Leaching of Plutonium from “Old” Samples of Single Phase Ceramics Based on Zr0.79Gd0.14Pu0.04O1.93 and La0.9Pu0.1PO4 Doped with 238Pu

MRS Advances ◽  
2016 ◽  
Vol 1 (63-64) ◽  
pp. 4249-4253 ◽  
Author(s):  
Bella Yu Zubekhina ◽  
Boris E. Burakov
Keyword(s):  
Mass Loss ◽  
Radiation Damage ◽  
Single Phase ◽  
Xrd Analysis ◽  
Distilled Water ◽  
High Radiation ◽  
Cubic Zirconia ◽  
Leach Test

ABSTRACTSamples of 238Pu-doped single-phase ceramics based on cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, and monazite, La0.9Pu0.1PO4, have been studied by static leach test in distilled water. Before leach test accumulated doses were (in alpha-decays/m3 x 1026): from 1.6 to 1.7 – for cubic zirconia; and 1.0 – for monazite. Despite high radiation damage both phases remained crystalline according to XRD analysis. The results of static leach tests demonstrate the following Pu normalized mass loss (in g/m2, 90°C, 28 days): from 0.3 to 0.7 – for cubic zirconia; and 1.6 – for monazite. These data are discussed in comparison with results of previous leach tests carried out at lower accumulated doses.

Thermal Analysis of Ca1+xCu3Ti4O12+x Precursor in Nitrogen and Oxygen Environment at 1000 °C

2020 ◽  
Vol 1010 ◽  
pp. 268-273
Author(s):  
Julie Juliewatty Mohamed ◽  
Noruzaman Daud ◽  
Mohamad Johari bin Abu ◽  
Mohd Fariz Ab Rahman ◽  
Siti Roshayu binti Hassan ◽  
...  
Keyword(s):  
Mass Loss ◽  
Room Temperature ◽  
Single Phase ◽  
Xrd Analysis ◽  
Phase Changes ◽  
Oxygen Absorption ◽  
Atmospheric Gases ◽  
Scanning Calorimetry ◽  
Nitrogen Gas ◽  
Ca Ions

The thermal kinetic analyses are prepared on Ca1+xCu3Ti4O12+x powders using simultaneous thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC) measurement in a dual atmospheric gases environment. Initially, the nitrogen gas flowed from room temperature to 1000 °C, and then the environment was shifted and hold for 1 hour with oxygen. The result shows that the TGA patterns of the temperature and mass loss are disorderly with x values. The mass loss % patterns slightly decreased with increased additional Ca-based element. The decreased of oxygen absorption as the values of x increased also can be explained by the reduction of single-phase CCTO structure when excess Ca ions. The DSC pattern shows two prominent endothermic peaks and two exothermic peaks that relate to the melting point of the reactant and crystalline phase changes of samples, while the significant endothermic peak at 1000 °C is corresponding to the formation of CCTO compounds as identified by XRD analysis.

Analysis of Physical Properties, Crystal Structure and Magnetic Properties of Barium Hexaferrite Doped with 2 % wt. of SrO and Prepared by Coprecipitation Method

2019 ◽  
Vol 966 ◽  
pp. 325-330
Author(s):  
Suprapedi ◽  
Muljadi ◽  
Djuhana ◽  
Ramlan
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Physical Properties ◽  
Single Phase ◽  
Raw Materials ◽  
Fine Powder ◽  
Barium Hexaferrite ◽  
Xrd Analysis ◽  
Coprecipitation Method ◽  
Distilled Water

The purpose of this study is to determine the effect of the addition of 2 % SrO on physical, magnetic properties and crystal structure of BaO6Fe2O3. In this study, the coprecipitation method was used with raw materials BaCl2, FeCl3 and SrCl3 and Ba-ferrite composition is used based on the ratio of mole BaO: Fe2O3 = 1: 6, while SrO is used 2% of the weight of Ba-ferrite. The raw materials are dissolved in distilled water, then added a solution (50%) of ammonia to form a perfect precipitate. The precipitate after filtering was dried in an oven at 100°C until dry, then crushed with mortar and partially taken for analysis with DTA / TG. The fine powder was calcined at 800 ° C and held for one hour using an electric furnace. The calcined samples were crushed with mortar and fine powder was added 1% wt.of PVA adhesive and formed with a pressure of 40 MPa to obtaine a pellet sample. The pellet samples were then sintered at 1150°C and hold for 1 hour. Furthermore, the sintered samples were characterized such as measurement of bulk density, magnetic properties with gauss meters and VSM and measurements with XRD. The results of characterization show that the addition of additives 2% of SrO can provide an increase in physical properties and magnetic properties (remanence). But for the crystal structure of XRD analysis there is no change, a single phase is formed, namely BaFe12O19.

Leaching of 137Cs from Chernobyl fuel debris: corium and “lava”

2019 ◽  
Vol 107 (12) ◽  
pp. 1155-1160 ◽  
Author(s):  
Bella Yu. Zubekhina ◽  
Boris E. Burakov ◽  
Oksana G. Bogdanova ◽  
Yuriy Yu. Petrov
Keyword(s):  
Mass Loss ◽  
Quantitative Data ◽  
Specific Activity ◽  
Chemical Durability ◽  
Distilled Water ◽  
Leach Test ◽  
Simulated Seawater

Abstract Samples of Chernobyl fuel debris such as corium and “lava” had been studied using repeated static leach test MCC-1 at temperature of 25 and 90 °C in distilled water and simulated seawater. A normalized 137Cs mass loss (NLCs) estimated for corium samples after 168 days in distilled and seawater was 3.2–3.5 g/m2 at 25 °C and 113–114 g/m2 at 90 °C. For “lava” samples NLCs varied from 1.4 to 13.2 g/m2 at 90 °C for 56 days (in distilled and seawater) and from 0.1 to 0.4 g/m2 at 25 °C in seawater for 140 days. Chemical durability of Chernobyl “lava” in distilled and seawater evaluated using 137Cs specific activity in leachates is higher than one for corium. Further study is proposed in order to obtain more quantitative data.

scholarly journals Long-Term Aging of Chernobyl Fuel Debris: Corium and “Lava”

2021 ◽  
Vol 13 (3) ◽  
pp. 1073
Author(s):  
Bella Zubekhina ◽  
Boris Burakov ◽  
Ekaterina Silanteva ◽  
Yuri Petrov ◽  
Vasiliy Yapaskurt ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Mass Loss ◽  
Nuclear Power ◽  
Distilled Water ◽  
Chemical Alteration ◽  
Laboratory Conditions ◽  
Fukushima Daiichi ◽  
Important Basis

Samples of Chernobyl fuel debris, including massive corium and “lava” were collected inside the Chernobyl “Sarcophagus” or “Shelter” in 1990, transported to Leningrad (St. Petersburg) and stored under laboratory conditions for many years. In 2011 aged samples were visually re-examined and it was confirmed that most of them remained intact, although some evidence of self-destruction and chemical alteration were clearly observed. Selected samples of corium and “lava” were affected by static leaching at temperatures of 25, 90 and 150 °C in distilled water. A normalized Pu mass loss (NLPu) from corium samples after 140 days was noted to be 0.5 g/m2 at 25 °C and 1.1 g/m2 at 90 °C. For “lava” samples NLPu was 2.2–2.3 g/m2 at 90 °C for 140 days. The formation of secondary uranyl phases on the surface of corium and “lava” samples altered at 150 °C was confirmed. The results obtained are considered as an important basis for the simulation of fuel debris aging at Fukushima Daiichi nuclear power plant (NPP).

Structural, Dielectric and Electrical Studies of Ba4CaRTi3Nb7O30 (R = Eu, Dy) Ferroelectric System

2013 ◽  
Vol 547 ◽  
pp. 41-48 ◽  
Author(s):  
Prasun Ganguly ◽  
A.M. Biradar ◽  
A.K. Jha
Keyword(s):  
Single Phase ◽  
Microstructural Analysis ◽  
Tungsten Bronze ◽  
Negative Temperature ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Paraelectric Phase Transition ◽  
Orthorhombic Crystal Structure

The polycrystalline samples of Ba4CaRTi3Nb7O30 (R = Eu, Dy), members of tungsten-bronze family, were prepared by high-temperature solid state reaction method and studied for their dielectric and electrical properties. X-ray diffraction (XRD) analysis reveals the formation of single-phase compounds having orthorhombic crystal structure at room temperature. Microstructural analysis by scanning electron microscope (SEM) shows that the compounds have well defined grains, which are distributed uniformly throughout the sample. Detailed dielectric properties of the compounds as a function of frequency and temperature show that the compounds undergo non-relaxor kind of ferroelectric-paraelectric phase transition of diffuse nature. Ferroelectric, piezoelectric and pyroelectric studies of the compounds have been discussed in this paper. The temperature dependence of dc conductivity of the compounds have been investigated. The conductivity study over a wide temperature range suggests that the compounds have negative temperature coefficient of resistance (NTCR) behaviour.

INVESTIGATIONS ON Sm- AND Nb-SUBSTITUTED PZT CERAMICS

2006 ◽  
Vol 20 (29) ◽  
pp. 1879-1882 ◽  
Author(s):  
CHANDRA PRAKASH ◽  
J. K. JUNEJA
Keyword(s):  
Dielectric Constant ◽  
Single Phase ◽  
Xrd Analysis ◽  
Chemical Formula ◽  
X Ray Diffraction ◽  
Pzt Ceramics ◽  
Ceramic Method ◽  
X Ray ◽  
Niobium Doping ◽  
Constant Versus

In the present paper, we report the effect of Samarium substitution and Niobium doping on the properties of a PZT(52:48). The properties studied are: structural, dielectric and ferroelectric. The samples with chemical formula Pb 0.99 Sm 0.01 Zr 0.52 Ti 0.48 O 3 were prepared by solid-state dry ceramic method. Small amount (0.5 wt%) of Nb 2 O 5 was also added. X-ray diffraction (XRD) analysis showed formation of a single phase with tetragonal structure. Dielectric properties were studied as a function of temperature and frequency. Transition temperature, Tc, was determined from dielectric constant versus temperature plot. The material shows well-defined ferroelectric (PE) hysteresis loop.

Analysis of Selected Area Diffraction Patterns With Winjade

1998 ◽  
Vol 4 (S2) ◽  
pp. 342-343 ◽  
Author(s):  
S. D. Walck ◽  
P. Ruzakowski-Athey
Keyword(s):  
Single Phase ◽  
Xrd Analysis ◽  
Analysis Program ◽  
X Ray Diffraction ◽  
Program Module ◽  
Vast Number ◽  
One Dimensional ◽  
X Ray ◽  
Diffraction Patterns ◽  
Xrd Patterns

The analysis of Selected Area Diffraction (SAD) patterns that are collected from a single phase material having sufficient crystallites to provide continuous rings is relatively straightforward. However, when this condition is not met and there may be several phases present having rings of a spotty nature, the pattern is complex and can be quite difficult to analyze manually because of the vast number of discrete spots. WinJade from MDI is an X-ray diffraction (XRD) analysis program with an Electron Diffraction Program Module (EDPM) that can be used to aid in the analysis of SAD patterns. The EDPM produces Integrated Circular Density Plots (ICDP), which are one-dimensional intensity profiles plotted as a function of equivalent XRD 20 values or crystal d-spacings. These ICDP's can be overlayed with XRD patterns or with reference lines from the NIST and JCPDS crystalline databases for direct comparisons.

scholarly journals The Role of Polypropylene Microfibers in Thermal Properties and Post-Heating Behavior of Cementitious Composites

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2676
Author(s):  
Mohammad R. Irshidat ◽  
Nasser Al-Nuaimi ◽  
Mohamed Rabie
Keyword(s):  
Melting Point ◽  
Heat Flow ◽  
Mass Loss ◽  
Failure Modes ◽  
Cement Mortar ◽  
Xrd Analysis ◽  
Cementitious Composites ◽  
Polypropylene Fibers ◽  
Scanning Calorimetry ◽  
Heating Behavior

This paper experimentally studied the effect of polypropylene (PP) microfibers on thermal and post-heating mechanical behaviors of cementitious composites. Cement mortars with small dosage of polypropylene fibers were prepared, heated at various temperatures (150 °C, 200 °C, 450 °C, and 600 °C), and then tested. The investigated parameters include residual compressive and flexural strengths, elastic modulus, fracture energy, stress intensity factors, failure modes, microstructure (scanning electron microscopy (SEM) imaging), thermal conductivity, heat flow (differential scanning calorimetry (DSC) test), mass loss (thermogravimetric analysis (TGA) test), and chemical composition (XRD analysis). The results showed the efficiency of PP fibers to enhance the post-heating behavior and the residual mechanical properties of cement mortar after heating. The presence of PP fibers did not affect the heat flow and the mass loss of cement mortar at room temperature. However, heating cement mortar at temperature beyond the melting point of the fibers negatively affected its thermal behavior. The presence of PP fibers played a major role in bridging the cracks and mitigating their propagation. Once the melting point of the polypropylene fibers is exceeded, the fibers melted and created extra voids in the microstructure of concrete.

Pb(Zr0.52Ti0.48)O3 Ceramics Synthesized Using Planetary Ball Mill

2012 ◽  
Vol 620 ◽  
pp. 486-490
Author(s):  
Shafiza Afzan Sharif ◽  
Julie Juliewatty Mohamed ◽  
W.A.W. Yusoff
Keyword(s):  
Lead Zirconate Titanate ◽  
Ball Mill ◽  
Single Phase ◽  
Perovskite Phase ◽  
Xrd Analysis ◽  
Lead Zirconate ◽  
Planetary Ball Mill ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Pzt Ceramics

Lead zirconate titanate Pb (Zr0.52Ti0.48)O3, (PZT) ceramic was successfully prepared from the mixture of commercial PbO, TiO2and ZrO2powders using planetary ball mill at room temperature. The phase formation and microstructure of the milled powders were characterized using X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). XRD results indicated that the perovskite phase of PZT was formed from the mixture of starting materials after milling for 40 h. The grain sizes of the powders have been estimated from the SEM images to be ~200 nm. The compacted PZT samples were then sintered at 950 °C for 1 h. The samples were characterized by XRD and SEM, meanwhile the density was measured by Archimedes principle. XRD analysis on the sintered samples revealed the formation of single phase Pb (Zr0.52Ti0.48)O3ceramics while the SEM images estimated the grain size to be ~2 µm. The relative density of the obtained sintered PZT ceramics was measured to be approximately 99.93 % of the theoretical density. The results hence indicate that planetary ball mill is an effective preparatory technique to improve the sinterability of PZT ceramics.

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