scholarly journals Characterization of Pseudotachylite and Fault Gouges in Drill Cores from Andong, Korea and Its Implications for Paleo-Earthquakes

2020 ◽  
Vol 12 (24) ◽  
pp. 10421
Author(s):  
Chang Oh Choo ◽  
Su Hyeon Jo ◽  
Sang-Youl Lee ◽  
Sang-Eun Lee ◽  
Gyo-Cheol Jeong
Keyword(s):  
Shear Stress ◽  
Nuclear Waste ◽  
Crystalline Rocks ◽  
Glassy Matrix ◽  
Granitic Gneiss ◽  
Grain Rotation ◽  
High Level Nuclear Waste ◽  
Fault Gouges ◽  
High Level

Pseudotachylite and fault gouges were observed in core samples of Precambrian granitic gneiss drilled from depths as great as 1000 m in Andong, Korea. Fault gouges were found in the upper parts of the borehole, whereas pseudotachylites developed in the lower parts. Pseudotachylite with widths varying from a few mm to 10 cm sharply contacted or were interlayered with the host rock. The quartz-rich portion of the granitic gneiss remained unaffected, but the mafic portion was melted preferentially. The glassy surface of pseudotachylite is characterized by a smooth, glassy matrix with an amorphous phase and silicate beads with diameters of ~200 nm, together with slickenlines. Slickenlines composed of parallel grooves showed a wavelength of 4–7 μm and an amplitude < 1–2 μm. Residual or surviving grains have rounded corners and edges, indicating that those grains experienced abrasion, possibly from grain rotation or shear stress. Both melting and crushing contribute to the formation of pseudotachylite. Fe was always enriched in the glassy matrix, indicating that the pseudotachylite matrix originated from mafic minerals. The occurrence of pseudotachylite related to paleo-earthquake events showed that crystalline rocks in this area are unsatisfactory candidates for deep-disposal sites for high-level nuclear waste.

Characterization of high level nuclear waste solutions from different origin

2019 ◽  
Vol 320 (3) ◽  
pp. 627-631
Author(s):  
Vidya Thorat ◽  
N. Soudamini ◽  
Arijit Sengupta ◽  
R. K. Mishra ◽  
Amar Kumar ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Different Origin

Characterization of Chromium(III) Hydroxide Solids and Their Oxidation by Hydrogen Peroxide

2004 ◽  
Vol 824 ◽  
Author(s):  
Zhicheng Zhang ◽  
Linfeng Rao ◽  
Dhanpat Rai ◽  
Sue B. Clark
Keyword(s):  
Hydrogen Peroxide ◽  
Nuclear Waste ◽  
Molten Glass ◽  
Alkaline Solutions ◽  
Uv Absorption Spectroscopy ◽  
Oxidative Leaching ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Oxidation By Hydrogen Peroxide

AbstractChromium is of great concern in the vitrification of high-level nuclear waste sludges because it forms separate crystallites in the molten glass. Inadequate removal of chromium from sludges could result in the production of an unacceptably large volume of HLW glass. Alkaline oxidative leaching is considered one of the pretreatment strategies to remove chromium before the vitrification.In this study, Cr(III) hydroxide solids were prepared under different conditions and characterized by EXAFS and IR. The rate of oxidation of the solids by hydrogen peroxide in alkaline solutions was studied by UV absorption spectroscopy. EXAFS and IR experiments indicate that the degree of oligomerization in the Cr(III) hydroxide solids increases with the increase in the concentration of NaOH in solution, the aging temperature and the aging time. The rate of oxidation of the solids follows the same order previously observed for Cr(III) oligomers in solution, i.e., species with higher degree of oligomerization are oxidized more slowly.

scholarly journals Application of intrinsic germanium spectral gamma-ray logging for characterization of high-level nuclear waste tank leaks

1993 ◽  
Author(s):  
J.R. Brodeur ◽  
J.P. Kiesler ◽  
S.E. Kos ◽  
C.J. Koizumi ◽  
W.F. Nicaise ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Gamma Ray ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Intrinsic Germanium

Characterization of High-Level Nuclear Waste Glass Using Magnetic Measurements

1993 ◽  
Vol 333 ◽  
Author(s):  
Frank E. Senftle ◽  
Arthur N. Thorpe ◽  
Julius R. Grant ◽  
Aaron Barkatt
Keyword(s):  
Nuclear Waste ◽  
Magnetic Measurements ◽  
Rapid Quenching ◽  
Small Sample ◽  
High Level Waste ◽  
Air Cooling ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Simulated High Level Waste

ABSTRACTMagnetic measurements constitute a promising method for the characterization of nuclear waste glasses in view of their simplicity and small sample weight requirements.Initial studies of simulated high-level waste glasses show that the Curie constant is generally a useful indicator of the Fe2+:Fe3+ ratio. Glasses produced by air-cooling in large vessels show systematic deviations between experimental and calculated values, which are indicative of the presence of small amounts of crystalline iron-containing phases. Most of the iron in these phases becomes dissolved in the glass upon re-heating and more rapid quenching. The studies further show that upon leaching the glass in water some of the iron in the surface regions of the glass is converted to a form which has high temperature-independent magnetic susceptibility.

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