Liquidus Temperature Model for Hanford High-Level Waste Glasses with High Concentrations of Zirconia

1996 ◽  
Vol 465 ◽  
Author(s):  
J. V. Crum ◽  
M. J. Schweiger ◽  
P. Hrma ◽  
J. D. Vienna
Keyword(s):  
Crystalline Phase ◽  
Liquidus Temperature ◽  
Heat Treating ◽  
Primary Phase ◽  
High Level Waste ◽  
Mass Fractions ◽  
High Concentrations ◽  
Phase Glass ◽  
High Level ◽  
Temperature Furnace

ABSTRACTA study was conducted on glasses based on a simulated transuranic waste with high concentrations of ZrO2and Bi2O3 to determine the compositional dependence of primary crystalline phases and liquidus temperature (TL). Starting from a baseline composition, glasses were formulated by changing mass fractions of Al2O3, B2O3, Bi2O3, CeO2, Li2O, Na2O, P2O5, SiO2, and ZrO2, one at a time, while keeping the remaining components in the same relative proportions as in the baseline glass. Liquidus temperature was measured by heat treating glass samples for 24 h in a uniform temperature furnace. The primary crystalline phase in the baseline glass and the majority of the glasses was zircon (ZrSiO4). A change in the concentration of certain components (Al2O3, ZrO2, Li2O, B2O3 and SiO2) changed the primary phase to baddeleyite (ZrO2), while cerium oxide (CeO2) precipitated from glasses with more than 3 wt% CeO2. Zircon TL was strongly increased by Al2O3, Zrb2 and CeO2, and slightly by P2O5 and SiO2; decreased strongly by Li2O and Na2O and moderately by B2O3. A first-order model was constructed for TL as a function of composition for zircon primary crystalline phase glass.

Liquidus Temperature of Spinel Precipitating High-Level Waste Glasses

1996 ◽  
Vol 465 ◽  
Author(s):  
M. Mika ◽  
M. J. Schweiger ◽  
J. D. Vienna ◽  
P. Hrma
Keyword(s):  
Mixture Models ◽  
Crystalline Phase ◽  
Liquidus Temperature ◽  
Glass Composition ◽  
High Level Waste ◽  
Hanford Site ◽  
High Iron ◽  
Negative Effect ◽  
High Level ◽  
Glass Viscosity

ABSTRACTThe liquidus temperature (TL) often limits the loading of high-level waste in glass through the constraint that TL must be at least 100°C below the temperature at which the glass viscosity is 5 Pa-s. In this study, values of TL for spinel primary crystalline phase were measured as a function of glass composition. The test glasses were based on high-iron Hanford Site tank wastes. All studied glasses precipitated spinel (Ni,Fe,Mn)(Cr,Fe)2O4 as the primary crystalline phase. TL was increased by additions of Cr2O3, NiO, Al2O3, Fe2O3, MgO, and MnO; while Li2O, Na2O, B2O3, and SiO2 had a negative effect. Empirical mixture models were fitted to data.

Liquidus Temperature of High-Level Waste Borosilicate Glasses With Spinel Primary Phase

1999 ◽  
Vol 608 ◽  
Author(s):  
Pavel Hrma ◽  
John Vienna ◽  
Jarrod Crum ◽  
Greg Piepel ◽  
Martin Mika
Keyword(s):  
Liquidus Temperature ◽  
Primary Phase ◽  
High Level Waste ◽  
Borosilicate Glasses ◽  
High Level

Spinel Settling in HLW Melters

2001 ◽  
Author(s):  
Josef Matyáš ◽  
Jaroslav Kloužek ◽  
Lubomír Němec ◽  
Miroslav Trochta
Keyword(s):  
Liquidus Temperature ◽  
Linear Growth ◽  
Critical Level ◽  
High Level Waste ◽  
Input Concentration ◽  
Average Temperature ◽  
Input Size ◽  
Waste Loading ◽  
High Level ◽  
The Impact

Abstract The efficiency of high-level waste (HLW) melters is limited by spinel settling and accumulation on the melter bottom if the waste loading is increased above a certain limit at which spinel crystallizes from the melt. Spinel accumulation interferes with melter operation and shortens melter lifetime. The mathematical modeling of spinel settling in a HLW melter was applied to define the critical level of spinel deposition during the lifetime of the melter and the corresponding increase in waste loading. In this study, spinel settled on the bottom, slant melter walls, and in the output pipe with a linear growth of spinel-sludge thickness after its concentration stabilized inside the melter. The calculations provided a higher concentration of spinel crystals in the melter regions where the temperature was lower then the liquidus temperature, i.e., T<TL. The effects of the following parameters on sludge-layer thickness were examined: 1) the impact of input concentration of spinel crystals of the same size, 2) the impact of different input size of spinel crystals of the same concentration entering from cold cap (melting batch on the melt surface), and 3) the influence of the average temperature (Tavg) inside of the melting space. The calculations showed that higher a concentration and bigger crystals caused thicker sludge layers in the melter, either because of a higher settling density of crystals or because of their higher settling rate. The nucleation of spinel crystals plays a more important role with decreasing of average temperature inside of the melter, and the thicker layer was formed at lower average temperatures.

Respirable Fines Produced by Impacts of Simulated Alternative High-Level Waste Materials

1981 ◽  
Vol 6 ◽  
Author(s):  
Leslie J. Jardine ◽  
Gerald T. Reedy ◽  
William J. Mecham
Keyword(s):  
Fragment Size ◽  
High Level Waste ◽  
Size Distributions ◽  
Savannah River ◽  
Waste Forms ◽  
Mass Fractions ◽  
High Silica ◽  
Weight Impact ◽  
High Level ◽  
Spinel Ceramic

ABSTRACTStandardized comparative drop weight impact tests were conducted on solid alternative waste forms under consideration for immobilizing Savannah River Laboratory (SRL) defense wastes. The fragment size distributions were measured in the size ranges of ֮5 to 8000 μm. All waste form fragment size distributions could be described accurately by lognormal plots. Respirable sizes (≤10 μm) were measured. Borosilicate glass and SYNROC specimens yielded the same mass fractions of respirable sizes; FUETAP concrete, high silica and alkoxide glass specimens yielded ֮2–3 times more mass fractions of particles of respirable sizes, whereas tailored (Spinel) ceramic specimens yielded the smallest mass fractions of respirable sizes, ֮2–1/2 times less.

scholarly journals The effect of high-level waste glass composition on spinel liquidus temperature

2014 ◽  
Vol 384 ◽  
pp. 32-40 ◽  
Author(s):  
Pavel Hrma ◽  
Brian J. Riley ◽  
Jarrod V. Crum ◽  
Josef Matyas
Keyword(s):  
Liquidus Temperature ◽  
Glass Composition ◽  
Waste Glass ◽  
High Level Waste ◽  
High Level

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.

scholarly journals Results from Phase 1, 2, and 3 Studies on Nepheline Formation in High-Level Waste Glasses Containing High Concentrations of Alumina

2016 ◽  
Author(s):  
Jared Kroll ◽  
John Vienna ◽  
Michael Schweiger ◽  
Gregory Piepel ◽  
Scott Cooley
Keyword(s):  
Phase 1 ◽  
High Level Waste ◽  
High Concentrations ◽  
High Level

The Effect of Glass Composition Containing RE Oxide Waste Glass on Liquidus Temperature

MRS Advances ◽  
2016 ◽  
Vol 1 (63-64) ◽  
pp. 4221-4225
Author(s):  
S. Mohd Fadzil ◽  
P. Hrma
Keyword(s):  
Crystalline Phase ◽  
Liquidus Temperature ◽  
Glass Composition ◽  
Primary Phase ◽  
Borosilicate Glasses ◽  
Secondary Phases ◽  
Order Model ◽  
Composition Data ◽  
First Order ◽  
Wide Range

ABSTRACTThe liquidus temperature (TL) of rare earth (RE) was determined for alumino-borosilicate glasses for treating americium and curium that have been studied previously. Their work covers a wide range of glass composition with various crystalline phases as primary phase. Present work is aimed at understanding the effect of glass composition on TL for waste glasses designed for vitrifying RE oxides wastes. In a sufficiently narrow composition region, this effect can be represented by a first-order model fitted measured TL versus composition data. Test glasses were formulated by varying of component fractions one-at-a-time. The glasses contained SiO2, B2O3, and Al2O3 as glass formers and Nd2O3 with CeO2 as simulated RE waste. Twenty glasses were made to investigate crystallization as a function of temperature and glass composition. The primary crystalline phase was Ce-borosilicate (Ce3BSi2O10), secondary phases were Al-containing crystals (Al2O3 and Al10Si2O19), and crystalline CeO2. A first-order model was fitted to crystal fraction versus glass composition data. Generally, SiO2 and B2O3 tend to suppress crystallization, Al2O3 has little effect, and, as expected, RE components (Nd2O3 and CeO2) promote it. The correlation coefficient, R2, was 0.89 for the primary crystalline phase TL as a linear function of composition.

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