Effects of Heat Treatment on the Microstructure of a Fully Simulated Nuclear Waste Glass

1990 ◽  
Vol 212 ◽  
Author(s):  
Terese V. Palmiter ◽  
I. Joseph ◽  
L. David Pye
Keyword(s):  
Heat Treatment ◽  
Nuclear Waste ◽  
Scanning Transmission Electron Microscopy ◽  
Waste Glass ◽  
Amorphous Phases ◽  
Transmission Electron ◽  
Heat Treated ◽  
Nuclear Waste Glass ◽  
Scanning Transmission

ABSTRACTSamples of a fully simulated nuclear waste glass under consideration for use in the West Valley Demonstration Project were isothermally heat treated and studied by scanning transmission electron microscopy (STEM). Both fully oxidized and partially reduced specimens were heat treated for 3 hours at 600°C, 700°C, 800°C and 900°C and for 45 days at 10°C above Tg (447°C -461°C) and at 10°C below TB (427°C -441°C). Microstructural features in untreated as well as the heat-treated glasses were studied using STEM. Analysis by energy dispersive spectroscopy (EDS) was used to identify the elemental compositions of the features observed.The predominant crystalline phase present in the samples heat treated for 3 hours was an Fe3O4 type spinel with Ni and Cr substituting for some of the Fe. The spinels varied in size from 0.02 to 10.0 µm, the larger crystals present at higher heat-treatment temperatures. Long term heat treatment above Tg resulted in the formation of small iron-containing crystals ranging in size from 10 to 35 nm. Heat treatment below Tg produced no crystalline or amorphous phases.

Materials Interactions Relating to Long-Term Geologic Disposal of Nuclear Waste Glass

1986 ◽  
Vol 84 ◽  
Author(s):  
Ned E. Bibler ◽  
Carol M. Jantzen
Keyword(s):  
Nuclear Waste ◽  
Review Paper ◽  
Waste Glass ◽  
Waste Form ◽  
Glass Waste ◽  
Waste Package ◽  
Geologic Disposal ◽  
Nuclear Waste Glass ◽  
Backfill Materials

AbstractIn the geologic disposal of nuclear waste glass, the glass will eventually interact with groundwater in the repository system. Interactions can also occur between the glass and other waste package materials that are present. These include the steel canister that holds the glass, the metal overpack over the canister, backfill materials that may be used, and the repository host rock. This review paper systematizes the additional interactions that materials in the waste package will impose on the borosilicate glass waste form-groundwater interactions. The repository geologies reviewed are tuff, salt, basalt, and granite. The interactions emphasized are those appropriate to conditions expected after repository closure, e.g. oxic vs. anoxic conditions. Whenever possible, the effect of radiation from the waste form on the interactions is examined. The interactions are evaluated based on their effect on the release and speciation of various elements including radionuclides from the glass. It is noted when further tests of repository interactions are needed before long-term predictions can be made.

Ion-Exchange Interdiffusion Model with Potential Application to Long-Term Nuclear Waste Glass Performance

2016 ◽  
Vol 120 (17) ◽  
pp. 9374-9384 ◽  
Author(s):  
James Joseph Neeway ◽  
Sebastien N. Kerisit ◽  
Jia Liu ◽  
Jiandong Zhang ◽  
Zihua Zhu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Nuclear Waste ◽  
Potential Application ◽  
Waste Glass ◽  
Nuclear Waste Glass

AEM study of reacted surface layer of borosilicate nuclear waste glasses

1992 ◽  
Vol 50 (1) ◽  
pp. 352-353
Author(s):  
L.M. Wang ◽  
S.A. Kaser ◽  
R.C. Ewing ◽  
J.K. Bates
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Nuclear Waste ◽  
Reaction Pathway ◽  
Sample Surface ◽  
Carbon Films ◽  
Waste Glass ◽  
Thin Sections ◽  
Nuclear Waste Glass

Analysis of the reacted surface layer of borosilicate glass is important to the understanding of the long term nuclear waste glass reaction process. The objective is to assess the simulated nuclear waste glass/water reaction pathway by identifying new crystalline phases that appear on the glass surfaces during the reaction. The results can be used to validate models generated to predict long-term performance of the nuclear waste glass under a range of conditions.In this study, extensive scanning electron microscopy (SEM) with qualitative energy dispersive x-ray spectroscopy (EDS) analysis, quantitative analytical and high resolution transmission electron microscopy (AEM and HRTEM) have been performed on two 202U glasses which were reacted in saturated water vapor for 14 and 23 days, respectively. In order to study the microchemical and microstructural changes with increasing depth from the reaction surface, TEM specimens were prepared in cross-section using the ultramicrotomy slicing technique similar to that described by Bates et al. In this process, small chunks containing the reacted surface layer and a thin layer of glass were first broken off from the sample surface and each of these chunks was then embedded in resin to form a block. Finally, thin sections, approximately 90 nm thick, were microtomed from these blocks and were transfered to copper mesh grids covered by holey carbon films for observation. AEM and HRTEM analyses were accomplished using a JEOL JEM-2000FX microscope attached with a Noran/TN-5500 EDS system at the University of New Mexico.

scholarly journals Synthesis and Characterisation of Nanocomposite Mo-Fe-B Thin Films Deposited by Magnetron Sputtering

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1739
Author(s):  
Paulius Malinovskis ◽  
Stefan Fritze ◽  
Justinas Palisaitis ◽  
Erik Lewin ◽  
Jörg Patscheider ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Scanning Transmission Electron Microscopy ◽  
X Ray Diffraction ◽  
Rich Phase ◽  
X Ray ◽  
Amorphous Phases ◽  
Transmission Electron ◽  
Fe Content ◽  
Direct Current Magnetron Sputtering ◽  
Scanning Transmission

Several ternary phases are known in the Mo-Fe-B system. Previous ab initio calculations have predicted that they should exhibit a tempting mix of mechanical and magnetic properties. In this study, we have deposited Mo-Fe-B films with a Fe-content varying from 0–37 at.% using non-reactive DC (direct current) magnetron sputtering. The phase composition, microstructure, and mechanical properties were investigated using X-ray diffraction, scanning transmission electron microscopy, and nanoindentation measurements. Films deposited at 300 °C and with >7 at.% Fe are nanocomposites consisting of two amorphous phases: a metal-rich phase and a metal-deficient phase. Hardness and elastic modulus were reduced with increasing Fe-content from ~29 to ~19 GPa and ~526 to ~353 GPa, respectively. These values result in H3/E2 ratios of 0.089–0.052 GPa, thereby indicating brittle behaviour of the films. Also, no indication of crystalline ternary phases was observed at temperatures up to 600 °C, suggesting that higher temperatures are required for such films to form.

Comparison of in Situ and Laboratory Corrosion Experiments with Borosilicate Nuclear Waste Glass

1991 ◽  
Vol 257 ◽  
Author(s):  
Werner Lutze ◽  
Rodney C. Ewing
Keyword(s):  
Nuclear Waste ◽  
Laboratory Data ◽  
Waste Glass ◽  
Simulation Test ◽  
In Situ Tests ◽  
Nuclear Waste Glass ◽  
Systems Simulation ◽  
Long Term Behavior

ABSTRACTThe comparison of laboratory data from the corrosion of borosilicate nuclear waste glass (German SM513LW11 and French R7T7) with data from the Materials Interface Interactions Test (MIIT) and Repository Systems Simulation Test (RSST) illustrates the inherent limitations of in situ tests. Although in situ tests may confirm the short term behavior of waste forms and identify phenomena associated with the repository system, they do not provide the fundamental basis for the extrapolation of long-term behavior.

scholarly journals Pourbaix Diagram for The Prediction of Waste Glass Durability in Geologic Environments

1987 ◽  
Vol 112 ◽  
Author(s):  
Carol M. Jantzen
Keyword(s):  
Nuclear Waste ◽  
Oxidation Potential ◽  
Waste Glass ◽  
Natural Environments ◽  
Long Term Effects ◽  
Pourbaix Diagrams ◽  
Nuclear Waste Glass ◽  
Corrosion Mechanisms ◽  
Different Time Scales

AbstractDissolution of nuclear waste glass occurs by corrosion mechanisms similar to those of metallurgical and mineralogic systems albeit on different time scales. The effects of imposed pH and oxidation potential (Eh) conditions existing in natural environments on metals and minerals have been quantatively and phenomenologically described in compendiums of Pourbaix (pH-potential) diagrams. Construction of Pourbaix diagrams to quantify the response of nuclear waste glasses to repository specific pH and Eh conditions is demonstrated. The expected long-term effects of groundwater contact on the durability of nuclear waste glasses can then be unified.

scholarly journals Essential effect of the electrolyte on the mechanical and chemical degradation of LiNi0.8Co0.15Al0.05O2 cathodes upon long-term cycling

2021 ◽  
Vol 9 (4) ◽  
pp. 2111-2119
Author(s):  
Xiaoming Liu ◽  
Xiaowen Zhan ◽  
Zachary D. Hood ◽  
Wangda Li ◽  
Donovan N. Leonard ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Chemical Degradation ◽  
Atomic Resolution ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Extended Charge ◽  
Charge Discharge

Atomic-resolution scanning transmission electron microscopy reveals the initiation and progression mechanism of microcracks and voids in LiNi0.8Co0.15Al0.05O2 (NCA) cathodes upon extended charge/discharge cycles.

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