Application of Synchrotron X-Ray Fluorescence Microscopy to the Study of Multi-Metal Oxide Ceramics

1998 ◽  
Vol 524 ◽  
Author(s):  
Dale L. Perry ◽  
Scott McHugo ◽  
Albert C. Thompson ◽  
Joseph C. Farmer ◽  
Bart B. Ebbinghaus ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Metal Oxide ◽  
Oxide Ceramics ◽  
Chemical Analyses ◽  
Elemental Mapping ◽  
X Ray ◽  
Long Term Storage ◽  
Term Storage ◽  
Actinide Elements

ABSTRACTSynchrotron x-ray fluorescence microscopy has been used to study multi-metal oxide ceramics that have been designed to sequester radioactive actinide elements for long-term storage and disposal. X-ray fluorescent lines for the various elements have been used for lateral elemental mapping of the materials, and the heterogeneity of the samples is discussed with respect to the elements in the crystallographic phases that have previously been documented by other means of structural and chemical analyses.

Dissolution Characteristics and Morphology of Large-sized Scorodite Particles Synthesized from Fe(II) and As(V) in Aqueous Solution

2012 ◽  
Vol 31 (4-5) ◽  
pp. 451-458 ◽  
Author(s):  
S. Fujieda ◽  
K. Shinoda ◽  
T. Inanaga ◽  
M. Abumiya ◽  
S. Suzuki
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Surface Defects ◽  
Atmospheric Temperature ◽  
Orthorhombic Structure ◽  
X Ray ◽  
Long Term Storage ◽  
Transmission Electron ◽  
Term Storage

AbstractA novel process for preparing scorodite particles with a diameter of approximately 20 µm from Fe(II) and As(V) in aqueous solution has been developed by DOWA Metals and Mining. In the present study, the dissolution characteristics of iron and arsenic from the scorodite particles synthesized by this process have been investigated under different conditions. The results show that the concentration of arsenic dissolved from the particles in aqueous solution is very low, but it has a complicated dependence on the temperature and pH of the solution. Transmission electron microscopy (TEM) with an energy dispersive X-ray spectrometer (EDS) was used to analyze the morphology, structure, and composition of the scorodite particles. The results indicate that the scorodite particles exhibit a nearly octahedral shape with planes composed of almost (111) planes in the orthorhombic structure. The concentration of iron at the surface of the particles is higher than that of iron inside of the particles. This characteristic morphology, along with the minimal surface defects of the scorodite particles, is considered to be responsible for the low dissolution of arsenic from the particles in aqueous solution. Atmospheric temperature and solution conditions were also found to be important for the safe, long-term storage of arsenic using scorodite particles.

scholarly journals XPS Investigation of ceramic matrixes for disposal of long-living radioactive waste products

2004 ◽  
Vol 19 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Yury Teterin ◽  
Serguei Stefanovskij ◽  
Serguei Yudintsev ◽  
George Bek-Uzarov ◽  
Anton Teterin ◽  
...  
Keyword(s):  
Electron Spectroscopy ◽  
Spectral Structure ◽  
Waste Products ◽  
X Ray ◽  
Air Atmosphere ◽  
Highly Active ◽  
Long Term Storage ◽  
Term Storage

The synthesis of ceramic matrixes for the long-term storage of highly active radionuclide wastes and determination of physical and chemical forms of radionuclides in them is one of the important problems in radioecology. It enables to create purpose fully materials for the long-term storage of radionuclides. In the present work the samples of ceramics [CaCe0.9Ti2O6.8(I) and CaCeTi2O7(II}] formed under various conditions were investigated with the X-ray photo electron spectroscopy. It is necessary for synthesis of ceramic matrixes, for the disposal of the plutonium and others tetravalent actinides. A technique was developed for the determination of cerium oxidation state (Ce3+ and Ce4+) on the basis of the X-ray photo electron spectroscopy spectral structure characteristics. It was established that the sample (I) formed at 300 MPa and T = 1400 ?C in the air atmosphere contained on the surface two types of cerium ions in the ratio ? 63 atomic % of Ce3+ and 37 atomic % of Ce4+, and the sample (II) formed at 300 MPa and T= 1300 ?C in the oxygen atmosphere contained on its surface two types of cerium ions also, but in the ratio ? 36 atomic % of Ce3+ and 64 atomic % of Ce4+. It was established that on the surface of the studied ceramics carbonates of calcium and/or cerium could be formed under influence of the environment that leads to the destruction of ceramics.

A simple hermetic sample holder for X-ray diffraction analysis of uranium hydride

2007 ◽  
Vol 40 (4) ◽  
pp. 796-798 ◽  
Author(s):  
Bingyun Ao ◽  
Xiaolin Wang ◽  
Yongjun Wei ◽  
Yanzhi Zhang
Keyword(s):  
Diffraction Analysis ◽  
Sample Holder ◽  
X Ray Diffraction ◽  
Aging Effects ◽  
X Ray ◽  
Long Term Storage ◽  
Toxic Materials ◽  
First Results ◽  
Term Storage

In order to help resolve unknowns regarding aging effects of uranium during long-term storage of tritium, a number of experiments have been carried out by several researchers. However, almost no literature is available on the structural change of uranium tritide, mainly because its high toxicity and air-sensitivity render appropriate experiments very difficult. In this paper, a simple hermetic sample holder that fits the Philips X'Pert Pro X-ray diffractometer is described. It may be used to study the aging effects of uranium tritide during storage. The sample holder mainly consists of an aluminium container for sample storage and a Mylar window for X-ray measurements. This sample holder can also be used with other air-sensitive, radioactive and toxic materials. In this paper, the first results obtained from X-ray diffraction analysis of uranium hydride are presented.

scholarly journals On the Suitability of Lanthanides as Actinide Analogs

2008 ◽  
Vol 1104 ◽  
Author(s):  
Kenneth Raymond ◽  
Geza Szigethy
Keyword(s):  
Chemical Separation ◽  
Careful Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Storage ◽  
Chemical Models ◽  
Bonding Properties ◽  
Materials Used ◽  
Term Storage

AbstractWith the current level of actinide materials used in civilian power generation and the need for safe and efficient methods for the chemical separation of these species from their daughter products and for long-term storage requirements, a detailed understanding of actinide chemistry is of great importance. Due to the unique bonding properties of the f-elements, the lanthanides are commonly used as structural and chemical models for the actinides, but differences in the bonding between these 4f and 5f elements has become a question of immediate applicability to separations technology. This brief overview of actinide coordination chemistry in the Raymond group at UC Berkeley/LBNL examines the validity of using lanthanide analogs as structural models for the actinides, with particular attention paid to single crystal X-ray diffraction structures. Although lanthanides are commonly accepted as reasonable analogs for the actinides, these comparisons suggest the careful study of actinide materials independent of their lanthanide analogs to be of utmost importance to present and future efforts in nuclear industries.

scholarly journals The influence of non-normative fuel on its operational properties

2019 ◽  
Vol 178 (3) ◽  
pp. 67-70
Author(s):  
Anna MATUSZEWSKA ◽  
Marlena OWCZUK
Keyword(s):  
Quality Standards ◽  
Chemical Analyses ◽  
Oxidation Processes ◽  
Long Term Storage ◽  
Physico Chemical ◽  
Resistance To Oxidation ◽  
Normative Requirements ◽  
Term Storage

Fuels that do not meet the requirements of quality standards cannot be used to power vehicle engines. The work involved physico-chemical analyses of non-normative fuel and its effect on the operational properties of the powered vehicle. The research fuels were two gasolines, characterized by a reduced resistance to oxidation processes due to their long-term storage. The results were compared to the properties of conventional fuels that met all normative requirements. The studies have shown that the fuel slightly deviating from the standard parameters does not noticeably affect the useful properties of the vehicle.

Behavior of 238Pu-Doped Cubic Zirconia under Self-Irradiation

2003 ◽  
Vol 807 ◽  
Author(s):  
Boris E. Burakov ◽  
Maria A. Yagovkina ◽  
Maria V. Zamoryanskaya ◽  
Alexander A. Kitsay ◽  
Vladimir M. Garbuzov ◽  
...  
Keyword(s):  
Alpha Decay ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cubic Zirconia ◽  
Long Term Storage ◽  
Fluorite Type ◽  
Image Position ◽  
Actinide Transmutation ◽  
Term Storage

ABSTRACTTo investigate the resistance of cubic zirconia to accelerated radiation damage, which simulates effects of long term storage, 238Pu-doped polycrystalline samples of cubic zirconia, (Zr,Gd,Pu)O2, were obtained and studied using X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), optical and scanning electron microscopy (SEM), and modified MCC-1 static leach test. The ceramic material was characterized by the following chemical composition (from EPMA in wt.% element): Zr = 50.2, Gd = 15.4, Pu = 12.2. This corresponds to the estimated formula, Zr0.79Gd0.14Pu0.07O1.99. The content of 238Pu estimated was approximately 9.9 wt.%. The XRD measurements were carried out after the following cumulative doses (in alpha decay/m3 × 1023): 3, 27, 62, 110, 134, 188, 234, and 277. Even after extremely high self-irradiation, cubic zirconia retained its crystalline structure. All XRD analyses showed no phases other than a cubic fluorite-type structure. The following results of normalized Pu mass loss (NL, in g/m2, without correction for ceramic porosity) were obtained from static leach tests (in deionized water at 90°C for 28 days) for 4 cumulative doses (in alpha decay/m3 × 1023):The results obtained confirm the high resistance of cubic zirconia to self-irradiation. This allows us to consider zirconia-based ceramic as the universal material that is suitable for actinide transmutation and geological disposal.

Isotopic Abundances Measurements a Key to Understanding the Oklo Phenomenon

1980 ◽  
Vol 35 (2) ◽  
pp. 171-179 ◽  
Author(s):  
J. C. Ruffenach ◽  
R. Hagemann ◽  
E. Roth
Keyword(s):  
Nuclear Reactions ◽  
Nuclear Reactors ◽  
Fission Products ◽  
Chemical Analyses ◽  
Pressurized Water ◽  
Long Term Storage ◽  
Isotopic Abundances ◽  
Water Reactors ◽  
Term Storage

AbstractThe Oklo natural nuclear reactors have been studied mainly by isotopic and chemical analyses of uranium and fission products. Interpretation of these analyses allows parameters which characterize these reactions (flux, fluence,...), and also the age and duration of the nuclear reactions to be evaluated. The mechanisms and extent of fission-product migration can also be discussed. The behaviour of various elements formed in the Oklo uraninite and in oxyde fuels of pressurized water reactors is compared and found to be similar. Therefore, experience gained from the study of the Oklo phenomenon can provide valuable information on the long-term storage of radioactive wastes in geological media.

scholarly journals Tc and Re Behavior in Borosilicate Waste Glass Vapor Hydration Tests

2006 ◽  
Vol 985 ◽  
Author(s):  
David A. McKeown ◽  
Andrew C. Buechele ◽  
Wayne W. Lukens ◽  
David K. Shuh ◽  
Ian L. Pegg
Keyword(s):  
High Mobility ◽  
Sample Surface ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Long Term Storage ◽  
Before And After ◽  
X Ray Absorption ◽  
Term Storage ◽  
Scanning Electron

AbstractTechnetium (Tc), found in some nuclear wastes, is of particular concern with regard to long-term storage, because of its long-lived radioactivity and high mobility in the environment. Tc and rhenium (Re), commonly used as a non-radioactive surrogate for Tc, were studied to assess their behavior in borosilicate glass under hydrothermal conditions in the Vapor Hydration Test (VHT). X-ray absorption spectroscopy (XAS) and scanning electron microscopy (SEM) measurements were made on the original Tc- and Re-containing glasses and their corresponding VHT samples, and show different behavior for Tc and Re under VHT conditions. XAS indicates that, despite starting with different Tc(IV) and Tc(VII) distributions in each glass, the VHT samples have 100% Tc(IV)O6 environments. SEM shows complete alteration of the original glass, Tc enrichment near the sample surface, and Tc depletion in the center. Perrhenate (Re(VII)O4−) is dominant in both Re-containing samples before and after the VHT, where Re is depleted near the VHT sample surface and more concentrated toward the center.

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