Ceramics for the Immobilization of Plutonium and Americium: Current Progress of R&D of the V.G. Khlopin Radium Institute

2003 ◽  
Vol 807 ◽  
Author(s):  
Evgeniy B. Anderson ◽  
Boris E. Burakov
Keyword(s):  
Sol Gel ◽  
Tetragonal Zirconia ◽  
Ceramic Materials ◽  
Khlopin Radium Institute ◽  
Radium Institute ◽  
Crystalline Materials ◽  
Synthesis Conditions ◽  
Mixed Oxide Fuel ◽  
Air Atmosphere ◽  
Environmentally Safe

ABSTRACTSince 1990, the Laboratory of Applied Mineralogy and Radiogeochemistry of the V.G. Khlopin Radium Institute (KRI) has been developing several different types of crystalline host-phases acceptable for the economically feasible and environmentally safe immobilization of actinide wastes. We proposed that ceramics that are based on host phases similar to naturally occurring accessory minerals including zircon, (Zr,Hf,…)SiO4; hafnon, (Hf,Zr,…)SiO4; baddeleyite (monoclinic zirconia), (Zr,Hf,…)O2; tazheranite (cubic zirconia), (Zr,Hf,Ca,Ti,…)O2; garnet, (Ca,Fe,Gd,…)3(Al,Fe,Si,…)5O12; perovskite, (Ca,Gd,…)(Al,Fe,Ti,…)O3, and monazite, (La,Ce,…)PO4, are the most efficient materials for actinide immobilization in deep geological formations. Solid solution of Pu in zirconia, (Zr,Pu)O2, could be used as a ceramic nuclear fuel that is competitive with mixed oxide fuel (MOX). To date, the following crystalline materials doped with 239Pu, 238Pu and 243Am have been successfully synthesized and studied at KRI: zircon; hafnon; cubic and tetragonal zirconia; monazite; aluminate garnet and perovskite. The maximum actinide loading was (in wt.% el.): 239Pu -37; 238Pu-10; 243Am-23. All Pu-Am-doped samples were made in air atmosphere under glove boxes conditions. Polycrystalline (ceramic) materials were made by sintering or melting of sol-gel, co-precipitated hydroxides, oxalates and phosphates or ground oxide precursors; single crystals were grown by a flux method. It was demonstrated that all ceramic samples obtained are characterized by high chemical durability and typical normalized actinide losses in deionized water at 90°C do not exceed 10−2–10−3 g/m2 (without correction for ceramic porosity). However, investigation of long-term behavior of ceramic waste forms requires taking into account the results of accelerated radiation damage study and modeling of ceramic alteration by underground solutions. The principal features of Pu-Am-doped samples obtained so far at KRI and their synthesis conditions are discussed.

scholarly journals Influence of Li2Co3 and V2O5 combined additions on the sintering and dielectric properties of Ca0.5Sr0.5TiO3 ceramics prepared from powders synthesized by sol-gel method

2014 ◽  
Vol 8 (2) ◽  
pp. 101-108
Author(s):  
Nouara Lamrani ◽  
Ahcène Chaouchi ◽  
Jerôme Bernard ◽  
Brahim Itaalit ◽  
David Houivet ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Lithium Carbonate ◽  
Ceramic Materials ◽  
Type I ◽  
Titanium Butoxide ◽  
Gel Method ◽  
Sol Gel Method ◽  
Air Atmosphere

In this work, we have studied the influence of lithium carbonate (Li2CO3) associated with the vanadium oxide (V2O5) on sintering and dielectrics properties of Ca0.5Sr0.5TiO3 ceramic materials obtained from nanopowder synthesized by sol-gel method. The nanopowder was obtained by controlled mixing of titanium butoxide dissolved in butanol-2 and acetic acid with a saturated aqueous solution of calcium acetate and strontium carbonate and subsequent drying of the formed gel at 80 ?C and calcination at 1100?C. The synthesized nanopowder was mixed with different amount of additives, and then uniaxally pressed and sintered in air atmosphere at temperature determined by dilatomertic measurements. The pure Ca0.5Sr0.5TiO3 sample obtained by this process required a sintering temperature around 1500?C. The addition of Li2CO3 combined with V2O5 improved sinterability and caused a shift of dilatimeric shrinkage curve to much lower temperatures. Thus, dense ceramics (98% of theoretical density) were obtained at sintering temperature ? 1300?C. The effect of adding Li2CO3-V2O5 on the structure of ceramics and the dielectric properties is discussed and show that type I dielectric properties (linear variation of the permittivity) are conserved, but with an increase of dielectric loss.

Low-temperature sol–gel synthesis of crystalline materials

RSC Advances ◽  
2014 ◽  
Vol 4 (86) ◽  
pp. 45903-45919 ◽  
Author(s):  
Alexandr V. Vinogradov ◽  
Vladimir V. Vinogradov
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Materials Science ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Crystalline Materials ◽  
New Era ◽  
Sol Gel Synthesis

Sol–gel chemistry has opened a new era of modern materials science by enabling the production of ceramic materials at near-room temperature.

Effect of synthesis conditions on the structure and properties of LiFeO2/ZnFe2O4 nanocomposites prepared by a sol-gel method

2021 ◽  
pp. 114379
Author(s):  
Sun Chang ◽  
Sun Mei ◽  
Ren qianqian ◽  
Li Yang ◽  
Li Yang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Structure And Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Synthesis Conditions

Sol-gel and SPS combined synthesis of highly porous wollastonite ceramic materials with immobilized Au-NPs

2017 ◽  
Vol 43 (11) ◽  
pp. 8509-8516 ◽  
Author(s):  
E.K. Papynov ◽  
O.O. Shichalin ◽  
V.Yu. Mayorov ◽  
E.B. Modin ◽  
A.S. Portnyagin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Ceramic Materials ◽  
Au Nps ◽  
Highly Porous

Control of Hierarchically Ordered Positive and Negative Replicas of Wood Cellular Structures by Surfactant-Directed Sol-Gel Mineralization

2002 ◽  
Vol 726 ◽  
Author(s):  
Yongsoon Shin ◽  
Jun Liu ◽  
Li-Qiong Wang ◽  
Jeong Ho Chang ◽  
William D. Samuels ◽  
...  
Keyword(s):  
Silicic Acid ◽  
Cell Walls ◽  
Cellular Structure ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Silica Particles ◽  
Low Ph ◽  
Cellular Structures ◽  
Inner Surface

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.

Porous Alumina Silicate Matrix Gubka for Solidification of 137Cs Strip Product

2006 ◽  
Vol 985 ◽  
Author(s):  
Albert Aloy ◽  
Alexander Strelnikov ◽  
Vyacheslav Essimantovskiy
Keyword(s):  
Remote Control ◽  
Radioactive Waste ◽  
Inorganic Material ◽  
Porous Alumina ◽  
Volume Reduction ◽  
Experimental Unit ◽  
Silicate Matrix ◽  
Khlopin Radium Institute ◽  
Radium Institute ◽  
Control Regime

AbstractSeparated liquid highâlevel radioactive waste (HLW) fractions, in particular, about 100 l of 137Cs strip product with activity up to ∼ 100 Ci/l (3.7 TBq/l) have been produced during the development and testing of partitioning technology and temporary stored at “V.G. Khlopin Radium Institute” (SaintâPetersburg, Russia). The benchâscale experimental unit designed for operation in the hot cell was developed for 137Cs strip product solidification with using of alumina silicate porous inorganic material (PIM) called Gubka.Conditions of saturation, drying and calcinations of the salts into Gubka pores were optimized and the operations under remote control regime were executed during tests with using of simulated strip product doped with 137Cs. The volume reduction coefficients were equal by a factor of 3.2â3.9 and 137Cs discharge into offâgas system was not detected. 137Cs leach rates from Gubka blocks after calcination at 800 °C were 1.0â1.5*10-3 g/m2*day.

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi1/2Mn1/2O2 by Sol Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Synthesis Conditions ◽  
A Current

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

Infrared Characterization of PMMA-SiO2 Hybrid Glasses Obtained by Sol-Gel Process

2010 ◽  
Vol 1278 ◽  
Author(s):  
L.L. Díaz-Flores ◽  
A. S. López Rodríguez ◽  
P. SifuentesGallardo ◽  
M.A. Hernàndez Rivera ◽  
M.a Garnica Romo ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Hybrid Coatings ◽  
Force Microscopy ◽  
Air Atmosphere ◽  
Atomic Force ◽  
Sol Gel Process ◽  
Traditional Process ◽  
And Chemical Properties

AbstractThis work is about the production of hybrid coatings of the system SiO2-PMMA (PMMA, polymethylmethacrylate). These materials have interesting mechanical and chemical properties useful for anticorrosive and wear resistance applications. SiO2-PMMA hybrids were obtained by the sol-gel traditional process, using tetraethylorthosilicate (TEOS) and methylmethacrylate (MMA) by Aldrich Co, as starting reagents. The SiO2:PMMA ratio was varied from 0:1 to about 1:1 at air atmosphere deposition. The coatings were obtained on acrylic sheets and silicon wafers. A diversity of coatings with chemical composition ranging from SiO2 and PMMA to obtain the SiO2-PMMA hybrids were obtained. Infrared (IR) and atomic force microscopy (AFM), were performed to determinate structural and morphological behavior.

scholarly journals Recent Advances in Applications of Ceramic Nanofibers

2021 ◽  
Author(s):  
Nuray Kizildag
Keyword(s):  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Ceramic Materials ◽  
Water Remediation ◽  
Mechanical And Thermal Properties ◽  
Chemical Erosion ◽  
Recent Advances ◽  
Wide Range ◽  
Ceramic Nanofibers

Ceramic materials are well known for their hardness, inertness, superior mechanical and thermal properties, resistance against chemical erosion and corrosion. Ceramic nanofibers were first manufactured through a combination of electrospinning with sol–gel method in 2002. The electrospun ceramic nanofibers display unprecedented properties such as high surface area, length, thermo-mechanical properties, and hierarchically porous structure which make them candidates for a wide range of applications such as tissue engineering, sensors, water remediation, energy storage, electromagnetic shielding, thermal insulation materials, etc. This chapter focuses on the most recent advances in the applications of ceramic nanofibers.

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