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.

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.

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.

Studies of Bloom Formation Using X-Ray Diffraction from Chocolates after Long-Term Storage

Lipid / Fett ◽  
1993 ◽  
Vol 95 (9) ◽  
pp. 340-343 ◽  
Author(s):  
D. J. Cebula ◽  
G. Ziegleder
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Storage ◽  
Bloom Formation ◽  
Term Storage

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.

Establishment of a long-term storage method for soft X-ray irradiated pollen in watermelon

Euphytica ◽  
2008 ◽  
Vol 164 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Masako Akutsu ◽  
Keita Sugiyama
Keyword(s):  
X Ray ◽  
Storage Method ◽  
Long Term Storage ◽  
Irradiated Pollen ◽  
Term Storage

Self-Irradiation of Monazite Ceramics: Contrasting Behavior of PuPO4 and (La,Pu)PO4 Doped with Pu-238

2004 ◽  
Vol 824 ◽  
Author(s):  
Boris E. Burakov ◽  
Maria A. Yagovkina ◽  
Vladimir M. Garbuzov ◽  
Alexander A. Kitsay ◽  
Vladimir A. Zirlin
Keyword(s):  
Radiation Damage ◽  
Crack Formation ◽  
Alpha Decay ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Deep Blue ◽  
Long Term Storage ◽  
First Time ◽  
Term Storage

AbstractTo investigate the behavior of monazite during accelerated radiation damage, which simulates effects of long term storage, 238Pu-doped polycrystalline samples of (La,Pu)PO4 and PuPO4 were synthesized for the first time ever and studied using powder X-ray diffraction (XRD) analysis and optical microscopy. The starting precursor materials were obtained by precipitation of La and (or) Pu from their aqueous nitrate solutions followed by calcination in air at 700°C for 1 hour, cold pressing, and sintering in air at 1200-1250°C for 2 hours. The 238Pu contents in ceramic samples measured using gamma spectrometry were (in wt.% el.): 8.1 for (La,Pu)PO4 and 7.2 for PuPO4. The (La,Pu)PO4 monazite remained crystalline at ambient temperature up to a cumulative dose of 1.19 × 1025 alpha decays/m3. In contrast, the PuPO4 monazite became nearly completely amorphous at a relatively low dose of 4.2 × 1024 alpha decays/m3. Swelling and crack formation due to the alpha decay damage was observed in the PuPO4 ceramic. Also, under self-irradiation this sample completely changed color from initial deep blue to black. The (La,Pu)PO4 monazite was characterized by a similar change in color from initial light blue to gray, however, no swelling or crack formation have so far been observed. The results of this study allow us to conclude that the radiation damage behavior of monazite strictly depends on the chemical composition. The justification of monazite-based ceramics as actinide waste forms requires additional investigation.

Elastic strains in polycrystalline UO2 samples implanted with He: micro Laue diffraction measurements and elastic modeling

2013 ◽  
Vol 1514 ◽  
pp. 125-130
Author(s):  
Axel Richard ◽  
Etienne Castelier ◽  
Herve Palancher ◽  
Jean-Sebastien Micha ◽  
Philippe Goudeau
Keyword(s):  
Spent Nuclear Fuel ◽  
Simple Expression ◽  
X Ray Diffraction ◽  
Laue Diffraction ◽  
X Ray ◽  
Elastic Stresses ◽  
Long Term Storage ◽  
Macro Scale ◽  
Grain Orientations

Abstract:In the framework of the study of long-term storage of the spent nuclear fuel, polycrystalline UO2 samples have been implanted with He ions. The thin implanted layer, close to the free surface is subjected to elastic stresses which are studied by x-ray diffraction (micro Laue diffraction) and a mechanical modeling. A simple expression of the displacement gradient tensor has been evidenced; it concerns only three terms (ε3, ε4 and ε5) which strongly evolve with considered grain orientations. Finally, we show that results obtained with micro diffraction are in very good agreement with conventional x-ray diffraction measurements done in laboratory at macro scale.

Cementitious Materials for Radioactive Waste Management Within IAEA Coordinated Research Project

2011 ◽  
Author(s):  
Zoran Drace ◽  
Michael I. Ojovan
Keyword(s):  
Radioactive Waste ◽  
Waste Management ◽  
Cementitious Materials ◽  
Radioactive Waste Management ◽  
Long Term Storage ◽  
Waste Immobilization ◽  
Materials Used ◽  
Cementitious Systems ◽  
Term Storage

The IAEA Coordinated Research Project (CRP) on cementitious materials for radioactive waste management was launched in 2007 [1, 2]. The objective of CRP was to investigate the behaviour and performance of cementitious materials used in radioactive waste management system with various purposes and included waste packages, wasteforms and backfills as well as investigation of interactions and interdependencies of these individual elements during long term storage and disposal. The specific research topics considered were: (i) cementitious materials for radioactive waste packaging: including radioactive waste immobilization into a solid waste form, (ii) waste backfilling and containers; (iii) emerging and alternative cementitious systems; (iv) physical-chemical processes occurring during the hydration and ageing of cement matrices and their influence on the cement matrix quality; (v) methods of production of cementitious materials for: immobilization into wasteform, backfills and containers; (vi) conditions envisaged in the disposal environment for packages (physical and chemical conditions, temperature variations, groundwater, radiation fields); (vii) testing and nondestructive monitoring techniques for quality assurance of cementitious materials; (viii) waste acceptance criteria for waste packages, waste forms and backfills; transport, long term storage and disposal requirements; and finally (ix) modelling or simulation of long term behaviours of cementations materials used for packaging, waste immobilization and backfilling, especially in the post-closure phase. The CRP has gathered overall 26 research organizations from 22 Member States aiming to share their research and practices on the use of cementitious materials [2]. The main research outcomes of the CRP were summarized in a summary report currently under preparation to be published by IAEA. The generic topical sections covered by report are: a) conventional cementitious systems; b) novel cementitious materials and technologies; c) testing and waste acceptance criteria; and d) modelling long term behaviour. These themes as well as all contributions of participating organizations were further developed in the individual reports to be presented in the IAEA publication. The CRP facilitated the exchange of information and research co-operation in resolving similar problems between different institutions and contributed towards improving waste management practices, their efficiency and general enhancement of safety.

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.

scholarly journals Effect of ageing on magnetic and electrical properties of Ti–substituted La-Sr manganites

2018 ◽  
Vol 185 ◽  
pp. 06002 ◽  
Author(s):  
A. Badelin ◽  
Z. Datskaya ◽  
S. Estemirova ◽  
V. Karpasyuk ◽  
D. Merkulov
Keyword(s):  
Curie Point ◽  
Storage Period ◽  
X Ray Diffraction ◽  
Electrical Parameters ◽  
Long Term Storage ◽  
Ti Content ◽  
Term Storage ◽  
Over Time ◽  
Error Of Measurement

The changes of structural, magnetic and electrical parameters of ceramic La0.8-xSr0.2+xMn1-xTixO3+γ (0.025 ≤ x ≤ 0.150) manganites during long-term storage at room temperature and after thermal cycling were investigated. The unit cell volume (V) of all manganites decreased over time. Most considerable decrease of V and broadening of X-ray diffraction lines width were observed in the samples with high quantity of titanium. During the storage period magnetization (σ) and Curie point (Tc) of manganites with relatively low Ti content decreased, while the compositions with high values of “x” exhibited some trend of σ and Tc increase. The resistance of the samples with x < 0.100 increased over time. Fluctuations of magnetization of all thermal-aged samples were within the error of measurement, and Curie point of manganites with x = 0.150 showed the rise. From the data obtained it might be inferred that ageing phenomena in Ti-substituted manganites can be associated with oxidation processes, the transfer of Ti4+ to vacant sites in rare-earth sublattice and formation of microinhomogeneities.

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