scholarly journals Formulation and Analysis of Compliant Grouted Waste Forms for SHINE Waste Streams

2014 ◽  
Author(s):  
William Ebert ◽  
Candido Pereira ◽  
Thad A. Heltemes ◽  
Amanda Youker ◽  
Vakhtang Makarashvili ◽  
...  
Keyword(s):  
Waste Streams ◽  
Waste Forms

scholarly journals Apatite- and Monazite-Bearing Glass-Crystal Composites for the Immobilization of Low-Level Nuclear and Hazardous Wastes

1995 ◽  
Vol 412 ◽  
Author(s):  
D. J. Wronkiewicz ◽  
S. F. Wolf ◽  
T. S. DiSanto
Keyword(s):  
Transition Metals ◽  
Nuclear Waste ◽  
Toxic Metals ◽  
Hazardous Wastes ◽  
Waste Streams ◽  
Waste Forms ◽  
Glass Crystal ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Crystal Composite

AbstractThis study demonstrates that glass-crystal composite waste forms can be produced from waste streams containing high proportions of phosphorus, transition metals, and/or halides. The crystalline phases produced in crucible-scale melts include apatite, monazite, spinels, and a Zr-Si-Fe-Ti phase. These phases readily incorporated radionuclide and toxic metals into their crystal structures, while corrosion tests have demonstrated that glass-crystal composites can be up to 300-fold more durable than simulated high-level nuclear waste glasses, such as SRL 202U.

Fixation of Leachable Elements in Composite Waste Forms from North Dakota Lignite Coal Conversion Ash

1987 ◽  
Vol 113 ◽  
Author(s):  
D. J. Hasseti ◽  
D. F. Hassett
Keyword(s):  
North Dakota ◽  
Coal Gasification ◽  
Tap Water ◽  
Liquid Waste ◽  
Waste Incinerator ◽  
Leaching Tests ◽  
Waste Streams ◽  
Ettringite Formation ◽  
Batch Tests ◽  
Waste Forms

ABSTRACTComposite waste forms prepared using solid and liquid waste streams from an integrated coal gasification facility at Beulah, North Dakota, were evaluated for the potential leachability of select trace elements using batch tests. Cylinders were fabricated from seven blends of the solid components using liquid waste incinerator blowdown, multi-effect evaporator concentrate, or tap water. Individual waste forms and composites were leached using the same protocols. Both long term and short term leaching tests were used to evaluate these composite waste forms.Comparisons of measured concentrations of elements with values calculated from data on individual components were used to determine any change in leachability that may have occurred. These changes were expressed as a fixation factor, which is a term derived by dividing the calculated leachability by the measured concentrations from the actual leaching tests. Results from these experiments indicated that leachability of some elements could be lowered by the mixing of various solid and liquid waste streams. Ettringite formation is one possible mechanism responsible for fixation of several of the elements.

Evaluation of thermally converted silicotitanate waste forms

1999 ◽  
Vol 556 ◽  
Author(s):  
Y. SU ◽  
M. L. Balmer ◽  
L. Wang ◽  
B. C. Bunker ◽  
M. Nyman ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Conversion ◽  
X Ray Diffraction ◽  
Ion Exchangers ◽  
Waste Streams ◽  
Silicate Phase ◽  
X Ray ◽  
Waste Forms ◽  
Heat Treated ◽  
Crystalline Silicotitanate

AbstractCrystalline silicotitanate ion exchangers are highly selective for separating Cs from Narich waste streams. However, use of these ion exchangers for removal of Cs from radioactive tank waste will result in large volumes of secondary wastes. Thermal conversion of silicotitanates produces a durable waste form with reduced volumes up to 40%. Leach tests (MCC-l and PCT) have shown that Cs leach rates of IE-91 1-Na (heat treated at 900°C for an hour) are extremely low, ranging from 0.1 to lwt% Cs loss in Cs fraction release, or 10-1 to 10-8g/m2day in normalized Cs mass loss. These are several orders of magnitude lower than that of borosilicate glass. In order to understand the interplay between the structure and high Cs durability, X-ray diffraction, 133Cs NMR, and thermogravimetric analysis have been used to identify phase(s) responsible for trapping Cs in these silicotitanates. Results indicate that Cs is likely to be contained in a crystalline silicate phase.

scholarly journals Glass Ceramic Waste Forms for Combined CS+LN+TM Fission Products Waste Streams

2010 ◽  
Author(s):  
Jarrod V. Crum ◽  
Laura A. Turo ◽  
Brian J. Riley ◽  
Ming Tang ◽  
Anna Kossoy ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Fission Products ◽  
Waste Streams ◽  
Ceramic Waste ◽  
Waste Forms

Synthesis of Zircon for Immobilization of Actinides

1995 ◽  
Vol 412 ◽  
Author(s):  
B. E. Burakov ◽  
E. B. Anderson ◽  
V. S. Rovsha ◽  
S. V. Ushakov ◽  
R. C. Ewing ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Mixed Oxide ◽  
Hot Pressing ◽  
Nuclear Power ◽  
Reactor Core ◽  
Chernobyl Nuclear Power Plant ◽  
Waste Streams ◽  
Waste Forms ◽  
Ideal Stoichiometry

AbstractA new method of synthesis for actinide-doped zircon is presented based on studies of zircons formed by crystallization from the reactor core melt generated in the course of the accident at the Chernobyl Nuclear Power Plant. These zircons have compositions in the range (Zr0.94, U0.06)SiO4 to (Zr0.9, U0.1)SiO4. Hot-pressing of oxides was studied to make Zr-based waste forms. The results demonstrate the efficacy of using metallic zirconium in synthesizing high-actinide zircons. In the event of deviations from zircon's ideal stoichiometry, ZrO2 forms, which is also an effective host phase for actinide elements. Waste streams high in zirconium and actinides could be converted into Zr-based waste forms. The adaptation and modification of the mixed-oxide reactor fuel (MOX) production process is proposed as a process for the production of (Zr,Pu)SiO4, a durable waste form for excess weapons plutonium.

scholarly journals Novel Zoned Waste-forms for High-Priority Radionuclide Waste Streams.

2019 ◽  
Author(s):  
Charles R. Bryan ◽  
Margaret Ellen Gordon ◽  
Jeffery A. Greathouse ◽  
Philippe F Weck ◽  
Eunja Kim
Keyword(s):  
Waste Streams ◽  
Waste Forms

High Resolution Observations of Ion-Milling Induced Transformation in Synthetic Hollandses

1981 ◽  
Vol 39 ◽  
pp. 114-115 ◽  
Author(s):  
T. J. Headley
Keyword(s):  
High Resolution ◽  
Radioactive Waste Disposal ◽  
Ion Milling ◽  
Minor Elements ◽  
Waste Forms ◽  
Carbon Substrates ◽  
Structural Differences ◽  
Oxide Phases ◽  
Argon Ions ◽  
High Resolution Microscopy

Oxide phases having the hollandite structure have been identified in multiphase ceramic waste forms being developed for radioactive waste disposal. High resolution studies of phases in the waste forms described in Ref. [2] were initiated to examine them for fine scale structural differences compared to natural mineral analogs. Two hollandites were studied: a (Ba,Cs,K)-titan-ate with minor elements in solution that is produced in the waste forms, and a synthesized BaAl2Ti6O16 phase containing ∼ 4.7 wt% Cs2O. Both materials were consolidated by hot pressing at temperatures above 1100°C. Samples for high resolution microscopy were prepared both by ion-milling (7kV argon ions) and by crushing and dispersing the fragments on holey carbon substrates. The high resolution studies were performed in a JEM 200CX/SEG operating at 200kV.

Waste Disposal in the Sea off Southern California

1986 ◽  
Vol 18 (11) ◽  
pp. 1-9 ◽  
Author(s):  
Willard Bascom
Keyword(s):  
Waste Water ◽  
Coastal Waters ◽  
Southern California ◽  
State Standards ◽  
Waste Streams ◽  
Cool Water ◽  
Water Research ◽  
The Pacific ◽  
Steady Improvement ◽  
Deep Cool

Southern California, with a coastal population of 12 million people, releases about 4.4 million cubic meters of treated waste water into the Pacific every day via outfalls that discharge three to six kilometers offshore at a depth of 60 meters. Diffusers cause each liter of waste to be diluted by 150 liters of deep cool water preventing it from reaching the surface except for short periods in winter. Data on the constituents of the four largest waste streams are presented and a brief account of the research done by the Southern California Coastal Water Research Project is given. Although the waste water now discharged meets rigorous state standards (with minor exceptions) and the steady improvement in sea conditions over a decade has been well documented, there is a continuing debate over whether our coastal waters are adequately protected. This is primarily because the damaging effects of DDT and PCBs that were discharged more than 14 years ago have been slow to go away. Although the amounts of DDT and PCB in sea animals are only one- tenth what they were a decade ago they tend to obscure the value of the improvements and the present discharge practices. The alternatives to sea disposal seem likely to cause greater damage to the overall environment.

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