scholarly journals Cement-Based Waste forms for Disposal of Savannah River Plant Low-Level Radioactive Salt Waste

1983 ◽  
Vol 26 ◽  
Author(s):  
Christine A. Langton ◽  
Michael D. Dukes ◽  
Randolph V. Simmons
Keyword(s):  
Disposal Site ◽  
Savannah River ◽  
Soluble Salts ◽  
X Ray Diffraction ◽  
Bulk Properties ◽  
X Ray ◽  
Low Level ◽  
Leach Rate ◽  
Savannah River Plant ◽  
Salt Waste

ABSTRACTDefense waste processing at the Savannah River Plant will include decontamination and disposal of approximately 100 million liters of soluble salts containing primarily NaNO3, NaOH, NaNO2, NaAl(OH)4, and Na2SO4. A cement-based waste form, “saltstone,” has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy of leached and unleached specimens were characterized by SEM and X-ray diffraction analyses, respectively. It has been concluded that the salt leach rate can be limited so that amounts of salt and radionuclides in the groundwater at the perimeter of the 100 acre disposal site will not exceed EPA drinking water standards.

Physical Properties of Saltstone: Physical Properties of Saltstone: A Savannah River Plant Waste Form

1984 ◽  
Vol 44 ◽  
Author(s):  
Christine A. Langton
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Field Tests ◽  
Waste Form ◽  
Savannah River ◽  
X Ray Diffraction ◽  
Near Surface ◽  
Leach Rate ◽  
Savannah River Plant ◽  
Water To Cement Ratio

AbstractA cement-based waste form, “saltstone,” has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Laboratory and field tests indicate that this stabilization process greatly reduces the mobility of all of the waste constituents in the surface and near-surface environment. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy were characterized by SEM and x-ray diffraction analyses.Compressive strength was found to increase as the water to cement ratio decreased. Porosity and mean pore size increased with increasing water to cement ratios. Bulk diffusivities of the various ions dissolved in the pore solutions were also found to increase as water to cement ratios increased.

Effects of Alpha, Gamma, and Alpha-Recoil Radiation on Borosilicate Glass Containing Savannah River Plant Defense High-Level Nuclear Waste

1981 ◽  
Vol 6 ◽  
Author(s):  
Ned E. Bibler
Keyword(s):  
Borosilicate Glass ◽  
Deionized Water ◽  
Savannah River ◽  
Γ Radiation ◽  
Leach Rate ◽  
Geologic Storage ◽  
Savannah River Plant ◽  
Pb Ions ◽  
High Level ◽  
Doped Glass

ABSTRACTAt 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 106y, the glass would be exposed to ∼3 × 1010 rad of β radiation, ∼1010 rad of γ radiation, and 1018 particles/g glass for both α and α-recoil radiation. This paper discusses tests of the effect of these radiations on the leachability and density of the glass. No effect of the radiations was detected that reduced the effectiveness of the glass for long-term storage of DHLW even at doses corresponding to 106 years storage for the actual glass. For the tests, glass containing simulated DHLW was prepared from frit of the reference composition. Three methods were used to irradiate the glass: external irradiations with beams of ∼200 keV or Pb ions, internal irradiations with Cm–244 doped glass, and external irradiations with Co–60 γ rays. Results with both Xe and Pb ions indicate that a dose of 3 × 1013 ions/cm2 (simulating >106 years storage) does not significantly increase the leachability of the glass in deionized water. Tests with Cm–244 doped glass show no increase in leach rate in deionized water up to a dose of 1.3 × 1018 α and α-recoils/g glass. The density of the Cm–244 doped glass has decreased by 1% at a dose of 1018 particles/g glass. With γ-radiation, the density has changed by <0.05% at a dose of 8.5 × 1010 rad. Results of leach tests in deionized water and brine indicated that this very large dose of γ-radiation increased the leach rate by only 20%. Also, the leach rates are 3 to 4 times lower in brine.

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.

Alteration of smectites induced by hydrolytic exchange

Clay Minerals ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 15-24 ◽  
Author(s):  
S. Ramirez ◽  
D. Righi ◽  
S. Petit
Keyword(s):  
Infrared Spectroscopy ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Relative Increase ◽  
Exchange Capacity ◽  
Capacity Analysis ◽  
Soluble Salts ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Layers

AbstractHydrolytic exchange was performed experimentally on four smectitic clays to evaluate the extent of clay alteration induced by this process and the associated ‘auto-transformation’ of H+ clays. Clay samples were Na-saturated and submitted to 10, 50 and 100 wetting-drying (WD) cycles and characterized after treatment using X-ray diffraction (XRD), infrared spectroscopy (FTIR) and cation exchange capacity analysis. Evidence for hydrolytic exchange was given by increasing amounts of exchangeable Mg2+ and precipitation of Na soluble salts for samples subjected to 100 WD cycles. Results indicated a decrease in the interlayer charge after 10 WD cycles but no further decrease was observed after 50 and 100 WD cycles. For one sample, XRD data indicated a decrease in the proportion of the smectite phase and a relative increase in the concentration of illite-smectite mixed layers also present in the sample. The results suggested that the reaction induces first a decrease in the layer charge and then a partial dissolution of some smectite layers.

scholarly journals Compressional Behavior of Hydrous Orthoenstatite: Insight into the Nature of LVZ under Continental Plate

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 71
Author(s):  
Florian Tian-Siang Hua ◽  
Przemyslaw Dera ◽  
Jennifer Kung
Keyword(s):  
Crystal Structure ◽  
Upper Mantle ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Low Velocity ◽  
X Ray ◽  
Low Level ◽  
Al Content ◽  
Continental Plate ◽  
Influence Of Water

A suite of hydrous orthoenstatite crystals were synthesized at 5–7 GPa and 1100–1300 °C, corresponding to the mid upper mantle conditions in continental regions. The synthetic crystals presented a clear, inclusion-free, and euhedral form with a size range from 100 to a few hundred microns. The Al- and water content of crystals were less than 2 wt. % and ranging from ~500 ppm to 1000 ppm, respectively, characterized by Raman and IR spectroscopy, electron microscopy, and SIMS. The analysis shows that the capability of water incorporation for this suite of hydrous orthoenstatite is correlated to the Al-content in the crystal structure. To understand how the detailed crystal structure reflects the influence of water and Al, single crystal X ray diffraction analysis was performed for this suite of hydrous orthoenstatite. By comparing the results obtained at ambient conditions, we find that for low-level of Al-content, <2 wt. %, the Al3+ cation tends to occupy one of tetrahedral sites (TB) only. Analysis of the X ray diffraction results under high pressure indicates that the elasticity of orthoenstatites is insensitive to the presence of low-level water and Al. We use this finding to evaluate the velocity profile at the mid upper mantle of continental regions to compare with seismic observation. The comparison indicates that the cause of the low velocity zone in continental regions originates from the geotherm profile rather than the effect of water on the elasticity of mantle phases.

Anisotropy in Epitaxial Fe3O4 and NiFe2O4 Thin Films

1994 ◽  
Vol 341 ◽  
Author(s):  
D. T. Margulies ◽  
F. T. Parker ◽  
F. E. Spada ◽  
A. E. Berkowitz
Keyword(s):  
Tensile Stress ◽  
Epitaxial Films ◽  
X Ray Diffraction ◽  
Bulk Properties ◽  
X Ray ◽  
Moment Distribution ◽  
Random Moment ◽  
Dc Magnetron Reactive Sputtering ◽  
Bulk Parameters ◽  
Applied Fields

AbstractFe3O4 and NiFe2O4 films were deposited on <100> and <110> MgO substrates by dc magnetron reactive sputtering. X-ray diffraction studies indicate epitaxial films under an inplane tensile stress. Magnetization studies show that the moments of the films are unsaturated in 70 kOe applied fields and they approach bulk values only in extrapolation. Conversion electron Mössbauer spectroscopy (CEMS) studies indicate bulk parameters for the Fe3O4 films, but show deviations from bulk properties for NiFe2O4 films. CEMS studies further indicate a random moment distribution for all films which is an unexpected property. In-plane torque curves are discussed in terms of single crystal behavior. The effect of the inplane tensile stress is also indicated in the torque curves.

Surface and bulk properties of ancient Egyptian mortars. Part I: X-ray diffraction studies

1986 ◽  
Vol 16 (6) ◽  
pp. 813-822 ◽  
Author(s):  
Hanaa Y. Ghorab ◽  
Jehane Ragai ◽  
Adel Antar
Keyword(s):  
X Ray Diffraction ◽  
Bulk Properties ◽  
X Ray ◽  
Ancient Egyptian

scholarly journals High-Level Radioactive Insoluble Waste Preparation for Vitrification

1984 ◽  
Vol 44 ◽  
Author(s):  
B. A. Hamm ◽  
R. E. Eibling ◽  
M. A. Ebra ◽  
T. Motyka ◽  
H. D. Martin
Keyword(s):  
Radioactive Waste ◽  
Borosilicate Glass ◽  
Savannah River ◽  
Soluble Salts ◽  
High Level Radioactive Waste ◽  
Savannah River Plant ◽  
High Level

AbstractAt the Savannah River Plant (SRP), a process has been developed for immobilizing high-level radioactive waste in a borosilicate glass. The waste is currently stored as soluble salts and insoluble solids. Insoluble waste as stored requires further processing before vitrification is possible. The processes required have been developed and demonstrated with actual waste. They include removal of aluminum in some waste, washing soluble salts out of the insoluble waste, and mercury stripping. Each of the processes and the results with actual SRP waste will be discussed. The benefits of each step will also be included.

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