scholarly journals X-Ray Diffraction and Product Consistency Test Results for the Phase 6 Study of Nepheline Formation in High-Level Waste Glasses

2019 ◽  
Author(s):  
Charmayne Lonergan ◽  
Jared Kroll ◽  
Chloe Skidmore ◽  
Zayne Nelson ◽  
John Vienna
Keyword(s):  
High Level Waste ◽  
Test Results ◽  
X Ray Diffraction ◽  
Consistency Test ◽  
X Ray ◽  
High Level

Effect of Li, Fe, and B Addition on the Crystallization Behavior of Sodium Aluminosilicate Glasses as Analogues for Hanford High Level Waste Glasses

MRS Advances ◽  
2016 ◽  
Vol 2 (10) ◽  
pp. 549-555 ◽  
Author(s):  
José Marcial ◽  
Mostafa Ahmadzadeh ◽  
John S. McCloy
Keyword(s):  
Function Analysis ◽  
High Level Waste ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Sodium ◽  
Chemical Ordering ◽  
Sodium Aluminosilicate ◽  
Aluminosilicate Glasses ◽  
Heat Treated ◽  
High Level

ABSTRACTCrystallization of aluminosilicates during the conversion of Hanford high-level waste (HLW) to glass is a function of the composition of the glass-forming melt. In high-sodium, high-aluminum waste streams, the crystallization of nepheline (NaAlSiO4) removes chemically durable glass-formers from the melt, leaving behind a residual melt that is enriched in less durable components, such as sodium and boron. We seek to further understand the effect of lithium, boron, and iron addition on the crystallization of model silicate glasses as analogues for the complex waste glass. Boron and iron behave as glass intermediates which allow for crystallization when present in low additions but frustrate crystallization in high additions. In this work, we seek to compare the average structures of quenched and heat treated glasses through Raman spectroscopy, X-ray diffraction, vibrating sample magnetometry, and X-ray pair distribution function analysis. The endmembers of this study are feldspathoid-like (LiAlSiO4, NaAlSiO4, NaBSiO4, and NaFeSiO4), pyroxene-like (LiAlSi2O6, NaAlSi2O6, NaBSi2O6, and NaFeSi2O6), and feldspar-like (LiAlSi3O8, NaAlSi3O8, NaBSi3O8, and NaFeSi3O8). Such a comparison will provide further insight on the complex relationship between the average chemical ordering and topology of glass on crystallization.

Cold Crucible Vitrification of U-bearing SRS SB4 HLW Surrogate

2010 ◽  
Vol 1265 ◽  
Author(s):  
Sergey Stefanovsky ◽  
Alexander Ptashkin ◽  
Oleg Knyazev ◽  
Olga Stefanovsky ◽  
James C Marra
Keyword(s):  
High Level Waste ◽  
Cold Crucible ◽  
Savannah River ◽  
X Ray Diffraction ◽  
Alumina Crucible ◽  
X Ray ◽  
Xrd Study ◽  
Processing Facility ◽  
High Level ◽  
River Site

AbstractSavannah River Site Defense Waste Processing Facility (DWPF) Sludge Batch 4 (SB4) high level waste (HLW) simulant at 55 wt % waste loading was produced in the demountable cold crucible and cooled to room temperature in the cold crucible. Appreciable losses of Cs, S and Cl took place during the melting. A second glass sample was subjected to canister centerline cooling (CCC) regime in an alumina crucible in a resistive furnace. X-ray diffraction (XRD) study showed that the glass blocks were composed of vitreous and spinel structure phases. No separate U-bearing phases were found.

Phase Relations and Chemical Durability of Ceramics in the Pseudo-Binary System: CaZrTi2O7–GdAlO3

2003 ◽  
Vol 807 ◽  
Author(s):  
N. P. Mikhailenko ◽  
A. V. Ochkin ◽  
S. V. Stefanovsky ◽  
O. I. Kirjanova
Keyword(s):  
Electron Microscopy ◽  
Binary System ◽  
Chemical Durability ◽  
Phase Relations ◽  
High Level Waste ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
High Level ◽  
System 1

ABSTRACTPhase relations in a pseudo-binary system (1-x) CaZrTi2O7- x GdAlO3 suggested for immobilization of a zirconium - rare earth – actinide fraction of high level waste were studied with X-ray diffraction and electron microscopy. Zirconolite and perovskite were found to be major phases in the ceramic samples prepared by cold pressing and sintering at 1400 and 1500 °C. At relatively low perovskite content (x < 0.5) zirconolite is the major host for Gd, which is considered as a trivalent surrogate for Am and Cm. At higher perovskite content, perovskite becomes the major host for Gd. Zirconolite is the major host phase for corrosion products (Al, Fe, Ti, Zr). Leach rates of Gd, 238Pu, and 241Am from the ceramics studied are 10−4–10−5 g/(m2d).

Effect of Molybdenum and Ruthenium on the Crystallization Tendency of a New Nuclear Glass Containing High Rare-earth Concentration

2010 ◽  
Vol 1265 ◽  
Author(s):  
Daniel Caurant ◽  
Nolwenn Chouard ◽  
Odile Majerus ◽  
Jean-Luc Dussossoy ◽  
Aurelien Ledieu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Nucleating Agent ◽  
High Level Waste ◽  
Optical Absorption Spectroscopy ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Level ◽  
The Impact ◽  
Crystallization Tendency

AbstractThe impact of Nd2O3, MoO3 and RuO2 addition on the competition between the crystallization of apatite Ca2Nd8(SiO4)6O2 and powellite CaMoO4 phases which both may appear in High Level Waste nuclear glass (under certain specific conditions of cooling and glass composition) has been studied on a simplified composition belonging to the system SiO2-Na2O-CaO-Al2O3-B2O3. X-ray diffraction (at room temperature and high temperature) and scanning electron microscopy measurements have been performed on five glasses under two different thermal treatments. We show that RuO2 acts as a nucleating agent for apatite. Moreover, neodymium and molybdenum cations seem to be very close in the glassy network as Nd2O3 addition stops the phase separation of molybdates and inhibits the crystallization of CaMoO4. On the contrary, MoO3 seems to favor the crystallization of apatite. For several samples, the evolution of the distribution of Nd3+ cations after crystallization was followed by optical absorption spectroscopy.

Nepheline Precipitation in High-Level Waste Glasses : Compositional Effects and Impact on the Waste Form Acceptability

1996 ◽  
Vol 465 ◽  
Author(s):  
H. Li ◽  
J. D. Vienna ◽  
P. Hrma ◽  
D. E. Smith ◽  
M. J. Schweiger
Keyword(s):  
Chemical Durability ◽  
Primary Phase ◽  
Waste Form ◽  
High Level Waste ◽  
X Ray Diffraction ◽  
Consistency Test ◽  
Compositional Effects ◽  
High Level ◽  
The Impact ◽  
Glass Compositions

ABSTRACTThe impact of crystalline phase precipitation in glass during canister cooling on chemical durability of the waste form limits waste loading in glass, especially for vitrification of certain high-level waste (HLW) streams rich in Na2O and Al2O3. This study investigates compositional effects on nepheline precipitation in simulated Hanford HLW glasses during canister centerline cooling (CCC) heat treatment. It has been demonstrated that the nepheline primary phase field defined by the Na2O-Al2O3-SiO2 ternary system can be used as an indicator for screening HLW glass compositions that are prone to nepheline formation. Based on the CCC results, the component effects on increasing nepheline precipitation can be approximately ranked as Al2O3 > Na2O > Li2O ≈ K2O ≈ Fe2O3 > CaO > SiC2. The presence of nepheline in glass is usually detrimental to chemical durability. Using x-ray diffraction data in conjunction with a mass balance and a second-order mixture model for 7-day product consistency test (PCT) normalized B release, the effect of glass crystallization on glass durability can be predicted with an uncertainty less than 50% if the residual glass composition is within the range of the PCT model.

Zirconolite-Based Ceramic Formulations for Immobilization of Zr-REE-Actinide Fraction of HLW

2004 ◽  
Vol 824 ◽  
Author(s):  
A.V. Ochkin ◽  
S.V. Stefanovsky ◽  
A.G. Ptashkin ◽  
N.S. Mikhailenko ◽  
O.I. Kirjanova
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
High Level Waste ◽  
X Ray Diffraction ◽  
Controlled Cooling ◽  
X Ray ◽  
Transmission Electron ◽  
High Level ◽  
Scanning Electron

AbstractTwo ceramics for immobilization of a Zr-REE-actinide fraction of high level waste (HLW) based on zirconolite or/and pyrochlore structures with minor brannerite/lucasite, and fluorite-structured dioxide-based solid solution, were synthesized and characterized. The samples were produced by melting of oxide mixtures at 1500 °C followed by controlled cooling for crystallization. Phase compositions of the samples obtained and waste elements partitioning among co-existing phases were investigated in detail using powder X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, and transmission electron microscopy. Cerium enters cerianite-based solid solution, lucasite (if present), and to a lesser extent, pyrochlore and zirconolite. Europium and gadolinium enter predominantly zirconolite and pyrochlore. The highest uranium concentrations were found in a uraninite-based cubic solid solution or pyrochlore and zirconolite.

Glass-Ceramic Waste Forms for Immobilizing Plutonium

1996 ◽  
Vol 465 ◽  
Author(s):  
T. P. O'Holleran ◽  
S. G. Johnson ◽  
S. M. Frank ◽  
M. K. Meyer ◽  
M. Noy ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
High Level Waste ◽  
Processing Plant ◽  
Chemical Processing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Waste ◽  
Waste Forms ◽  
Diffraction Patterns ◽  
High Level

ABSTRACTResults are reported on several new glass and glass-ceramic waste formulations for plutonium disposition. The approach proposed involves employing existing calcined high level waste (HLW) present at the Idaho Chemical Processing Plant (ICPP) as an additive to: 1) aid in the formation of a durable waste form and 2) decrease the attractiveness level of the plutonium from a proliferation viewpoint. The plutonium, PuO2, loadings employed were 15 wt% (glass) and 17 wt% (glass-ceramic). Results in the form of x-ray diffraction patterns, microstructure and durability tests are presented on cerium surrogate and plutonium loaded waste forms using simulated calcined HLW and demonstrate that durable phases, zirconia and zirconolite, contain essentially all the plutonium.

Effect of cooling profile on crystalline phases, oxidation state, and chemical partitioning of complex glasses

MRS Advances ◽  
2020 ◽  
Vol 5 (11) ◽  
pp. 569-579
Author(s):  
J. Marcial ◽  
O. K. Neill ◽  
M. Newville ◽  
J. V. Crum ◽  
J. McCloy
Keyword(s):  
Oxidation State ◽  
High Level Waste ◽  
Crystal Glass ◽  
Treatment Schedule ◽  
X Ray Diffraction ◽  
Chemical Partitioning ◽  
X Ray ◽  
Spatially Resolved ◽  
Isothermal Heat Treatments ◽  
High Level

Abstract:Investigations of the crystallization of aluminosilicate phases within Hanford nuclear waste glasses typically involve subjecting samples to the canister centerline cooling (CCC) schedule. This cooling schedule is representative of the slowest cooling thermal profile which these glasses will experience after the glass is poured into the high level waste (HLW) container. However, few investigations have observed how the crystallization behavior changes by varying the heat treatment schedule. In the present study, three Hanford HLW glasses are subjected to CCC and isothermal heat treatments (IHT) to better understand the evolution of phases and the chemical partitioning due to temperature schedule. Samples were characterized using electron probe microanalysis, X-ray diffraction, micro X-ray fluorescence, and micro X-ray absorption spectroscopy. From IHT, eucryptite and apatite phases were observed which were not observed during CCC. Spatially-resolved measurements demonstrated that the oxidation state of the iron was similar among glass and crystal, and we suggest a mechanism to describe the compositional fluctuations near the crystal-glass interface which influence crystallization.

Transient liquid phase bonding of Cu and Al using metallic particles interlayers

2021 ◽  
pp. 095440542098823
Author(s):  
Alireza Zaheri ◽  
Mohammadreza Farahani ◽  
Alireza Sadeghi ◽  
Naser Souri
Keyword(s):  
Liquid Phase ◽  
Mechanical Test ◽  
Transient Liquid Phase ◽  
Transient Liquid Phase Bonding ◽  
Joint Interface ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallic Particles ◽  
Powder Interlayer

The bonding strength, and microstructures of Cu and Al couples using metallic powders as interlayer during transient liquid phase bonding (TLP bonding) were investigated. The interfacial morphologies and microstructures were studied by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. First, to explore the optimum bonding time and temperature, nine samples were bonded without interlayers in a vacuum condition. Mechanical test results indicated that bonding at 560°C in 20 min returns the highest bond strength (84% of Al). This bonding condition was used to join ten samples with powder interlayers. Powders were prepared by mixing different combinations of Cu, Al (+Fe nanoparticles) and Zn. In the bonding zone, different Cu9Al4, CuAl, and CuAl2 intermetallic co-precipitate. The strongest bonding is formed in the sample with the 70Al (+Fe)-30Cu powder interlayer. Powder interlayers present thinner and more uniform intermetallic layers at the joint interface.

scholarly journals Shape Tuning of Magnetite Nanoparticles Obtained by Hydrothermal Synthesis: Effect of Temperature

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Nayely Torres-Gómez ◽  
Osvaldo Nava ◽  
Liliana Argueta-Figueroa ◽  
René García-Contreras ◽  
Armando Baeza-Barrera ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Nanoparticle Synthesis ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pure Phase ◽  
High Level ◽  
Shape Tuning ◽  
Magnetite Phase

In this work, we present a simple and efficient method for pure phase magnetite (Fe3O4) nanoparticle synthesis. The phase structure, particle shape, and size of the samples were characterized by Raman spectroscopy (Rm), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDS), and transmission electron microscopy (TEM). The morphology tuning was controlled by the temperature of the reaction; the nanoparticles were synthesized via the hydrothermal method at 120°C, 140°C, and 160°C, respectively. The Rm and XRD spectra showed that all the nanoparticles were Fe3O4 in a pure magnetite phase. The obtained nanoparticles exhibited a high level of crystallinity with uniform morphology at each temperature, as can be observed through TEM and SEM. These magnetic nanoparticles exhibited good saturation magnetization and the resulting shapes were quasi-spheres, octahedrons, and cubes. The samples showed striking magnetic properties, which were examined by a vibrating sample magnetometer (VSM). It has been possible to obtain a good morphological control of nanostructured magnetite in a simple, economical, and scalable method by adjusting the temperature, without the modification of any other synthesis parameter.

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