PRODUCTION AND RESEARCH OF TABLETS OF MIXED URANIUM, PLUTONIUM, AMERICIUM AND NEPTUNIUM NITRIDES

2021 ◽  
Vol 22 (1) ◽  
pp. 36-43
Author(s):  
M. A. Kuzin ◽  
◽  
S. V. Abramov ◽  
O. N. Nikitin ◽  
S. V. Kuz'min ◽  
...  
Keyword(s):  
Mass Fraction ◽  
Uranium Oxide ◽  
Hydrogen Atmosphere ◽  
Plutonium Dioxide ◽  
X Ray ◽  
Crystallization Method ◽  
The Press ◽  
Neptunium Dioxide ◽  
Uranium Plutonium ◽  
Carbothermic Synthesis

The method of carbothermic synthesis produced 260 g tablets of mixed nitrides of uranium, plutonium, americium and neptunium with a mass fraction of americium 0.61%. For the production of tablets were used uranium oxide manufactured by the water method, as well as plutonium dioxide containing impurities of uranium and americium oxides with a mass of 0.9 g americium, obtained by volumetric crystallization method in a NaCl — 2CsCl melt. Neptunium dioxide and americium oxide were added to the mixture of uranium and plutonium oxides before carbothermic synthesis. The resulting tablets had a density of 11.6-11.9 g / cm3. By methods of gamma-spectrometry, scanning electron microscopy and x-ray microanalysis is showed that the heat treatment of the mixture of the source chemicals - oxides of uranium, plutonium, americium, neptunium with carbon black at a temperature 1600-1500 °C for 72 h (24 h in nitrogen and 48 h in nitrogen-hydrogen atmospheres), and also the subsequent sintering synthesized by the press powders for 48 h at a temperature of 1800°C in nitrogen-hydrogen atmosphere doesn't leads in average to the significant losses of americium.

A technique for uranium and plutonium determination using coulometric potentiostatic facility UPK-19 for analysis of mixed-oxide fuel

2020 ◽  
Vol 86 (12) ◽  
pp. 15-22
Author(s):  
N. A. Bulayev ◽  
E. V. Chukhlantseva ◽  
O. V. Starovoytova ◽  
A. A. Tarasenko
Keyword(s):  
Acid Solution ◽  
Mass Fraction ◽  
Background Electrolyte ◽  
Stable State ◽  
Sulfamic Acid ◽  
Oxide Fuel ◽  
Oxidation Current ◽  
Mox Fuel ◽  
Mass Fractions ◽  
Uranium Plutonium

The content of uranium and plutonium is the main characteristic of mixed uranium-plutonium oxide fuel, which is strictly controlled and has a very narrow range of the permissible values. We focused on developing a technique for measuring mass fractions of uranium and plutonium by controlled potential coulometry using a coulometric unit UPK-19 in set with a R-40Kh potentiostat-galvanostat. Under conditions of sealed enclosures, a special design of the support stand which minimized the effect of fluctuations in ambient conditions on the signal stability was developed. Optimal conditions for coulometric determination of plutonium and uranium mass fractions were specified. The sulfuric acid solution with a molar concentration of 0.5 mol/dm3 was used as a medium. Lead ions were introduced into the background electrolyte to decrease the minimum voltage of hydrogen reduction to –190 mV. The addition of aluminum nitride reduced the effect of fluoride ions participating as a catalyst in dissolving MOX fuel samples, and the interfering effect of nitrite ions was eliminated by introducing a sulfamic acid solution into the cell. The total content of uranium and plutonium was determined by evaluation of the amount of electricity consumed at the stage of uranium and plutonium co-oxidation. Plutonium content was measured at the potentials, at which uranium remains in the stable state, which makes it possible to subtract the contribution of plutonium oxidation current from the total oxidation current. The error characteristics of the developed measurement technique were evaluated using the standard sample method and the real MOX fuel pellets. The error limits match the requirements set out in the specifications for MOX fuel. The technique for measuring mass fractions of uranium and plutonium in uranium-plutonium oxide nuclear fuel was certified. The relative measurement error of the mass fraction of plutonium and uranium was ±0.0070 and ±0.0095, respectively. The relative error of the ratio of the plutonium mass fraction to the sum of mass fractions of uranium and plutonium was ±0.0085.

scholarly journals Mixed H2O/H2 Plasma-Induced Redox Reactions of Thin Uranium Oxide Films under UHV Conditions

2021 ◽  
Author(s):  
Ghada El Jamal ◽  
Thomas Gouder ◽  
Rachel Eloirdi ◽  
Evgenia Tereshina-Chitrova ◽  
Lukáš Horák ◽  
...  
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Redox Reactions ◽  
Uranium Oxide ◽  
Oxide Films ◽  
X Ray ◽  
Gas Plasma

X-Ray Photoelectron Spectroscopy (XPS) has been used to study the effect of mixed H2O/H2 gas plasma on the surface of UO2, U2O5 and UO3 thin films at 400 °C. The...

Preparation of β-PbO2 and β-PbO2-MnO2 Coating on Stainless Steel Substrate

2012 ◽  
Vol 490-495 ◽  
pp. 3486-3490
Author(s):  
Qiang Yu ◽  
Zhen Chen ◽  
Zhong Cheng Guo
Keyword(s):  
Stainless Steel ◽  
Mass Fraction ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Substrate Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Plating Solution ◽  
Element Mass Fraction

In order to prepare a new type of anode material, stainless steel was selected as substrate material. The β-PbO2 coating on stainless steel substrate was prepared under the appropriate plating solution, and the PbO2-MnO2 coating was prepared with thermal decomposition. The crystal structure was determined by X-ray diffraction; Surface morphology was test by Scanning Electron Microscopy; the energy spectrum was used to determine element mass-fraction and the ratio of atomic number of the coatings.

scholarly journals In-Situ X-ray Diffraction Measurement for Pure Niobium Metal in High Temperature Hydrogen Atmosphere

2006 ◽  
Vol 70 (6) ◽  
pp. 467-472 ◽  
Author(s):  
Tomonori Nambu ◽  
Nobue Shimizu ◽  
Hisakazu Ezaki ◽  
Hiroshi Yukawa ◽  
Masahiko Morinaga ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Atmosphere ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Niobium

Synthesis of Li0.6Zn1.2PO4 and its Selectivity to Li+ Exchange

2012 ◽  
Vol 442 ◽  
pp. 54-57
Author(s):  
Heng Li
Keyword(s):  
Solid State ◽  
Ion Exchange ◽  
Chemical Analysis ◽  
Surface Adsorption ◽  
Insertion Reaction ◽  
Spinel Type ◽  
X Ray ◽  
Crystallization Method ◽  
Treated Sample ◽  
Saturation Capacity

The ion-exchanger Li0.6Zn1.2PO4of spinel type was prepared by a solid state reaction crystallization method. The extraction/insertion reaction with this material was investigated by X-ray, saturation capacity of exchange, and Kd measurement. The experimental results have proved that the acid-treated sample has a capacity of exchange 2.4mmol•g-1for Li+in the solution, The chemical analysis showed that the Li+extraction/insertion progressed mainly by ion-exchange mechanism and surface adsorption.

Effect of technological parameters of gas-dynamic deposition on structural-phase transformations in “brass” type coating

2020 ◽  
pp. 554-559
Author(s):  
V.E. Arkhipov ◽  
T.I. Murav’eva ◽  
M.S. Pugachev ◽  
I.V. Shkaley
Keyword(s):  
Deposition Temperature ◽  
Mass Fraction ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
Technological Parameters ◽  
X Ray ◽  
Type Compound ◽  
Gas Dynamic ◽  
Ε Phase ◽  
Overlap Coefficient

The results of effect of deposition temperature and the overlap coefficient on the formation of the phase composition of coating based on Cu, Zn and Al2O3 particles mixture applied by cold gas-dynamic deposition are presented. Using X-ray diffraction and X-ray spectral analysis, it is shown that when using the 55 % overlap coefficient electron-type compound based on CuZn3 (ε-phase) is formed in the coating, the mass fraction of which increases to 11.4 % with increase in the deposition temperature. Deposition with 64 % overlap coefficient is accompanied by the formation not only of the ε-phase, but of electron-type compound based on Cu5Zn8 (γ-phase), the mass fraction of which increases to 33 % at temperature of 450 °C. In the process of coating deposition, the predominant diffusion copper into zinc takes place; the calculations show high value of the diffusion coefficient copper — 1,56•10–13 m2 /s.

scholarly journals MSMEG_6292, a Mycobacterium smegmatis RNA polymerase secondary channel-binding protein: purification, crystallization and X-ray diffraction analysis

2018 ◽  
Vol 74 (9) ◽  
pp. 543-548
Author(s):  
Abyson Joseph ◽  
Valakunja Nagaraja ◽  
Ramanathan Natesh
Keyword(s):  
Rna Polymerase ◽  
Mycobacterium Smegmatis ◽  
Transcriptional Activity ◽  
Molecular Replacement ◽  
X Ray Diffraction ◽  
Secondary Channel ◽  
X Ray ◽  
Cell Parameters ◽  
Crystallization Method ◽  
Better Than

The transcriptional activity of RNA polymerase (RNAP) is controlled by a diverse set of regulatory factors. A subset of these regulators modulate the activity of RNAP through its secondary channel. Gre factors reactivate stalled elongation complexes by enhancing the intrinsic cleavage activity of RNAP. In the present study, the protein MSMEG_6292, a Gre-factor homologue from Mycobacterium smegmatis, was expressed heterologously in Escherichia coli and purified using standard chromatographic techniques. The hanging-drop vapour-diffusion crystallization method yielded diffraction-quality crystals. The crystals belonged to the trigonal space group P3121 (or its enantiomorph P3221), with unit-cell parameters a = b = 83.15, c = 107.07 Å, α = β = 90, γ = 120°. The crystals diffracted to better than 3.0 Å resolution. Molecular-replacement attempts did not yield any phasing models; hence, platinum derivatization was carried out with K2PtCl4 and derivative data were collected to 3.4 Å resolution.

scholarly journals The Effect of Immersion Time of Coconut Fiber in Limestone Water on Tensile Strength and Surface Morphology

2020 ◽  
Vol 55 (3) ◽  
Author(s):  
Sutrisno ◽  
Rudy Soenoko ◽  
Yudy Surya Irawan ◽  
Teguh Dwi Widodo
Keyword(s):  
Tensile Strength ◽  
Surface Morphology ◽  
Mass Fraction ◽  
Immersion Time ◽  
Testing Machine ◽  
Coconut Fiber ◽  
Tensile Testing Machine ◽  
X Ray ◽  
Coir Fibers ◽  
Infrared Spectrometer

This study aims to identify the effect of immersion of coconut fiber in limestone water on surface morphology and tensile strength, including chemical reactions during immersion. Coconut coir fibers were immersed in a solution of limestone water for 0, 4, 8, 12, 16, and 20 hours, with a mass fraction of limestone of 5%, then dried for 1 hour. Coconut fiber was characterized by a single fiber tensile testing machine, Scanning Electron Microscope, X-ray diffractometer, and Fourier transform infrared spectrometer. The results showed that the percentage of 5% with 8 hours of immersion in the fiber had a cleaner surface morphology with a tensile strength of 234.62 MPa. Therefore, as an alternative to improving the characteristics of a single thread, immersion in limestone water needs to be applied.

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