R. Dupree; J. A. Johnson; C. E. Johnson

2003-01-01

149

An alternative host matrix based on iron phosphate glasses for the vitrification of specialized nuclear waste forms. 1998 annual progress report  

SciTech Connect

'Certain high level wastes (HLW) in the US contain components such as phosphates, heavy metals, and halides which make them poorly suited for disposal in borosilicate glasses. Iron phosphate glasses appear to be a technically feasible alternative to borosilicate glasses for vitrifying these HLWs. The iron phosphate glasses mentioned above and their nuclear wasteforms are relatively new, so little is known about their atomic structure, redox equilibria, structure-property relationships, and crystallization products and characteristics. The objective of this research is to gain such information for the binary iron-phosphate glasses as well as iron phosphate wasteforms so that a comprehensive scientific assessment can be made of their usefulness in nuclear waste disposal. This report summarizes the work undertaken and completed in the first 20 months of a three year project. Approximately 250 samples, binary iron phosphate glasses and iron phosphate glasses containing one or two common nuclear waste components such as UO{sub 2} , Na{sub 2}O, Bi{sub 2}O{sub 3} , Cs{sub 2}O, SrO, and MoO{sub 3}, have been prepared. Weight loss has been used to measure the chemical durability and the redox equilibria between Fe(II) and Fe(III) has been investigated using Moessbauer spectroscopy. The atomic structure has been investigated using a variety of techniques including Mossbauer, Raman, X-ray absorption (XAS), and X-ray photoelectron (XPS) spectroscopies and neutron/high energy X-ray scattering. Glass forming and crystallization characteristics have been investigated using differential thermal analysis (DTA). In addition, information necessary for glass manufacturing such as suitable refractories and Joule heating parameters also have been obtained.'

Day, D.E.; Ray, C.S.; Marasinghe, G.K.; Karabulut, M.; Fang, X.

1998-06-01

150

Minor component study for simulated high-level nuclear waste glasses (Draft)  

SciTech Connect

Hanford Site single-shell tank (SSI) and double-shell tank (DSI) wastes are planned to be separated into low activity (or low-level waste, LLW) and high activity (or high-level waste, HLW) fractions, and to be vitrified for disposal. Formulation of HLW glass must comply with glass processibility and durability requirements, including constraints on melt viscosity, electrical conductivity, liquidus temperature, tendency for phase segregation on the molten glass surface, and chemical durability of the final waste form. A wide variety of HLW compositions are expected to be vitrified. In addition these wastes will likely vary in composition from current estimates. High concentrations of certain troublesome components, such as sulfate, phosphate, and chrome, raise concerns about their potential hinderance to the waste vitrification process. For example, phosphate segregation in the cold cap (the layer of feed on top of the glass melt) in a Joule-heated melter may inhibit the melting process (Bunnell, 1988). This has been reported during a pilot-scale ceramic melter run, PSCM-19, (Perez, 1985). Molten salt segregation of either sulfate or chromate is also hazardous to the waste vitrification process. Excessive (Cr, Fe, Mn, Ni) spinel crystal formation in molten glass can also be detrimental to melter operation.

Li, H.; Langowskim, M.H.; Hrma, P.R.; Schweiger, M.J.; Vienna, J.D.; Smith, D.E.

1996-02-01

151

Induction glass melting under conditioning highly- and moderately active nuclear wastes  

SciTech Connect

The most reliable method of HLW stabilization is vitrification. To be solidified radioactive waste as a solution of salts of different humidities or mixed oxides are pre-mixed with glass-formers need to produce glass, fed to be concentrated and then into a melter. The paper discusses the results of the work to vitrify liquid HLW by a two stage process using a direct flow evaporator (DFE) For the deep concentration of fluxed solution at the first stage. The second stage employs an induction melter with a cold crucible (IMCC) to convert the deeply evaporated solution to vitreous phosphate, borosilicate and alumosilicate materials. The principal electrical and technological characteristics of the vitrificaiton process are described. Meltings of model compositions of wastes have been carried out in the developed furnaces which gave phosphate, borosilicate and silicate glasses, as well as mineral-like glass-crystal materials. Acid-alkaline properties of the produced melts influence the temperature of glass mass production, convective mixung and specific out-put of the melted wastes.

Petrov, Y.B.; Lopukh, D.B.; Lyubomirov, A.M. [and others

1993-12-31

152

Fluorescent microscopic determination of proteins in human serum with the self-ordered ring of nuclear fast red formed on the solid support of glass slides  

Microsoft Academic Search

A self-ordered ring (SOR) technique based on the assembly of fluorescent molecules on the solid support of glass slides is presented for the detection of trace amount of proteins by using fluorescence microscope. At pH 6.62 and with the aid of poly(vinyl alcohol)-124 (PVA-124), a droplet of nuclear fast red (NFR) solution can form a fluorescent SOR on hydrophobic glass

Yu Chun Chen; Cheng Zhi Huang

2003-01-01

153

Electron-nuclear double resonance study of molecular librations of nitroxides in molecular glasses: Quantum effects at low temperatures, comparison with low-frequency Raman scattering  

Microsoft Academic Search

Pulsed electron-nuclear double resonance applied to 15N nitroxide spin probes in molecular glasses is shown to be very sensitive to measurement of the AXX principal value of the hyperfine interaction tensor. For molecules experiencing fast restricted orientational motions (molecular librations), this provides a precise tool to determine the motion-averaged value. For nitroxides in glycerol and o-terphenyl glasses, the observed

L. V. Kulik; L. L. Rapatsky; A. V. Pivtsov; N. V. Surovtsev; S. V. Adichtchev; I. A. Grigor'ev; S. A. Dzuba

2009-01-01

154

Extruder glass-melter process for vitrification of nuclear and other toxic wastes  

US Patent & Trademark Office Database

A toxic waste and glass frit are fed into an extruder having a helical screw. The glass frit, as well as any glassy material and glass-forming component in the waste, are melted in the extruder as the screw transports the waste and the frit through the extruder. The screw further mixes the waste and the frit and homogenizes the resulting mixture. The extruder is designed to generate high shear rates and high internal friction and at least a portion of the heat for melting is produced by such friction. A vitrified mass of the toxic waste is discharged from the extruder. The vitrified mass can be stored as is or can be pelletized and/or encapsulated.

1999-09-07

155

On the cooperative nature of the ?-process in neat and binary glasses: A dielectric and nuclear magnetic resonance spectroscopy study  

NASA Astrophysics Data System (ADS)

By means of dielectric as well as 2H and 31P nuclear magnetic resonance spectroscopy (NMR) the component dynamics of the binary glass tripropyl phosphate (TPP)/polystyrene (PS/PS-d3) is selectively investigated for concentrations distributed over the full range. We study the secondary (?-) relaxation below Tg, which is found in all investigated samples containing TPP, but not in neat polystyrene. The dielectric spectrum of the ?-process is described by an asymmetric distribution of activation energies, essentially not changing in the entire concentration regime; its most probable value is E/k ? 24 Tg. Persistence of the ?-process is confirmed by 31P NMR Hahn-echo and spin-lattice relaxation experiments on TPP, which identify the nature of the ?-process as being highly spatially hindered as found for other (neat) glasses studied previously, or re-investigated within this work. The corresponding 2H NMR experiments on PS-d3 confirm the absence of a ?-process in neat PS-d3, but reveal a clear signature of a ?-process in the mixture, i.e., polystyrene monomers perform essentially the same type of secondary relaxation as the TPP molecules. Yet, there are indications that some fractions of PS-d3 as well as TPP molecules become immobilized in the mixture in contrast to the case of neat glasses. We conclude that in a binary glass the ?-process introduced by one component induces a highly similar motion in the second component, and this may be taken as an indication of its cooperative nature.

Bock, D.; Kahlau, R.; Micko, B.; Pötzschner, B.; Schneider, G. J.; Rössler, E. A.

2013-08-01

156

ANNUAL REPORT. IRON PHOSPHATE GLASSES: AN ALTERNATIVE FOR VITRIFYING CERTAIN NUCLEAR WASTES  

EPA Science Inventory

The two multifaceted objectives of this research project are to (1) investigate the feasibility of vitrifying 2 or 3 high priority wastes, as identified by the Tank Focus Area group, using iron phosphate glasses (i.e., determine chemical durability as a function of waste loading,...

157

Waste glass weathering  

Microsoft Academic Search

The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared

J. K. Bates; E. C. Buck

1993-01-01

158

Quasicrystalline Approach to Prediting the Spinel-Nepheline Liquidus: Application to Nuclear Waste Glass Processing  

Microsoft Academic Search

The crystal-melt equilibria in complex fifteen component melts are modeled based on quasicrystalline concepts. A pseudobinary phase diagram between acmite (which melts incongruently to a transition metal ferrite spinel) and nepheline is defined. The pseudobinary lies within the AlâOâ-FeâOâ-NaâO-SiOâ quaternary system that defines the crystallization of basalt glass melts. The pseudobinary provides the partitioning of species between the melt and

Jantzen; Carol

2005-01-01

159

Development and testing of matrices for the encapsulation of glass and ceramic nuclear waste forms.  

SciTech Connect

This report details the results of research on the matrix encapsulation of high level wastes at PML over the past few years. The demonstrations and tests described were designed to illustrate how the waste materials are effected when encapsulated in an inert matrix. Candidate materials evaluated for potential use as matrices for encapslation of pelletized ceramics or glass marbles were categorized into four groups: metals, glasses, ceramics, and graphite. Two processing techniques, casting and hot pressing, were investigated as the most promising methods of formation or densification of the matrices. The major results reported deal with the development aspects. However, chemical durability tests (leach tests) of the matrix materials themselves and matrix-waste form composites are also reported. Matrix waste forms can provide a low porosity, waste-free barrier resulting in increased leach protection, higher impact strength and improved thermal conductivity compared to unencapsulated glass or ceramic waste materials. Glass marbles encapsulated in a lead matrix offer the most significant improvement in waste form stability of all combinations evaluated. This form represents a readily demonstrable process that provides high thermal conductivity, mechanical shock resistance, radiation shielding and increased chemical durability through both a chemical passivation mechanism and as a physical barrier. Other durable matrix waste forms evaluated, applicable primarily to ceramic pellets, involved hot-pressed titanium or TiO/sub 2/ materials. In the processing of these forms, near 100% dense matrices were obtained. The matrix materials had excellent compatibility with the waste materials and superior potential chemical durability. Cracking of the hot-pressed ceramic matrix forms, in general, prevented the realization of their optimum properties.

Wald, J.W.; Brite, D.W.; Gurwell, W.E.; Buckwalter, C.Q.; Bunnell, L.R.; Gray, W.J.; Blair, H.T.; Rusin, J.M.

1982-02-01

160

Effect of Alumina Source on the Rate of Melting Demonstrated with Nuclear Waste Glass Batch  

SciTech Connect

The melting behaviors of three glass batches formulated to vitrify high-level waste were compared. These batches, otherwise identical, differed in the alumina source: one was prepared with corundum (Al2O3), another with gibbsite [Al(OH)3], and the other with boehmite [AlO(OH)]. Batch samples, in the form of loose batches or pressed pellets, were heated at 5°C/min up to 1200°C. The expansion of pellets was monitored photographically. Quenched samples of batches, heated in crucibles, were thin-sectioned, investigated with optical microscopy, and analyzed with X-ray diffraction to quantify crystalline phases. Finally, batch-to-glass conversion was investigated with thermal analysis. Corundum was still present in one batch up to 900°C whereas gibbsite and boehmite dissolved below 500°C. In the batch with corundum, quartz, the source of silica, dissolved marginally earlier than in the batches with gibbsite and boehmite. Unlike the batch with corundum that exhibited considerable foaming, the batches with gibbsite and boehmite did not produce primary foam and made a more homogeneous glass. The occurrence of primary foam in the batch with corundum is a likely cause of a low rate of melting within the cold cap of a large-scale electric melter.

Pierce, David A.; Hrma, Pavel R.; Marcial, Jose; Riley, Brian J.; Schweiger, Michael J.

2012-03-30

161

The role of natural glasses as analogues in projecting the long-term alteration of high-level nuclear waste glasses: Part 1  

Microsoft Academic Search

The common observation of glasses persisting in natural environments for long periods of time (up to tens of millions of years) provides compelling evidence that these materials can be kinetically stable in a variety of subsurface environments. This paper reviews how natural and historical synthesized glasses can be employed as natural analogues for understanding and projecting the long-term alteration of

Mazer

1993-01-01

162

Quantitative fluid inclusion gas analysis of airburst, nuclear, impact and fulgurite glasses.  

SciTech Connect

We present quantitative fluid inclusion gas analysis on a suite of violently-formed glasses. We used the incremental crush mass spectrometry method (Norman & Blamey, 2001) to analyze eight pieces of Libyan Desert Glass (LDG). As potential analogues we also analyzed trinitite, three impact crater glasses, and three fulgurites. The 'clear' LDG has the lowest CO{sub 2} content and O{sub 2}/Ar ratios are two orders of magnitude lower than atmospheric. The 'foamy' glass samples have heterogeneous CO{sub 2} contents and O{sub 2}/Ar ratios. N{sub 2}/Ar ratios are similar to atmospheric (83.6). H{sub 2} and He are elevated but it is difficult to confirm whether they are of terrestrial or meteoritic origin. Combustion cannot account for oxygen depletion that matches the amount of CO{sub 2} produced. An alternative mechanism is required that removes oxygen without producing CO{sub 2}. Trinitite has exceedingly high CO{sub 2} which we attribute to carbonate breakdown of the caliche at ground zero. The O{sub 2}/Ar ratio for trinitite is lower than atmospheric but higher than all LDG samples. N{sub 2}/Ar ratios closely match atmospheric. Samples from Lonar, Henbury and Aouelloul impact craters have atmospheric N{sub 2}/Ar ratios. O{sub 2}/Ar ratios at Lonar and Henbury are 9.5 to 9.9 whereas the O{sub 2}/Ar ratio is 0.1 for the Aouelloul sample. In most fulgurites the N{sub 2}/Ar ratio is higher than atmospheric, possibly due to interference from CO. Oxygen ranges from 1.3 to 19.3%. Gas signatures of LDG inclusions neither match those from the craters, trinitite nor fulgurites. It is difficult to explain both the observed depletion of oxygen in the LDG and a CO{sub 2} level that is lower than it would be if the CO{sub 2} were simply a product of hydrocarbon combustion in air. One possible mechanism for oxygen depletion is that as air turbulently mixed with a hot jet of vaporized asteroid from an airburst and expanded, the atmospheric oxygen reacted with the metal vapor to form metal oxides that condensed. This observation is compatible with the model of Boslough & Crawford (2008) who suggest that an airburst incinerates organic materials over a large area, melting surface materials that then quench to form glass. Bubbles would contain a mixture of pre-existing atmosphere with combustion products from organic material and products of the reaction between vaporized cosmic materials (including metals) and terrestrial surface and atmosphere.

Parnell, John (University of Aberdeen, Aberdeen, UK); Newsom, Horton E. (University of New Mexico, Albuquerque, NM); Blamey, Nigel J. F. (New Mexico Tech, Socorro, NM); Boslough, Mark Bruce Elrick

2010-10-01

163

Chemical decomposition of high-level nuclear waste storage/disposal glasses under irradiation. 1997 annual progress report  

SciTech Connect

'The objective of this research is to use the sensitive technique of electron spin resonance (ESR) to look for evidence of radiation-induced chemical decomposition of vitreous forms contemplated for immobilization of plutonium and/or high-level nuclear wastes, to interpret this evidence in terms of existing knowledge of glass structure, and to recommend certain materials for further study by other techniques, particularly electron microscopy and measurements of gas evolution by high-vacuum mass spectroscopy. Previous ESR studies had demonstrated that an effect of y rays on a simple binary potassium silicate glass was to induce superoxide (O{sub 2}{sup -}) and ozonide (O{sub 3}{sup -}) as relatively stable product of long-term irradiation Accordingly, some of the first experiments performed as a part of the present effort involved repeating this work. A glass of composition 44 K{sub 2}O: 56 SiO{sub 2} was prepared from reagent grade K{sub 2}CO3 and SiO{sub 2} powders melted in a Pt crucible in air at 1,200 C for 1.5 hr. A sample irradiated to a dose of 1 MGy (1 MGy = 10{sup 8} rad) indeed yielded the same ESR results as before. To test the notion that the complex oxygen ions detected may be harbingers of radiation-induced phase separation or bubble formation, a small-angle neutron scattering (SANS) experiment was performed. SANS is theoretically capable of detecting voids or bubbles as small as 10 \\305 in diameter. A preliminary experiment was carried out with the collaboration of Dr. John Barker (NIST). The SANS spectra for the irradiated and unirradiated samples were indistiguishable. A relatively high incoherent background (probably due to the presence of protons) may obscure scattering from small gas bubbles and therefore decrease the effective resolution of this technique. No further SANS experiments are planned at this time.'

Griscom, D.L.; Merzbacher, C.I.

1997-01-01

164

The nuclear deal with North Korea: Is the glass half empty or half full?  

Microsoft Academic Search

North Korea's record on the nuclear question gives no reason to trust in its compliance with the October 1994 agreement with the United States. This article traces the development of the North Korean nuclear program and the negotiations with the International Atomic Energy Agency and the United States, as well as Pyongyang's clandestine chemical?biological weapons production and missile programs. In

Kathleen C. Bailey

1995-01-01

165

Direct observations of the leaching of a simulated nuclear waste glass in a radiation environment  

Microsoft Academic Search

The durability of the media proposed for the containment of commercial nuclear waste will be affected not only by the differences in groundwater composition that they might encounter but also by the changes that their own irradiation fields will make to these solutions. Experimental results that question the ability of current leaching experiments to predict the stability of nuclear waste

D. K. McElfresh; J. F. DeNatale; D. G. Howitt; E. P. Butler

1983-01-01

166

NOTE The effect of 13C enrichment in the glassing matrix on dynamic nuclear polarization of [1-13C]pyruvate  

Microsoft Academic Search

Dimethyl sulfoxide (DMSO) can effectively form a glassy matrix necessary for dynamic nuclear polarization (DNP) experiments. We tested the effects of 13C enrichment in DMSO on DNP of [1-13C]pyruvate doped with trityl radical OX063Me. We found that the polarization build-up time tau of pyruvate in 13C-labeled DMSO glassing solution is twice as fast as the unenriched DMSO while the nuclear

Lloyd Lumata; Zoltan Kovacs; Craig Malloy; A. Dean Sherry; Matthew Merritt

2011-01-01

167

The effect of 13C enrichment in the glassing matrix on dynamic nuclear polarization of [1-13C]pyruvate  

Microsoft Academic Search

Dimethyl sulfoxide (DMSO) can effectively form a glassy matrix necessary for dynamic nuclear polarization (DNP) experiments. We tested the effects of 13C enrichment in DMSO on DNP of [1-13C]pyruvate doped with trityl radical OX063Me. We found that the polarization build-up time tau of pyruvate in 13C-labeled DMSO glassing solution is twice as fast as the unenriched DMSO while the nuclear

Lloyd Lumata; Zoltan Kovacs; Craig Malloy; A. Dean Sherry; Matthew Merritt

2011-01-01

168

Characterisation of heterogeneous molybdate and chromate phase assemblages in model nuclear waste glasses by multinuclear magnetic resonance spectroscopy.  

PubMed

A series of sodium borosilicate glasses containing cesium, molybdenum, and chromium was prepared to investigate the partitioning of chromium amongst the glass and phase-separated crystalline molybdates. The precipitates were examined by (133)Cs, (23)Na, and (95)Mo MAS NMR, revealing a phase assemblage consisting of Na(2)MoO(4), Na(2)MoO(4)·2H(2)O, Cs(2)MoO(4), Cs(2)CrO(4), CsNaMoO(4)·2H(2)O, and Cs(3)Na(MoO(4))(2). (133)Cs MAS NMR indicates random substitution of Cr into the Mo sites of Cs(3)Na(MoO(4))(2) and provides a quantitative assessment of Cr incorporation. The sample compositions were verified by various analytical techniques and highlight the centrality of NMR in the identification and quantification of heterogeneous crystalline composites, including sensitivity to cationic substitution. The observation and facile interconversion of hydrated phases invites careful consideration of these materials for nuclear waste disposal. PMID:22532058

Greer, Brandon J; Kroeker, Scott

2012-04-25

169

The use of natural and archeological analogues for understanding the long-term behavior of nuclear glasses  

NASA Astrophysics Data System (ADS)

The knowledge of the long-term behavior of nuclear waste in anticipation of ultimate disposal in a deep geological formation is of prime importance in a waste management strategy. If phenomenological models have been developed to predict the long-term behavior of these materials, validating these models remains a challenge, when considering the time scale of radioactive decay of radionuclides of environmental concern, typically 10 4-10 5 yrs. Here we show how natural or archaeological analogues provide critical constraints not only on the phenomenology of glass alteration and the mechanisms involved, but also on the ability of experimental short-term data to predict long-term alteration in complex environments.

Libourel, Guy; Verney-Carron, Aurelie; Morlok, Andreas; Gin, Stéphane; Sterpenich, Jérôme; Michelin, Anne; Neff, Delphine; Dillmann, Philippe

2011-02-01

170

Effect of composition and radiation on the Hertzian indentation behavior of nuclear waste glasses. [77-MeV alpha particles  

SciTech Connect

The Hertzian indentation technique has been used to determine the fracture toughness, K/sub Ic/ of two borosilicate glasses developed to contain high-level nuclear waste. For the product VG 98/12, adding selected groups of fission products leaves K/sub Ic/ unchanged, but addition of Pb lowers K/sub Ic/ by approx. 20%. Radiation with 77 MeV ..cap alpha..-particles to a dose of approx. 10/sup 15/ ..cap alpha../cm/sup 2/ increases K/sub Ic/ by approx. 75%. For the product SM 58 LW 11, the fracture toughness was measured on pieces taken from different parts of a large cylinder to investigate the effects of segregation phenomena and of partial crystallization and formation of small cristobalite inclusions which decrease K/sub Ic/ by approx. 25%.

Matzke, H.; Kahl, L.; Routbort, J.L.; Saidl, J.

1983-01-01

171

Solid-state nuclear magnetic resonance studies of HIV and influenza fusion peptide orientations in membrane bilayers using stacked glass plate samples  

Microsoft Academic Search

The human immunodeficiency virus (HIV) and influenza virus fusion peptides are ?20-residue sequences which catalyze the fusion of viral and host cell membranes. The orientations of these peptides in lipid bilayers have been probed with 15N solid-state nuclear magnetic resonance (NMR) spectroscopy of samples containing membranes oriented between stacked glass plates. Each of the peptides adopts at least two distinct

Christopher M. Wasniewski; Paul D. Parkanzky; Michele L. Bodner; David P. Weliky

2004-01-01

172

Raman, Brillouin, and nuclear magnetic resonance spectroscopic studies on shocked borosilicate glass  

NASA Astrophysics Data System (ADS)

Using Brillouin and Raman scattering and NMR techniques, we have investigated the elastic and structural properties of four post-shocked specimens of borosilicate glass, recovered from peak pressures of 19.8, 31.3, 40.3, and 49.1 GPa. The Raman spectra of shock-wave compressed borosilicate glass for peak pressures of 19.8 and 31.3 GPa show two new peaks at 606 cm-1 and near 1600 cm-1, while a peak at ~923 cm-1 disappears in these glasses following shock-loading. The mode at 606 cm-1 is correlated with four-membered rings, composed of one BO4 and three SiO4 tetrahedra (a reedmergneritelike configuration). Modes near ~1600 cm-1 are of uncertain origin, while that at 923 cm-1 may associated with silica tetrahedra with two nonbridging oxygens, although standard models of this type of glass suggest that total nonbridging oxygen contents should be low. The Raman spectra for the shocked samples at 40.3 and 49.1 GPa are similar to that of the unshocked sample, suggesting that much of the irreversible density and structural changes are recoverable following adiabatic decompression and thermal relaxation. This reversibility for the highest pressure shocked samples is in accord with the Brillouin results, which show an increase in the product of sound velocity and index of refraction at pressures up to 20 GPa. The Raman band initially at 450 cm-1, which corresponds to the bending vibration mode of the Si-O-Si, Si-O-B (with primarily six-membered rings in the network) reaches a maximum frequency of 470 cm-1 and narrowing at a peak shock pressure of 31.3 GPa, and then also decreases to its initial values for samples shocked at 40.3 and 49.1 GPa. This shift toward higher frequency under shock-wave compression indicates the average Si-O-Si, Si-O-B angles decrease with pressure. The narrowing of this band suggests a narrower distribution of Si-O-Si angles in the shocked samples for peak pressures of 19.8 and 31.3 GPa. 11B NMR spectra for all four shocked glasses are similar, and indicate ratios of BO3 to BO4 that are not greatly changed from the starting material. However, changes in peak shapes suggest significant changes in the connectivity of the B and Si components of the network, with more silicon neighbors surrounding BO4 tetrahedra in the shocked glasses, and a modest increase in the number of nonring related BO3 groups following shock-loading. Thus, the irreversible effects of shock-loading appear to be to generate smaller rings of tetrahedra (hence decreasing the average T-O-T bond angle), and to increase the average number of neighbors of Si around boron tetrahedra.

Manghnani, Murli H.; Hushur, Anwar; Sekine, Toshimori; Wu, Jingshi; Stebbins, Jonathan F.; Williams, Quentin

2011-06-01

173

An alternative host matrix based on iron phosphate glasses for the vitrification of specialized nuclear waste forms. Annual progress report, September 15, 1996--September 14, 1997  

SciTech Connect

'Objectives of this project are to: (1) investigate the glass composition and processing conditions that yield optimum properties for iron phosphate glasses for vitrifying radioactive waste, (2) determine the atomic structure of iron phosphate glasses and the structure-property relationships, (3) determine how the physical and structural properties of iron phosphate glasses are affected by the addition of simulated high level nuclear waste components, and (4) investigate the process and products of devitrification of iron phosphate waste forms. The glass forming ability of about 125 iron phosphate melts has been investigated in different oxidizing to reducing atmospheres using various iron oxide raw materials such as Fe{sub 2}O{sub 3}, FeO, Fe{sub 3}O{sub 4}, and FeC{sub 2}O{sub 4} 2H{sub 2}O. The chemical durability, redox equilibria between Fe(II) and Fe(III), crystallization behavior and structural features for these glasses and their crystalline forms have been investigated using a variety of techniques including Mossbauer spectroscopy, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), Extended x-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) analysis, differential thermal and thermogravimetric analysis (DTA/TGA), and X-ray and neutron diffraction.'

Day, D.E.; Ray, C.S.; Marasinghe, K.

1997-09-23

174

Ferrous/ferric Mossbauer analysis of simulated nuclear waste glass with and without computer fitting  

SciTech Connect

Wet-chemical and /sup 57/Fe Mossbauer analyses of ferrous/ferric ratios in complex borosilicate and simple silicate glasses were compared. The results support the validity of the colorimetric wet-chemical procedure and establish a linear calibration for the Mossbauer data. The resulting correlation indicates that using area ratios from Mossbauer spectra will overestimate the proportion of ferrous iron by a factor of 1.2. The linear calibration was achieved only after statistically optimizing the peak line shape for each Mossbauer spectrum. Samples with a greater proportion of ferrous iron tended to have a greater Gaussian contribution to the peak line shape. A procedure to determine ferrous/ferric ratios from measured intensity data at three velocity locations was developed. With instrument modification, this result will lead to a substantial reduction in data collection time and the elimination of complex spectral fitting.

Goldman, D.S.; Bewley, D.E.

1985-12-01

175

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

SciTech Connect

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.

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

2012-08-13

176

Radioisotope generators for nuclear medicine based on Fajans adsorption on glass microspheres  

SciTech Connect

Several radioisotope generator systems exist in which the carrier-free daughter product would precipitate if present in macro amounts at pH levels at which the parent is soluble. Included among these are the {sup 68}Ge/{sup 68}Ga, {sup 90}Sr/{sup 90}Y, and {sup 47}Ca/{sup 47}Sc pairs. This paper reveals that in these systems, chemical separation can be achieved by Fajans adsorption of the radiocolloidal daughter products onto surfaces such as activated glass microspheres at an appropriate pH. This is followed by washing to remove the parent solution and desorption of the daughter crop by acid washes. Investigation of the Ge/Ga and Sr/Y systems demonstrated that this solid-phase extraction method is erratic, but can give daughter yields as high at 89% with separation factors up to {approximately} 10,000 form parent isotope. This method has the potential for producing daughter isotopes with a minimum of metal and organic impurities for labeling cells, receptor binding ligands, and antibodies for diagnostic and radiotherapeutic purposes.

Ehrhardt, G.J.; Symes, S.; Guimon, R.K.; Zinn, K.R. (Univ. of Missouri, Research Reactor, Columbia, MO (US))

1992-04-01

177

Nuclear Spin Lattice Relaxation and Conductivity Studies of the Non-Arrhenius Conductivity Behavior in Lithium Fast Ion Conducting Sulfide Glasses  

SciTech Connect

As time progresses, the world is using up more of the planet's natural resources. Without technological advances, the day will eventually arrive when these natural resources will no longer be sufficient to supply all of the energy needs. As a result, society is seeing a push for the development of alternative fuel sources such as wind power, solar power, fuel cells, and etc. These pursuits are even occurring in the state of Iowa with increasing social pressure to incorporate larger percentages of ethanol in gasoline. Consumers are increasingly demanding that energy sources be more powerful, more durable, and, ultimately, more cost efficient. Fast Ionic Conducting (FIC) glasses are a material that offers great potential for the development of new batteries and/or fuel cells to help inspire the energy density of battery power supplies. This dissertation probes the mechanisms by which ions conduct in these glasses. A variety of different experimental techniques give a better understanding of the interesting materials science taking place within these systems. This dissertation discusses Nuclear Magnetic Resonance (NMR) techniques performed on FIC glasses over the past few years. These NMR results have been complimented with other measurement techniques, primarily impedance spectroscopy, to develop models that describe the mechanisms by which ionic conduction takes place and the dependence of the ion dynamics on the local structure of the glass. The aim of these measurements was to probe the cause of a non-Arrhenius behavior of the conductivity which has been seen at high temperatures in the silver thio-borosilicate glasses. One aspect that will be addressed is if this behavior is unique to silver containing fast ion conducting glasses. more specifically, this study will determine if a non-Arrhenius correlation time, {tau}, can be observed in the Nuclear Spin Lattice Relaxation (NSLR) measurements. If so, then can this behavior be modeled with a new single distribution of activation energies (DAE) to calculate the corresponding conductivity and relaxation rates as a function of temperature and frequency?

Benjamin Michael Meyer

2003-05-31

178

Thermal Conductivity of Glasses Induced by Nuclear Quadrupole Interaction at Ultra Low Temperatures  

NASA Astrophysics Data System (ADS)

It is investigated how nuclear degrees of freedom of tunneling system (TS) inherent in amorphous solids influence its acoustic properties. It was shown in our previous papers that below 10 mK nuclear quadrupole interaction breaks down the coherent tunneling. This phenomenon results in appearance of the quasi-gap in the distribution function for the tunneling amplitude splitting. The quasi-gap is responsible for the plateau in the temperature dependence of the real part of a dielectric permittivity or speed of sound. In this paper we are interested in ultrasonic absorption and thermal conductivity which are intimately connected. We demonstrate that there exists a temperature interval in a millikelvin region where the sound absorption behavior changes drastically from the behavior predicted by the standard tunneling model (STM). In particular, the sound absorption increases approximately by an order of magnitude. Since in the millikelvin region the heat transport is due to acoustic phonons, the thermal conductivity also should demonstrate a strong increase as compared to standard tunneling model. The application of a strong magnetic field is known to restore the coherent tunneling and the standard distribution for the tunneling splitting amplitude. Thus, one can expect that in a strong magnetic field the thermal conductivity should drop in the temperature interval where the coherent tunneling was initially destroyed.

Polishchuk, I. Y.; Burin, A. L.

2011-03-01

179

Micro-fluidics and integrated optics glass sensor for in-line micro-probing of nuclear samples  

SciTech Connect

We study the miniaturisation of Thermal Lens Spectrometry (TLS) towards Lab-on-chip integration in order to reduce the volume of fluid assays in nuclear process control. TLS is of great interest in this context since it combines the advantages of optical detection methods with an inherent suitability for small-scale samples. After validating the experimental principle in a classical thermal lens crossed-beam setup, we show the integration of a Young-interferometer with a microcapillary on a glass substrate, reducing the necessary sample size to 400 nl. The interferometer translates the photo-thermally induced refractive index change in the fluid to a phase shift of the fringe pattern, which can then be detected by a camera. Measurements of Co(II) in ethanol yield a detection limit of c = 5 x 10{sup -4} M for the crossed-beam setup and c = 6x10{sup -3} M for the integrated sensor. At an interaction length of 10 {mu}m, it detects a minimum absorbance of AU = 6 x 10{sup -5} in a probed volume of 10 pl. (authors)

Schimpf, A. [Institut de Microelectronique, Electromagnetisme et Photonique IMEP-LAHC Minatec, Batiment INP Grenoble, 3, parvis Louis Neel, BP 257, 38016 Cedex 1 (France); Canto, F. [Commissariat a l'Energie Atomique CEA de Marcoule, DEN - DRCP - SEAA - LAMM, BP17171, 30207 Bagnols sur Ceze Cedex (France); Bucci, D. [Institut de Microelectronique, Electromagnetisme et Photonique IMEP-LAHC Minatec, Batiment INP Grenoble, 3, parvis Louis Neel, BP 257, 38016 Cedex 1 (France); Magnaldo, A.; Couston, L. [Commissariat a l'Energie Atomique CEA de Marcoule, DEN - DRCP - SEAA - LAMM, BP17171, 30207 Bagnols sur Ceze Cedex (France); Broquin, J. E. [Institut de Microelectronique, Electromagnetisme et Photonique IMEP-LAHC Minatec, Batiment INP Grenoble, 3, parvis Louis Neel, BP 257, 38016 Cedex 1 (France)

2011-07-01

180

Local structures of mesoporous bioactive glasses and their surface alterations in vitro: inferences from solid-state nuclear magnetic resonance  

PubMed Central

We review the benefits of using 29Si and 1H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy for probing the local structures of both bulk and surface portions of mesoporous bioactive glasses (MBGs) of the CaO–SiO2?(P2O5) system. These mesoporous materials exhibit an ordered pore arrangement, and are promising candidates for improved bone and tooth implants. We discuss experimental MAS NMR results from three MBGs displaying different Ca, Si and P contents: the 29Si NMR spectra were recorded either directly by employing radio-frequency pulses to 29Si, or by magnetization transfers from neighbouring protons using cross polarization, thereby providing quantitative information about the silicate speciation present in the pore wall and at the MBG surface, respectively. The surface modifications were monitored for the three MBGs during their immersion in a simulated body fluid (SBF) for intervals between 30 min and one week. The results were formulated as a reaction sequence describing the interconversions between the distinct silicate species. We generally observed a depletion of Ca2+ ions at the MBG surface, and a minor condensation of the silicate-surface network over one week of SBF soaking.

Gunawidjaja, Philips N.; Mathew, Renny; Lo, Andy Y. H.; Izquierdo-Barba, Isabel; Garcia, Ana; Arcos, Daniel; Mattias Eden, Maria Vallet-Regi

2012-01-01

181

Properties and behavior of the platinum group metals in the glass resulting from the vitrification of simulated nuclear fuel reprocessing waste  

Microsoft Academic Search

Two types of platinum group metal particles were found in borosilicate nuclear waste glasses: needle-shaped RuOâ particles and spherical PdRh{sub {ital x}}Te{sub {ital y}} alloys. They form a dense sediment of high electrical conductivity and relatively high viscosity at the bottom of the ceramic melting furnace. The sludge shows a non-Newtonian flow behavior. The viscosity and conductivity of the sludge

Ch. Krause; B. Luckscheiter

1991-01-01

182

Does six-coordinate germanium exist in Na 2O–GeO 2 glasses? Oxygen17 nuclear magnetic resonance measurements  

Microsoft Academic Search

Sodium germanate glasses of compositions Na2O·9GeO2 and 2Na2O·9GeO2 have been studied using solid-state 17O nuclear magnetic resonance (NMR). Quartz-type and rutile-type GeO2 were used as examples of oxygen connected to 4-fold and 6-fold coordinated germanium. The 17O spectra yielded nuclear quadrupole coupling constants, (e2qQ\\/h), asymmetry parameters, (?), and isotropic chemical shifts, (?i), from line shape simulations. The chemical shifts of

R. Hussin; D Holland; R Dupree

1998-01-01

183

Phosphorus oxynitride glasses  

Microsoft Academic Search

The properties and structural role of nitrogen in phosphorus oxynitride glasses are reported. Properties summarized for several compositions include the dissolution rate in water, thermal expansion coefficient, viscosity and refractive index. The bonding and coordination number of nitrogen in the glass network has been deduced from nuclear magnetic resonance, X-ray photoelectron spectroscopy and Raman spectroscopy. The existing evidence shows that

Mary R. Reidmeyer; Delbert E. Day

1995-01-01

184

Orientational glasses  

NASA Astrophysics Data System (ADS)

This review summarizes experimental evidence for the freezing of reorienting moments in solids. The moments may be of dipolar or quadrupolar nature, or both; they belong to one of the constituents of a mixed-crystal solid. Extensive results are reported for the following systems: KCl doped with hydroxyl, potassium tantalate doped with Li, Na and Nb, alkali halide cyanides and alkali-alkali cyanides, rubidium ammonium dihydrogen phosphate, solid ortho-para hydrogen and argon-nitrogen mixtures. These have clearly glass-like properties. In other systems, results are limited to one or two methods hinting at glass formation; some of those are also reported. Clustering phenomena and the slowdown of reorientations at the freezing temperature are observed in susceptibility measurements and by local probing on nuclear spins. The modulation of the structure by cluster formation is revealed by diffraction experiments. These phenomena are confronted with model predictions and numerical simulations.

Höchli, U. T.; Knorr, K.; Loidl, A.

2002-03-01

185

Intrinsic dosimetry of glass containers used to transport nuclear materials: Potential implications to the fields of waste management and nuclear forensics  

SciTech Connect

Thermoluminescence (TL) and Electron Paramagnetic Resonance (EPR) dosimetry were used to measure dose effects in borosilicate glass with time, from 10 min to w60 days following exposure to a dose of up to 100 Gy. TL and EPR results were consistent and performed similarly, with both techniques capable of achieving an estimated limit of detection of between 0.5 and 1 Gy. Three peaks were identified in the TL glow curve at roughly 110 C, 205 C, and 225 C. The intensity of the 205 C peak was the dominant peak over the time period of this study. The stability of all of the peaks with time since irradiation increased with their corresponding temperature and no significant variation was observed in the glow curve response to a specified total dose attained at different dose rates. The intensity of the 205 C peak decreased logarithmically with time regardless of total dose. Based upon a conservative limit of detection of 3.3 Gy, a 100 Gy dose would still be detected 2.7E3 years after exposure. Here, we introduce the concept of intrinsic dosimetry, the measurement of the total absorbed dose received by the walls of a container containing radioactive material. The foreseen advantage of intrinsic dosimetry comes from considering the measured absorbed dose received by containers in concert with the characteristics (amount, type) of the source of that dose, the radioactive material contained within the walls of the container, in order to provide enhanced information about the history of an unknown sample in question. Three hypothetical scenarios are presented to introduce this method and to illustrate how intrinsic dosimetry might benefit the fields of nuclear forensics and waste management.

Schwantes, Jon M.; Miller, Steve D.; Piper, Roman K.; Murphy, Mark K.; Amonette, James E.; Bonde, Steven E.; Duckworth, Douglas C.

2009-04-12

186

Fluorescent microscopic determination of proteins in human serum with the self-ordered ring of nuclear fast red formed on the solid support of glass slides.  

PubMed

A self-ordered ring (SOR) technique based on the assembly of fluorescent molecules on the solid support of glass slides is presented for the detection of trace amount of proteins by using fluorescence microscope. At pH 6.62 and with the aid of poly(vinyl alcohol)-124 (PVA-124), a droplet of nuclear fast red (NFR) solution can form a fluorescent SOR on hydrophobic glass slide, and the presence of proteins can enhance its fluorescence intensity. When the volume of the droplet is 0.2 microl, linear response is observed in the range 0-100 pg, and the limit of determination is 2.44 pg for BSA and 0.91 pg for HSA (3sigma). The results of determination for three human serum samples were identical with those obtained according to the Bradford method using Coomassie Brilliant Blue (CBB G-250). PMID:18968956

Chen, Yu Chun; Huang, Cheng Zhi

2003-03-10

187

Characterization of glass surfaces  

NASA Astrophysics Data System (ADS)

Significant advances have been made during the last 15 years in our understanding of glass surfaces and their environmental reactivity. The major reason for this advancement is the large array of surface analytical techniques that has been developed and applied to many industrial problems. One specific area of research where surface analysis has been proven valuable is glass corrosion. Until recently, the principal methods for studying degradation of glasses were weight loss measurements and solution analytical techniques. Neither of these provide information on surface alterations resulting from corrosion. Consequently, very little was known about the variety of mechanisms by which glass corrosion occurs. Currently, a multi-technique approach is being used in many laboratories around the world in order to achieve a better understanding of corrosion on glasses designed for immobilizing nuclear wastes. Similar approaches are being taken to solve problems related to conventional glass fabrication, glass preservation, and to new glass manufacturing processes based on sol-gel technology. In the present paper several techniques which are being routinely used to characterize glass surfaces are discussed. These include Fourier transform infrared reflection spectroscopy (FT-IRRS), secondary ion mass spectroscopy (SIMS), Auger electron spectroscopy coupled with ion milling (AES-IM) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). Each of these techniques provide unique information about glass surfaces, and when used in combination can yield solutions to complex industrial and scientific problems.

Lee, C. T.; Clark, D. E.

1985-02-01

188

Secondary phase formation and the microstructural evolution of surface layers during vapor phase alteration of the French SON 68 nuclear waste glass at 200{degrees}C  

SciTech Connect

The SON 68 inactive {open_quotes}R7T7{close_quotes} composition is the French reference glass for the LWR nuclear waste glass. Vapor phase alteration was used to accelerate the reaction progress of glass corrosion and to develop the characteristic suite of secondary, alteration phases. Extensive solid-state characterization (AEM/SEM/HRTEM) was completed on six inactive R7T7 waste glasses which were altered in the presence of saturated water vapor (200{degrees}C) for 91, 241, 908, 1000, 1013, and 1021 days. The AEM samples were examined in cross-section (lattice-fringe imaging, micro-diffraction, and quantitative thin-film EDS analysis). The glass monoliths were invariably covered with a thin altered rind. The layer became thicker with time: 0.5 {mu}m for 22 days; 4 {mu}m for 91 days; 6 {mu}m for 241 days; 10 {mu}m for 908 days; 26 {mu}m for 1013 days; and <35 {mu}m for 1021 days. The composite alteration layer of the SON 68 samples is at least four time less thick than that of the SRL 131 glass composition. Six distinctive zones, based on phase chemistry and microstructure, were distinguished within the well-developed surface layers. Numerous crystalline phases such as analcime, tobermorite, apatite, and weeksite were identified on the surfaces of the reacted glasses as precipitates. Two crystalline phases, Ag{sub 2}TeO{sub 3} and (Ca,Sr)Mo{sub 3}O{sub 9}(OH){sub 2}, were found within the inner zones of surface layers, and they must have nucleated in situ, indicating that Ag, Te, Sr, and Mo can be retained within the surface layer. The majority of the surface layer volume is composed of two morphologically and chemically different structures: one consists of well-crystallized fibrous smectite aggregates occurring along with cavities, the A-domain; and the other consists of poorly-crystallized regions containing needle-like smectite (montmorillonite) crystallites, a silica-rich amorphous matrix, and possibly ZrO{sub 2} particles, the B-domain.

Gong, W.L.; Ewing, R.C.; Wang, L.M. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

1995-12-31

189

The effect of 13C enrichment in the glassing matrix on dynamic nuclear polarization of [1-13C]pyruvate  

NASA Astrophysics Data System (ADS)

Dimethyl sulfoxide (DMSO) can effectively form a glassy matrix necessary for dynamic nuclear polarization (DNP) experiments. We tested the effects of 13C enrichment in DMSO on DNP of [1-13C]pyruvate doped with trityl radical OX063Me. We found that the polarization build-up time ? of pyruvate in 13C-labeled DMSO glassing solution is twice as fast as the unenriched DMSO while the nuclear magnetic resonance enhancement was unchanged. This indicates that 13C-13C spin diffusion is a limiting factor in the kinetics of DNP in this system, but it has a minimal effect on the absolute value of polarization achievable for the target.

Lumata, Lloyd; Kovacs, Zoltan; Malloy, Craig; Sherry, A. Dean; Merritt, Matthew

2011-03-01

190

NOTE The effect of 13C enrichment in the glassing matrix on dynamic nuclear polarization of [1-13C]pyruvate  

NASA Astrophysics Data System (ADS)

Dimethyl sulfoxide (DMSO) can effectively form a glassy matrix necessary for dynamic nuclear polarization (DNP) experiments. We tested the effects of 13C enrichment in DMSO on DNP of [1-13C]pyruvate doped with trityl radical OX063Me. We found that the polarization build-up time ? of pyruvate in 13C-labeled DMSO glassing solution is twice as fast as the unenriched DMSO while the nuclear magnetic resonance enhancement was unchanged. This indicates that 13C-13C spin diffusion is a limiting factor in the kinetics of DNP in this system, but it has a minimal effect on the absolute value of polarization achievable for the target.

Lumata, Lloyd; Kovacs, Zoltan; Malloy, Craig; Sherry, A. Dean; Merritt, Matthew

2011-03-01

191

Application of EQ3/6 to modeling of nuclear waste glass behavior in a tuff repository  

SciTech Connect

Modeling of glass degradation based on sound geochemical principles appears to be possible with revisions to EQ3/6. Realistic source terms for several repository scenarios may be generated with such a model. One scenario which appears very likely and which is also amenable to modeling using EQ3/6 is that in which an intact but perforated canister holds water in contact with waste glass. The water overflows continuously or periodically, allowing radionuclides to come in contact with repository rock. This isolated-type scenario will be the first realistic modeling effort because it limits complex interactions between rock and glass. However, EQ3/6 modeling should be possible even for very complicated scenarios if sufficient experimental data are available on rates and thermodynamics. This will be the limiting factor in progress toward modeling the complete system.

Aines, R.D.

1986-05-01

192

DEVELOPMENT OF GLASS COMPOSITIONS TO IMMOBILIZE ALKALI, ALKALINE EARTH, LANTHANIDE AND TRANSITION METAL FISSION PRODUCTS FROM NUCLEAR FUEL REPROCESSING  

SciTech Connect

The Advanced Fuel Cycle Initiative (AFCI) waste management strategy revolves around specific treatment of individual or groups of separated waste streams. A goal for the separations processes is to efficiently manage the waste to be dispositioned as high level radioactive waste. The Advanced Fuel Cycle Initiative (AFCI) baseline technology for immobilization of the lanthanide (Ln) and transition metal fission product (TM) wastes is vitrification into a borosilicate glass. A current interest is to evaluate the feasibility of vitrifying combined waste streams to most cost effectively immobilize the wastes resulting from aqueous fuel reprocessing. Studies showed that high waste loadings are achievable for the Ln only (Option 1) stream. Waste loadings in excess of 60 wt % (on a calcined oxide basis) were demonstrated via a lanthanide borosilicate (LaBS) glass. The resulting glasses had excellent relative durability as determined by the Product Consistency Test (PCT). For a combined Ln and TM waste stream glass (Option 2), noble metal solubility was found to limit waste loading. However, the measured PCT normalized elemental releases for this glass were at least an order of magnitude below that of Environmental Assessment (EA) glass. Current efforts to evaluate the feasibility of vitrifying combined Ln, TM, alkali (Cs is the primary radionuclide of concern) and alkaline earth (Sr is the primary radionuclide of concern) wastes (Option 3) have shown that these approaches are feasible. However, waste loading limitations with respect to heat load (Cs/Sr loading), molybdenum solubility and/or noble metal solubility will likely be realized and must be considered in determining the cost effectiveness of these approaches.

Marra, J.; Billings, A.

2009-06-24

193

DEVELOPMENT OF GLASS COMPOSITIONS TO IMMOBILIZE ALKALI, ALKALINE EARTH, LANTHANIDE AND TRANSITION METAL FISSION PRODUCTS FROM NUCLEAR FUEL REPROCESSING  

SciTech Connect

The Advanced Fuel Cycle Initiative (AFCI) waste management strategy revolves around specific treatment of individual or groups of separated waste streams. A goal for the separations processes is to efficiently manage the waste to be dispositioned as high level radioactive waste. The Advanced Fuel Cycle Initiative (AFCI) baseline technology for immobilization of the lanthanide (Ln) and transition metal fission product (TM) wastes is vitrification into a borosilicate glass. A current interest is to evaluate the feasibility of vitrifying combined waste streams to most cost effectively immobilize the wastes resulting from aqueous fuel reprocessing. Studies showed that high waste loadings are achievable for the Ln only (Option 1) stream. Waste loadings in excess of 60 wt % (on a calcined oxide basis) were demonstrated via a lanthanide borosilicate (LaBS) glass. The resulting glasses had excellent relative durability as determined by the Product Consistency Test (PCT). For a combined Ln and TM waste stream glass (Option 2), noble metal solubility was found to limit waste loading. However, the measured PCT normalized elemental releases for this glass were at least an order of magnitude below that of Environmental Assessment (EA) glass. Current efforts to evaluate the feasibility of vitrifying combined Ln, TM, alkali (Cs is the primary radionuclide of concern) and alkaline earth (Sr is the primary radionuclide of concern) wastes (Option 3) have shown that these approaches are feasible. However, waste loading limitations with respect to heat load (Cs/Sr loading), molybdenum solubility and/or noble metal solubility will likely be realized and must be considered in determining the cost effectiveness of these approaches.

Marra, James C.; Billings, Amanda Y.; Crum, Jarrod V.; Ryan, Joseph V.; Vienna, John D.

2010-02-26

194

High-resolution magic-angle spinning 1H nuclear magnetic resonance studies of lipid dispersions using spherical glass ampoules  

Microsoft Academic Search

A very useful high-resolution magic-angle spinning (MAS) 1H NMR method for studying lipid dispersions is presented. The sample can be loaded into the spherical glass ampoule very easily, and a spinning speed of more than 10 kHz can be achieved without the problems of sample leakage or water loss. The line width at half height for the HDO peak is

Zhe Zhou; Brian G Sayer; Ruth E Stark; Richard M Epand

1997-01-01

195

Mapping of rare earth elements in nuclear waste glass-ceramic using micro laser-induced breakdown spectroscopy  

NASA Astrophysics Data System (ADS)

A micro-LIBS system was set up based on a quadruple Nd:YAG laser at 266 nm coupled with a microscope. Elemental mapping was performed on a Mo-rich glass-ceramic sample containing CaMoO4 crystallites hundreds of microns in length and about 25 ?m in section diameter. The topography of single-shot laser-induced craters was characterized using an atomic force microscope (AFM), which revealed a crater size less than 7 ?m. Mappings of Mo, Ca, Sr, Al, Fe, Zr and rare earth elements such as Eu, Nd, Pr and La were undertaken. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was conducted to validate the micro-LIBS analysis. Principal components analysis calculation was used to investigate the correlation of elements in the two phases of glass-ceramic. Correlation between Ca, Sr, rare earth elements and Mo indicates their preferential incorporation into the calcium molybdate crystalline phase. Anti-correlation between Fe, Zr, Al and Mo revealed their affinity to the glass phase.

Wang, X.; Motto-Ros, V.; Panczer, G.; De Ligny, D.; Yu, J.; Benoit, J. M.; Dussossoy, J. L.; Peuget, S.

2013-09-01

196

An alternative host matrix based on iron phosphate glasses for the vitrification of specialized nuclear waste forms. Annual progress report, September 15, 1996September 14, 1997  

Microsoft Academic Search

'Objectives of this project are to: (1) investigate the glass composition and processing conditions that yield optimum properties for iron phosphate glasses for vitrifying radioactive waste, (2) determine the atomic structure of iron phosphate glasses and the structure-property relationships, (3) determine how the physical and structural properties of iron phosphate glasses are affected by the addition of simulated high level

D. E. Day; C. S. Ray; K. Marasinghe

1997-01-01

197

Glass leaching performance  

SciTech Connect

Current understanding of the leaching performance of high-level nuclear waste (HLW) glass is summarized. The empirical model of waste glass leaching behavior developed shows that at high water flow rates the glass leach rate is kinetically limited to a maximum value. At intermediate water flow rates, leaching is limited by the solution concentration of silica and decreases with decreasing water flow rates. Release of soluble elements is controlled by silica dissolution because silica forms the binding network of the glass. At low water flow rates, mass loss rates reach values controlled by formation rates of alteration minerals, or by diffusion of dissolution products through essentially stagnant water. The parameters reviewed with respect to their quantifiable influence on leaching behavior include temperature, pH, leachant composition, glass composition, thermal history, and radiation. Of these, temperature is most important since the rate of mass loss approximately doubles with each 10/sup 0/C increase in dilute solutions. The pH has small effects within the 4 to 10 range. The chemical composition of the leachant is most important with regard to its influence on alteration product formation. Glass composition exhibits the largest effects at high flow rates where improved glasses leach from ten to thirty times slower than glass 76 to 68. The effects of the thermal history (devitrification) of the glass are not likely to be significant. Radiation effects are important primarily in that radiolysis can potentially drive pH values to less than 4. Radiation damage to the glass causes insignificant changes in leaching performance.

Chick, L.A.; Turcotte, R.P.

1983-05-01

198

Chemical decomposition of high-level nuclear waste storage/disposal glasses under irradiation. 1997 annual progress report.  

National Technical Information Service (NTIS)

The objective of this research is to use the sensitive technique of electron spin resonance (ESR) to look for evidence of radiation-induced chemical decomposition of vitreous forms contemplated for immobilization of plutonium and/or high-level nuclear was...

D. L. Griscom C. I. Merzbacher

1997-01-01

199

Simultaneous Nuclear Reaction Analysis of Boron and Phosphorus in Thin Borophosphosilicate Glass Films Using (A,P) Reactions  

SciTech Connect

A method combining ({alpha},p) NRA and ellipsometry has been developed for measuring the Boron and Phosphorus content of borophosphosilicate glass (BPSG) used for interlevel dielectrics in integrated circuits. Yields from the {sup 31}P({alpha},p{sub 0}){sup 34}S (Q = 0.63 MeV) and {sup 10}B({alpha},p{sub 0}) {sup 13}C (Q = 4.06 MeV) reactions are coupled with ellipsometry thickness measurements to calculate the average atomic percent of B and P in the film. Due to the relatively low Q value of the {sup 31}P({alpha},p{sub 0}){sup 34}S reaction and the thickness range of the glass films ({le} 1.2 micrometers) they analyze, fairly high energy alpha particles, and Mylar range foils on the detector are required. Alpha energy, detector angle and range foil thickness were determined by reaction yields and the need to separate the yield peaks of interest from competing ({alpha},p) reactions and backscattered alphas. They have determined that 6.0 MeV incident alphas with a detector angle of 135{degree} and about 100 micrometers of Mylar range foil are optimum for the system. The yield for the {sup 10}B({alpha},p{sub 0}) {sup 13}C reaction is quite constant in the energy range of interest ({approximately} 5.8 to 6 MeV) but the yield for the {sup 31}P({alpha},p{sub 0}){sup 34}S is not. Consequently, a simple conversion from standard BPSG reference samples (independently quantified by ICP mass spectrometry) is adequate to calculate a film's %B content. The %P calculation is more complex, involving a three-dimensional fit of the P yield data and measured film thickness to the film %P content. This fit is based upon yield data from a matrix of standard film samples. The technique is sensitive to 0.1% with an accuracy of {+-}3 to {+-}10% depending on the sample. This measurement method is used routinely at Sandia National Laboratories in support of their fabrication process lines.

Walsh, D.S.; Doyle, B.L.

1999-06-22

200

Defense Waste Processing Facility (DWPF) startup test program: Glass characterization  

Microsoft Academic Search

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be processed in the Defense Waste Processing Facility (DWPF) and poured into stainless steel canisters for eventual geologic disposal. Six simulated glass compositions will be processed in the DWPF during initial startup. The glass in 86 of the first

Jantzen

1992-01-01

201

Frosty Glasses  

NSDL National Science Digital Library

In this activity, learners explore why frost forms. They create their own frost using a solution of ice water and salt in a glass. The salt allows the temperature of the water to drop below the normal freezing point, so that water vapor in the air turns directly into solid ice on the surface of the glass.

Cosi

2009-01-01

202

Glass Electrolytes.  

National Technical Information Service (NTIS)

The objective of this research is a glass electrolyte for use in sodium/sulfur batteries that has a low resistivity (100 ohm-cm at 300 exp 0 C) and is stable in the cell environment. Experiments in this program are focussed on glasses in the quaternary sy...

1984-01-01

203

Glass Wings  

NSDL National Science Digital Library

Glass Wings has now opened its doors onto the electronic frontier. This Australian site covers a wide range of interests including news, games, entertainment, humour, travel, books and magazines, the environment, human rights, food, health, the educational, sexuality, the arts and a writers forum. Glass Wings is a companion project of Xanadu Australia.

204

Glass-An Environmental Protector  

SciTech Connect

From asbestos abatement to lead paint removal to nuclear waste stabilization and even to heavy metal removal using microorganisms, glass has great potential as a solution to many environmental problems. The ability to accommodate an array of chemical elements within the glass structure has facilitated the use of glass as a medium for the stabilization of numerous hazardous substances. The resulting glasses have proven to be durable enough for direct land disposal. In many cases, the stabilized forms have been deemed suitable for re-use in other applications. As recycling and hazardous material treatment become even more important in the global materials cycle, it is a certainty that glass will assume a prominent role.

MARRA, JAMES

2004-11-01

205

Tempered glass  

SciTech Connect

This document describes a demonstration for making tempered glass using minimal equipment. The demonstration is intended for a typical student of materials science, at the high school level or above. (JL)

Bunnell, L.R.

1991-11-01

206

Glass electrolytes  

SciTech Connect

The objective of this research is a glass electrolyte for use in sodium/sulfur batteries that has a low resistivity (100 ohm-cm at 300/sup 0/C) and is stable in the cell environment. Experiments in this program are focussed on glasses in the quaternary system: soda, alumina, zirconia and silica. The FY 1983 research on glass analogs of NASICON, parallel thermodynamic calculations, and a review of the literature in the areas of glass conductivity and corrosion resistance led to selection of this system for more detailed investigation. The main program elements are: (1) conductivity measurements at 300 to 500/sup 0/C; (2) differential thermal analysis for determination of glass-transition and crystallization temperatures; (3) static corrosion tests at 400/sup 0/C using Na, Na/sub 2/S/sub 4/, and S; (4) mechanical strength and fracture toughness measurements; and (5) sodium/sulfur cell tests at 350/sup 0/C. Elements (1) and (2) are nearly completed; element (3) is being initiated using the glasses prepared for (1) and (2), and elements (4) and (5) will begin in the first and second quarters of FY 1985, respectively. Fourteen quaternary glasses having a broad range of compositions have been made. The resistivities of these glasses at 300/sup 0/C extended from 130 to 3704 ohm-cm; the activation energies for conduction extended from 0.488 to 0.684 eV, and the glass transition temperatures extended from 397 to 685/sup 0/C. Through a multiple linear regression analysis of these data response surfaces were generated for resistivity, activation energy for conduction, and glass transition temperature over the composition region within the quaternary system that is bounded by SiO/sub 2/, Na/sub 2/O/sub 3/, Na/sub 2/AlO/sub 4/ and Na/sub 2/ZrO/sub 3/. These response surfaces indicated a new region of high conductivity and high glass transition temperature in the neighborhood of 42% soda, 31% silica and 27% alumina plus zirconia.

Not Available

1984-06-25

207

Effects of alpha, gamma, and alpha-Recoil Radiation on Borosilicate Glass Containing Savannah River Plant Defense High-Level Nuclear Waste.  

National Technical Information Service (NTIS)

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 exp 6 y, the glass would be exposed to approx. 3 x 1...

N. E. Bibler

1981-01-01

208

MIIT: International in-situ testing of nuclear-waste glasses: Performance of SRS simulated waste glass after five years of burial at the Waste Isolation Pilot Plant (WIPP)  

SciTech Connect

In July of 1986, the first in-situ test involving burial of simulated high-level waste (HLW) forms conducted in the United States was started. This program, called the Materials Interface Interactions Test or MIIT, comprises the largest, most cooperative field-testing venture in the international waste management community. In July of 1991, the experimental portion of the 5-year MIIT study was completed on schedule. During this time interval, many in-situ measurements were performed, thousands of brine analyses conducted, and hundreds of waste glass and package components exhumed and evaluated after 6 mo., 1 yr., 2 yr. and 5 yr. burial periods. Although analyses are still in progress, the performance of SRS waste glass based on all data currently available has been seen to be excellent thus far. Initial analyses and assessment of Savannah River (SR) waste glass after burial in WIPP at 90{degrees}C for 5 years are presented in this document.

Wicks, G.G. (Westinghouse Savannah River Co., Aiken, SC (United States)); Lodding, A.R. (Chalmers Univ. of Technology, Goeteborg (Sweden)); Macedo, P.B. (Catholic Univ. of America, Washington, DC (United States)); Clark, D.E. (Florida Univ., Gainesville, FL (United States))

1991-01-01

209

MIIT: International in-situ testing of nuclear-waste glasses: Performance of SRS simulated waste glass after five years of burial at the Waste Isolation Pilot Plant (WIPP)  

SciTech Connect

In July of 1986, the first in-situ test involving burial of simulated high-level waste (HLW) forms conducted in the United States was started. This program, called the Materials Interface Interactions Test or MIIT, comprises the largest, most cooperative field-testing venture in the international waste management community. In July of 1991, the experimental portion of the 5-year MIIT study was completed on schedule. During this time interval, many in-situ measurements were performed, thousands of brine analyses conducted, and hundreds of waste glass and package components exhumed and evaluated after 6 mo., 1 yr., 2 yr. and 5 yr. burial periods. Although analyses are still in progress, the performance of SRS waste glass based on all data currently available has been seen to be excellent thus far. Initial analyses and assessment of Savannah River (SR) waste glass after burial in WIPP at 90{degrees}C for 5 years are presented in this document.

Wicks, G.G. [Westinghouse Savannah River Co., Aiken, SC (United States); Lodding, A.R. [Chalmers Univ. of Technology, Goeteborg (Sweden); Macedo, P.B. [Catholic Univ. of America, Washington, DC (United States); Clark, D.E. [Florida Univ., Gainesville, FL (United States)

1991-12-31

210

Failure analysis of the lithium battery: A study of the header deposit on the cell top and diffusion within the electrode glass seal using nuclear microanalysis and FFTIR spectroscopy  

NASA Astrophysics Data System (ADS)

The Solid Rocket Booster Range Safety System (SRBRSS) uses a lithium/poly-carbon monofluoride primary battery as a source of electrical power. After cell fabrication and activation, some battery cells have shown self discharge. One possible source of this cell discharge has been suggested to be the formation and growth of a conducting crystallized chemical compound across the glass bead insulator, electrically shorting the glass bead to the casing. This laboratory has begun an analysis of this compound, the glass seal holding the cathode into place, and the cell electrolyte, using Fast Fourier Transform Infrared (FFTIR) Analysis, Rutherford Backscattering Spectroscopy (RBS), and Nuclear Reaction Microanalysis. Preliminary measurements have confirmed the existence of lithium, nitrogen, fluorine, and oxygen on a reddish-brown deposit covering parts of the glass seal holding the positive electrode in place. Cells using Li metal electrodes, have many advantages over conventional primary batteries. One principal disadvantage of using Li batteries on a commercial basis would be the environmental impact of the fluorocarbon material. Another would be the relatively high expense of (CF)n.

Hassan, Razi A.

1991-10-01

211

Plutonium dioxide dissolution in glass  

SciTech Connect

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

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

1996-09-01

212

Fluoride glasses  

SciTech Connect

Crystalline fluorides play a significant role in materials science, e.g. as lenses in infrared (IR) optics (CaF{sub 2}), laser hosts (LaF{sub 3}, CaF{sub 2}), fast ion conductors ({beta}PbF{sub 2}), and fluoride ion sensitive electrodes (LaF{sub 3}). Their melts, however, are very fluid, largely ionic, and unlikely candidates for glass formation. Nevertheless, many fluoride glass forming systems have been identified, with useful properties such as extended IR transmission, and the added advantage of ease of fabrication. The development of these materials, with special emphasis on optical fibers, is considered in this paper. Fluoride glasses are often referred to by acronyms based on the initial letters of the component cation chemical symbols, in a sequence based more on historical development than amounts present. Examples include ZBLAN(ZrF{sub 4}-BaF{sub 2}-LaF{sub 3}-A1F{sub 3}-NaF), CLAP (CdF{sub 2}-LiF-A1F{sub 3}-PbF{sub 2}), and BZnYbT (BaF{sub 2}-ZnF{sub 2}-YbF{sub 3}- ThF{sub 4}) glasses. ZBLAN glasses have been studied in most detail and are the basis of much of the discussion here.

Parker, J.M. (School of Materials, Univ. of Sheffield, Elmfield, Northumberland Road, Sheffield S10 2TZ (GB))

1989-01-01

213

DURABLE GLASS FOR THOUSANDS OF YEARS  

SciTech Connect

The durability of natural glasses on geological time scales and ancient glasses for thousands of years is well documented. The necessity to predict the durability of high level nuclear waste (HLW) glasses on extended time scales has led to various thermodynamic and kinetic approaches. Advances in the measurement of medium range order (MRO) in glasses has led to the understanding that the molecular structure of a glass, and thus the glass composition, controls the glass durability by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. During the early stages of glass dissolution, a 'gel' layer resembling a membrane forms through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer ages into clay or zeolite minerals by Ostwald ripening. Zeolite mineral assemblages (higher pH and Al{sup 3+} rich glasses) may cause the dissolution rate to increase which is undesirable for long-term performance of glass in the environment. Thermodynamic and structural approaches to the prediction of glass durability are compared versus Ostwald ripening.

Jantzen, C.

2009-12-04

214

Durability of Silicate Glasses: An Historical Approach  

SciTech Connect

We present a short review of current theories of glass weathering, including glass dissolution, and hydrolysis of nuclear waste glasses, and leaching of historical glasses from an XAFS perspective. The results of various laboratory leaching experiments at different timescales (30 days to 12 years) are compared with results for historical glasses that were weathered by atmospheric gases and soil waters over 500 to 3000 years. Good agreement is found between laboratory experiments and slowly leached historical glasses, with a strong enrichment of metals at the water/gel interface. Depending on the nature of the transition elements originally dissolved in the melt, increasing elemental distributions are expected to increase with time for a given glass durability context.

Farges, Francois; /Museum Natl. Hist. Natur. /Stanford U., Geo. Environ. Sci.; Etcheverry, Marie-Pierre; /Marne la Vallee U.; Haddi, Amine; /Marne la Valle U.; Trocellier, Patrick; /Saclay; Curti, Enzo; /PSI, Villigen; Brown, Gordon E., Jr.; /SLAC, SSRL

2007-01-02

215

Glass Ceramic Formulation Data Package  

SciTech Connect

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

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

2012-06-17

216

Phase Stability Determinations of DWPF Waste Glasses  

Microsoft Academic Search

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.

Marra

1999-01-01

217

Glass Furnace Project: April-September 1981.  

National Technical Information Service (NTIS)

The purpose of the Glass Furnace Project is to evaluate the use of joule-heated glass furnace, fitted with a Mound-developed offgas system, to reduce the volume of contaminated waste typical of that from nuclear power plants. As part of the project, sever...

K. Armstrong L. M. Klingler

1981-01-01

218

Phase Stability Determinations of DWPF Waste Glasses  

SciTech Connect

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.

Marra, S.L.

1999-10-22

219

Glass furnance project: April - September 1981  

Microsoft Academic Search

The use of a joule-heated glass furnace, fitted with a Mound-developed offgas system, to reduce the volume of contaminated waste typical of that from nuclear power plants. Preparations, including completion of the offgas scrubbing system and installation of utilities were made for the receipt of the glass melter at Mound. The melter was delivered on September 22, 1981, and assembly

K. Armstrong; L. M. Klingler

1981-01-01

220

Analytical electron microscopy study of surface layers formed on the French SON68 nuclear waste glass during vapor hydration at 200°C  

Microsoft Academic Search

Extensive solid-state characterization (AEM\\/SEM\\/HRTEM) was completed on six SON68 (inactive R7T7) waste glasses which were altered in the presence of saturated water vapor (200°C) for 22, 91, 241, 908, 1000, 1013, and 1021 days. The samples were examined by AEM in cross-section (lattice-fringe imaging, micro-diffraction, and quantitative thin-film EDS analysis). The glass monoliths were invariably covered by a thin altered

W. L. Gong; L. M. Wang; R. C. Ewing; E. Vernaz; J. K. Bates; W. L. Ebert; CEA-VALRHO

1998-01-01

221

The incorporation of P, S, Cr, F, Cl, I, Mn, Ti, U, and Bi into simulated nuclear waste glasses: Literature study  

SciTech Connect

Waste currently stored on the Hanford Reservation in underground tanks will be into High Level Waste (HLW) and Low Level Waste (LLW). The HLW melter will high-level and transuranic wastes to a vitrified form for disposal in a geological repository. The LLW melter will vitrify the low-level waste which is mainly a sodium solution. Characterization of the tank wastes is still in progress, and the pretreatment processes are still under development Apart from tank-to-tank variations, the feed delivered to the HLW melter will be subject to process control variability which consists of blending and pretreating the waste. The challenge is then to develop glass formulation models which can produce durable and processable glass compositions for all potential vitrification feed compositions and processing conditions. The work under HLW glass formulation is to study and model glass and melt pro functions of glass composition and temperature. The properties of interest include viscosity, electrical conductivity, liquidus temperature, crystallization, immiscibility durability. It is these properties that determine the glass processability and ac waste glass. Apart from composition, some properties, such as viscosity are affected by temperature. The processing temperature may vary from 1050{degrees}C to 1550{degrees}C dependent upon the melter type. The glass will also experience a temperature profile upon cooling. The purpose of this letter report is to assess the expected vitrification feed compositions for critical components with the greatest potential impact on waste loading for double shell tank (DST) and single shell tank (SST) wastes. The basis for critical component selection is identified along with the planned approach for evaluation. The proposed experimental work is a crucial part of model development and verification.

Langowski, M.H.

1996-02-01

222

Nuclear  

NSDL National Science Digital Library

What part does nuclear energy play in satisfying energy demands? This informational piece, part of a series about the future of energy, introduces students to the uranium atom as an energy source. Here students read about the history of nuclear energy, how energy is derived from uranium, and benefits of nuclear energy. Information is also provided about limitations, particularly disposal problems and radioactivity, and geographical considerations of nuclear power in the United States. Thought-provoking questions afford students chances to reflect on what they've read about the uses of nuclear power. Articles and information on new nuclear plant design and nuclear accidents are available from a sidebar. Five energy-related PBS NewsHour links are provided. A web link to the U.S. Nuclear Regulatory Commission is included. Copyright 2005 Eisenhower National Clearinghouse

Project, Iowa P.

2004-01-01

223

Vitrification chemistry and nuclear waste  

Microsoft Academic Search

The vitrification of nuclear waste offers unique challenges to the glass technologist. The waste contains 50 or 60 elements, and often varies widely in composition. Most of these elements are seldom encountered in processing commercial glasses. The melter to vitrify the waste must be able to tolerate these variations in composition, while producing a durable glass. This glass must be

Plodinec

1985-01-01

224

Prediction of glass durability as a function of glass composition and test conditions: Thermodynamics and kinetics  

SciTech Connect

The long-term durability of nuclear waste glasses can be predicted by comparing their performance to natural and ancient glasses. Glass durability is a function of the kinetic and thermodynamic stability of glass in solution. The relationship between the kinetic and thermodynamic aspects of glass durability can be understood when the relative contributions of glass composition and imposed test conditions are delineated. Glass durability has been shown to be a function of the thermodynamic hydration free energy which can be calculated from the glass composition. Hydration thermodynamics also furnishes a quantitative frame of reference to understand how various test parameters affect glass durability. Linear relationships have been determined between the logarithmic extent of hydration and the calculated hydration free energy for several different test geometries. Different test conditions result in different kinetic reactivity parameters such as the exposed glass surface area (SA), the leachant solution volume (V), and the length of time that the glass is in the leachant (t). Leachate concentrations are known to be a function of the kinetic test parameter (SAV)t. The relative durabilities of glasses, including pure silica, obsidians, nuclear waste glasses, medieval window glasses, and frit glasses define a plane in three dimensional ..delta..G/sub hyd/-concentration-(SAV)t space. At constant kinetic conditions, e.g., test geometry and test duration, the three dimensional plane is intersected at constant (SAV)t and the ..delta..G/sub hyd/-concentration plots have similar slopes. The slope represents the natural logarithm of the theoretical slope, (12.303 RT), for the rate of glass dissolution. 53 refs., 4 figs.

Jantzen, C M

1988-01-01

225

Pinhole Glasses  

ERIC Educational Resources Information Center

Eye aberrations are commonly corrected by lenses that restore vision by altering rays before they pass through the cornea. Some modern promoters claim that pinhole glasses are better than conventional lenses in correcting all kinds of refractive defects such as myopia (nearsighted), hyperopia (farsighted), astigmatisms, and presbyopia. Do pinhole…

Colicchia, Giuseppe; Hopf, Martin; Wiesner, Hartmut; Zollman, Dean

2008-01-01

226

Pinhole Glasses  

ERIC Educational Resources Information Center

|Eye aberrations are commonly corrected by lenses that restore vision by altering rays before they pass through the cornea. Some modern promoters claim that pinhole glasses are better than conventional lenses in correcting all kinds of refractive defects such as myopia (nearsighted), hyperopia (farsighted), astigmatisms, and presbyopia. Do pinhole…

Colicchia, Giuseppe; Hopf, Martin; Wiesner, Hartmut; Zollman, Dean

2008-01-01

227

Effects of glass composition on the liquidus surfaces of high zirconia containing waste glasses  

NASA Astrophysics Data System (ADS)

Waste glasses must meet a variety of requirements for processing and product performance. Processing property constraints such as liquidus temperature (TL) and viscosity, and the product performance constraints such as durability have to be considered when formulating glass for waste immobilization. In this study, TL, glass transition temperature (Tg, and chemical durability of borosilicate waste glasses containing ZrO 2 concentrations from 6--12 mole% were determined. The concentrations of SiO2, ZrO2, Al2O3, B2 O3, Li2O, Na2O, and CaO were varied using a modified extreme vertices approach. Fifty-three statistically designed glasses were hatched and fabricated. Of the 53 glasses, 19 were not fully characterized due to the presence of undissolved solids (i.e., inhomogeneous glass) although extremely high melt temperatures were utilized (>1500°C). Liquidus temperature, glass transition temperature, and durability of the remaining glasses were examined. Liquidus temperatures (TL) were measured using a series of isothermal heat treatments to narrow the TL to within +/-10°C. The primary crystalline phases were identified using optical microscopy and XRD. The three primary phase fields of Parakeldyshite (Na 2ZrSi2O7) Zircon (ZrSiO4), and Baddeleyite (ZrO2) were encountered for the glass composition region evaluated. Glasses with Parakeldyshite as a primary phase were found to have lower liquidus temperatures, than those glasses having, Zircon or Baddeleyite as the primary phase field. Glass transition temperatures and crystallization temperature were determined using DTA. Glass transition temperatures of glass compositions containing higher percentages of alkali were often lower than those with lower percentages of alkali. This is primary due to a reduction in the connectivity of the glass network. Chemical durability was determined using the Product Consistency Test. The most durable glasses were glasses with lower Na2O content and contained both Al2O3 and CaO. This study showed that the effects of oxide components on glass properties were extremely important for selecting a glass formulation with maximum waste loading. The principles of glass structure such as bridging and nonbridging oxygens and polarizability concept were used to understand the effects. Empirical models were developed based on measured data which related liquidus temperature, glass transition temperature, and durability to glass composition. The experimental data was compared to the predicted data of the model. The purpose of these models were to assist in selecting glasses that offer a maximum ZrO2 waste loading for nuclear waste glasses.

Jiemsirilers, Sirithan Bulpakdi

228

Glass: Rotary Electric Glass Furnace  

SciTech Connect

Compared to conventional gas-fired furnaces, the new rotary electric furnace will increase energy efficiency while significantly reducing air emissions, product turnaround time, and labor costs. As this informative new fact sheet explains, the thousand different types of glass optical blanks produced for the photonics industry are used for lasers, telescopes, cameras, lights, and many other products.

Recca, L.

1999-01-29

229

Bonding in simple phosphate glass  

SciTech Connect

The bonding configurations for simple phosphate glasses are quantitatively described by both the relative concentrations of different polyhedral phosphate sites (i.e., the Q{sup n} description) determined by {sup 31}p magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and by the relative concentrations of bridging and nonbridging oxygen as measured by x-ray photoelectron spectroscopy (XPS). Both spectroscopies illustrate the depolymerizing effects of modifier additions in two series of Na{sub 2}O and ZnO-P{sub 2}0{sub 5} glasses.

Brow, R.K.

1992-09-01

230

Bonding in simple phosphate glass  

SciTech Connect

The bonding configurations for simple phosphate glasses are quantitatively described by both the relative concentrations of different polyhedral phosphate sites (i.e., the Q{sup n} description) determined by {sup 31}p magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and by the relative concentrations of bridging and nonbridging oxygen as measured by x-ray photoelectron spectroscopy (XPS). Both spectroscopies illustrate the depolymerizing effects of modifier additions in two series of Na{sub 2}O and ZnO-P{sub 2}0{sub 5} glasses.

Brow, R.K.

1992-01-01

231

Glass melter off-gas system pluggages: Cause, significance, and remediation  

Microsoft Academic Search

Liquid high-level nuclear waste will be immobilized at the Savannah River Site (SRS) by vitrification in borosilicate glass. The glass will be produced in the Defense Waste Processing Facility (DWPF) where the glass will be poured into stainless steel canisters for eventual disposal in a geologic repository. Experimental glass melters used to develop the vitrification process for immobilization of the

Jantzen

1991-01-01

232

Nonequilibrium viscosity of glass  

Microsoft Academic Search

Since glass is a nonequilibrium material, its properties depend on both composition and thermal history. While most prior studies have focused on equilibrium liquid viscosity, an accurate description of nonequilibrium viscosity is essential for understanding the low temperature dynamics of glass. Departure from equilibrium occurs as a glass-forming system is cooled through the glass transition range. The glass transition involves

John C. Mauro; Douglas C. Allan; Marcel Potuzak

2009-01-01

233

Metal glasses  

NASA Astrophysics Data System (ADS)

Methods of producing amorphous alloys of various systems (e.g., Pd-Si, Fe-B, Ni-P, Ni-Nb, Ni-Ta, Co-Gd, Fe-Gd, Mg-Zn,and Ca-Al) are briefly discussed, and the atomic structure and properties of such alloys are examined. In particular, attention is given to anomalies in the low-temperature behavior of amorphous alloys, their electrical and magnetic properties, strength, ductility, and corosion stability. Some aplications of metal glasses are mentioned.

Belen'kii, Aleksei Iakovlevich

1987-02-01

234

High Temperature IR Glasses.  

National Technical Information Service (NTIS)

Fields of glass formation, crystalline phases in these fields, ranges of immiscibility, and the relation of composition as well as heat treatment to the glass temperature in selected chalcogenide glass systems were investigated. The main objective of the ...

N. J. Kreidl

1971-01-01

235

Integrated Glass Ceramic Systems.  

National Technical Information Service (NTIS)

Integrated glass ceramic spacecraft include a plurality of glass ceramic components including molded, tempered, annealed, and patterned glass ceramic components coupled together for forming a support structure or frame or housing through which is communic...

H. Helvajian S. W. Janson

2003-01-01

236

Borosilicate glass alteration driven by magnesium carbonates  

NASA Astrophysics Data System (ADS)

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/hydromagnesite ratio strongly supports the basic modeling hypothesis.

Debure, M.; Frugier, P.; de Windt, L.; Gin, S.

2012-01-01

237

Results from the Long-Term Interaction and Modeling of SRL-131 Glass with Aqueous Solutions.  

National Technical Information Service (NTIS)

Leaching studies of SRL-131 simulated defense nuclear waste glass have been carried out to two years duration, in leachants that simulate groundwaters of different ionic strengths. The leachability of SRL-131 glass followed the trend: deionized water > si...

D. M. Strachan L. R. Pederson R. O. Lokken

1985-01-01

238

Chemical Principles Revisited: The Chemistry of Glass.  

ERIC Educational Resources Information Center

|Presents a detailed discussion on the chemistry of glass. Topics discussed include: natural glass, early history, modern glass composition, raw materials for glass melting, chemically modified glasses, modern glass forming, glass ceramics, and new developments in glass research. (BT)|

Kolb, Doris; Kolb, Kenneth E.

1979-01-01

239

Alteration of glasses by micro-organisms  

NASA Astrophysics Data System (ADS)

Micro-organisms are suspected to play a basic part in materials alteration. Obviously, they will be present in nuclear waste repositories, either introduced by technological activity or laid by fluids circulation. Their metabolism may induce chemical modifications to the surrounding media and then affect the durability of storage materials. Biodegradation of glasses is studied in the Pierre Süe Laboratory. In the frame of a collaboration with microbiologists interested in stained glasses alteration, leaching experiments with various species of bacteria and fungi are carried out. Ion beam analysis techniques are performed to quantify surface modification of glasses and elemental incorporation in micro-organisms. Analyses of the solutions will lead to a complete assessment of elemental exchanges between glass sample, culture media and micro-organisms. In this paper, preliminary results on characterisation of glasses and micro-organisms and the first results of leaching experiments are presented.

Gallien, J.-P.; Gouget, B.; Carrot, F.; Orial, G.; Brunet, A.

2001-07-01

240

Analytical electron microscopy study of surface layers formed on the french SON68 nuclear waste glass during vapor hydration at 200{degree}C.  

SciTech Connect

Extensive solid-state characterization (AEM/SEM/HRTEM) was completed on six SON68 (inactive R7T7) waste glasses which were altered in the presence of saturated water vapor (200{sup o}C) for 22, 91, 241, 908, 1000, 1013, and 1021 days. The samples were examined by AEM in cross-section (lattice-fringe imaging, micro-diffraction, and quantitative thin-film EDS analysis). The glass monoliths were invariably covered by a thin altered rind, and the surface layer thickness increased with increasing time of reaction, ranging from 0.5 to 30 {mu}m in thickness. Six distinctive zones, based on phase chemistry and microstructure, were distinguished within the well-developed surface layers. Numerous crystalline phases such as analcime, gyrolite, tobermorite, apatite, and weeksite were identified on the surfaces of the reacted glasses as precipitates. The majority of the surface layer volume was composed of two basic structures that are morphologically and chemically distinct: The A-domain consisted of well-crystallized fibrous smectite aggregates; and the B-domain consisted of poorly-crystallized regions containing smectite, possibly montmorillonite, crystallites and a ZrO{sub 2}-rich amorphous silica matrix. The retention of the rare-earth elements, Mo, and Zr mostly occurred within the B-domain; while transition metal elements, such as Zn, Cr, Ni, Mn, and Fe, were retained in the A-domain. The element partitioning among A-domains and B-domains and recrystallization of the earlier-formed B-domains into the A-domain smectites were the basic processes which have controlled the chemical and structural evolution of the surface layer. The mechanism of surface layer formation during vapor hydration are discussed based on these cross-sectional AEM results.

Gong, W. L.; Wang, L. M.; Ewing, R. C.; Vernaz, E.; Bates, J. K.; Ebert, W. L.; Chemical Engineering; Univ. of New Mexico; CEA-VALRHO

1998-04-01

241

Low frequency dielectric investigation of Rb0.5(ND4)0.5D2PO4 dipolar glass: Comparison with nuclear magnetic resonance investigations  

NASA Astrophysics Data System (ADS)

The dielectric response of Rb0.5(ND4)0.5D2PO4 (DRADP-50) dipolar glass has been studied at low temperatures. From the experimental results, the distribution of the relaxation times and of the local polarization at various temperatures is calculated. It is shown that the local-polarization distribution function obtained from the dielectric response ?*(?,T) is consistent with that obtained from NMR results. The results also show that the dielectric dispersion is due to diffusion, creation, and annihilation of Takagi groups.

Banys, J.; Macutkevic, J.; Lapinskas, S.; Pirc, R.; Kutnjak, Z.; Blinc, R.

2011-06-01

242

Defect diffusion in ion implanted glasses  

SciTech Connect

Ion implantation in glasses produces structure modifications at depths greater than those of the implanted ion range. Such a result is evidenced by means of leaching experiments, alkali element depletion, distribution of gaseous implanted species, etching rate as function of depth. A systematic study with the aim to evidence a threshold in the nuclear deposited energy for defect diffusion is presented. Fourier transform infrared spectroscopy measurements confirm the glass modifications at extended depths. 20 refs., 5 figs.

Arnold, G.W. (Sandia National Labs., Albuquerque, NM (United States)); Battaglin, G. (Venice Univ. (Italy). Dipt. di Chimica Fisica); Boscolo-Boscoletto, A. (Centro Ricerche Montedipe, Venice (Italy)); Caccavale, F.; De Marchi, G.; Mazzoldi, P. (Pauda Univ. (Italy). Dipt. di Fisica); Miotello, A. (Trento Univ. (Italy). Dipt. di Fisica)

1991-01-01

243

Glass furnance project: April - September 1981  

NASA Astrophysics Data System (ADS)

The use of a joule-heated glass furnace, fitted with a Mound-developed offgas system, to reduce the volume of contaminated waste typical of that from nuclear power plants. Preparations, including completion of the offgas scrubbing system and installation of utilities were made for the receipt of the glass melter at Mound. The melter was delivered on September 22, 1981, and assembly and consolidation of the entire system immediately began. Preliminary work was initiated on procedural development, and an interface was established with the Mound glass ceramics laboratory to pinpoint areas requiring study.

Armstrong, K.; Klinger, L. M.

1981-11-01

244

Microorganisms and Volcanic Glass  

Microsoft Academic Search

Volcanic glass is primarily found on Earth as quenched basalt magma or as high-silica ash deposits. Basalt magma is quenched to glass as it erupts into water or sediment, making pillow lavas, sheet flows, or highly fractured rocks (hyaloclastites). Silicic, explosive volcanism produces thick deposits of ash composed primarily of glass shards. Volcanic glass is unstable in the presence of

M. Fisk; C. di Meo; I. Thorseth; S. Giovannoni; M. Storrie-Lombardi

2002-01-01

245

Comparison of mechanical properties of glass-bonded sodalite and borosilicate glass high-level waste forms  

SciTech Connect

Argonne National Laboratory has developed a glass-bonded sodalite waste form to immobilize the salt waste stream from electrometallurgical treatment of spent nuclear fuel. The waste form consists of 75 vol.% crystalline sodalite and 25 vol.% glass. Microindentation fracture toughness measurements were performed on this material and borosilicate glass from the Defense Waste Processing Facility using a Vickers indenter. Palmqvist cracking was confined for the glass-bonded sodalite waste form, while median-radial cracking occurred in the borosilicate glass. The elastic modulus was measured by an acoustic technique. Fracture toughness, microhardness, and elastic modulus values are reported for both waste forms.

O'Holleran, T. P.; DiSanto, T.; Johnson, S. G.; Goff, K. M.

2000-05-09

246

DEVELOPMENT OF GLASS MATRICES FOR HLW RADIOACTIVE WASTES  

SciTech Connect

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

Jantzen, C.

2010-03-18

247

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

Microsoft Academic Search

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

W. L. Bourcier; D. W. Peiffer; K. G. Knauss; K. D. McKeegan; D. K. Smith

1989-01-01

248

Application of nuclear and physico-chemical analysis methods in the study of an after-implanting bioactive glass deposition on a titanium alloy, in view of optimizing the long-term bio-compatibility and operability.  

National Technical Information Service (NTIS)

To improve the anchorage of orthopedic prosthesis into surrounding bone, osteo-conductive biomaterials are usually used as coatings. Among usual coatings, we find bioactive glasses. The bioactive glass A9 is analyzed before and after implantation. It is p...

V. Brun

1999-01-01

249

Glasses in the D'Orbigny angrite  

NASA Astrophysics Data System (ADS)

The angrites are a small and heterogeneous group of achondritic meteorites with highly unusual chemical and mineralogical features. The abundant presence of glasses in D'Orbigny makes this rock a unique member of the angrite group. Glasses fill open spaces, form pockets, and occur as inclusions in olivines. Their physical settings exclude an incorporation from an external source. Major and trace element (rare earth elements [REE], Li, B, Be, transition elements, N and C) contents of these glasses and host olivines were measured combining laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), secondary-ion mass spectrometry (SIMS), Nuclear Reaction Analysis (NRA), and EMP techniques. Based on the major element composition, glasses filling voids could represent either a melt formed by melting an angritic rock or a melt from which angrites could have crystallized. Trace element contents of these glasses strongly indicate a direct link to the D'Orbigny bulk meteorite. They are incompatible with the formation of the glasses by partial melting of a chondritic source rock or by shock melting. The refractory elements (e.g., Al, Ti, Ca) have about 10 × CI abundances with CaO/TiO 2 and FeO/MnO ratios being approximately chondritic. Trace element abundances in the glasses appear to be governed by volatility and suggest that the refractory elements in the source had chondritic relative abundances. Although the glasses (and the whole rock) lack volatile elements such as Na and K, they are rich in some moderately volatile elements such as B, V, Mn, Fe (all with close to CI abundances), and Li (about 3-5 × CI). These elements likely were added to the glass in a sub-solidus metasomatic elemental exchange event. We have identified a novel mechanism for alteration of glass and rock compositions based on an exchange of Al and Sc for Fe and other moderately volatile elements in addition to the well-known metasomatic exchange reactions (e.g., Ca-Na and Mg-Fe). Because glass inclusions in olivine were partly shielded from the metasomatic events by the host crystal, their chemical composition is believed to be closer to the original composition than that of any other glasses. The relative trace element abundances in glasses of glass inclusions in olivine and glass pockets are also unfractionated and at the 10 to 20 × CI level. These glasses are chemically similar to the common void-filling glasses but show a much wider compositional variation. Inclusion glasses demonstrate that at least olivine grew with the help of a liquid. In analogy to olivines in carbonaceous chondrites, initial formation could also have been a vapor-liquid-solid condensation process. At that time, the glass had a purely refractory composition. This composition, however, was severely altered by the metasomatic addition of large amounts of FeO and other moderately volatile elements. The presence of volatile elements such as carbon and nitrogen in glasses of glass inclusions is another feature that appears to give these glasses a link with those hosted by olivines of carbonaceous chondrites. All these features point to an origin from a vapor with relative abundances of condensable elements similar to those in the solar nebula.

Varela, Maria Eugenia; Kurat, Gero; Zinner, Ernst; Métrich, Nicole; Brandstätter, Franz; Ntaflos, Theodoros; Sylvester, Paul

2003-12-01

250

Role of structure in ion movement of glasses  

SciTech Connect

Three kinds of experiments were performed: modified random network model and ion movement; role of melt structure in ion transport in glassy state; and ion movement in fluorozirconate glass (breakdown of correspondence between electrical and nuclear spin relaxation). A comment is offered on dielectric loss peak in glasses. 11 refs, 1 fig. (DLC)

Jain, H.

1992-11-03

251

FOAM GLASS INSULATION FROM WASTE GLASS  

EPA Science Inventory

Waste glass has proven to be effective for the production of foam glass insulation both in the bulk or rigid board form and pellet form. Problems inherent with the use of water, carbon black and calcium carbonate as the foaming agents, have been identified and many have been solv...

252

Commercial Ion Exchange Resin Vitrification in Borosilicate Glass.  

National Technical Information Service (NTIS)

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...

C. A. Cicero-Herman P. Workman K. Poole D. Erich J. Harden

1998-01-01

253

Practice of Waste Glass Recovery.  

National Technical Information Service (NTIS)

Based on the slogan ''old glass is not waste, but raw material'' the glass container industry of West Germany is promoting glass recycling. Programs for encouraging individuals, civic groups, and communities to collect used glass are described. (ERA citat...

H. Knoche

1975-01-01

254

Room temperature corrosion of museum glass: an investigation using low-energy SIMS  

NASA Astrophysics Data System (ADS)

Glass is often regarded as a stable durable material and the wide range of contemporary applications of glass reinforces this belief. There is nothing inherent in the glassy state, however, that confers stability, and the problem of glass corrosion has been well documented since the 17th century. Glass corrosion still affects commercial float glass production and glasses used to contain high level nuclear waste, but one area in particular where glass corrosion is very common is in the museum environment. In order to conserve these artefacts it is essential to understand fully both the composition of the corroded glass and the corrosion mechanism. In this study, the application of low-energy SIMS for the depth profiling of corroded glass is studied with the aim of finding a suitable environment for the safe storage of glass objects in a museum.

Fearn, Sarah; McPhail, David S.; Oakley, Victoria

2004-06-01

255

Glass in Class  

ERIC Educational Resources Information Center

|Glass is reviewed from fabrication to application, laying emphasis on the wide-ranging physics involved. This begins with liquids and solids and the way in which glasses are defined and can be demonstrated in the classroom. At the atomic level the regular structure of crystals and their irregular counterparts in glasses are explained through…

Greaves, Neville

2005-01-01

256

Strength of inorganic glass  

Microsoft Academic Search

This book presents information on the following topics: a look at the history of glass strength; atomistic theory of fracture; surface chemistry in relation to the strength and fracture of silicate glasses; high-speed photographic investigations of the dynamic localized loading of some oxide glasses; a correction for measurements of contact area using Newton's rings; envionmentally enhanced crack growth; fatigue in

Kurkjian

1985-01-01

257

Defect diffusion in ion implanted glasses  

Microsoft Academic Search

Ion implantation in glasses produces structure modifications at depths greater than those of the implanted ion range. Such a result is evidenced by means of leaching experiments, alkali element depletion, distribution of gaseous implanted species, etching rate as function of depth. A systematic study with the aim to evidence a threshold in the nuclear deposited energy for defect diffusion is

G. W. Arnold; G. Battaglin; A. Boscolo-Boscoletto; F. Caccavale; G. de Marchi; P. Mazzoldi; A. Miotello

1992-01-01

258

Defect diffusion in ion implanted glasses  

Microsoft Academic Search

Ion implantation in glasses produces structure modifications at depths greater than those of the implanted ion range. Such a result is evidenced by means of leaching experiments, alkali element depletion, distribution of gaseous implanted species, etching rate as function of depth. A systematic study with the aim to evidence a threshold in the nuclear deposited energy for defect diffusion is

G. W. Arnold; G. Battaglin; A. Boscolo-Boscoletto; F. Caccavale; G. De Marchi; P. Mazzoldi; A. Miotello

1991-01-01

259

Kinetic model for borosilicate glass dissolution based on the dissolution affinity of a surface alteration layer.  

National Technical Information Service (NTIS)

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) lay...

W. L. Bourcier D. W. Peiffer K. G. Knauss K. D. McKeegan D. K. Smith

1989-01-01

260

Predicting Phase Equilibria of Spinel-Forming Constituents in Waste Glass Systems  

Microsoft Academic Search

A modified associate species thermochemical model has been developed for the liquid\\/glass in nuclear waste glass systems, and provides a simple means for relatively accurately representing the thermochemistry of the liquid\\/glass phase. A modification of the methodology is required when two immiscible liquids are present, such that a positive interaction energy is included in the representation. The approach has been

Theodore M. Besmann; Nagraj S. Kulkarni; Karl E. Spear; John D. Vienna

2004-01-01

261

High-Temperature Studies of Glass Dissolution Rates Close to Saturation  

SciTech Connect

Most long-lived radionuclides associated with an underground nuclear test are incorporated into a melt glass and are released by glass dissolution to become part of the hydrologic source term (HST) (Pawloski et al., 2001). Although the rates of rhyolite glass dissolution are well known under conditions where the fluid is far from saturation with respect to glass, the rates are not well known under conditions where the fluid approaches saturation. These rates are commonly much lower than the far-fromsaturation rates, often by a factor greater than 100. In recent HST simulations (Pawloski et al., 2001; Pawloski et al., 2000; Tompson et al., 1999), we conservatively estimated steady-state release rates based on a far-from-saturation fluid conditions. In recent CHESHIRE near-field simulations (Pawloski et al., 2001), it was predicted that {approx}30% of the nuclear melt glass dissolved over 1000 years. Although the ''far-from-saturation rate'' approach provides a conservative estimate of glass dissolution, it may greatly overestimate the rates of melt glass dissolution. At CHESHIRE, less conservative estimates suggest that only {approx}1% of the nuclear melt glass will dissolve in 1000 years. Lower glass dissolution rates result in lower radionuclide release rates from nuclear melt glass. The following report documents glass dissolution experiments performed to measure glass dissolution rates close to saturation.

Zavarin, M; Roberts, S; Zhao, P; Williams, R; Rose, T; Rainer, A; Pawloski, G

2004-06-14

262

Database and Interim Glass Property Models for Hanford HLW and LAW Glasses  

SciTech Connect

This report discusses a methodology for increasing the efficiency and decreasing the cost of vitrifying nuclear waste by optimizing waste-glass formulation. This methodology involves collecting and generating a property-composition database (for glass properties that determine waste-glass processability and acceptability) and relating these properties to glass composition via property-composition models. The report explains how the property-composition models are developed, fitted to data and evaluated, validated using additional data, used for glass-formulation optimization, and continuously updated in response to changes in waste-composition estimates and processing technologies. Further, the report describes a waste-glass property-composition database compiled from literature sources and presents the results from a critical evaluation and screening of the data for applicability to Hanford waste glasses. Finally, the report provides interim property-composition models for melt viscosity, liquidus temperature (with spinel and zircon primary crystalline phases), and Product Consistency Test normalized releases of B, Na, and Li. Models were fitted to a subset of the database deemed most relevant for the anticipated Hanford waste-glass composition region.

Vienna, John D. (BATTELLE (PACIFIC NW LAB)); Kim, Dong-Sang (BATTELLE (PACIFIC NW LAB)); Hrma, Pavel R. (BATTELLE (PACIFIC NW LAB))

2002-09-27

263

Do cathedral glasses flow?  

NASA Astrophysics Data System (ADS)

A general belief among members of the scientific community is that glass articles can be bent irreversibly and that they flow at ambient temperature. This myth is mostly based on widespread stories that stained-glass windows of medieval cathedrals are thicker in the lower parts. In this paper I estimate the time periods required for glass to flow and deform at ordinary temperatures, using calculated viscosity curves for several modern and ancient glass compositions. The conclusion is that window glasses may flow at ambient temperature only over incredibly long times, which exceed the limits of human history.

Zanotto, Edgar Dutra

1998-05-01

264

Oxynitride glass production procedure  

SciTech Connect

This patent describes the invention of a process for the preparation of high quality oxynitride glasses without resorting to high pressures. Nitrogen-containing compounds such as Si{sub 3}N{sub 4} are first encapsulated in a low melting temperature glass. Particles of the encapsulated nitrogen-containing compound are mixed with other oxide glass-formers and melted in an atmosphere of flowing nitrogen and in the presence of buffering gas to form the oxynitride glass. Glasses containing up to 15 at % nitrogen have been prepared by this method.

Weidner, J.R.; Schuetz, S.T.; O'Brien, M.H.

1991-04-09

265

Radiation coloration resistant glass  

DOEpatents

A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10[sup 7] rad, the coloration resistant glass does not lose transparency. 3 figs.

Tomozawa, M.; Watson, E.B.; Acocella, J.

1986-11-04

266

Oxynitride glass production procedure  

DOEpatents

The invention is a process for the preparation of high quality oxynitride glasses without resorting to high pressures. Nitrogen-containing compounds such as Si{sub 3}N{sub 4} are first encapsulated in a low melting temperature glass. Particles of the encapsulated nitrogen-containing compound are mixed with other oxide glass-formers and melted in an atmosphere of flowing nitrogen and in the presence of buffering gas to form the oxynitride glass. Glasses containing up to 15 at% nitrogen have been prepared by this method. 4 tabs.

Weidner, J.R.; Schuetz, S.T.; O' Brien, M.H.

1990-03-28

267

Rare Earth Phosphate Glass and Glass-Ceramic Proton Conductors  

Microsoft Academic Search

The structure and conductivity of cerium and lanthanum phosphate glasses and glass-ceramics were investigated. The effects of varying the metal to phosphate ratio in the glasses, doping LaP3O9 glasses with Ce, and recrystallization of CeP3O9 glasses, on the glasses' microstructure and total conductivity were investigated using XRD, SEM, and AC impedance techniques. Strong increases in conductivity occurred when the glasses

Lutgard C. De Jonghe; Hannah L. Ray; Ruigang Wang

2008-01-01

268

Application of the hydration thermodynamic model for glass durability under saturated tuff repository conditions  

SciTech Connect

The effects of tuff repository groundwater on glass dissolution and surface layer formation was examined utilizing the hydration thermodynamic model. A 28 day MCC-1 monolithic durability test was performed on the following glasses: SiO{sub 2}, obsidian, basalt, medieval window glasses, frit glass, and simulated nuclear waste glass. Silica dissolution was compared with the pH corrected free energy of hydration and shown to have the theoretical slope, ln(1/2.303RT), in agreement with MCC-1 tests using deionized water. X-ray diffraction and scanning electron microscopy identified clays of the saponite family and carbonates, on the glass surfaces leached in tuff groundwater. 31 refs.

Ramsey, W.G. [Clemson Univ., SC (USA); Jantzen, C.M. [Westinghouse Savannah River Co., Aiken, SC (USA)

1990-12-31

269

Weathering of glass in moist and polluted air  

NASA Astrophysics Data System (ADS)

During the present century, stained glass windows in European cathedrals have shown a rapid deterioration due to weathering. It is widely believed that this rapid deterioration is a result of airborne pollutants not present for most of the 6-8 centuries since these cathedrals were built. To explore this idea, we have exposed soda-lime glass samples to ambients in which temperature, relative humidity (RH), and pollutant (SO2 and NO2) concentration were systematically varied. After exposure, the surfaces of these glass samples were analyzed using nuclear reaction analysis (NRA) (to measure hydrogen profiles) and Rutherford backscattering. Glasses subject to cracking during hydration, such as the glass used in many historic stained glass windows, are also discussed.

Cummings, K.; Lanford, W. A.; Feldmann, M.

1998-03-01

270

Evidence for interdiffusion of hydronium and alkali ions in leached glasses  

SciTech Connect

The interdiffusion mechanism governing the leaching (or hydration) of glasses is studied using the /sup 19/F resonant nuclear reaction. By measuring the number of hydrogen ions in the surface layers of leached glasses, we have identified that a hydronium-sodium ion exchange process is in operation in leached commercial glasses while it is less conclusive as to the exact mechanism responsible for the leaching of simple laboratory binary and ternary glasses.

Tsong, I.S.T.; Houser, C.A.; White, W.B.; Wintenberg, A.L.; Miller, P.D.; Moak, C.D.

1981-10-15

271

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

Microsoft Academic Search

Liquid high-level nuclear waste at the Savannah River Site (SRS) will be immobilized by vitrification in borosilicate glass. The glass will be produced and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). Other waste form producers, such as West Valley Nuclear Services (WVNS) and the Hanford Waste Vitrification Project (HWVP), will also immobilize high-level radioactive waste

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

1992-01-01

272

Mechanical Properties of Some Candidate Glasses for High-Level Radioactive Waste Management.  

National Technical Information Service (NTIS)

The biaxial flexure fracture stress, fracture toughness and Young's modulus were measured for different nuclear glass compositions. The KIC values of all the nuclear glasses tested ranged from 0.90 to 1.10 MPa.msup(1/2), slightly higher than for Pyrex. Cr...

E. Vernaz P. Deymier N. Jacquet-Francillon

1983-01-01

273

Thermodynamics of Glass Melting  

NASA Astrophysics Data System (ADS)

First, a model based on linear algebra is described by which the thermodynamic properties of industrial multi-component glasses and glass melts can be accurately predicted from their chemical composition. The model is applied to calculate the heat content of glass melts at high temperatures, the standard heat of formation of glasses from the elements, and the vapor pressures of individual oxides above the melt. An E-fiber glass composition is depicted as an example. Second, the role of individual raw materials in the melting process of E-glass is addressed, with a special focus on the decomposition kinetics and energetic situation of alkaline earth carriers. Finally, the heat of the batch-to-melt conversion is calculated. A simplified reaction path model comprising heat turnover, content of residual solid matter, and an approach to batch viscosity is outlined.

Conradt, Reinhard

274

Method for making glass  

DOEpatents

A method is discussed for making better quality molten borosilicate glass in a glass melter, the glass having the desired viscosity and, preferably, also the desired resistivity so that the glass melt can be established effectively and the product of the glass melter will have the desired level of quality. The method includes the adjustment of the composition of the glass constituents that are fed into the melter in accordance with certain correlations that reliably predict the viscosity and resistivity from the melter temperature and the melt composition, then heating the ingredients to the melter`s operating temperature until they melt and homogenize. The equations include the calculation of a ``non-bridging oxygen`` term from the numbers of moles of the various ingredients, and then the determination of the viscosity and resistivity from the operating temperature of the melter and the non-bridging oxygen term.

Jantzen, C.M.

1991-12-31

275

Method for making glass  

DOEpatents

A method is discussed for making better quality molten borosilicate glass in a glass melter, the glass having the desired viscosity and, preferably, also the desired resistivity so that the glass melt can be established effectively and the product of the glass melter will have the desired level of quality. The method includes the adjustment of the composition of the glass constituents that are fed into the melter in accordance with certain correlations that reliably predict the viscosity and resistivity from the melter temperature and the melt composition, then heating the ingredients to the melter's operating temperature until they melt and homogenize. The equations include the calculation of a non-bridging oxygen'' term from the numbers of moles of the various ingredients, and then the determination of the viscosity and resistivity from the operating temperature of the melter and the non-bridging oxygen term.

Jantzen, C.M.

1991-01-01

276

Bulk Metallic Glasses  

SciTech Connect

Bulk Metallic Glasses explores an emerging field of materials known as bulk metallic glasses. It summarizes the rapid development of these materials over the last decade and includes documentation on diverse applications of bulk metallic glasses; from structural applications to microcomponents. Some of the applications covered are pressure sensors, microgears for motors, magnetic cores for power supplies, and nano-dies for replacing next generation DVDs. The chapters cover current theories and recent research including an atomistic theory of local topological fluctuations, atomistic simulations, and unique microstructures of these amorphous materials. Other topics include glass formation, glass forming ability, and the underlying mechanisms and physical insights of these criteria. The mechanical deformation of bulk metallic glasses, fatigue, fracture, and corrosion behaviors of these materials are also reviewed.

Miller, Michael K [ORNL; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2007-01-01

277

Silane treated glass fibers  

Microsoft Academic Search

There is a cogent body of evidence showing that the physical properties of glass reinforced plastics (GRP) can be vastly improved,\\u000a by pre-treatment of the glass fibers with appropriate coupling agents or sizes. This is the fourth part of a research series\\u000a investigating different silanes with non-aqueous solvents and their effect upon silane deposition onto glass fibers.\\u000a \\u000a A sample of

H. Watson; A. Jokinen; P. Mikkola; J. Matisons; J. Rosenholm

278

EXELFS of Metallic Glasses  

Microsoft Academic Search

The feasibility of using extended energy-loss fine structure (EXELFS) obtained from â¼1 nm regions of metallic glasses to study their short-range order has been examined. Ionization edges of the metallic glasses in the electron energy-loss spectrum (EELS) have been obtained from PdNiP bulk metallic glass and NiâP polycrystalline powder in a transmission electron microscope. The complexity of EXELFS analysis of

Y. Ito; F. M. Alamgir; R. B. Schwarz; H. Jain; D. B. Williams

1999-01-01

279

Nonequilibrium viscosity of glass  

NASA Astrophysics Data System (ADS)

Since glass is a nonequilibrium material, its properties depend on both composition and thermal history. While most prior studies have focused on equilibrium liquid viscosity, an accurate description of nonequilibrium viscosity is essential for understanding the low temperature dynamics of glass. Departure from equilibrium occurs as a glass-forming system is cooled through the glass transition range. The glass transition involves a continuous breakdown of ergodicity as the system gradually becomes trapped in a subset of the available configurational phase space. At very low temperatures a glass is perfectly nonergodic (or “isostructural”), and the viscosity is described well by an Arrhenius form. However, the behavior of viscosity during the glass transition range itself is not yet understood. In this paper, we address the problem of glass viscosity using the enthalpy landscape model of Mauro and Loucks [Phys. Rev. B 76, 174202 (2007)] for selenium, an elemental glass former. To study a wide range of thermal histories, we compute nonequilibrium viscosity with cooling rates from 10-12 to 1012K/s . Based on these detailed landscape calculations, we propose a simplified phenomenological model capturing the essential physics of glass viscosity. The phenomenological model incorporates an ergodicity parameter that accounts for the continuous breakdown of ergodicity at the glass transition. We show a direct relationship between the nonequilibrium viscosity parameters and the fragility of the supercooled liquid. The nonequilibrium viscosity model is validated against experimental measurements of Corning EAGLE XG™ glass. The measurements are performed using a specially designed beam-bending apparatus capable of accurate nonequilibrium viscosity measurements up to 1016Pas . Using a common set of parameters, the phenomenological model provides an accurate description of EAGLE XG™ viscosity over the full range of measured temperatures and fictive temperatures.

Mauro, John C.; Allan, Douglas C.; Potuzak, Marcel

2009-09-01

280

Scintillating Fluorohafnate Glasses  

Microsoft Academic Search

Data are presented on the roentgenoluminescence and gamma-radiation resistance of Ce3+-doped fluorohafnate glasses prepared under different redox conditions and containing different additions. The glasses are shown to contain several types of luminescence centers and radiation-induced color centers, whose concentrations are governed by the preparation conditions and the nature of the dopants. The radiation resistance and light output of the glasses

S. Kh. Batygov; M. N. Brekhovskikh; N. N. Vinogradova; L. N. Dmitruk; L. V. Moiseeva; V. A. Fedorov

2002-01-01

281

Containerless processing of glass  

Microsoft Academic Search

Ground-based research on the containerless melting of glass and experiments performed during a flight on the SPAR 6 are described. Experiments leading to selection of the flight sample composition, a silica-modified gallia\\/calcia glass, and the preparation of a one quarter inch diameter flight sample are described. During the flight experiment, a sample of the glass was containerless melted and cooled

R. A. Happe

1981-01-01

282

Containerless processing of glass  

NASA Astrophysics Data System (ADS)

Ground-based research on the containerless melting of glass and experiments performed during a flight on the SPAR 6 are described. Experiments leading to selection of the flight sample composition, a silica-modified gallia/calcia glass, and the preparation of a one quarter inch diameter flight sample are described. During the flight experiment, a sample of the glass was containerless melted and cooled to a clear glass in a single axis acoustic positioning apparatus. The functioning of the flight experimental hardware was evaluated. The evaluation of the sample is presented.

Happe, R. A.

1981-10-01

283

Helium diffusion in curium-doped borosilicate waste glass  

NASA Astrophysics Data System (ADS)

The isothermal release of helium from 244Cm-doped borosilicate glass has been studied as a function of time at different annealing temperatures. Helium measurements were performed using a micro gas chromatograph coupled to a furnace installed in a hot cell at ATALANTE nuclear research facility. Plane-parallel glass samples were prepared from glass discs that had been stored for 5.1 years at room temperature, accumulating around 1019 alpha decays per gram of glass, a level that will be reached in current nuclear glass packages several thousand years after disposal.The experimental helium release data were simulated using a 3D numerical model to determine the helium diffusion coefficients. The extracted diffusion coefficients follow the Arrhenius law with an activation energy of 0.61 ± 0.03 eV and a pre-exponential factor of (5.7 ± 1.6) × 10-3 cm2 s-1. The results were compared with literature data on damaged and undamaged glasses to assess the effect of glass damage on helium release. The helium release results are consistent with a thermal diffusion mechanism involving only one population of helium atoms. The helium diffusion coefficients were unaffected by the glass alpha damage.

Fares, T.; Peuget, S.; Bouty, O.; Deschanels, X.; Magnin, M.; Jégou, C.

2011-09-01

284

Rare Earth Phosphate Glass and Glass-Ceramic Proton Conductors  

SciTech Connect

The structure and conductivity of cerium and lanthanum phosphate glasses and glass-ceramics were investigated. The effects of varying the metal to phosphate ratio in the glasses, doping LaP3O9 glasses with Ce, and recrystallization of CeP3O9 glasses, on the glasses' microstructure and total conductivity were investigated using XRD, SEM, and AC impedance techniques. Strong increases in conductivity occurred when the glasses were recrystallized: the conductivity of a cerium metaphosphate glass increased conductivity after recrystallization from 10-7.5 S/cm to 10-6 S/cm at 400oC.

De Jonghe, Lutgard C.; Ray, Hannah L.; Wang, Ruigang

2008-12-03

285

Glass Transitions in Polylactides  

Microsoft Academic Search

The review focuses on the relationship between the structure and the glass transition temperature in polylactide and its derivatives. Simple design rules for controlling the glass transition temperature are developed and illustrated using examples from homopolymers, copolymers, and polymers derived from AB glycolide monomers. These materials have important applications as structural materials and in biomedical applications for drug delivery, surgical

Gregory L. Baker; Erin B. Vogel; Milton R. Smith III

2008-01-01

286

Breaking Glass with Sound  

NSDL National Science Digital Library

This video from MIT TechTV demonstrates how to break a glass using sound. The demonstrator determines the resonant frequency of the glass and plays a tone of that frequency with a function generator. The video page has a description of the phenomenon beneath the video.

2009-11-16

287

Supercooled Liquids and Glasses  

Microsoft Academic Search

Selected aspects of recent progress in the study of supercooled liquids and glasses are presented in this review. As an introduction for nonspecialists, several basic features of the dynamics and thermodynamics of supercooled liquids and glasses are described. Among these are nonexponential relaxation functions, non-Arrhenius temperature dependences, and the Kauzmann temperature. Various theoretical models which attempt to explain these basic

M. D. Ediger; C. A. Angell; Sidney R. Nagel

1996-01-01

288

Photoprotection by window glass, automobile glass, and sunglasses.  

PubMed

In daily activity, much time is spent indoors and in vehicles. Although the adverse effect of ultraviolet (UV) radiation is now well recognized and active public education programs on photoprotection have been undertaken, the role of window glass in photoprotection has been rarely addressed. It has been known for some time that window glass filters out UVB and transmits UVA and visible light. Recent developments in the glass industry have resulted in glass that provides broad UV protection without the historically associated loss of visible light transmission. Factors affecting UV-protective properties of glass are glass type, glass color, interleave between glass, and glass coating. In this article, photoprotection by window glass, automobile glass, and sunglasses is reviewed. PMID:16635665

Tuchinda, Chanisada; Srivannaboon, Sabong; Lim, Henry W

2006-05-01

289

Development and characterization of basalt-glass ceramics for the immobilization of transuranic wastes  

SciTech Connect

Basalt-based waste forms were developed for the immobilization of transuranic (TRU) contaminated wastes. The specific waste studied is a 3:1 blend of process sludge and incinerator ash. Various amounts of TRU blended waste were melted with Pomona basalt powder. The vitreous products were subjected to a variety of heat treatment conditions to form glass ceramics. The total crystallinity of the glass ceramic, ranging from 20 to 45 wt %, was moderately dependent on composition and heat treatment conditions. Three parent glasses and four glass ceramics with varied composition and heat treatment were produced for detailed phase characterization and leaching. Both parent glasses and glass ceramics were mainly composed of a continuous, glassy matrix phase. This glass matrix entered into solution during leaching in both types of materials. The Fe-Ti rich dispersed glass phase was not significantly degraded by leaching. The glass ceramics, however, exhibited four to ten times less elemental releases during leaching than the parent glasses. The glass ceramic matrix probably contains higher Fe and Na and lower Ca and Mg relative to the parent glass matrix. The crystallization of augite in the glass ceramics is believed to contribute to the improved leach rates. Leach rates of the basalt glass ceramic are compared to those of other TRU nuclear waste forms containing /sup 239/Pu.

Lokken, R.O.; Chick, L.A.; Thomas, L.E.

1982-09-01

290

Defense HLW Glass Degradation Model  

SciTech Connect

The purpose of this report is to document the development of a model for calculating the release rate for radionuclides and other key elements from high-level radioactive waste (HLW) glasses under exposure conditions relevant to the performance of the repository. Several glass compositions are planned for the repository, some of which have yet to be identified (i.e., glasses from Hanford and Idaho National Engineering and Environmental Laboratory). The mechanism for glass dissolution is the same for these glasses and the glasses yet to be developed for the disposal of DOE wastes. All of these glasses will be of a quality consistent with the glasses used to develop this report.

D. Strachan

2004-10-20

291

Engineering Glass Passivation Layers -Model Results  

SciTech Connect

The immobilization of radioactive waste into glass waste forms is a baseline process of nuclear waste management not only in the United States, but worldwide. The rate of radionuclide release from these glasses is a critical measure of the quality of the waste form. Over long-term tests and using extrapolations of ancient analogues, it has been shown that well designed glasses exhibit a dissolution rate that quickly decreases to a slow residual rate for the lifetime of the glass. The mechanistic cause of this decreased corrosion rate is a subject of debate, with one of the major theories suggesting that the decrease is caused by the formation of corrosion products in such a manner as to present a diffusion barrier on the surface of the glass. Although there is much evidence of this type of mechanism, there has been no attempt to engineer the effect to maximize the passivating qualities of the corrosion products. This study represents the first attempt to engineer the creation of passivating phases on the surface of glasses. Our approach utilizes interactions between the dissolving glass and elements from the disposal environment to create impermeable capping layers. By drawing from other corrosion studies in areas where passivation layers have been successfully engineered to protect the bulk material, we present here a report on mineral phases that are likely have a morphological tendency to encrust the surface of the glass. Our modeling has focused on using the AFCI glass system in a carbonate, sulfate, and phosphate rich environment. We evaluate the minerals predicted to form to determine the likelihood of the formation of a protective layer on the surface of the glass. We have also modeled individual ions in solutions vs. pH and the addition of aluminum and silicon. These results allow us to understand the pH and ion concentration dependence of mineral formation. We have determined that iron minerals are likely to form a complete incrustation layer and we plan to look more closely at Vivianite [Fe3(PO4)2-8(H2O)] and Siderite [FeCO3] in the next stage of the project.

Skorski, Daniel C.; Ryan, Joseph V.; Strachan, Denis M.; Lepry, William C.

2011-08-08

292

Carbonatitic glasses and melts  

NASA Astrophysics Data System (ADS)

We perform first-principles molecular dynamics (MD) calculations to study C-bearing melts along the T=3000K isotherm up to high pressure. Then we use the melts to study the quenched glasses. We consider pure forsteritic compositions, atomic C-, CO2- and MgCO3- bearing compositions. We discuss in detail the behavior of the glass structure under compression and the changes in coordination polyhedra, and we compare the glasses to the equivalent high-temperature melts. We use several thermodynamic paths to obtain the glasses: (i) instantaneous quench at P=0GPa, then coldly compress, (ii) instantaneous quench at various high pressures and (iii) quench in 1K/MD step at various high pressures. Differences in glass structure and in equations of state develop between the different paths. They become larger at high pressure and are smoothed out by annealing. All glasses exhibit increase in Si-O and C-O coordination numbers, but at a smaller rate than the melts. Important structural rearrangements develop in all glasses around V/V0 compression of about 0.7.

Cohen, Ronald E.; Caracas, Razvan

2013-04-01

293

EB reinforced glass  

NASA Astrophysics Data System (ADS)

Effects of EB irradiation on fracture toughness were studied for soda lime glass and glass fiber. The EB irradiation improved the hardness, ductility, fracture stress and fracture toughness. The fracture stress was 1.43 GPa for the glass fiber before EB treatment. The irradiation enhanced the fracture stress. The fracture stress at Pf=0.5 was 1.89 GPa for glass fiber samples treated by 65 Mrad-irradiation. It was approximately 0.46 GPa larger than that before EB treatment. Based on ESR results, the reinforcement can be explained. The changes in fracture stress were in good agreement with the density change in dangling bonds, because a high tensile glass fiber was obtained at 65 Mrad-irradiation. Thus, we confirmed that the glassy cluster structure with high dangling bond density was obtained in high tensile glass fibers prepared by 65 Mrad-irradiation. The EB irradiation controlled the fracture toughness of glasses. To confirm the mechanism, an alpha-aluminum oxide crystal sheet was also studied.

Nishi, Yoshitake; Irisawa, Hayato; Yamaguchi, Naoki; Takahashi, Kousuke; Yamada, Kunio; Oguri, Kazuya; Tonegawa, Akira

2002-12-01

294

Ages of Darwin Glass, Macedon Glass, and Far Eastern tektites  

Microsoft Academic Search

A group of possibly related glasses from the Far East, including seven samples of Darwin Glass and the two known samples of Macedon Glass, have been dated by the fission track technique. With the exception of a lower age for one Darwin Glass sample and one Muong Nong tektite all ages are indistinguishable, suggesting that the Darwin and Macedon impact

R. L. Fleischer; P. B. Price; J. R. M. Viertl; R. T. Woods

1969-01-01

295

Fracture toughness and fracture surface energy of lead borate glasses  

Microsoft Academic Search

The structure of lead borate glasses has been investigated in detail by Bray and his co-workers using nuclear magnetic resonance (NMR) techniques [1,2]. They revealed that the fraction of four-co-ordinated boron atoms shows a maximum at about 50 tool % PbO and that the lead enters the glass as modifier Pb 2+ ions at lower PbO content but, with increasing

N. Miyata; H. Jinno

1982-01-01

296

Residual stresses in glasses.  

PubMed

The history dependence of glasses formed from flow-melted steady states by a sudden cessation of the shear rate ?[over ?] is studied in colloidal suspensions, by molecular dynamics simulations and by mode-coupling theory. In an ideal glass, stresses relax only partially, leaving behind a finite persistent residual stress. For intermediate times, relaxation curves scale as a function of ?[over ?]t, even though no flow is present. The macroscopic stress evolution is connected to a length scale of residual liquefaction displayed by microscopic mean-squared displacements. The theory describes this history dependence of glasses sharing the same thermodynamic state variables but differing static properties. PMID:23745896

Ballauff, M; Brader, J M; Egelhaaf, S U; Fuchs, M; Horbach, J; Koumakis, N; Krüger, M; Laurati, M; Mutch, K J; Petekidis, G; Siebenbürger, M; Voigtmann, Th; Zausch, J

2013-05-24

297

Polar glass ceramics  

Microsoft Academic Search

Pyroelectric-piezoelecric glass ceramics of polar materials like Li2Si2O5, Ba2TiGe2O8, Ba2TiSi2O8, and Various compositions in the systems Li2O-B2O3, Li2O-SiO2-ZnO, Li2O-SiO2-B2O3 have been prepared by oriented recrystallization of the glasses under a strong temperature gradient, providing a simple inexpensive process for preparing piezoelectric and pyroelectric materials. High pyroelectric responses were observed in these glass-ceramics. Values of piezoelectric d33 coefficients, frequency constants, electromechanical

A. Halliyal; A. S. Bhalla; R. E. Newnham; L. E. Cross

1981-01-01

298

Glass electrolyte composition  

DOEpatents

An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na/sub 2/O, ZrO/sub 2/, Al/sub 2/O/sub 3/ and SiO/sub 2/ in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2 x 10/sup -3/ (ohm-cm)/sup -1/ at 300/sup 0/C and a glass transition temperature in excess of 500/sup 0/C.

Kucera, G.H.; Roche, M.F.

1985-01-08

299

Glass electrolyte composition  

DOEpatents

An ionically conductive glass is disclosed for use as electrolyte in a high temperature electrochemical cell, particularly a cell with sodium anode and sulfur cathode. The glass includes the constituents Na.sub.2 O, ZrO.sub.2, Al.sub.2 O.sub.3 and SiO.sub.2 in selected proportions to be a single phase solid solution substantially free of crystalline regions and undissolved constituents. Other advantageous properties are an ionic conductivity in excess of 2.times.10.sup.-3 (ohm-cm).sup.-1 at 300.degree. C. and a glass transition temperature in excess of 500.degree. C.

Kucera, Gene H. (Downers Grove, IL); Roche, Michael F. (Downers Grove, IL)

1985-01-01

300

EXELFS of Metallic Glasses  

SciTech Connect

The feasibility of using extended energy-loss fine structure (EXELFS) obtained from {approximately}1 nm regions of metallic glasses to study their short-range order has been examined. Ionization edges of the metallic glasses in the electron energy-loss spectrum (EELS) have been obtained from PdNiP bulk metallic glass and Ni{sub 2}P polycrystalline powder in a transmission electron microscope. The complexity of EXELFS analysis of L- and M-ionization edges of heavy elements (Z>22, i.e. Ni and Pd) is addressed by theoretical calculations using an ab initio computer code, and its results are compared with the experimental data.

Ito, Y.; Alamgir, F.M.; Schwarz, R.B.; Jain, H.; Williams, D.B.

1999-11-30

301

Glasses for Immobilizing Lanthanide, Alkali, and Alkali-earth Fission Products  

SciTech Connect

A series of glasses were formulated for the immobilization of a potential waste stream from commercial nuclear fuel reprocessing, the combined lanthanide (LN), alkali, and alkaline earth (Cs/Sr) fission products. These glasses were formulated to meet repository disposal requirements while being processable in a cold-crucible melter. The glasses were fabricated and tested for product consistency test response, phase characterization, density, and glass transition temperature. The results suggest that the combined fission product waste forms are likely to meet repository requirements and generate less glass than if individual streams were vitrified.

Crum, Jarrod V.; Vienna, John D.

2009-08-03

302

Comparison of the corrosion behaviors of the glass-bonded sodalite ceramic waste form and reference HLW glasses.  

SciTech Connect

A glass-bonded sodalite ceramic waste form is being developed for the long-term immobilization of salt wastes that are generated during spent nuclear fuel conditioning activities. A durable waste form is prepared by hot isostatic pressing (HIP) a mixture of salt-loaded zeolite powders and glass frit. A mechanistic description of the corrosion processes is being developed to support qualification of the CWF for disposal. The initial set of characterization tests included two standard tests that have been used extensively to study the corrosion behavior of high level waste (HLW) glasses: the Material Characterization Center-1 (MCC-1) Test and the Product Consistency Test (PCT). Direct comparison of the results of tests with the reference CWF and HLW glasses indicate that the corrosion behaviors of the CWF and HLW glasses are very similar.

Ebert, W. L.; Lewis, M. A.

1999-05-06

303

Reference commercial high-level waste glass and canister definition.  

SciTech Connect

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.

Slate, S.C.; Ross, W.A.; Partain, W.L.

1981-09-01

304

Reference commercial high-level waste glass and canister definition  

NASA Astrophysics Data System (ADS)

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 are presented. The borosilicate glass contained in the stainless steel canister represents the probable type of high level waste product that is 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.

Slate, S. C.; Ross, W. A.; Partain, W. L.

1981-09-01

305

Experimental hydration studies of natural and synthetic glasses  

SciTech Connect

The results of a series of hydration experiments on natural glasses (Hawaiian basalt, obsidian) and the nuclear waste glass WV-44 done to examine laboratory methods of accelerating reaction processes are summarized. The glasses were reacted in hydrothermal solution and in saturated vapor water. It was found that different reaction rates and processes were found using the differing conditions, and that laboratory efforts to accelerate and duplicate natural processes must amount for the physical processes that occur naturally. 18 refs., 5 figs., 1 tab.

Bates, J.K.; Abrajano, T.A. Jr.; Ebert, W.L.; Mazer, J.J.; Gerding, T.J.

1988-01-01

306

Phase coexistence in proton glass  

SciTech Connect

Proton glasses are crystals of composition M{sub 1{minus}x}(NW{sub 4}){sub x}W{sub 2}AO{sub 4}, where M = K,Rb, W = H,D, A = P,As. For x = 0 there is a ferroelectric (FE) transition, while for x = 1 there is an antiferroelectric (AFE) transition. In both cases, the transition is from a paraelectric (PE) state of tetragonal structure with dynamically disordered hydrogen bonds to an ordered state of orthorhombic structure. For an intermediate x range there is no transition, but the hydrogen rearrangements slow down, and eventually display nonergodic behavior characteristic of glasses. The authors and other have shown from spontaneous polarization, dielectric permittivity, nuclear magnetic resonance, and neutron diffraction experiments that for smaller x there is coexistence of ferroelectric and paraelectric phases, and for larger x there is coexistence of antiferroelectric and paraelectric phases. The authors present a method for analytically describing this coexistence, and the degree to which this coexistence is spatial or temporal.

Schmidt, V.H. [Montana State Univ., Bozeman, MT (United States). Physics Dept.; Trybula, Z. [Polish Academy of Sciences, Poznan (Poland). Inst. of Molecular Physics; Pinto, N.J. [Univ. of Puerto Rico, Humacao (Puerto Rico); Shapiro, S.M. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.

1996-11-01

307

Lacerations from glass in childhood  

Microsoft Academic Search

A study of 62 glass injuries to children serious enough to warrant admission to hospital showed that 30 were due to architectural glass in doors or windows and 26 of these occurred in houses. Glass bottles caused 12 injuries. Architectural glass produced more serious injuries affecting major arteries, nerves and tendons, and internal viscera. In view of the frequency and

R H Jackson

1981-01-01

308

Structural design of sealing glasses  

Microsoft Academic Search

Requirements for enhanced component performance and reliability have led to the development of novel glass compositions for a variety of hermetic sealing applications. The development of technologically useful glass compositions was based on an understanding of the relationships between the molecular-level glass structure and important physical properties. The properties of the alkaline earth aluminoborate glasses for lithium batteries are sensitive

Richard K. Brow; David R. Tallant

1997-01-01

309

Seeing Glass Contractors Clearly.  

ERIC Educational Resources Information Center

|Offers seven tips for finding and working with an effective glass contractor. For example, schools should consider the company's reputation and longevity of service, and whether it has in-house engineering capabilities. (EV)|

Deliberato, Jerry

2003-01-01

310

Ultrastable nanostructured polymer glasses  

NASA Astrophysics Data System (ADS)

Owing to the kinetic nature of the glass transition, the ability to significantly alter the properties of amorphous solids by the typical routes to the vitreous state is restricted. For instance, an order of magnitude change in the cooling rate merely modifies the value of the glass transition temperature (Tg) by a few degrees. Here we show that matrix-assisted pulsed laser evaporation (MAPLE) can be used to form ultrastable and nanostructured glassy polymer films which, relative to the standard poly(methyl methacrylate) glass formed on cooling at standard rates, are 40% less dense, have a 40?K higher Tg, and exhibit a two orders of magnitude enhancement in kinetic stability at high temperatures. The unique set of properties of MAPLE-deposited glasses may make them attractive in technologies where weight and stability are central design issues.

Guo, Yunlong; Morozov, Anatoli; Schneider, Dirk; Chung, Jae Woo; Zhang, Chuan; Waldmann, Maike; Yao, Nan; Fytas, George; Arnold, Craig B.; Priestley, Rodney D.

2012-04-01

311

Metallic Spin Glasses  

NASA Astrophysics Data System (ADS)

Metallic Spin-glasses have drawn much experimental and theoretical attention in recent years(A. M. Sengupta and A. Georges, Phys. Rev. B52, 10295 (1995); S. Sachdev, N. Read and R. Opperman, Phys. Rev. B52, 10286 (1995); F. Steglich, et al., J. Phys. Condens. Matter 8, 99099 (1996).). One particularly interesting aspect of this system is the non-fermi-liquid behavior near the zero temperature transition between paramagnetic phase and spin-glass phase. In this talk we discuss a local mean-field theory which addresses some of the main issues. We also point out some major differences between Ising Spin-glass and Heisenberg spin-glass near the transition, within this mean field theory.(A. M. Sengupta, preprint, Cond-Mat. 9707316.)

Sengupta, Anirvan

1998-03-01

312

Whisker reinforced glass ceramic  

SciTech Connect

The process for making an in-situ whisker reinforced glass-ceramic that is up to 1.5 times as strong as conventional glass-ceramics was developed at Virginia Tech and patented in 1993. This technology has been identified as having commercial potential for use in high temperature heat exchanger applications for the electric power generation field by the National Center for Appropriate Technology (NCAT). This technology was licensed by MATVA, Inc., a small Virginia business, for further development. In particular, the goal of this project was to develop a property database and conduct initial testing of heat exchanger prototypes to demonstrate its potential application. This final report describes how the glass precursor was formed, physical properties of the glass-ceramic, techniques for making heat exchanger prototypes.

Hirschfeld, D.A.; Brown, J.J. Jr.

1996-06-03

313

Chemical Processing of Glasses.  

National Technical Information Service (NTIS)

The development of chemical processing methods for the fabrication of glass and ceramic shapes for photonic applications is frequently Edisonian in nature. In Part, this is because the numerous variables that must be optimized to obtain a given material w...

R. M. Laine

1992-01-01

314

Method for making glass nonfogging  

DOEpatents

A method for rendering glass nonfogging (to condensation fog) by sandwiching the glass between two electrodes such that the glass functions as the dielectric of a capacitor, a large alternating current (AC) voltage is applied across the electrodes for a selected time period causing the glass to absorb a charge, and the electrodes are removed. The glass absorbs a charge from the electrodes rendering it nonfogging. The glass surface is undamaged by application of the AC voltage, and normal optical properties are unaffected. This method can be applied to optical surfaces such as lenses, auto windshields, mirrors, etc., wherever condensation fog on glass is a problem.

Lord, David E. (Livermore, CA); Carter, Gary W. (Livermore, CA); Petrini, Richard R. (Livermore, CA)

1979-01-01

315

Nucleation in ZBLAN glasses  

Microsoft Academic Search

Nucleation rates were measured in a ZrFâ-BaFâ-NaF-LaFâ-AlFâ glass (ZBLAN) using an optical technique. The results were compared with a similar glass having a slightly different composition. The difference in the nucleation rate is explained by classical nucleation theory using calculated free-energy differences between the ZBLAN liquid and the BaZrFâ crystal, which is found as the precipitating phase.

Gerard de Leede; H. deWaal; Frank Hakkens

1989-01-01

316

Glass fiber insulation  

SciTech Connect

A composition for a glass fiber insulation is described comprising a loose mat of glass fibers having at least a portion of the surface coated with a water insoluble, non-hygroscopic, amorphous aluminum phosphate polymer having a molar ratio of Al[sub 2]O[sub 3] to P[sub 2]O[sub 5] of less than 1 and providing a substantial thermal resistance.

Griffith, E.J.; Ngo, T.M.

1993-06-29

317

Fluoride glass compositions  

SciTech Connect

This invention relates to Fluoride-based glasses that exhibit a high degree of transparency throughout the near ultraviolet visible and mid infrared portions of the spectrum. The glasses are composed of MgF2 and ZnF2 as essential compositional ingredients together with at least two other metallic fluorides from the group of YbF3, ThF4, PbF2, A1F3 and MnF2.

El-Bayoumi, O.

1983-08-09

318

Microstructuring of Photosensitive Glass  

NASA Astrophysics Data System (ADS)

Femtosecond laser direct writing followed by thermal treatment and successive wet etching can form three-dimensional (3D) hollow microstructures inside photosensitive glass. The principles and procedures of this process are explained. Next, the fabrication of 3D microfluidic structures and optical microcomponents is reviewed. Finally, the manufacture of functional microchip devices such as a microfluidic dye laser, optofluidics, and a nano-aquarium by integrating the microcomponents in a single glass chip is demonstrated.

Sugioka, Koji

319

Perspective: The glass transition.  

PubMed

We provide here a brief perspective on the glass transition field. It is an assessment, written from the point of view of theory, of where the field is and where it seems to be heading. We first give an overview of the main phenomenological characteristics, or "stylised facts," of the glass transition problem, i.e., the central observations that a theory of the physics of glass formation should aim to explain in a unified manner. We describe recent developments, with a particular focus on real space properties, including dynamical heterogeneity and facilitation, the search for underlying spatial or structural correlations, and the relation between the thermal glass transition and athermal jamming. We then discuss briefly how competing theories of the glass transition have adapted and evolved to account for such real space issues. We consider in detail two conceptual and methodological approaches put forward recently, that aim to access the fundamental critical phenomenon underlying the glass transition, be it thermodynamic or dynamic in origin, by means of biasing of ensembles, of configurations in the thermodynamic case, or of trajectories in the dynamic case. We end with a short outlook. PMID:23556751

Biroli, Giulio; Garrahan, Juan P

2013-03-28

320

Porous silicon oxycarbide glasses  

SciTech Connect

High-surface-area silicon oxycarbide gels and glasses were synthesized from mixtures of methyldimethoxysilane (MDMS) and tetraethoxysilane (TEOS) through acidic hydrolysis and condensation. A surface area of {approximately}275 m{sup 2}/g and an average pore size of {approximately}0 {angstrom} was obtained for a 50% MDMS-50% TEOS glass at 800 C under a flowing argon atmosphere. The average pore size was increased by aging the precursor gels in ammonium hydroxide. The increased average pore size and the higher strength of the mesoporous gel network enhanced the surface-area stability of the glasses: in this case, surface areas >200 m{sup 2}/g were retained at 1,200 C under an argon atmosphere. {sup 29}Si MAS NMR spectra revealed that an oxycarbide structure was established in the mesoporous glasses obtained after pyrolysis of the aged gels. The role of carbon was demonstrated by comparing the surface-area stability of the oxycarbide glasses with that of pure silica and that of oxycarbide glasses where all the carbon groups were removed through low-temperature plasma-oxidation treatments. In the absence of carbon, the thermal stability of the surface area decreased dramatically.

Singh, A.K.; Pantano, C.G. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

1996-10-01

321

H diffusion in diopside and anorthite glasses  

NASA Astrophysics Data System (ADS)

Water or hydrogen content of silicate glasses and melts has a strong influence on many properties and processes. Consequently, H or water diffusion in glasses plays an important role in several processes such as corrosion of glass and degassing of industrial melts or natural magmas. However, it has been difficult to determine H diffusion in glasses at relatively low temperatures. We have developed a method to produce nanometer scale thin films of complex hydrous silicates by pulsed laser deposition (PLD). This enables us to measure diffusivity of H at conditions that were difficult to access before. Anhydrous silicate glasses with compositions along the join anorthite (CaAl2Si2O8) - diopside (CaMgSi2O6) were synthesized at 1600 °C in a box furnace, rapidly quenched and cut in cylinders (3 mm diameter - 2 mm thickness) of which one end was polished. Portions of the dry glasses were powdered and sealed in AuPd capsules with an adequate amount of distilled water to produce hydrous glasses containing up to 4 wt% H2O at pressures below 10 kbar in a Piston Cylinder Apparatus. Water diffusion was investigated using the diffusion couple method. The diffusion couples were prepared by depositing thin films (150 - 200 nm) of the hydrous glasses on the dry cylinders of the same composition using PLD. This has not been possible until now, to the best of our knowledge. Diffusion couple experiments were carried out in cold seal pressure vessels at temperature ranging from 400 - 200 °C and at a pressure of 2 kbar for durations of 2 h and 10 days, respectively. H concentration profiles were measured using Nuclear Reaction Analyses (NRA) at the Dynamitron Tandem Accelerator facility of the University, before and after diffusion experiments. In our first successful experiment carried out on An50Di50 at 350 °C, 2 kbar for 16 h, diffusivity of H is 4.7 10-16 m2/s. This value is about 0.7 log units slower than the proton diffusion coefficient inferred from conductivity data on glasses of the same composition using the Nernst-Einstein equation.

Fanara, S.; Becker, H.; Rogalla, D.; Chakraborty, S.

2010-12-01

322

Competitive formation of glasses and glass-matrix composites  

SciTech Connect

By systematically investigating the effect of chemical composition on the competitive formation of glasses in various systems, we attempt to address two long-standing scientific puzzles upon metallic glasses, i.e., (i) which composition is the best for forming glasses and glass-matrix composites and (ii) what determines the easy glass-forming composition range in a given alloy system. Our findings have led to the construction of a qualitative microstructure selection map, which is useful for guiding the design of bulkier metallic glasses and glass-matrix composites. In addition, our analysis demonstrates that the classical kinetic treatment of glass formation is insufficient; to analyze glass formation properly, it is necessary to go beyond simple assumptions of single polymorphic solidification during crystallization.

Lu, Zhao Ping [ORNL; Ma, D. [University of Wisconsin, Madison; Liu, Chain T [ORNL; Chang, Y. Austin [University of Wisconsin, Madison

2007-01-01

323

DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION  

SciTech Connect

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

Adamson, D; Bradley Pickenheim, B

2008-11-24

324

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

Microsoft Academic Search

Liquid high-level nuclear waste at the Savannah River Site (SRS) will be immobilized by vitrification in borosilicate glass. The glass will be produced and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). Other waste form producers, such as West Valley Nuclear Services (WVNS) and the Hanford Waste Vitrification Project (HWVP), will also immobilize high-level radioactive waste

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

1992-01-01

325

Characterization of the Defense Waste Processing Facility (DWPF) Environmental Assessment (EA) glass Standard Reference Material. Revision 1  

Microsoft Academic Search

Liquid high-level nuclear waste at the Savannah River Site (SRS) will be immobilized by vitrification in borosilicate glass. The glass will be produced and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). Other waste form producers, such as West Valley Nuclear Services (WVNS) and the Hanford Waste Vitrification Project (HWVP), will also immobilize high-level radioactive waste

C. M. Jantzen; N. E. Bibler; D. C. Beam; C. L. Crawford; M. A. Pickett

1993-01-01

326

Oxygen-17 nuclear magnetic resonance study of the structure of mixed cation calcium-sodium silicate glasses at high pressure: implications for molecular link to element partitioning between silicate liquids and crystals.  

PubMed

The structure of silicate glasses and the corresponding liquids at high pressure and their structure-property relations remain difficult questions in modern physical chemistry, geochemistry, and condensed matter physics. Here we report high- resolution solid-state O-17 3QMAS NMR spectra for mixed cation Ca-Na silicate glasses quenched from melts at high pressure up to 8 GPa. The spectra provide the experimental evidence for the varying pressure-dependence in two different types of nonbridging oxygen (NBO) environments (i.e., Na-O-Si and mixed (Ca,Na)-O-Si) in the single glass composition. The percentage of NBO drops significantly with increasing pressure and is a complex function of melt composition, including cation field strength of network modifying cations. A decrease in NBO fraction with pressure is negatively correlated with the element partitioning coefficient between crystals and liquids at high pressure. PMID:18712911

Lee, Sung Keun; Cody, George D; Fei, Yingwei; Mysen, Bjorn O

2008-08-20

327

Electrical properties of phosphate glasses  

NASA Astrophysics Data System (ADS)

Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

Mogus-Milankovic, A.; Santic, A.; Reis, S. T.; Day, D. E.

2009-07-01

328

Effect of Gamma Irradiation on Alkali Borate Glasses by EPR Spectroscopy  

NASA Astrophysics Data System (ADS)

Alkali borate glasses interesting application in safe nuclear fuel disposal were investigated under gamma irradiation. Glasses with different composition were prepared by conventional melt quench technique. In order to explore the defects created in the glass structure due to gamma irradiation, the EPR spectrum has been taken before and after high dose rate. The results revealed that the signal of involved paramagnetic species after irradiation shown slow time decay. Annealing procedure was performed to recover radiation damage.

Catallo, N.; Baccaro, S.; Colacicchi, S.; Gualtieri, G.; Ferrara, G.; Sharma, G.

2010-04-01

329

Ion-implantation effects in glasses  

SciTech Connect

Ion implantation can be used to introduce network damage and to alter the chemical composition in glasses. Structural changes can be inferred from IR measurements near 1000 cm/sup -1/ and by optical absorption near 2150 A. Implantation induced damage decreases the implanted volume in fused silica with consequent changes in the refractive index, near-surface hardness, and surface tensile stress. Prior work in these areas is reviewed. Implantation into alkali silicate glasses depletes the alkali content in the implanted region. These changes allow preferential surface crystallization in Li/sub 2/O . 2SiO/sub 2/ glasses. Crystallization of amorphous SiO/sub 2/ can be induced by implantation of Li. Insight into the crystallization process is obtained by observing the associated ion movement using elastic recoil detection (ERD) and optical techniques. Implantation of 20 keV H shows that saturation of implanted H-sites in fused silica occurs at about 2.2 x 10/sup 21/ H/cm/sup 3/ in agreement with estimates of the number of available interstitial sites. Details of H and D interactions in fused silica were studied as a function of fluence and temperature. Results are of interest to studies of corrosion in glasses considered for nuclear waste encapsulation and for components in fusion reactors.

Arnold, G.W.

1981-01-01

330

Modifier coordination and phosphate glass networks  

SciTech Connect

The addition of up to approximately 16 mole% Cs{sub 2}O to vitreous P{sub 2}O{sub 5} reduces the glass transition temperature (T{sub g}) by 150 K, whereas further additions up to 50 mole% produce little additional change in T{sub g}. {sup 31}P magic angle spinning nuclear magnetic resonance spectra indicate that the phosphate network is progressively dipolymerized over the entire range of compositions. The property trend is explained by a transition in the Cs{sup +} coordination environment, from isolated Cs-polyhedra below {approximately}16 mole% Cs{sub 2}O to a corner-sharing Cs-polyhedral sub-structure in the glasses with greater Cs{sub 2}O contents. This modifier transition does not occur in Al-phosphate glasses. {sup 27}Al MAS NMR spectra indicate that the average Al coordination number decreases with increasing Al{sub 2}O{sub 3} content to avoid the formation of Al-O-Al bonds in these binary phosphate glasses.

Brow, R.; Click, C.A.; Alam, T.M.

1999-11-30

331

Glass matrix armor  

DOEpatents

An armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material. The glass may be in monolithic form or particles of ceramic may be dispersed in a glass matrix. The ceramic material may be in monolithic form or may be in the form of particles dispersed in glass or dispersed in said polymer.

Calkins, Noel C. (Los Alamos, NM)

1991-01-01

332

Jet penetration in glass  

SciTech Connect

We describe a phenomenological model which accounts for the mechanical response of glass to intense impulsive loading. An important aspect of this response is the dilatancy accompanying fracture. We have also conducted a number of experiments with 38.1-mm diameter precision shaped charges to establish the performance against various targets and to allow evaluation of our model. At 3 charge diameters standoff, the data indicate that both virgin and damaged glass offer better (Bernoulli-scaled) resistance to penetration than either of 4340 steel, or 6061-T6 aluminum alloy. Time-resolved measurements indicate two distinct phases of jet penetration in glass: An initial hydrodynamic phase, and a second phase characterized by a slower penetration velocity. Our calculations show that at early time, a crater is formed around the jet and only the tip of the undisturbed jet interacts with the glass. At late time the glass has collapsed on the jet and degraded penetration continues via a disturbed and fragmented jet.

Moran, B.; Glenn, L.A.; Kusubov, A.

1991-05-01

333

Museum of Glass  

NSDL National Science Digital Library

The Museum of Glass in Tacoma, Washington maintains a well crafted website for their spectacular museum. Founded in part by the famous glass artist Dale Chihuly, a Tacoma native, this museum highlights glass artists from the Pacific Northwest. Visitors won't want to miss any of the breathtaking online exhibits on this website, but one of the most spectacular is the "Chihuly Bridge of Glass" under the "Exhibitions & Collections" tab, in the "Outdoor Art" link. The slideshow of five photos shows a 500-foot pedestrian bridge that connects the Museum to downtown Tacoma. The bridge is composed of three distinct sections, one of which allows visitors to "experience a seemingly underwater world of glass shapes and forms a few feet above their heads." Also found under the "Exhibitions & Collections" tab, in the "Current Exhibitions" link, visitors will enjoy a multimedia treatment of the work "Glimmering Gone". Visitors can listen to poems by university students inspired by the exhibit, watch a "Residency" video of the artist who created the work, and view a video tour of the catalog for the exhibit.

334

Failure analysis of the lithium battery: A study of the header deposit on the cell top and diffusion within the electrode glass seal using nuclear microanalysis and FFTIR spectroscopy  

Microsoft Academic Search

The Solid Rocket Booster Range Safety System (SRBRSS) uses a lithium\\/poly-carbon monofluoride primary battery as a source of electrical power. After cell fabrication and activation, some battery cells have shown self discharge. One possible source of this cell discharge has been suggested to be the formation and growth of a conducting crystallized chemical compound across the glass bead insulator, electrically

Razi A. Hassan

1991-01-01

335

Multicomponent aluminosilicate glasses: Structure and acid corrosion  

NASA Astrophysics Data System (ADS)

The structure, acid durability, and surface layer formation of two series of fully polymerized aluminosilicate glasses with (CaO+Na2O):(Al 2O3) molar ratios of unity were examined. In particular, the effects of varying the network composition (Al2O3:SiO 2) on bulk glass structure, acid dissolution rate, and surface layer structure were determined. Surface layer formation and structure was investigated using a host of analytical techniques as a function of these compositional variables. It is shown that although the (CaO+Na2O):(Al2O 3) molar ratio remains unity throughout the series, a fully polymerized structure (expected based on "traditional" glass structure models) could not be validated. Bulk glass structures were determined experimentally with ultra-violet Raman spectroscopy (UV-Raman), infrared absorption spectroscopy (IR-absorption), and 29Si magic angle spinning nuclear magnetic resonance (29Si MAS-NMR), and were modeled with molecular dynamic (MD) simulations. The relative concentration of network bonding structures including: non-bridging oxygen (NBO) species, Al-O-Al bonding, and oxygen triclusters, were determined. These characteristics were used to explain dissolution rate, modifier release rate, and surface layer formation of the glasses when exposed to acid. Dissolution rate decreases with increasing Si-O-Si concentration. Dissolution and surface layer formation were the result of breaking network forming bonds (Al-O-Si and Al-O-Al), release of aluminum, sodium, and calcium at equal rates, and rapid re-polymerization of insoluble silica. The surface layers did not form through diffusion-limited ion-exchange between proton-bearing solution species and modifier ions within the glass. The transformed surface layers were found to be microporous, more structurally ordered than the bulk glass, and to contain primarily 3-membered and 4-membered silicate rings (with terminal silanols and trapped molecular water). The processes involved in the layer transformation were simulated using MD, and the resultant layer structures were consistent with the experimental 29Si MAS-NMR results; specifically localized condensation (relaxation) of insoluble silica as the reaction proceeds into the bulk glass.

Mellott, Nathan Petteys

336

Nonequilibrium thermodynamics of glasses  

NASA Astrophysics Data System (ADS)

We consider the nonequilibrium thermodynamics of glasses from various perspectives. For the commonly used equilibriumlike approach based on Gibbs’ fundamental form with an additional pair of conjugate variables, we discuss possible choices of the independent out-of-equilibrium variable and we illustrate some implications by concrete results for a well-known exactly solvable lattice model. The choice of variables is further illuminated from the complementary atomistic perspective offered by the inherent-structure formalism. A general formalism of nonequilibrium thermodynamics is employed (i) to derive the standard equilibriumlike approach, (ii) to formulate two self-contained levels to describe glassy dynamics and thermodynamics, and (iii) to offer guidance for future simulations of glasses. The thermodynamic approach suggests to introduce four-point correlation functions associated with structural rearrangements after imposed deformations, which might offer a possibility to detect a growing length scale at the glass transition without employing any dynamic information.

Christian Öttinger, Hans

2006-07-01

337

Nonequilibrium thermodynamics of glasses.  

PubMed

We consider the nonequilibrium thermodynamics of glasses from various perspectives. For the commonly used equilibriumlike approach based on Gibbs' fundamental form with an additional pair of conjugate variables, we discuss possible choices of the independent out-of-equilibrium variable and we illustrate some implications by concrete results for a well-known exactly solvable lattice model. The choice of variables is further illuminated from the complementary atomistic perspective offered by the inherent-structure formalism. A general formalism of nonequilibrium thermodynamics is employed (i) to derive the standard equilibriumlike approach, (ii) to formulate two self-contained levels to describe glassy dynamics and thermodynamics, and (iii) to offer guidance for future simulations of glasses. The thermodynamic approach suggests to introduce four-point correlation functions associated with structural rearrangements after imposed deformations, which might offer a possibility to detect a growing length scale at the glass transition without employing any dynamic information. PMID:16907066

Ottinger, Hans Christian

2006-07-21

338

Characterization of Analytical Reference Glass-1 (ARG-1)  

SciTech Connect

High-level radioactive waste may be immobilized in borosilicate glass at the West Valley Demonstration Project, West Valley, New York, the Defense Waste Processing Facility (DWPF), Aiken, South Carolina, and the Hanford Waste Vitrification Project (HWVP), Richland, Washington. The vitrified waste form will be stored in stainless steel canisters before its eventual transfer to a geologic repository for long-term disposal. Waste Acceptance Product Specifications (WAPS) (DOE 1993), Section 1.1.2 requires that the waste form producers must report the measured chemical composition of the vitrified waste in their production records before disposal. Chemical analysis of glass waste forms is receiving increased attention due to qualification requirements of vitrified waste forms. The Pacific Northwest Laboratory (PNL) has been supporting the glass producers` analytical laboratories by a continuing program of multilaboratory analytical testing using interlaboratory ``round robin`` methods. At the PNL Materials Characterization Center Analytical Round Robin 4 workshop ``Analysis of Nuclear Waste Glass and Related Materials,`` January 16--17, 1990, Pleasanton, California, the meeting attendees decided that simulated nuclear waste analytical reference glasses were needed for use as analytical standards. Use of common standard analytical reference materials would allow the glass producers` analytical laboratories to calibrate procedures and instrumentation, to control laboratory performance and conduct self-appraisals, and to help qualify their various waste forms.

Smith, G.L.

1993-12-01

339

Compositions and Durabilities of Glasses for Immobilization of Plutonium and Uranium  

SciTech Connect

As the nuclear weapon arsenals of the United States and the Former Soviet Union are reduced, metric tonnage quantities of fissile material must be dispositioned. One of the potential disposition options for fissile weapons material is vitrification into a stable form -- essentially a plutonium or uranium single phase glass product. Savannah River Technology Center (SRTC) at Savannah River Site (SRS) is actively developing suitable glass formulations for the long term safe storage of plutonium and uranium. These investigations are also being extended to develop glasses for the stabilization and storage of kilogram amounts of neptunium, americium, and curium that are currently stored as solutions in the process canyons at SRS -- thus the glasses are called actinide glasses. SRTC is also in the process of developing a remote process demonstration which can produce metric tonnage quantities of the glasses. This paper discusses the chemical compositions and durabilities of two types of actinide glasses under development. One of the glasses is a borosilicate, and the other an iron phosphate. In this initial study thorium and uranium were used as the actinides. Because of the low radioactivity of these elements, the glasses could be prepared and tested on the bench top. In studies beginning in FY `95, glasses containing neptunium, plutonium, americium and curium will be produced. These glasses will be prepared and tested remotely in the shielded cells and glovebox facilities at Savannah River Technology Center. In the initial study, a considerable number (>20) of thorium and uranium bearing glasses have been prepared. An equivalent number of rare earth surrogate (non-radioactive) glasses have also been prepared and tested. The glasses were prepared by mixing dry chemicals and melting them at 1425C for the borosilicate glasses and at 1100C for the iron phosphate glasses. (Abstract Truncated)

Ramsey, W.G.; Bibler, N.E.; Meaker, T.F.

1995-02-28

340

Recycling of waste glasses into partially crystallized glass foams  

Microsoft Academic Search

Waste soda-lime glass, alone or mixed with wastes from the manufacturing of glass fibers, was successfully converted into\\u000a partially crystallized glass foams by a particularly simple and economic processing, consisting of a direct heating of glass\\u000a powders at temperatures from 900 to 1050 °C. The foaming operated by the oxidation of SiC, inserted as powder additive, was\\u000a found to depend on

Enrico Bernardo; Giovanni Scarinci; Paolo Bertuzzi; Piero Ercole; Ludovico Ramon

2010-01-01

341

Characterization of projected DWPF glasses heat treated to simulate canister centerline cooling  

Microsoft Academic Search

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

S. L. Marra; C. M. Jantzen

1992-01-01

342

Characterization of projected DWPF glasses heat treated to simulate canister centerline cooling. Revision 1  

Microsoft Academic Search

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

S. L. Marra; C. M. Jantzen

1993-01-01

343

Role of structure in ion movement of glasses. Progress report, January 5, 1992--November 1, 1992  

SciTech Connect

Three kinds of experiments were performed: modified random network model and ion movement; role of melt structure in ion transport in glassy state; and ion movement in fluorozirconate glass (breakdown of correspondence between electrical and nuclear spin relaxation). A comment is offered on dielectric loss peak in glasses. 11 refs, 1 fig. (DLC)

Jain, H.

1992-11-03

344

Crystallisation of Magnox waste glass under conditions of high temperature, very deep, geological disposal  

Microsoft Academic Search

The behaviour of a simulant Magnox waste glass was investigated under the likely conditions of high tempera- ture, very deep, geological disposal, namely 760° C and 0· 15GPa, to assess the suitability of this scheme for dis- posal of high level vitrified nuclear waste. Partial crys- tallisation of the glass is observed under these conditions with the formation of LnBSiO

N. C. Hyatt; K. J. Taylor; F. G. F. Gibb; W. E. Lee

345

Nucleation in ZBLAN glasses  

SciTech Connect

Nucleation rates were measured in a ZrF{sub 4}-BaF{sub 2}-NaF-LaF{sub 3}-AlF{sub 3} glass (ZBLAN) using an optical technique. The results were compared with a similar glass having a slightly different composition. The difference in the nucleation rate is explained by classical nucleation theory using calculated free-energy differences between the ZBLAN liquid and the BaZrF{sub 6} crystal, which is found as the precipitating phase.

Leede, G.d.; deWaal, H.; Hakkens, F. (Eindhoven Univ. of Technology, Eindhoven (NL))

1989-10-01

346

Crystalline fragments in glasses  

NASA Astrophysics Data System (ADS)

The nature of tetrahedral molecular fragments is investigated in SiSe2 glasses using the molecular-dynamics method. The glass consists of both edge-sharing (ES) and corner-sharing tetrahedra. The ES tetrahedra are the building blocks of chain-like-molecular fragments. The two-edge-sharing tetrahedra are the nucleus, and corner-sharing configurations provide connecting hinges between fragments. Statistics of rings and fragments reveals that threefold and eightfold rings are most abundant, chainlike fragments that are typically 10-15 Å long occur mostly in eightfold rings, and the longest fragments occur in elevenfold rings.

Antonio, Giomal A.; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

1992-04-01

347

Prediction of radioactive waste glass durability by the hydration thermodynamic model: Application to saturated repository environments  

SciTech Connect

The effects of groundwater chemistry on glass durability were examined using the hydration thermodynamic model. The relative durabilities of SiO{sub 2}, obsidians, basalts, nuclear waste glasses, medieval window glasses, and a frit glass were determined in tuffaceous groundwater, basaltic groundwater, WIPP-A brine, and Permian-A brine using the monolithic MCC-1 durability test. For all the groundwaters, the free energy of hydration, calculated from the glass composition and the final experimental pH, was linearly related to the logarithm of the measured silica concentration. The linear equation was identical to that observed previously for these glasses during MCC-1 testing in deionized water. In the groundwater-dominated MCC-1 experiments, the pH values for all the glasses tested appeared to be buffered by the groundwater-precipitate chemistry. The behavior of poorly durable glasses demonstrated that the silica release is a function of the ionic strength of the solution. The ionic strength, in turn, reflects the effect of the groundwater chemistry on the pH. Using the hydration thermodynamic model, nuclear waste glass durability in saturated repository environments can be predicted from the glass composition and the groundwater and the groundwater pH. 47 refs., 3 figs. 1 tab.

Jantzen, C.M. (Westinghouse Savannah River Co., Aiken, SC (USA)); Ramsey, W.G. (Clemson Univ., SC (USA). Dept. of Ceramic Engineering)

1989-01-01

348

Parametric testing of a DWPF glass  

SciTech Connect

A series of tests has been performed to characterize the chemical stability of a DWPF borosilicate glass sample as part of the Waste Package Task of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. This material was prepared at the Savannah River Laboratory for the purpose of testing the 165-frit matrix doped with a simulated nonradioactive waste. All tests were conducted at 90{sup 0}C using deionized water and J-13 water (a tuffaceous formation ground water). In the deionized water tests, both monoliths and crushed glass were tested at various ratios of surface area of the sample to volume of water in order to compare leach rates for different sample geometries or leaching times. Effects on the leach rates as a result of the presence of crushed tuff and stainless steel material were also investigated in the tests with J-13 water. 3 refs., 12 figs., 7 tabs.

Bazan, F.; Rego, J.

1985-03-01

349

Recent experimental advances in spin glasses  

SciTech Connect

We present a working definition and a general description of a spin glass. A number of different systems, including metals, semiconductors, and insulators, are discussed. This review presents the current status of experimental spin-glass research with special emphasis on the extent to which the results of this research yield information on spin dynamics. We review the salient features of a series of recent experimental results, published in the past five years, on the susceptibility, magnetization, heat capacity, high-pressure effects, phonon-thermal conductivity, neutron scattering, nuclear, electron, and muon spin resonance. The successful applications of the fractional exponential relaxation function to the frequency dependence of the susceptibility and the time dependence of the thermoremanent magnetization are demonstrated. Concerning the possible existence of the phase transition at the susceptibility cusp temperature, we summarize the experimental evidences. 179 references, 31 figures.

Huang, C.Y.

1983-01-01

350

On the strength of glass  

NASA Astrophysics Data System (ADS)

Glass has been ignored by most of the structural engineering community because of its brittle nature. Glass is an indispensable material in optical systems and sometimes safety, even human safety, depends upon optical glass elements to behave in a structurally reliable manner. One such occasion is to accommodate survey cameras in transport-class aircraft. Fortunately, glass has reliable structural properties and the methods for structural analysis and testing for glass have been well developed. Unfortunately, the glass suppliers have not chosen to publish the appropriate strength properties for many of their glasses. This paper describes the physics of the strength of glass and the engineering application of that physics to an airborne survey aircraft for the safety of its inhabitants.

Hatheway, Alson E.

2013-09-01

351

Chemical Properties of Metallic Glasses.  

National Technical Information Service (NTIS)

Research into chemical properties of metallic glasses has revealed promising behavior in the areas of corosion resistance and catalysis. Metallic glasses containing a film-forming element exhibit resistance to uniform and localized corrosion that is super...

R. B. Diegle

1983-01-01

352

The Upgrading of Glass Microballoons.  

National Technical Information Service (NTIS)

The processes and mechanisms involved in producing glass microballoons of acceptable quality for laser fusion by gas jet levitation and manipulation were studied. Glass microballoons (GMBs) levitated at temperatures below, as well as above the liquidus, a...

S. Gunter S. A. Dunn

1979-01-01

353

Fabrication of Hard Glass Plates.  

National Technical Information Service (NTIS)

This report describes the fabrication of hard glass for use in ballistic application. The work consisted of establishing optimum composition and process conditions for several different glasses. Properties such as Knoop hardness, density, flexural strengt...

A. Z. Hed M. A. Ali

1974-01-01

354

Product Consistency Testing of Three Reference Glasses in Stainless Steel and Perfluoroalkoxy Resin Vessels.  

National Technical Information Service (NTIS)

Because of their chemical durability, silicate glasses have been proposed and researched since the mid-1950s as a medium for incorporating high-level radioactive waste (HLW) generated from processing of nuclear materials. A number of different waste forms...

G. L. Smith K. M. Olson S. C. Marschman

1995-01-01

355

Antagonist effects of calcium on borosilicate glass alteration  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

356

Spectroscopic studies of glass structure  

SciTech Connect

Today`s understanding of the molecular-level structure of inorganic glasses has been transformed by the availability of a wide range of sensitive spectroscopic probes. Today we can relate glass composition to quantitative distributions of glass-forming cations and to changes in oxygen bonding and modifying cation geometries. Future spectroscopic studies will result in improved descriptions of anion and cation geometries and should provide glass scientists with the capability to optimize atomic arrangements for specific optical, electrical, and thermal properties.

Brow, R.K.

1994-08-01

357

Neutron-sensing scintillating glass optical fiber detectors  

SciTech Connect

Pacific Northwest Laboratory (PNL) has developed and tested the highest-transmission neutron-sensing glass fibers reported in the open literature to date. By developing glass compositions specifically for fiber drawing and by using superior oxidationstate controls and rapid quenching, PNL produces, fiber with useful lengths in excess of 200 cm. These long fibers can be used in detectors. Test results on the fibers used as a form-fitting detector around a small storage container containing neutron and gamma ray sources are reported. Excellent neutron-gamma ray discrimination has been achieved. These neutron-sensing glass optical fibers provide for new methods for monitoring the inventory of, preventing the diversion of, and detecting the unauthorized transport of sensitive nuclear materials. As such, it represents a significant potential element in countering the threat of nuclear terrorism.

Bliss, M.; Reeder, P.L.; Craig, R.A.

1994-07-01

358

Shimmering Stained Glass.  

ERIC Educational Resources Information Center

|Presents an art lesson for fifth- and sixth-graders where they create a translucent design of colored cellophane on black paper inspired by the stained-glass windows of the Middle Ages and the artwork of Lewis Comfort Tiffany. Enables the students to become crafts people rather than just observers of the past. (CMK)|

Simon, Gail Murray

1998-01-01

359

CADMIUM PHOSPHATE GLASS  

DOEpatents

A method of preparing a cadmium phosphate glass that comprises providing a mixture of solid inorganic compounds of cadmuim and phosphate having vaporizable components and heating the resulting composition to a temperature of at least 850 un. Concent 85% C is presented. (AEC)

Carpenter, H.W.; Johnson, P.D.

1963-04-01

360

“Through-glass” injuries  

Microsoft Academic Search

This prospective trial collected all cases where injuries had resulted from the hand passing through or striking glass and had been referred to a hand injury service during 1 year. Eighty-seven cases were referred and the factors relating to these injuries were examined. A record was made of the structures damaged, the surgery performed and prevailing socioeconomic factors. These injuries

L. R. Irwin; J. C. Daly; J. H. James; C. L. Muwanga; L. Williams

1996-01-01

361

Light Bends Glass  

NSDL National Science Digital Library

This site, from Physical Review Focus, describes a recent experiment to find out how the momentum of a photon changes when it passes from a glass fiber into air. The article describes the 100-year-old controversy on this question and explains the results of this experiment. Links are provided for more information.

2009-02-26

362

What Glass Ceiling?  

ERIC Educational Resources Information Center

|A recent study drawing on data from the Census Bureau and the Bureau of Labor Statistics suggests that the wage gap between men and women has virtually disappeared, and that the so-called "glass ceiling" results more from age and qualifications than from explicit discrimination. (SLD)|

Lynch, Michael; Post, Katherine

1996-01-01

363

Glass microbubble composite foam  

Microsoft Academic Search

Composite foams have been prepared from blends of Kerimid 601 polyimide resin and different types of glass microbubbles. Kerimid 601 is an addition type polyimide that offers many processing advantages over other types of polyimides. In an addition reaction, no volatiles are evolved during cure and weight loss and shrinkage during cure are small. Also, since the resin is a

McIlroy

1978-01-01

364

Metallic Glass Composition.  

National Technical Information Service (NTIS)

This patent pertains to a metallic glass alloy that is either iron-based or nickel-based or based on a mixture of iron and nickel, containing lesser amounts of elements selected from the group boron, silicon, carbon and phosphorous to which is added an am...

D. M. Kroeger C. C. Koch

1984-01-01

365

"Stained Glass" Landscape Windows  

ERIC Educational Resources Information Center

|Both adults and children alike marvel at the grand vivid stained-glass windows created by American artist Louis Comfort Tiffany. Today he is commonly recognized as one of America's most influential designers and artists throughout the last nineteenth and early twentieth century. In the lesson described in this article, students created their own…

Vannata, Janine

2008-01-01

366

The Glass Cockpit  

Microsoft Academic Search

In modern air craft, the cockpit is often referred to as a glass cockpit because of the replacement of traditional banks of mechanical dials with computer monitors. Behind these modern displays is a variety of interconnected computers, sensors, and actuators that constitute the avionics system. Avionics systems are technological wonders that increase our safety while flying, improve the efficiency of

John Knight

2007-01-01

367

Barstow heliostat mirror glass characterization  

SciTech Connect

The technical analysis performed on the special run of low iron float glass procured from the Ford Glass Division for the ten megawatt solar thermal/electric pilot power plant to be constructed at Barstow, California is discussed. The topics that are addressed include the optical properties and the relative durability of the glass. Two optical parameters, solar transmittance and optical flatness, were measured as referenced in the specification and found to be better than the stated tolerances. The average solar transmittance exceeded 0.890 transmittance units. The glass also exhibited optical angular flatness deviations less than +-1.0 mrad as required. Both qualitative and quantitative accelerated weathering tests were performed on the glass in order to compare its durability to other soda lime float glass and alternate composition glasses of interest to the solar community. In both the quantitative leaching experiments and the more qualitative room temperature and elevated temperature water vapor exposure experiments the heliostat glass exhibited the same characteristics as the other soda-lime silicate float glasses. As a final test for mirroring compatability, selected samples of the production run of the glass were sent to four different commercial manufacturers for mirror coating. None of the manufacturers reported any difficulty silvering the glass. Based on the tests performed, the glass meets or exceeds all optical specifications for the Barstow heliostat field.

Lind, M.A.; Buckwalter, C.Q.

1980-09-01

368

Post-Tensioned Glass Beams  

Microsoft Academic Search

At Delft University, glass researchers have developed a revolutionary safety concept for glass beams. This safety concept\\u000a shows some analogy with reinforced concrete; glass beams are reinforced and\\/or post-tensioned by adding (stainless) steel\\u000a to the layout of the beam.

C. Louter; J. van Heusden; F. Veer; J. Vambersky; H. Boer; J. Versteegen

369

Nonsilica glasses for holey fibers  

Microsoft Academic Search

The authors of this paper investigated the thermal properties and optical properties of typical nonsilica glasses, including viscosity, surface tension, thermal conductivity, transmission, linear and nonlinear refractive index, and fiber attenuation in order to judge the feasibility of using nonsilica glasses as the background material of holey fibers (HFs). Novel techniques were presented to fabricate the nonsilica glass microstructured fiber

Xian Feng; Arshad K. Mairaj; Daniel W. Hewak; Tanya M. Monro

2005-01-01

370

Yesterday's Trash Makes Tomorrow's "Glass"  

ERIC Educational Resources Information Center

In this article, the author describes a glass art project inspired by Dale Chihuly. This project uses two-liter plastic soda bottles which are cut apart and trimmed. Applying heat using a hair dryer, the plastic curls and takes an uneven blown-glass quality. The "glass" is then painted using acrylic paint. (Contains 2 resources and 1 online…

Wayne, Dale

2010-01-01

371

Yesterday's Trash Makes Tomorrow's "Glass"  

ERIC Educational Resources Information Center

|In this article, the author describes a glass art project inspired by Dale Chihuly. This project uses two-liter plastic soda bottles which are cut apart and trimmed. Applying heat using a hair dryer, the plastic curls and takes an uneven blown-glass quality. The "glass" is then painted using acrylic paint. (Contains 2 resources and 1 online…

Wayne, Dale

2010-01-01

372

Heliostat glass survey and evaluation  

Microsoft Academic Search

The glass characterization and specification task included a comprehensive survey of both foreign and domestic sources of low distortion, low iron, .125 nominal flat glass for use in heliostat applications. PNL attempted to determine the availability of production lines, estimate industry interest, lead times, and costs for producing glass for second surface heliostat mirrors for the Barstow pilot plant and

M. A. Lind; J. M. Russin

1978-01-01

373

Local and Medium Range Order Around Fission Products in Inactive Waste Glasses: Implication for Glass Structure and Stability  

NASA Astrophysics Data System (ADS)

Borosilicate glasses are used to store high level nuclear waste in France (R7T7 glass). The structure of the glass around elements such as fission products controls important parameters as the homogeneity of the glass and/or the melted glass rheology. Data on the local and medium range order structure of these glasses could help improving the resistance toward leaching and/or irradiation, in relation with surface or geological storage of these vitrified wastes. Due to the complex composition of these glasses (up to 30 oxides), chemically selective methods are required to understand the environment of elements. X-ray Absorption Spectroscopy (XAS) is, from this point of view, a powerful tool as it provides a direct access to the investigation of the structure around specific cations in this multicomponent amorphous material, to specify their role in the glass durability. We will present different XAS studies (synchrotrons in LURE and ESRF, France) on the inactive amorphous analog for the R7T7 glass (the SON 68 glass). This report will illustrate the potentialities of this approach through the determination of the environment around fission products such as Zr, Zn and Mo. XAS shows the peculiarity of the sites occupied by these glass components of technological interest. Coordination numbers are shown to be systematically smaller than in crystalline compounds with close composition. Below the definition of the sites occupied by the chemical elements, XAS allows to detect some degree of medium range order which gives insight on the bonding of the site to the poymeric borosilicate network and allow to link precisely experimental data to theoretical calculations. Eventually, XAS is used to study the interaction between noble metals (Pd and Ru) and the glassy matrix. These elements are at the origin of small precipitates that induce changes in the melt vicosity. They occur as a result of the non-insertion of these elements in the glassy matrix. To accurate and precise structural interpretations, a direct comparison with MD calculations on simplified nuclear glass comprising 5 oxides, is performed.

Galoisy, L.; Calas, G.; Ghaleb, D.; Morin, G.

2002-12-01

374

Bioactive calcium pyrophosphate glasses and glass-ceramics.  

PubMed

Calcium phosphate glass-based materials in the pyrophosphate region are briefly reviewed. Calcium pyrophosphate glasses can be prepared by including a small amount of TiO(2) (glasses in simulated body fluid. By heating powder-compacts of the glasses, they are crystallized and subsequently are sintered, resulting in fabrication of high-strength glass-ceramics with machinability; they are easier to be machined using conventional tools in comparison with conventional calcium phosphate ceramics. beta-Ca(2)P(2)O(7) crystal formed in the glass-ceramics plays an important role in the machinability. Their apatite-forming ability in simulated body fluid is drastically enhanced after autoclaving in distilled water. The glass-ceramics can be easily coated on a new beta-type titanium alloy using a conventional glazing technique. PMID:16701780

Kasuga, Toshihiro

2005-01-01

375

Apollo 12 ropy glasses revisited  

NASA Astrophysics Data System (ADS)

We analyzed ropy glasses from Apollo 12 soils 12032 and 12033 by a variety of techniques including SEM/EDX, electron microprobe analysis, INAA, and Ar-39-Ar-40 age dating. The ropy glasses have potassium rare earth elements phosphorous (KREEP)-like compositions different from those of local Apollo 12 mare soils; it is likely that the ropy glasses are of exotic origin. Mixing calculations indicate that the ropy glasses formed from a liquid enriched in KREEP and that the ropy glass liquid also contained a significant amount of mare material. The presence of solar Ar and a trace of regolith-derived glass within the ropy glasses are evidence that the ropy glasses contain a small regolith component. Anorthosite and crystalline breccia (KREEP) clasts occur in some ropy glasses. We also found within these glasses clasts of felsite (fine-grained granitic fragments) very similar in texture and composition to the larger Apollo 12 felsites, which have a Ar-39-Ar-40 degassing age of 800 +/- 15 Ma. Measurements of 39-Ar-40-Ar in 12032 ropy glass indicate that it was degassed at the same time as the large felsite although the ropy glass was not completely degassed. The ropy glasses and felsites, therefore, probably came from the same source. Most early investigators suggested that the Apollo 12 ropy glasses were part of the ejecta deposited at the Apollo 12 site from the Copernicus impact. Our new data reinforce this model. If these ropy glasses are from Copernicus, they provide new clues to the nature of the target material at the Copernicus site, a part of the Moon that has not been sampled directly.

Wentworth, S. J.; McKay, D. S.; Lindstrom, D. J.; Basu, A.; Martinez, R. R.; Bogard, D. D.; Garrison, D. H.

1994-05-01

376

Colloid formation in implanted glasses  

SciTech Connect

Metal colloids in glasses can yield an enhanced ([chi]([sup 3])) susceptibility which leads to an intensity dependent refractive index. Ion implantation is a convenient means of introducing the metal species. The host glass plays an important role in colloid formation. We have characterized Ag-colloid formation in various silicate glasses and, in addition, have studied the formation of colloids in Ag-doped phosphate glass as a function of N and H implantation. Some preliminary results for Cu-implanted glasses are presented.

Arnold, G.W. (Sandia National Labs., Albuquerque, NM (United States)); Mazzoldi, P.; Tramontin, L. (Padua Univ. (Italy)); Boscolo-Boscoletto, A. (ECP-EniChem Polimeri, Porto Marghera (Italy)); Battaglin, G. (Venice Univ. (Italy))

1992-01-01

377

Colloid formation in implanted glasses  

SciTech Connect

Metal colloids in glasses can yield an enhanced ({chi}({sup 3})) susceptibility which leads to an intensity dependent refractive index. Ion implantation is a convenient means of introducing the metal species. The host glass plays an important role in colloid formation. We have characterized Ag-colloid formation in various silicate glasses and, in addition, have studied the formation of colloids in Ag-doped phosphate glass as a function of N and H implantation. Some preliminary results for Cu-implanted glasses are presented.

Arnold, G.W. [Sandia National Labs., Albuquerque, NM (United States); Mazzoldi, P.; Tramontin, L. [Padua Univ. (Italy); Boscolo-Boscoletto, A. [ECP-EniChem Polimeri, Porto Marghera (Italy); Battaglin, G. [Venice Univ. (Italy)

1992-12-31

378

'ULISSE' Project for the Treatment of Radioactive Wastes of ENEA (European Nuclear Energy Agency) Department of Fuel. A Comparative Study for Defining the Glass Matrix to Immobilize High Activity Wastes.  

National Technical Information Service (NTIS)

The high-level liquid wastes produced by the Nuclear Fuel Cycle Department of the Italian Committee for R and D of Nuclear and Alternative Energy since 1970 are characterized by a very high aluminum content which would seriously limit the option of their ...

M. Broglia

1988-01-01

379

Commercial and Experimental Glass Fibers  

NASA Astrophysics Data System (ADS)

Continuous glass fibers can be formed from melts with a wide range of compositions and viscosities. This chapter reviews pure silica fibers which are formed from highly viscous melts, silicate glass fibers with 50-70% SiO2 which are formed from moderately viscous melts, aluminate glass fibers with 50-80% Al2O3, as well as yttria-alumina-garnet (YAG) glass fibers which are formed from inviscid (literally non-viscous) melts. Commercial glass fibers are made for a variety of applications from pure silica rods and from silicate melts containing 50-70% SiO2 and 10-25% Al2O3. Boron-free, essentially boron-free, and borosilicate E-glass are general-purpose fibers. ERC-glass offers high corrosion resistance, HS-glass offers high-strength composites, D-glass offers a low dielectric constant, and A-glass offers the possibility of using waste container glass for less demanding applications.

Wallenberger, Frederick T.

380

Profiles in garbage glass containers  

SciTech Connect

Glass containers are made from sand, limestone, soda ash, cullet (crushed bottles), and various additives, including those used to color brown, green, or blue bottles. Sixty percent of the glass used in the US is clear (flint) and one-fourth is brown (amber). Almost half of the green bottles are imported wind and beer bottles. Other glass products include flat glass such as windows; fiberglass insulation; and glassware. These products use different manufacturing processes and different additives than container glass. This profile covers only container glass. Glass bottles are commonly collected in curb-side programs. Losses due to breakage and the abrasiveness of glass during collection and processing offset their low collection and processing costs. Breakage solutions include installation of interior baffles or nets in the collection trucks, special glass-only truck compartments, and limiting the number of times glass is transferred after collection before final processing. Ten states require deposits on glass bottles for beer and soft drinks and related items.

Miller, C. [Environmental Industry Associations, Washington, DC (United States)

1997-09-01

381

Quality of glass marbles and the preparation of bubble-free glass for fiber production  

Microsoft Academic Search

Before the glass marbles are produced the glass-making process has been completed and the glass has passed through all the glass-making stages, including that of fining. A microscopic analysis of a batch of glass marbles showed that they contained no gas inclusions in the volume. To work the glass fiber it is necessary that the molten glass be at a

V. V. Ulybyshev; T. A. Vlasova; V. Vo Yurchenko

1986-01-01

382

Production of glass or glass-ceramic to metal seals with the application of pressure  

DOEpatents

In a process for preparing a glass or glass-ceramic to metal seal comprising contacting the glass with the metal and heat-treating the glass and metal under conditions whereby the glass to metal seal is effected and, optionally, the glass is converted to a glass-ceramic, an improvement comprises carrying out the heat-treating step using hot isostatic pressing.

Kelly, M.D.; Kramer, D.P.

1985-01-04

383

Production of glass or glass-ceramic to metal seals with the application of pressure  

DOEpatents

In a process for preparing a glass or glass-ceramic to metal seal comprising contacting the glass with the metal and heat-treating the glass and metal under conditions whereby the glass to metal seal is effected and, optionally, the glass is converted to a glass-ceramic, an improvement comprises carrying out the heat-treating step using hot isostatic pressing.

Kelly, Michael D. (West Alexandria, OH); Kramer, Daniel P. (Dayton, OH)

1987-11-10

384

Low Temperature Sintering of P2O5Added Cordierite Glass with Borosilicate Glass  

Microsoft Academic Search

Borosilicate glass was adopted as a sintering aid to improve the sinterability of P2O5-added cordierite glass. The flux effect of borosilicate glass aids the coalescence of cordierite glass particles, which promotes the densification. Crystallization of cordierite glass is the major reaction during the sintering of cordierite glass with borosilicate glass. Besides the advantage of lower sintering temperature, the addition of

Shen-Li Fu; Lih-Shan Chen

1993-01-01

385

Low Temperature Sintering of P2O5Added Cordierite Glass with Lead Borosilicate Glass  

Microsoft Academic Search

Cordierite was prepared by the sintering of cordierite glass and lead borosilicate glass. With the addition of lead borosilicate glass, P2O5-added cordierite glass can be densified at lower sintering temperature. Owing to the flux effect of lead borosilicate glass, the coalescence of glass particles was aided by the viscous flow of the glass. Besides the advantage of lower temperature sintering,

Lih-Shan Chen; Shen-Li Fu

1992-01-01

386

Bulk metallic glass matrix composites  

SciTech Connect

Composites with a bulk metallic glass matrix were synthesized and characterized. This was made possible by the recent development of bulk metallic glasses that exhibit high resistance to crystallization in the undercooled liquid state. In this letter, experimental methods for processing metallic glass composites are introduced. Three different bulk metallic glass forming alloys were used as the matrix materials. Both ceramics and metals were introduced as reinforcement into the metallic glass. The metallic glass matrix remained amorphous after adding up to a 30 vol{percent} fraction of particles or short wires. X-ray diffraction patterns of the composites show only peaks from the second phase particles superimposed on the broad diffuse maxima from the amorphous phase. Optical micrographs reveal uniformly distributed particles in the matrix. The glass transition of the amorphous matrix and the crystallization behavior of the composites were studied by calorimetric methods. {copyright} {ital 1997 American Institute of Physics.}

Choi-Yim, H.; Johnson, W.L. [W. M. Keck Laboratory of Engineering Materials, Mail Code 138-78, California Institute of Technology, Pasadena, California 91125 (United States)

1997-12-01

387

Structural interpretations of aluminosilicate glasses  

NASA Astrophysics Data System (ADS)

This manuscript presents a theoretical analysis of the correlation between the bulk moduli and the structure of a series of multicomponent aluminosilicate glasses in terms of the bond compression model. The main parameters in the analysis were the computed elastic moduli, the average stretching-force constant and the average atomic ring size. These parameters were calculated for every glass series and for every glass composition. The results showed that the average force constant of these glasses increases and the elastic moduli decrease with the increase in the SiO2 content (pure covalent bonds). This behaviour was attributed to the decrease in the molar volume, and the role of both CaO and Al2O3. The average atomic ring size of the studied glasses are about two-thirds of pure SiO2, whilst the elastic moduli of pure SiO2 glass are about two thirds of these glasses.

Saddeek, Yasser B.

2005-06-01

388

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

SciTech Connect

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

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

1992-09-30

389

NUCLEAR WASTE VITRIFICATION EFFICIENCY COLD CAP REACTIONS  

Microsoft Academic Search

The cost and schedule of nuclear waste treatment and immobilization are greatly affected by the rate of glass production. Various factors influence the performance of a waste-glass melter. One of the most significant, and also one of the least understood, is the process of batch melting. Studies are being conducted to gain fundamental understanding of the batch reactions, particularly those

KRUGER AA; HRMA PR; POKORNY R

2011-01-01

390

Chalcogenide glass bolometers.  

PubMed

The chalcogenide glass Tl(2)SeAs(2) Te(3) has been evaluated as a thermistor bolometer material for room temperature operation. Thin film bolometers were fabricated on mica, glass, and sapphire substrates by both hot-pressing and rf sputtering techniques. Best results were achieved with 10-micro thick Tl(2)SeAs(2) Te(3) elements on thin mica substrates. Using a 500 K blackbody at a 10-Hz chopping frequency, a 2.5 x10(_3)cm(2) device yielded an NEP of 2.3 x 10(_9) W Hz(_4) cm(-2) device achieved an NEP of 7.7 x 10(-10) W Hz(-1/2) The ac performance of these devices is limited by their inherently long response times (tau congruent with 1 sec). PMID:20125232

Bishop, S G; Moore, W J

1973-01-01

391

Chalcogenide glass photonic crystals  

NASA Astrophysics Data System (ADS)

All-optical switching devices are based on a material possessing a nonlinear optical response, enabling light to control light, and are enjoying renewed interest. Photonic crystals are a promising platform for realizing compact all-optical switches operating at very low power and integrated on an optical integrated circuit. In this review, we show that by making photonic crystals from a highly nonlinear chalcogenide glass, we have the potential to integrate a variety of active devices into a photonic chip. We describe the fabrication and testing of two-dimensional Ge33As12 Se55 chalcogenide glass photonic crystal membrane devices (waveguides and microcavities). We then demonstrate the ability to post-tune the devices using the material photosensitivity. In one proposal we hope to introduce a double-heterostructure microcavity using the photosensitivity alone.

Freeman, Darren; Grillet, Christian; Lee, Michael W.; Smith, Cameron L. C.; Ruan, Yinlan; Rode, Andrei; Krolikowska, Maryla; Tomljenovic-Hanic, Snjezana; de Sterke, C. Martijn; Steel, Michael J.; Luther-Davies, Barry; Madden, Steve; Moss, David J.; Lee, Yong-Hee; Eggleton, Benjamin J.

2008-04-01

392

Glass matrix armor  

SciTech Connect

This patent describes an armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the insides surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material.

Calkins, N.C.

1991-09-03

393

Ductile bulk metallic glass.  

PubMed

We report on experimental evidence of pronounced global plasticity measured in monolithic Pt57.5Cu14.7Ni5.3P22.5 bulk metallic glass under both bending and unconfined compression loading conditions. A plastic strain of 20% is measured, never before seen in metallic glasses. Also, permanent deformation and a strain exceeding 3% before failure is observed during bending of 4 mm thick samples. To date, no monolithic metallic material has exhibited such a combination of high strength, extensive ductility, and high elastic limit. The large plasticity is reflected in a high Poisson ratio of 0.42, which causes the tip of a shear band to extend rather than initiate a crack. This results in the formation of multiple shear bands and is the origin of the observed large global ductility and very high fracture toughness, approximately 80 MPa m(-1/2). PMID:15697909

Schroers, Jan; Johnson, William L

2004-12-16

394

Metallic Spin Glasses  

Microsoft Academic Search

Metallic Spin-glasses have drawn much experimental and theoretical attention in recent years(A. M. Sengupta and A. Georges, Phys. Rev. B52, 10295 (1995); S. Sachdev, N. Read and R. Opperman, Phys. Rev. B52, 10286 (1995); F. Steglich, et al., J. Phys. Condens. Matter 8, 99099 (1996).). One particularly interesting aspect of this system is the non-fermi-liquid behavior near the zero temperature

Anirvan Sengupta

1998-01-01

395

Solarization of heliostat glasses  

Microsoft Academic Search

A solar-induced decrease in Fe(2+) absorption was observed in heliostat glasses from the solar furnace at Odeillo, France. This decrease occurs throughout the sample and is of sufficient magnitude to result in an increase of 2.5% in solar transmittance in a period of nine years. Optical and ESR studies did not detect a corresponding increase in Fe(3+) concentration. The effect

J. Vitko Jr.; J. E. Shelby

1980-01-01

396

Glass microbubble composite foam  

SciTech Connect

Composite foams have been prepared from blends of Kerimid 601 polyimide resin and different types of glass microbubbles. Kerimid 601 is an addition type polyimide that offers many processing advantages over other types of polyimides. In an addition reaction, no volatiles are evolved during cure and weight loss and shrinkage during cure are small. Also, since the resin is a powder that melts and flows before curing, low density foams can be prepared. Processes were developed to blend, mold, and cure the foam formulations. The powered resin and glass microbubbles were mixed together in a twin shell blender. Three methods of molding were considered: a sintering process, vacuum bag molding, and compression molding; however, all of the foams were made by the vacuum bag method. The standard cure recommended by the manufacturer of Kerimid 601 was used to cure and postcure the foam samples. Test results show that foams with compressive strengths ranging from 500 to 26,000 psi (3.45 to 179 MPa) can be prepared depending upon the type of GMB used and the density of the foam composite. Foam made from B40A glass microbubbles had the best strength to weight ratio, but the lowest foam density possible using the B40A bubbles is only about 0.35 g/cm/sup 3/. Low density composites require low density glass microbubbles. Foams with densities of about 0.2 g/cm/sup 3/ were made with the B18A bubbles, but the compressive strength was about 500 psi (3.45 MPa).

McIlroy, H.M.

1978-02-01

397

Athermal photofluidization of glasses  

NASA Astrophysics Data System (ADS)

Azobenzene and its derivatives are among the most important organic photonic materials, with their photo-induced trans-cis isomerization leading to applications ranging from holographic data storage and photoalignment to photoactuation and nanorobotics. A key element and enduring mystery in the photophysics of azobenzenes, central to all such applications, is athermal photofluidization: illumination that produces only a sub-Kelvin increase in average temperature can reduce, by many orders of magnitude, the viscosity of an organic glassy host at temperatures more than 100?K below its thermal glass transition. Here we analyse the relaxation dynamics of a dense monolayer glass of azobenzene-based molecules to obtain a measurement of the transient local effective temperature at which a photo-isomerizing molecule attacks its orientationally confining barriers. This high temperature (Tloc~800?K) leads directly to photofluidization, as each absorbed photon generates an event in which a local glass transition temperature is exceeded, enabling collective confining barriers to be attacked with near 100% quantum efficiency.

Fang, G. J.; Maclennan, J. E.; Yi, Y.; Glaser, M. A.; Farrow, M.; Korblova, E.; Walba, D. M.; Furtak, T. E.; Clark, N. A.

2013-02-01

398

Athermal photofluidization of glasses.  

PubMed

Azobenzene and its derivatives are among the most important organic photonic materials, with their photo-induced trans-cis isomerization leading to applications ranging from holographic data storage and photoalignment to photoactuation and nanorobotics. A key element and enduring mystery in the photophysics of azobenzenes, central to all such applications, is athermal photofluidization: illumination that produces only a sub-Kelvin increase in average temperature can reduce, by many orders of magnitude, the viscosity of an organic glassy host at temperatures more than 100?K below its thermal glass transition. Here we analyse the relaxation dynamics of a dense monolayer glass of azobenzene-based molecules to obtain a measurement of the transient local effective temperature at which a photo-isomerizing molecule attacks its orientationally confining barriers. This high temperature (T(loc)~800?K) leads directly to photofluidization, as each absorbed photon generates an event in which a local glass transition temperature is exceeded, enabling collective confining barriers to be attacked with near 100% quantum efficiency. PMID:23443549

Fang, G J; Maclennan, J E; Yi, Y; Glaser, M A; Farrow, M; Korblova, E; Walba, D M; Furtak, T E; Clark, N A

2013-01-01

399

Molten Glass for Thermal Storage: Advanced Molten Glass for Heat Transfer and Thermal Energy Storage  

SciTech Connect

HEATS Project: Halotechnics is developing a high-temperature thermal energy storage system using a new thermal-storage and heat-transfer material: earth-abundant and low-melting-point molten glass. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Halotechnics new thermal storage material targets a price that is potentially cheaper than the molten salt used in most commercial solar thermal storage systems today. It is also extremely stable at temperatures up to 1200°C—hundreds of degrees hotter than the highest temperature molten salt can handle. Being able to function at high temperatures will significantly increase the efficiency of turning heat into electricity. Halotechnics is developing a scalable system to pump, heat, store, and discharge the molten glass. The company is leveraging technology used in the modern glass industry, which has decades of experience handling molten glass.

None

2012-01-01

400

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

SciTech Connect

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

Eppler, F.H.; Yim, M.S. [North Carolina State Univ., Raleigh, NC (United States)

1998-09-01

401

Cluster-assembled metallic glasses.  

PubMed

A bottom-up approach to nanofabricate metallic glasses from metal clusters as building blocks is presented. Considering metallic glasses as a subclass of cluster-assembled materials, the relation between the two lively fields of metal clusters and metallic glasses is pointed out. Deposition of selected clusters or collections of them, generated by state-of-the-art cluster beam sources, could lead to the production of a well-defined amorphous material. In contrast to rapidly quenched glasses where only the composition of the glass can be controlled, in cluster-assembled glasses, one can precisely control the structural building blocks. Comparing properties of glasses with similar compositions but differing in building blocks and therefore different in structure will facilitate the study of structure-property correlation in metallic glasses. This bottom-up method provides a novel alternative path to the synthesis of glassy alloys and will contribute to improving fundamental understanding in the field of metallic glasses. It may even permit the production of glassy materials for alloys that cannot be quenched rapidly enough to circumvent crystallization. Additionally, gaining deeper insight into the parameters governing the structure-property relation in metallic glasses can have a great impact on understanding and design of other cluster-assembled materials. PMID:23899019

Kartouzian, Aras

2013-07-30

402

Cluster-assembled metallic glasses  

NASA Astrophysics Data System (ADS)

A bottom-up approach to nanofabricate metallic glasses from metal clusters as building blocks is presented. Considering metallic glasses as a subclass of cluster-assembled materials, the relation between the two lively fields of metal clusters and metallic glasses is pointed out. Deposition of selected clusters or collections of them, generated by state-of-the-art cluster beam sources, could lead to the production of a well-defined amorphous material. In contrast to rapidly quenched glasses where only the composition of the glass can be controlled, in cluster-assembled glasses, one can precisely control the structural building blocks. Comparing properties of glasses with similar compositions but differing in building blocks and therefore different in structure will facilitate the study of structure-property correlation in metallic glasses. This bottom-up method provides a novel alternative path to the synthesis of glassy alloys and will contribute to improving fundamental understanding in the field of metallic glasses. It may even permit the production of glassy materials for alloys that cannot be quenched rapidly enough to circumvent crystallization. Additionally, gaining deeper insight into the parameters governing the structure-property relation in metallic glasses can have a great impact on understanding and design of other cluster-assembled materials.

Kartouzian, Aras

2013-07-01

403

Analytical Plan for Roman Glasses  

SciTech Connect

Roman glasses that have been in the sea or underground for about 1800 years can serve as the independent “experiment” that is needed for validation of codes and models that are used in performance assessment. Two sets of Roman-era glasses have been obtained for this purpose. One set comes from the sunken vessel the Iulia Felix; the second from recently excavated glasses from a Roman villa in Aquileia, Italy. The specimens contain glass artifacts and attached sediment or soil. In the case of the Iulia Felix glasses quite a lot of analytical work has been completed at the University of Padova, but from an archaeological perspective. The glasses from Aquileia have not been so carefully analyzed, but they are similar to other Roman glasses. Both glass and sediment or soil need to be analyzed and are the subject of this analytical plan. The glasses need to be analyzed with the goal of validating the model used to describe glass dissolution. The sediment and soil need to be analyzed to determine the profile of elements released from the glass. This latter need represents a significant analytical challenge because of the trace quantities that need to be analyzed. Both pieces of information will yield important information useful in the validation of the glass dissolution model and the chemical transport code(s) used to determine the migration of elements once released from the glass. In this plan, we outline the analytical techniques that should be useful in obtaining the needed information and suggest a useful starting point for this analytical effort.

Strachan, Denis M.; Buck, Edgar C.; Mueller, Karl T.; Schwantes, Jon M.; Olszta, Matthew J.; Thevuthasan, Suntharampillai; Heeren, Ronald M.

2011-01-01

404

Bioactive glass in tissue engineering  

PubMed Central

This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed.

Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

2011-01-01

405

Physical Properties of Multicomponent Borosilicate Glasses: a Study of Viscosity, Processing and Durability.  

NASA Astrophysics Data System (ADS)

The physical and chemical properties of multicomponent borosilicate glasses, in particular viscosity and chemical durability, are sensitive functions of their composition. In order to understand and systematize the effects of various oxide components on the properties of the glass it is necessary to analyze their effect on the glass structure, which is based on a three-dimensional network of silica tetrahedra. The particular context in which these properties are explored in this dissertation is the development of glasses for nuclear waste immobilization. This requires the development of models of compositional dependence which would pave the way towards preparing glasses with high durability over long periods of time, and at the same time, sufficiently low viscosities for rapid production at moderate processing temperatures (around 1100 centigrade); furthermore, appropriate modelling can define the composition range and the amount of control which is necessary to ensure that the melt viscosity and the glass durability will remain within the required range. The viscosity model is based on a correlation between the viscosity and the amount of non-bridging oxygens in the glass structure. Non-bridging oxygens lead to a looser structure and thus a lower viscosity. Their number is related to the relative proportions of glass forming cations and network modifiers. Established glass melt viscosity theories such as the Arrhenius equation and the Fulcher equation to take account of the temperature dependence are employed to develop a quantitative, predictive model for the viscosities of these glass melts. The process model uses first order error analysis to determine the overall compositional errors in the continuous melter process for the production of nuclear waste glass. This approach evaluates the use of frit as the primary glass former and determines the overall variability in glass composition. The section on glass durability comprises a comparison between long term extrapolation based on laboratory tests on microtektites, a class of natural glasses, with the observed extent of their corrosion in nature. Based on these tests, one can validate the leach test methodology currently used in the durability testing of nuclear waste glasses.

Saad, Elie Eugene

406

Atomic dynamics of tin nanoparticles embedded into porous glass  

SciTech Connect

The method of resonant nuclear inelastic absorption of synchrotron radiation has been used to study the phonon spectrum for tin nanoparticles (with a natural isotope mixture) embedded into a porous glassy (silica) matrix with an average pore diameter of 7 nm in comparison to the analogous spectrum of bulk tin enriched with {sup 119}Sn isotope. Differences between the spectra have been observed, which are related to both the dimensional effects and specific structural features of the porous glass-tin nanocomposite. Peculiarities in the dynamics of tin atoms embedded into nanopores of glass are interpreted in terms of a qualitative model of the nanocomposite structure.

Parshin, P. P.; Zemlyanov, M. G., E-mail: zeml@isssph.kiae.ru; Panova, G. Kh.; Shikov, A. A. [Russian Research Centre Kurchatov Institute (Russian Federation); Kumzerov, Yu. A.; Naberezhnov, A. A. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Sergueev, I.; Crichton, W. [European Synchrotron Radiation Facility (France); Chumakov, A. I. [Russian Research Centre Kurchatov Institute (Russian Federation); Rueffer, R. [European Synchrotron Radiation Facility (France)

2012-03-15

407

Waste product profile: Glass containers  

SciTech Connect

In 1992, Waste Age initiated the Waste Product Profile series -- brief, factual listings of the solid waste management characteristics of materials in the solid waste stream. This popular series of profiles high-lighted a product, explained how it fit into integrated waste management systems, and provided current data on recycling and markets for the product. Glass containers are made from sand, limestone, soda ash, cullet (crushed bottles), and various additives, including those used to produce green, brown, and blue glass. Other glass products include flat glass, such as windows, and fiberglass products, such as insulation and glassware. These products are manufactured using different processes and different additives than container glass. This profile covers only glass containers.

Miller, C. [Environmental Industry Associations, Washington, DC (United States)

1995-09-01

408

Crystallization of bismuth borate glasses.  

PubMed

Bismuth borate glasses with Bi(2)O(3) concentration of 20-66 mol% were prepared by melt quenching and devitrified by heat treatment above their glass transition temperatures. All glasses show a strong tendency towards crystallization on annealing that increases with Bi(2)O(3) concentration. The crystalline phases formed on devitrification were characterized by FTIR absorption spectroscopy and DSC measurements. Our studies reveal that phases produced in glasses are strongly determined by initial glass composition and the two most stable crystalline phases are: Bi(3)B(5)O(12) and Bi(4)B(2)O(9). The metastable BiBO(3) phase can also be formed by devitrification of glass with 50 mol% of Bi(2)O(3). This phase is, however, unstable and decomposes into Bi(3)B(5)O(12) and Bi(4)B(2)O(9) on prolonged heat treatment. PMID:21817270

Bajaj, Anu; Khanna, Atul

2008-12-11

409

Colloid formation in implanted glasses  

Microsoft Academic Search

Metal colloids in glasses can yield an enhanced ([chi]([sup 3])) susceptibility which leads to an intensity dependent refractive index. Ion implantation is a convenient means of introducing the metal species. The host glass plays an important role in colloid formation. We have characterized Ag-colloid formation in various silicate glasses and, in addition, have studied the formation of colloids in Ag-doped

G. W. Arnold; P. Mazzoldi; L. Tramontin; A. Boscolo-Boscoletto; G. Battaglin

1992-01-01

410

Colloid formation in implanted glasses  

Microsoft Academic Search

Metal colloids in glasses can yield an enhanced (Ï(³)) susceptibility which leads to an intensity dependent refractive index. Ion implantation is a convenient means of introducing the metal species. The host glass plays an important role in colloid formation. We have characterized Ag-colloid formation in various silicate glasses and, in addition, have studied the formation of colloids in Ag-doped phosphate

G. W. Arnold; P. Mazzoldi; L. Tramontin; A. Boscolo-Boscoletto; G. Battaglin

1992-01-01

411

Transparent Ferroelectric Glass-Ceramics  

Microsoft Academic Search

In recent years, there has been a resurgence of interest in transparent ferroelectric glass-ceramics (TFGCs), which are a special class of glass-ceramic composites that combine the low cost of fabrication and forming of transparent glass with the superior nonlinear optical and electro-optical properties of ferroelectric crystals. In this paper, we present a review of the current status, focusing on the

H. JAIN

2004-01-01

412

Chalcogenide glasses for nonlinear photonics  

Microsoft Academic Search

Chalcogenide glasses are important amorphous semiconductors used for phase-change memories, solar cells and in photonics. Here I will review their photonic applications with an emphasis on new glasses for high speed all-optical signal processing. Chalcogenide glasses (ChGs) contain one or more of the chalcogen elements (S, Se, Te) covalently bonded to network formers such as As, Ge, Sb, etc. Research

Barry Luther-Davies; Xin Gai; Amrita Prasad; Steve Madden; Duk-Yong Choi; Rongping Wang

2010-01-01

413

Rare-earth-doped transparent glass ceramics  

Microsoft Academic Search

Glass ceramics are a known class of polycrystalline ceramic materials, where, depending on the glass matrix and the particular crystalline phases, one can obtain materials with improved mechanical, thermal, electrical or optical properties. The characteristics and applications of optical glass ceramics are reviewed, with particular emphasis on rare-earth-doped transparent glass ceramics for photonics, including the search for new transparent glass

M Clara Gonçalves; Luís F Santos; Rui M Almeida

2002-01-01

414

Recycled crushed glass in road work applications  

Microsoft Academic Search

A comprehensive suite of geotechnical laboratory tests was undertaken on samples of recycled crushed glass produced in Victoria, Australia. Three types of recycled glass sources were tested being coarse, medium and fine sized glass. Laboratory testing results indicated that medium and fine sized recycled glass sources exhibit geotechnical behavior similar to natural aggregates. Coarse recycled glass was however found to

M. M. Disfani; A. Arulrajah; M. W. Bo; R. Hankour

2011-01-01

415

Testing Laminated Glass for Impact Resistance  

Microsoft Academic Search

Comparative testing of laminated glass made up by different combinations for impact resistance has been performed. The testing corroborates the possibility of using glass subjected to special thermal treatment (STT) in the production of impact-resistant laminated glass. Glasses based on STT glass satisfy the impact resistance requirements of GOST R 51136–98, and their thickness and weight are a factor of

A. I. Shutov; A. N. Frank; I. A. Novikov; A. S. Ostapko; A. S. Bonchuk; A. N. Burdov

2004-01-01

416

Glass laceration injuries and prevention.  

PubMed

Accidents involving glass in doors, sidelights, specially vulnerable windows, and shower screens are an important cause of injury, and occasionally death. Most of the injuries are superficial cuts and abrasions, but many involve deep lacerations of tendons, nerves and muscles. The accidents occur mainly in children and young adults with the highest rate being among males aged from 15 to 19 years. The number and severity of these injuries could be reduced through the wider use of appropriate forms of safety glazing: laminated glass or toughened glass in new installlations, and the application of a plastic safety film to existing glass. PMID:449776

Oliver, T I; Lawson, J S

1979-03-10

417

Failure studies of glass fibers  

NASA Astrophysics Data System (ADS)

This dissertation is divided into six sections. The first section includes a review of the literature on the mechanical properties of glass, including glass strength. Section two describes a study of the effects of composition of calcium aluminoborosilicate glasses on the inert and room temperature two-point bending failure characteristics of glass fibers, including fatigue and aging effects. Sections three and four include studies of the effects of composition and structure of alkali silicate and aluminosilicate glasses on the inert two-point bending fiber failure properties. Section five describes the inert two-point bending failure results of sodium borate glass fibers. Section six includes a study of the effects of melting time and temperature (i.e. thermal history) on the resulting two-point bending failure properties of glass fibers produced from a variety of glass compositions. Throughout the course of this work, new experimental equipment and techniques were developed so that high quality failure measurements could be obtained. When glass melts were prepared to ensure homogeneity, the failure properties were shown to be sensitive to glass composition and structure and the reproducibility of the failure data was less than for a variety of different silicate glass compositions. Fibers have also been aged under controlled humidity and temperature conditions to characterize the effects of aging time on the failure strain. With the ability to produce and test high quality fiber, a new failure property of glass has been observed. Fibers tested under liquid nitrogen produce failure strains that depend on the testing rate of the two-point bending equipment. In the case of silica glass fibers, failure strain increases with increasing testing rate, an effect attributed to 'normal' inert fatigue behavior. However, some glasses, such as the high alkali silicates and soda lime silicates, show the opposite dependence of failure strain on testing rate, where slower testing rates produce greater failure strains (i.e. an "inert delayed failure effect"). With the ability to determine the intrinsic (flaw-free) failure properties of glass and the dependence of these properties on testing rate, a new insight to the understanding of glass failure and strength with relation to composition and structure may be possible.

Lower, Nathan Paul

418

Phosphate base laser glasses  

SciTech Connect

A phosphate base laser glass comprising 55-70% P2O5, 1-15% Al2O3, 0-25% Li2O, 0-25% Na2O, 0-8% K2O, the total proportion of Li2O, Na2O, and K2O being 10-25%, 0-15% BaO, 0-15% ZnO, 0-15% CaO , 0-15%, sro, 0-15% MgO, the total proportion of BaO, ZnO, CaO, SrO, and MgO being 5-15%, 0-5% Y2O3, 0-5% La2O3, 0-5% GeO2, 0-5% CeO2, 0-3% Nb2O5, 0-3% MnO2, 0-2% Ta2O5, 0-1% Sb2O3, and 0.01-5% Nd2O3, all % being mole %. The phosphate base laser glass of this invention has a high induced emission cross section, a low non-linear refractive index coefficient, and excellent acid resistance and divitrification resistance. By replacing partially or wholely one or more of LiO2, Na2O, K2O, BaO, ZnO, CaO, SrO, MgO or Al2O3 by LiF, NaF, KF , BaF2ZnF2, CaF2, SrF2, MgF2 or AlF3, respectively, the above properties of the laser glass are further improved.

Izumitani, T.; Tsuru, M.

1980-12-16

419

Performance rating of glass windows and glass windows with films in aspect of thermal comfort and heat transmission  

Microsoft Academic Search

This article is about a study on glass window and glass window with film of different types in aspect of thermal comfort and heat transmission. Different types of glass window, clear glass, tinted glass, reflective glass, double pane glass, and low-e glass were investigated. Films with different spectral optical properties were then adhered to the glass windows of different types

Somsak Chaiyapinunt; Bunyarit Phueakphongsuriya; Khemmachart Mongkornsaksit; Nopparat Khomporn

2005-01-01

420

Glass rupture disk  

DOEpatents

A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

Glass, S. Jill (Albuquerque, NM); Nicolaysen, Scott D. (Albuquerque, NM); Beauchamp, Edwin K. (Albuquerque, NM)

2002-01-01

421

Lightguiding in photochromic glasses.  

PubMed

Lightguiding in ion-exchanged photochromic glass layers is reported. The guides were formed by ion exchange of Ag(+) for Na(+) or by outdiffusion of F. Guide attenuation was less than 0.2 dB/cm in many cases. The attenuation in the guide was varied over a range of Deltaalpha = 30 dB/cm by illuminating the guide with (1) uv radiation to darken the guide or order of seconds. (2) visible radiation to bleach the guide. Switching times were in the order of seconds. PMID:20134933

Crow, J D; Borrelli, N F; Seward Iii, T P; Chodak, J

1975-03-01

422

Examination of glass-silicon and glass-glass bonding techniques for microfluidic systems  

SciTech Connect

We report here on the results of experiments concerning particular bonding processes potentially useful for ultimate miniaturization of microfluidic systems. Direct anodic bonding of continuous thin pyrex glass of 250 {mu}m thickness to silicon substrates gives multiple, large voids in the glass. Etchback of thick glass of 1200 {mu}m thickness bonded to silicon substrates gives thin continuous glass layers of 189 {mu}m thickness without voids over areas of 5 cm {times} 12 cm. Glass was also successfully bonded to glass by thermal bonding at 800{degrees}C over a 5 cm {times} 7 cm area. Anticipated applications include microfabricated DNA sequencing, flow injection analysis, and liquid and gas chromatography microinstruments.

Raley, N.F.; Davidson, J.C.; Balch, J.W.

1995-10-23

423

Structural characterization of Nd-doped calcium aluminosilicate glasses designed for the preparation of zirconolite (CaZrTi2O7) -based glass-ceramic  

Microsoft Academic Search

This work concerns glasses belonging to SiO2-Al2O3-CaO-ZrO2-TiO2-Nd2O3 system that lead to zirconolite crystallization in their bulk after nucleation + crystal growth thermal treatments and that could find application as nuclear waste form. The understanding of crystallization processes in glasses implied to investigate their structure. The environment around Ti, Zr (nucleating agents) and Nd was characterized for various Nd2O3 loadings. Electron

Pascal Loiseau; Daniel Caurant; Noël Baffier; Kathy Dardenne; Jörg Rothe; Melissa A. Denecke; Stefan Mangold

2011-01-01

424

High-Level Waste Glass Formulation Model Sensitivity Study. 2009 Glass Formulation Model versus 1996 Glass Formulation Model.  

National Technical Information Service (NTIS)

This document presents the differences between two HLW glass formulation models (GFM): The 1996 GFM and 2009 GFM. A glass formulation model is a collection of glass property correlations and associated limits, as well as model validity and solubility cons...

F. L. Meinert J. D. Belsher

2009-01-01

425

Alkaline phosphatase grafting on bioactive glasses and glass ceramics  

Microsoft Academic Search

Bone integration of orthopaedic or dental implants and regeneration of damaged bone at the surgical site are still unresolved problems in prosthetic surgery. For this reason, biomimetic surfaces (i.e. both inorganic and biological bioactive surfaces) represent a challenge for bone implantation. In this research work a hydrolase enzyme (alkaline phosphatase) was covalently grafted to inorganic bioactive glass and glass ceramic

Enrica Verné; Sara Ferraris; Chiara Vitale-Brovarone; Silvia Spriano; Claudia L. Bianchi; Alberto Naldoni; Marco Morra; Clara Cassinelli

2010-01-01

426

Thermochemical study of rare earth and nitrogen incorporation in glasses  

NASA Astrophysics Data System (ADS)

Rare earth containing aluminosilicate, borosilicate, aluminate and nitrogen containing aluminosilicate glasses are technically important materials. They have extraordinary physical and chemical properties such as high glass transition temperature, very low electrical conductivity, and excellent chemical stability. These unique properties lead to applications as coatings on metals and ceramics, optical fibers, semiconductors, and nuclear waste containment materials. In addition, such systems contain the most widely used additives for sintering of Si3N4, SiAlON and SiC ceramics for high temperature applications. Thermodynamic properties and the relations among energetics, structure and bonding are essential to controlling processing parameters to synthesize, at lower cost, materials having better properties. Earlier investigations mainly pertained to specific physical properties of rare-earth doped oxide and oxynitride glasses. Work on the thermodynamic stability and materials compatibility has been very sparse. High temperature solution calorimetry in molten oxide solvents is a powerful tool for the thermodynamic study of refractory materials. With implementation and improvement, this technique has been applied to the first measurement of enthalpies of formation of RE-Si-Al-O glasses, REAlO3 glasses, RE-Si-Al-O-N glasses, and Si3N 4 and Ge3N4 with high pressure spinel structure. The first successful synthesis of REAlO3 glasses has been achieved by containerless melting. Their large enthalpies of crystallization confirm that they are reluctant glass formers. For glasses along the 2REAlO3 -3SiO2 join, the strongly negative heats of mixing support the absence of miscibility gaps except possibly at very high silica content. Energetic evidence has been presented for incipient phase-ordered regions in Gd- or Hf-containing sodium alumino-borosilicate glasses for plutonium immobilization. Linear relations between enthalpies of formation of RESiAlON glasses from elements and nitrogen content indicate that within the experimental composition range, sites occupied by nitrogen ions are roughly energetically equivalent in a given substitution series. The energetics of difference rare-earth substitution appears to be dominated by differences in the acid/base character of the cations.

Zhang, Yahong

427

Fabrication and characterization of 20 nm planar nanofluidic channels by glass–glass and glass–silicon bonding  

Microsoft Academic Search

We have characterized glass-glass and glass-Si bonding processes for the fabrication of wide, shallow nanofluidic channels with depths down to the nanometer scale. Nanochannels on glass or Si substrate are formed by reactive ion etching or a wet etching process, and are sealed with another flat substrate either by glass-glass fusion bonding (550 uC) or an anodic bonding process. We

Pan Maoa; Jongyoon Han

2005-01-01

428

Quinary metallic glass alloys  

DOEpatents

At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d.multidot.y is less than 10 atomic percent, and x/z ranges from 0.5 to 2.

Lin, Xianghong (Pasadena, CA); Johnson, William L. (Pasadena, CA)

1998-01-01

429

Quinary metallic glass alloys  

DOEpatents

At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10{sup 3}K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf){sub a}(Al,Zn){sub b}(Ti,Nb){sub c}(Cu{sub x}Fe{sub y}(Ni,Co){sub z}){sub d} wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d{hor_ellipsis}y is less than 10 atomic percent, and x/z ranges from 0.5 to 2.

Lin, X.; Johnson, W.L.

1998-04-07

430

Commercial Ion Exchange Resin Vitrification in Borosilicate Glass  

SciTech Connect

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.

Cicero-Herman, C.A.; Workman, P. [Westinghouse Savannah River Co., Aiken, SC (United States); Poole, K.; Erich, D.; Harden, J. [Clemson Environmental Technologies Laboratory, Anderson, SC (United States)

1998-05-01

431

7 CFR 3201.30 - Glass cleaners.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Glass cleaners. 3201.30 Section 3201...PROCUREMENT Designated Items § 3201.30 Glass cleaners. (a) Definition. Cleaning...designed specifically for use in cleaning glass surfaces, such as windows,...

2013-01-01

432

ConcepTest: Glass-Rock Analogy  

NSDL National Science Digital Library

Glass is made by melting silica-rich sand. The molten glass is then formed into shapes as it cools. Glass making could be seen as an analog for the formation of a. igneous rock b. metamorphic rock c. sedimentary ...

433

Colloid formation in implanted glasses.  

National Technical Information Service (NTIS)

Metal colloids in glasses can yield an enhanced ((chi)((sup 3))) susceptibility which leads to an intensity dependent refractive index. Ion implantation is a convenient means of introducing the metal species. The host glass plays an important role in coll...

G. W. Arnold P. Mazzoldi L. Tramontin A. Boscolo-Boscoletto G. Battaglin

1992-01-01

434

Polyamorphic transitions in network glasses  

Microsoft Academic Search

We have used a combination of Brillouin and Raman scattering, and molecular dynamics computer simulations to investigate the nature of polyamorphic transitions in network glasses. The manifestation and consequence of pressure-induced structural transitions in silica and boron oxide, i.e., glasses with tetrahedral and trigonal network building blocks are contrasted. In both materials different transition mechanisms are observed depending on the

L. Huang; J. D. Nicholas; J. Kieffer; S. Sinogeikin; J. D. Bass

2004-01-01

435

Refractory Glass Seals for SOFC  

Microsoft Academic Search

One of the critical challenges facing planar solid oxide fuel cell (SOFC) technology is the need for reliable sealing technology. Seals must exhibit long-term stability and mechanical integrity in the high temperature SOFC environment during normal and transient operation. Several different approaches for sealing SOFC stacks are under development, including glass or glass-ceramic seals, metallic brazes, and compressive seals. Among

Y. S. Chou; Jeffry W. Stevenson

2011-01-01

436

Chemical properties of metallic glasses  

Microsoft Academic Search

Research into chemical properties of metallic glasses has revealed promising behavior in the areas of corosion resistance and catalysis. Metallic glasses containing a film-forming element exhibit resistance to uniform and localized corrosion that is superior to that of many crystalline stainless steels. This resistance is due to the presence of passive films that are enriched in the film-forming element. Cr

Diegle

1983-01-01

437

Method of determining glass durability  

DOEpatents

A process is described for determining one or more leachate concentrations of one or more components of a glass composition in an aqueous solution of the glass composition by identifying the components of the glass composition, including associated oxides, determining a preliminary glass dissolution estimator, {Delta}G{sub p}, based upon the free energies of hydration for the component reactant species, determining an accelerated glass dissolution function, {Delta}G{sub a}, based upon the free energy associated with weak acid dissociation, {Delta}G{sub a}{sup WA}, and accelerated matrix dissolution at high pH, {Delta}G{sub a}{sup SB} associated with solution strong base formation, and determining a final hydration free energy, {Delta}G{sub f}. This final hydration free energy is then used to determine leachate concentrations for elements of interest using a regression analysis and the formula log{sub 10}(N C{sub i}(g/L))=a{sub i} + b{sub i}{Delta}G{sub f}. The present invention also includes a method to determine whether a particular glass to be produced will be homogeneous or phase separated. The present invention is also directed to methods of monitoring and controlling processes for making glass using these determinations to modify the feedstock materials until a desired glass durability and homogeneity is obtained. 4 figs.

Jantzen, C.M.; Pickett, J.B.; Brown, K.G.; Edwards, T.B.

1998-12-08

438

Heliostat glass survey and analysis  

Microsoft Academic Search

A comprehensive survey of both foreign and domestic sources of low distortion, high transmission flat glass with a nominal thickness of 3 mm was undertaken. The purpose of the survey was to determine the characteristics, availability and cost of glass for use in second surface heliostat mirrors for the Barstow pilot plant and future commercial central receiver plants. Information obtained

M. A. Lind; J. M. Rusin

1978-01-01

439

Making a Better Beer Glass.  

ERIC Educational Resources Information Center

|A class activity is detailed in which alternative designs for glasses are examined. The goal is to design a glass which is built tilted, so that beer can be poured in without creating a foam problem. The activity is viewed as one leading to interesting questions. (MP)|

Hoffer, Alan R.

1982-01-01

440

Superionic glasses: theories and applications  

Microsoft Academic Search

Applications of superionic glasses in electrochemistry include solid state batteries for which new glass compositions are being developed for their enhanced conductivity and chemical stability. The focus of fundamental investigations remains the search for a generally accepted mechanism of ion transport.

Malcolm D Ingram

1997-01-01

441

Nanocomposites glass\\/conductive polymers  

Microsoft Academic Search

We report on the preparation and characterization of two glass\\/conducting polymer nanocomposites obtained by the in situ oxidative polymerization of pyrrole and aniline inside the pores of Porous Vycor Glass (PVG). Oxidative polymerization of pyrrole was done via Cu2+ cation impregnated in the PVG pores. The polymerization of aniline was undertaken by impregnating PVG with the monomer, followed by an

Aldo J. G. Zarbin; Marco-A. De Paoli; Oswaldo L. Alves

1999-01-01

442

Dehydroxylation of phosphate laser glass  

NASA Astrophysics Data System (ADS)

Rates of dehydroxylation of two Nd-doped metaphosphate laser glasses (LG-770 and LHG-8) are measured and modeled. Glass melts ranging in size from 100 g to 2.8 kg were bubbled with O2 containing various H2O partial pressures (PH(subscript 2O)) and with O2/Cl2 mixtures at temperatures ranging from 925 - 1300 degree(s)C. The OH content in the glass was measured by monitoring the OH absorption at 3.333 micrometers at various bubbling times. The OH removal by inert gas bubbling (e.g. O2 bubbling) is governed by the transport (diffusion) of OH to the glass liquid/vapor interface and by the chemical equilibrium between OH at the surface and H2O in the gas phase. The equilibrium OH content in glass melts bubbled with O2 containing different PH(subscript 2O) varies as PH(subscript 2O)1/2.

Thorsness, C. B.; Suratwala, Tayyab I.; Steele, Rusty A.; Campbell, Jack H.; Hayden, Joseph S.; Pucilowski, S. A.; Suzuki, K.

2000-10-01

443

Database and Interim Glass Property Models for Hanford HLW Glasses  

SciTech Connect

The purpose of this report is to provide a methodology for an increase in the efficiency and a decrease in the cost of vitrifying high-level waste (HLW) by optimizing HLW glass formulation. This methodology consists in collecting and generating a database of glass properties that determine HLW glass processability and acceptability and relating these properties to glass composition. The report explains how the property-composition models are developed, fitted to data, used for glass formulation optimization, and continuously updated in response to changes in HLW composition estimates and changes in glass processing technology. Further, the report reviews the glass property-composition literature data and presents their preliminary critical evaluation and screening. Finally the report provides interim property-composition models for melt viscosity, for liquidus temperature (with spinel and zircon primary crystalline phases), and for the product consistency test normalized releases of B, Na, and Li. Models were fitted to a subset of the screened database deemed most relevant for the current HLW composition region.

Hrma, Pavel R; Piepel, Gregory F; Vienna, John D; Cooley, Scott K; Kim, Dong-Sang; Russell, Renee L

2001-07-24

444

Product consistency testing of West Valley Compositional Variation Glasses  

SciTech Connect

Nuclear waste glass produced by the West Valley Demonstration Project (WVDP) must meet the requirements of the Waste Acceptance Preliminary Specification (WAPS) as developed by the US Department of Energy (DOE). To assist WVDP in complying with WAPS, the Materials Characterization Center (MCC) at Pacific Northwest Laboratory (PNL) used the Product Consistency Test (PCT) to evaluate 44 West Valley glasses that had previously been tested in FY 1987 and FY 1988. This report summarizes the results of the PCTs. The glasses tested, which were fabricated as sets of Compositional Variation Glasses for studies performed by the West Valley Support Task (WVST) at PNL during FY 1987 and FY 1988, were doped with Th and U and were variations of West Valley reference glasses. In addition, Approved Reference Material-1 (ARM-1) was used as a test standard (ARM-1 is supplied by the MCC). The PCT was originated at Westinghouse Savannah River Company (WSRC) by C. M. Jantzen and N. R. Bibler (Jantzen and Bibler 1989). The test is a seven-day modified MCC-3 test that uses crushed glass in the size range -100 +200 mesh with deionized water in a Teflon container. There is no agitation during the PCT, and no attempt to include CO{sub 2} from the test environment. Based on B and Li release, the glasses performed about the same as in previous modified MCC-3 testing performed in FY 1987 and FY 1988 (Reimus et al. 1988). The modified MCC-3 tests performed by Reimus et al. were similar to the PCT containers and the exclusion of CO{sub 2} from the tests.

Olson, K.M.; Marschman, S.C.; Piepel, G.F.; Whiting, G.K.

1994-11-01

445

High level nuclear waste  

SciTech Connect

The DOE Division of Waste Products through a lead office at Savannah River is developing a program to immobilize all US high-level nuclear waste for terminal disposal. DOE high-level wastes include those at the Hanford Plant, the Idaho Chemical Processing Plant, and the Savannah River Plant. Commercial high-level wastes, for which DOE is also developing immobilization technology, include those at the Nuclear Fuel Services Plant and any future commercial fuels reprocessing plants. The first immobilization plant is to be the Defense Waste Processing Facility at Savannah River, scheduled for 1983 project submission to Congress and 1989 operation. Waste forms are still being selected for this plant. Borosilicate glass is currently the reference form, but alternate candidates include concretes, calcines, other glasses, ceramics, and matrix forms.

Crandall, J L

1980-01-01

446

Structure, surface reactivity and physico-chemical degradation of fluoride containing phospho-silicate glasses  

SciTech Connect

We report on the structure, apatite-forming ability and physicochemical degradation of glasses along fluorapatite [FA; Ca5(PO4)3F] - diopside (Di; CaMgSi2O6) join. A series of glasses with varying FA/Di ratio have been synthesised by melt-quenching technique. The amorphous glasses could be obtained only for compositions up to 40 wt.% of FA. The detailed structural analysis of glasses has been made by infra-red spectroscopy (FTIR), Raman spectroscopy and magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR). Silicon was predominantly present as Q2 (Si) species while phosphorus was found in orthophosphate type environment in all the investigated glasses. The apatite forming ability of glasses was investigated by immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1 h – 28 days. An extensive precipitation of calcite (CaCO3) after immersion in SBF was found in all the glasses which considerably masked the formation of hydroxyapatite [HA; Ca5(PO4)3OH] as depicted by X-ray diffraction (XRD) and FTIR. The possible mechanism favouring formation of calcite instead of HA has been explained on the basis of experimental results obtained for structure of glasses, leaching profile of glass powders in SBF solution and pH variation in SBF solution. Further, physico-chemical degradation of glasses has been studied in accordance with ISO 10993-14 “Biological evaluation of medical devices – Part 14: Identification and quantification of degradation products from ceramics” in Tris HCl and citric acid buffer. All the FA containing glasses exhibited a weight gain (instead of weight loss) after immersion in citric acid buffer due to the formation of different crystalline products.

Kansal, Ishu; Goel, Ashutosh; Tulyaganov, Dilshat U.; Santos, Luis F.; Ferreira, Jose M.

2011-03-28

447

Chemical effects of lanthanides and actinides in glasses determined with electron energy loss spectroscopy  

SciTech Connect

Chemical and structural environments of f-electron elements in glasses are the origin of many of the important properties of materials with these elements; thus oxidation state and chemical coordination of lanthanides and actinides in host materials is an important design consideration in optically active glasses, magnetic materials, perovskite superconductors, and nuclear waste materials. We have made use of the line shapes of Ce to determine its oxidation state in alkali borosilicate glasses being developed for immobilization of Pu. Examination of several prototype waste glass compositions with EELS shows that the redox state of Ce doped to 7 wt% could be varied by suitable choice of alkali elements. EELS for a Pu-doped glass illustrate the small actinide N{sub 4}/N{sub 5} intensity ratio and show that the Pu-N{sub 4,5} white line cross section is comparable to that of Gd M{sub 4,5}.

Fortner, J.A.; Buck, E.C.; Ellison, A.J.G.; Bates, J.K.

1996-07-01

448

Simulation of cooling and solidification of three-dimensional bulk borosilicate glass: effect of structural relaxations  

NASA Astrophysics Data System (ADS)

The modeling of the viscoelastic stress evolution and specific volume relaxation of a bulky glass cast is presented in this article and is applied to the experimental cooling process of an inactive nuclear waste vitrification process. The concerned borosilicate glass is solidified and cooled down to ambient temperature in a stainless steel canister, and the thermomechanical response of the package is simulated. There exists a deviant compression of the liquid core due to the large glass package compared to standard tempered glass plates. The stress load development of the glass cast is finally studied for different thermal load scenarios, where the cooling process parameters or the final cooldown rates were changed, and we found a great influence of the studied cooldown rates on the maximum stress build-up at ambient temperature.

Barth, N.; George, D.; Ahzi, S.; Rémond, Y.; Joulaee, N.; Khaleel, M. A.; Bouyer, F.

2013-04-01

449

The rheology of solid glass  

NASA Astrophysics Data System (ADS)

As the glass transition is approached from the high temperature side, viewed as a liquid, the properties of the ever more viscous supercooled liquid are continuous functions of temperature and pressure. The point at which we decide to classify the fluid as a solid is therefore subjective. This subjective decision does, however, have discontinuous consequences for how we determine the rheological properties of the glass. We apply the recently discovered relaxation theorem to the time independent, nondissipative, nonergodic glassy state to derive an expression for the phase space distribution of an ensemble of glass samples. This distribution is then used to construct a time dependent linear response theory for aged glassy solids. The theory is verified using molecular dynamics simulations of oscillatory shear for a realistic model glass former with excellent agreement being obtained between the response theory calculations and direct nonequilibrium molecular dynamics calculations. Our numerical results confirm that unlike all the fluid states, including supercooled liquids, a solid glass (in common with crystalline states) has a nonzero value for the zero frequency shear modulus. Of all the states of matter, a supercooled fluid approaching the glass transition has the highest value for the limiting zero frequency shear viscosity. Finally, solid glasses like dilute gases and crystals have a positive temperature coefficient for the shear viscosity whereas supercooled and normal liquids have a negative temperature coefficient.

Williams, Stephen R.; Evans, Denis J.

2010-05-01

450

Chemical properties of metallic glasses  

SciTech Connect

Research into chemical properties of metallic glasses has revealed promising behavior in the areas of corosion resistance and catalysis. Metallic glasses containing a film-forming element exhibit resistance to uniform and localized corrosion that is superior to that of many crystalline stainless steels. This resistance is due to the presence of passive films that are enriched in the film-forming element. Cr is particularly effective, especially if P is present as in transition metal-Cr-P glasses. Protective coatings are an obvious application of metallic glasses. Metallic glasses also show promise as catalysts and electrocatalysts. Some glasses containing Pd and P offer better reactivity and resistance to corrosion than crystalline noble elements for electrolytic chlorine production. Others have demonstrated an ability as catalysts to oxidize methanol for fuel cell application, and also for hydrogenation of carbon monoxide. The very uniform structure and unique meta-stable compositions characteristic of metallic glasses are keys to understanding the chemical behavior of this exciting class of materials.

Diegle, R.B.

1983-01-01

451

Development of an ASTM standard glass durability test, the Product Consistency Test (PCT), for high level radioactive waste glass  

SciTech Connect

The nation`s first, and the world`s largest, facility to immobilize high-level nuclear waste in durable borosilicate glass has started operation at the Savannah River Site (SRS) in Aiken, South Carolina. The product specifications on the glass wasteform produced in the Defense Waste Processing Facility (DWPF) required extensive characterization of the glass product before actual production began and for continued characterization during production. To aid in this characterization, a glass durability (leach) test was needed that was easily reproducible, could be performed remotely on highly radioactive samples, and could yield results rapidly. Several standard leach tests were examined with a variety of test configurations. Using existing tests as a starting point, the DWPF Product Consistency Test (PCT was developed in which crushed glass samples are exposed to 90 {plus_minus} 2{degree}C deionized water for seven days. Based on extensive testing, including a seven-laboratory round robin and confirmatory testing with radioactive samples, the PCT is very reproducible, yields reliable results rapidly, and can be performed in shielded cell facilities with radioactive samples.

Jantzen, C.M.; Bibler, N.E.; Beam, D.C.; Ramsey, W.G.

1994-06-01

452

HIGH-LEVEL WASTE GLASS FORMULATION MODEL SENSITIVITY STUDY 2009 GLASS FORMULATION MODEL VERSUS 1996 GLASS FORMULATION MODEL  

Microsoft Academic Search

This document presents the differences between two HLW glass formulation models (GFM): The 1996 GFM and 2009 GFM. A glass formulation model is a collection of glass property correlations and associated limits, as well as model validity and solubility constraints; it uses the pretreated HLW feed composition to predict the amount and composition of glass forming additives necessary to produce

BELSHER JD; MEINERT FL

2009-01-01

453

Resonant susceptibility of dielectric glasses in magnetic field  

Microsoft Academic Search

The anomalous magnetic field dependence of dielectric properties of\\u000ainsulating glasses in the temperature interval $10mKnuclear\\u000aquadrupole interaction of these spins with lattice and, thus, affects the

Y. Sereda; I. Ya. Polishchuk; A. L. Burin

2007-01-01

454

GLASS COMPOSITION-TCLP RESPONSE MODEL FOR WASTE GLASSES  

SciTech Connect

A first-order property model for normalized Toxicity Characteristic Leaching Procedure (TCLP) release as a function of glass composition was developed using data collected from various studies. The normalized boron release is used to estimate the release of toxic elements based on the observation that the boron release represents the conservative release for those constituents of interest. The current TCLP model has two targeted application areas: (1) delisting of waste-glass product as radioactive (not mixed) waste and (2) designating the glass wastes generated from waste-glass research activities as hazardous or non-hazardous. This paper describes the data collection and model development for TCLP releases and discusses the issues related to the application of the model.

Kim, Dong-Sang; Vienna, John D.

2004-01-01

455

Glass enamel and glass-ceramic coatings for chemical apparatus  

SciTech Connect

Among the known anticorrosion coatings used in chemical engineering, glass enamel base coatings are distinguished by such advantages as a high degree of continuity and chemical resistance. The paper describes basic principles for the creation of acid and alkali resistant glass enamel and ceramic coatings for chemical apparatus. As the result of investgations, glass enamel coatings with increased electrical conductivity and also experimental production compositions of chemical, temperature and radiation resistant coatings for protection of chemical equipment of 12Kh18N10T stainless steel have been developed. The coatings have successfully passed testing under service conditions. A new type of coating is short-term glass enamel, which may be recommended for use in chemical machinery manufacturing and other branches of industry in oxidation-free heating and forming of stainless steels.

Es'kov, A.S.; Oleinik, M.I.; Shabrova, E.A.

1984-05-01