scholarly journals Glass waste forms for the Na-bearing high activity waste fractions

1995 ◽  
Author(s):  
K. Vinjamuri
Keyword(s):  
High Activity ◽  
Glass Waste ◽  
Waste Forms

Screening of Candidate Low‐Temperature Glass Waste Forms for Technetium from Hanford Effluent Management Facility Evaporator Bottoms

2018 ◽  
Author(s):  
Rebecca M. Chamberlin ◽  
Ming Tang ◽  
Rosendo Borjas Nevarez ◽  
Gordon Dennis Jarvinen ◽  
Daniel Koury ◽  
...  
Keyword(s):  
Low Temperature ◽  
Glass Waste ◽  
Waste Forms

Analytical Electron Microscopy Study of Electron Radiation Damage in Iron Phosphate Glass Waste Forms

2002 ◽  
Vol 757 ◽  
Author(s):  
K. Sun ◽  
L. M. Wang ◽  
R. C. Ewing
Keyword(s):  
Electron Microscopy ◽  
Phosphate Glass ◽  
Analytical Electron Microscopy ◽  
Phase Segregation ◽  
Iron Phosphate ◽  
Microscopy Study ◽  
High Electron ◽  
Glass Waste ◽  
Waste Forms ◽  
Analytical Electron

ABSTRACTA series of iron phosphate glass waste forms with compositions of 45Fe2O3-55P2O5, 20Fe2O3-80P2O5, and 20Fe2O3-20Na2O-60P2O5, namely FeP-1, FeP-2 and FeP-3, was studied by analytical electron microscopy (AEM). Transmission electron microscopy (TEM) bright-field (BF) imaging showed that under the electron irradiation, phase segregation occurred in both the FeP-1 and FeP-2 samples at high electron doses (3.84×1026 e/m2). In contrast, bubbles formed in the FeP-3 sample, even at a relatively low dose (2.88×1025 e/m2), which may be attributed to the migration of Na under irradiation as in the case in sodium borosilicate glass. Series electron energy-loss spectroscopy (EELS) analysis showed that the glass materials experienced mass-loss and composition variation. No obvious Fe valence state changes under irradiation were observed within the irradiation period.

EXAFS/XANES studies of plutonium-loaded sodalite/glass waste forms

2001 ◽  
Vol 297 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Michael K. Richmann ◽  
Donald T. Reed ◽  
A.Jeremy Kropf ◽  
Scott B. Aase ◽  
Michele A. Lewis
Keyword(s):  
Glass Waste ◽  
Waste Forms

scholarly journals The role of Th-U minerals in assessing the performance of nuclear waste forms

2014 ◽  
Vol 78 (5) ◽  
pp. 1071-1095 ◽  
Author(s):  
G. R. Lumpkin ◽  
Yan Gao ◽  
R. Gieré ◽  
C. T. Williams ◽  
A. N. Mariano ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Nuclear Waste ◽  
Low Temperatures ◽  
Elevated Temperatures ◽  
Glass Ceramics ◽  
Hydrothermal Systems ◽  
Fluid Composition ◽  
Geological Time ◽  
Glass Waste ◽  
Waste Forms

AbstractMaterials designed for nuclear waste disposal include a range of ceramics, glass ceramics and glass waste forms. Those with crystalline phases have provided the momentum for studies of minerals as a means to understand aspects of waste-form crystal chemistry, behaviour in aqueous systems and radiation damage over geological periods of time. Although the utility of natural analogue studies varies, depending upon the degree of analogy to the proposed geological repository and other factors such as chemical composition, the available data suggest that Th-U host phases such as brannerite, monazite, pyrochlore, zircon and zirconolite are resistant generally to dissolution in aqueous fluids at low temperatures. Geochemical durability may or may not extend to hydrothermal systems depending on the specifics of fluid composition, temperature and pressure. At elevated temperatures, for example, davidite may break down to new phase assemblages including titanite, ilmenite and rutile. Perovskite is generally less resistant to dissolution at low temperatures and breaks down to TiO2, releasing A-site cations to the aqueous fluid. Studies of radiation damage indicate that the oxide and silicate phases become amorphous as a result of the gradual accumulation of alpha-recoil collision cascades. Monazite tends to remain crystalline on geological time scales, a very attractive property that potentially eliminates major changes in physical properties such as density and volume, thereby reducing the potential for cracking, which is a major concern for zircon. In spite of recent success in describing the behaviour of Th-U minerals in geological systems, considerable work remains in order to understand the P-T-X conditions during alteration and T-t history of the host rocks.

Dissolution of Technetium From Nuclear Waste Forms

1983 ◽  
Vol 26 ◽  
Author(s):  
M. Yasser Khalil ◽  
William B. White
Keyword(s):  
Nuclear Waste ◽  
Borosilicate Glass ◽  
Stability Field ◽  
Glass Waste ◽  
Waste Forms ◽  
Reducing Conditions ◽  
Valence States ◽  
The Stability ◽  
Nuclear Waste Forms ◽  
Similar Kinetic

ABSTRACTThe immobilization of 99Tc in both ceramic and borosilicate glass waste forms and the mechanism of dissolution of technetium from these waste forms are complicated by the range of technetium valence states. Metallic Tc,ionic Tc4+ oxides, and volatile molecular species containing Tc7+ all occur within the stability field of water. Tc4+ will substitute readily for Ti4+ in titanatebased ceramics in such phases as perovskite (CaTiO3) and spinel (Mg2TiO4). Tc4+ can be homogeneously distributed in borosilicate glass by re-melting the glass under closed system conditions to prevent the re-oxidation of technetium. The dissolution of technetium from both glass and ceramic waste forms follow similar kinetic behavior although the dissolution rate from the titanate is two orders of magnitude lower. Dissolution under highly reducing conditions is too slow to measure on the time scale of the experiments.

scholarly journals Iron phosphate glass waste forms for vitrifying Hanford AZ102 low activity waste (LAW), part I: Glass formation model

2017 ◽  
Vol 458 ◽  
pp. 149-156 ◽  
Author(s):  
Chandra S. Ray ◽  
V.A. Samaranayake ◽  
Ali Mohammadkhah ◽  
Thomas E. Day ◽  
Delbert E. Day
Keyword(s):  
Phosphate Glass ◽  
Glass Formation ◽  
Iron Phosphate ◽  
Formation Model ◽  
Glass Waste ◽  
Waste Forms ◽  
Low Activity

Iron phosphate glass waste forms for vitrifying Hanford AZ102 Low Activity Waste (LAW), part II: Property-composition model

2018 ◽  
Vol 495 ◽  
pp. 107-116 ◽  
Author(s):  
Chandra S. Ray ◽  
V.A. Samaranayake ◽  
Ali Mohammadkhah ◽  
Thomas E. Day ◽  
Delbert E. Day
Keyword(s):  
Phosphate Glass ◽  
Iron Phosphate ◽  
Glass Waste ◽  
Waste Forms ◽  
Low Activity

Coupling of Fluid Flow with Stepwise Alteration of Glass Waste Forms

1987 ◽  
pp. 211-223
Author(s):  
M.J. Apted ◽  
R.R. Adee ◽  
D.L. Lane ◽  
C.C. Allen ◽  
S.A. Rawson
Keyword(s):  
Fluid Flow ◽  
Glass Waste ◽  
Waste Forms
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