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.

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.

scholarly journals Scientific support for innovative development of wheat bread long-term storage production

2020 ◽  
Vol 176 ◽  
pp. 03021
Author(s):  
Natalia Zavorokhina ◽  
Natalia Pankratyeva ◽  
Nadezhda Goncharova
Keyword(s):  
Shelf Life ◽  
Fatty Acid Esters ◽  
Wheat Bread ◽  
Innovative Development ◽  
Long Term Storage ◽  
High Degree ◽  
First Time ◽  
Term Storage ◽  
Acid Esters

Nowadays in the context of innovative development the bread intended for long-term storage is necessary in hard-to-reach areas of Sverdlovsk region, participants of expeditions, workers of logging, geological parties, etc. Taking into account the constant demand for such products, it is necessary to develop new approaches to their creation.The aim of the study was the development of long-term storage bread from wheat flour, preserving consumer characteristics throughout the shelf life.The synergism of betulin,nisin and ascorbic acid was studied for the first time when they are used together to inhibit potato bread disease (hereinafter CBH). It is proved that the use of additives, including 0.015% nisin together with 0.005% betulin to the mass of flour increases the shelf life of wheat bread up to 7 days since betulin inhibits CBH, nisin inhibits the development of mold under pH conditions in the range of 5.5-6.5.For the first time, a technique is proposed for producing betulin nanosuspension with a high degree of dispersion. The effect of betulin nanosuspension with emulsifiers of calcium lactylate, polyglycerol fatty acid esters, lecithin on the inhibition of CBH and an increase in the shelf life of wheat bread was studied.

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.

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.

Implications of alpha-decay for long term storage of advanced heavy water reactor fuels

2017 ◽  
Vol 110 ◽  
pp. 400-405 ◽  
Author(s):  
J. Pencer ◽  
M.H. McDonald ◽  
D. Roubtsov ◽  
G.W.R. Edwards
Keyword(s):  
Heavy Water ◽  
Alpha Decay ◽  
Water Reactor ◽  
Long Term Storage ◽  
Heavy Water Reactor ◽  
Term Storage

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 ANALYSIS OF STRUCTURAL TRANSFORMATIONS IN NATURAL QUARTZITES UNDER THE INFLUENCE OF GAMMA IRRADIATION

2021 ◽  
pp. 37-41
Author(s):  
E.P. Bereznyak ◽  
N.P. Dikiy ◽  
I.V. Kolodiy ◽  
E.P. Medvedeva ◽  
Yu.S. Khodyreva
Keyword(s):  
Xrd Analysis ◽  
Initial Structure ◽  
High Radiation ◽  
Γ Irradiation ◽  
Crystalline Quartz ◽  
Long Term Storage ◽  
Geological Formation ◽  
Radiation Annealing ◽  
Term Storage

Using the methods of IR spectroscopy, crystal-optical and XRD analysis the evolution of the structure of Ovruch deposit natural quartzites under the influence of γ-irradiation in the range of absorbed doses (Dabs =106…3.5107 Gy) has been researched. The elemental composition of natural quartzites was determined by the gamma activation method on a linear electron accelerator. It was found that as a result of irradiation the crystal structure of quartz, which forms the basis of quartzite, is improved due to radiation annealing of the defects in the initial structure. At the same time crystallization of amorphous silica, which fringes large grains of quartz, occurs with its transformation into fine-crystalline quartz. These processes do not lead to cracking in the quartzite rock. Obtained data indicates a high radiation resistance of the Ovruch deposit quartzites and confirms the prospects of using this geological formation as a natural barrier for the construction of radioactive waste long-term storage.

scholarly journals Long-term storage of mouse spermatozoa after evaporative drying

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 919-929 ◽  
Author(s):  
Ming W Li ◽  
John D Biggers ◽  
Heidi Y Elmoazzen ◽  
Mehmet Toner ◽  
Lynda McGinnis ◽  
...  
Keyword(s):  
Storage Temperature ◽  
Blastocyst Formation ◽  
Nitrogen Gas ◽  
Transfer Rates ◽  
Fertilization Rates ◽  
Long Term Storage ◽  
First Time ◽  
Term Storage ◽  
Better Than

To determine if mouse spermatozoa could be preserved long-term without using liquid nitrogen, mouse spermatozoa in trehalose–EGTA solution were partially evaporatively dried under nitrogen gas (5 min at flow rate10 l/min) and stored for 1 week and 5 months at 4, −20, and −80 °C before intracytoplasmic sperm injection. Fertilization rates were neither different with spermatozoa stored at 4, −20, or −80 °C for 1 week or 1, 3, and 5 months respectively, nor blastocyst formation rates with spermatozoa stored for 1 week and 1 month. However, spermatozoa stored at 4 and −20 °C for 3 months resulted in fewer blastocysts (35.1 and 54.3% respectively) when compared with spermatozoa stored at −80 °C (74.4%). Blastocyst formation rates using spermatozoa stored for 5 months at −20 °C (57.4%) or −80 °C (74.5%) were not significantly different from those stored for 3 months at the same temperatures respectively, but were significantly better than those stored for 5 months at 4 °C (10.2%). Blastocysts derived from spermatozoa stored for 3 and 5 months at −20 and −80 °C respectively, were then transferred to pseudopregnant mothers to develop into healthy liveborn offspring. No significant differences were found in embryo transfer rates (number of pups born/number of embryos transferred), weaning rates, or sex ratios of resultant pups, which were healthy and reproductively sound. These results demonstrate for the first time that partially evaporatively dried mouse spermatozoa in trehalose–EGTA solution can be preserved for long term at −20 and −80 °C. The possibility that the storage temperature must be less than the glass transition temperature is discussed.

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

Synchrotron Diffraction Study of the Isothermal Oxidation of Uranium Dioxide at 250°C

2003 ◽  
Vol 802 ◽  
Author(s):  
Gurvan Rousseau ◽  
Lionel Desgranges ◽  
Jean-Claude Nièpce ◽  
Jean-François Bérar ◽  
Gianguido Baldinozzi
Keyword(s):  
Spent Nuclear Fuel ◽  
Structural Evolution ◽  
Isothermal Oxidation ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Long Term Storage ◽  
Instrumental Resolution ◽  
Term Storage

ABSTRACTThe structural evolution of UO2 during its oxidation to U3O8 at 250°C in air was studied by in-situ synchrotron X-ray diffraction on the D2AM-CRG beamline at ESRF. The aim of this study is to determine the phases that are likely to appear during the long-term storage of spent nuclear fuel. Our results are in disagreement with the literature in which the existence of an intermediate cubic phase is not reported. Instead, an α-U3O7 tetragonal phase (c/a < 1) was mentioned but not definitively observed. These previous interpretations may have been the result of poor instrumental resolution.

Sign in / Sign up

Export Citation Format

Share Document