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Uranium mineralization in the Krkonoše permian piedmont basin: Radioactive elements in the Rudník horizon near Vrchlabí
Novák, Dominik ; Goliáš, Viktor (advisor) ; Tuhý, Marek (referee)
This paper focuses on artificial outcrop of permian lacustrine sediments of the Rudník horizon (298-297 Ma) and red siltstones of the Vrchlabí formation near Vrchlabí, where increased concentrations of uranium and thorium radionuclides were observed during previous researches. Radionuclides are concentrated in a few layers of black, grey and red shales, which makes about 20 m of the whole 250 m long studied profile. Rock samples were collected from localised radioactive layers and studied for mineralogical compositions, concentrations of radionuclides and autoradiographic and microscopic study of uranium and thorium bonds in these rocks. Laboratory measurements confirmed increased concentrations of both uranium and thorium in collected samples. Highest amount of uranium was measured in anoxic black shale (106,9 ppm U), highest amount of thorium in anomalous sample of red siltstone (76,6 ppm Th). Shales and siltstones main contents are albite, analcime, calcite, dolomite, muscovite and potasium feldspars. Acording to the study it is assumed, that the main source of radionuclides were redeposited pyroclastics from the Krkonoše piedmont basin area or synchronous volcanic activity. It is likely, that during late tectonic development of the basin, these radionuclides were redistributed by hydrothermal...
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Enrichment and reprocessing of nuclear fuel
Janoušek, Petr ; Elbl, Patrik (referee) ; Sitek, Tomáš (advisor)
Nuclear fuel is one form of electricity generation. This bachelor thesis deals with its modification and processing as this fuel has to undergo special processes to ensure its good usability. The aim of the thesis is to list and analyze the main processes involved in the production of nuclear fuel. The thesis is, in particular, focused on the enrichment of nuclear fuel, which is the process of enhancing its properties. The first and second chapter of the paper discusses basic issues of first nuclear energy and then nuclear fuel. The third chapter of the thesis explains in detail the enrichment of nuclear fuel and also describes different methods of enrichment. Another process taking place after nuclear fuel is used is it's reprocessing. This method of converting used fuel into fuel that can be reused is dealt with in the last chapter of the thesis.
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Radioactivity of granitoids of the Krkonoše-Jizera pluton
Černík, Tomáš ; Goliáš, Viktor (advisor) ; Matolín, Milan (referee)
2. SUMMARY This thesis is focused on the natural radioactivity of the Krkonoše pluton, which is divided in 6 particular types of granite: the Jizera, the Liberec, the Fojtka, the Tanvald, the Harrachov, the Krkonoše ones. The goal of the thesis was to compare these values and find out whether there was an unlike element (U, Th, K) content difference. Based on literature data about the Czech and Polish part of pluton, there was assigned data of the analysed samples (of contents of K, U, Th) to each type of granite. The literature data was refined on the base of the current knowledge. The localized collection points were assigned to the particular types of the Krkonoše - Jizera granitoids. The analytic data collection was statistically evaluated. On the base of the statistic data evaluation significant differences of the radioactive element content of the particular types of granite was proved. The most radioactive one is the Harrachov granite. The Tanvald one has a distinctively anomalous ratio of U to Th higher than 1. The other types of granite have only an average level of radioactivity. There was also checked a significant aerial gamaspectrometric anomaly in the south - west direction of Hejnice. There was made a field gamaspectrometric measurement, which did not prove the significant increase in an...
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Uranium content in macrofungi
Kubrová, Jaroslava ; Borovička, Jan (advisor) ; Řanda, Zdeněk (referee)
In the leading part of this work I presented general information on the kingdom of fungi and fungal ecology focused on marofungi (macromycetes). Furthermore, I reviewed the phenomenon of trace elements accumulation in macrofungal fruit-bodies, particularly focused on uranium and its biogeochemistry. In the experimental part, results of my own research are presented. I determined concentrations of uranium, thorium, silver and lead by use of HR- ICP-MS and ENAA. The macrofungal samples were collected 1/ in clean areas with diverse geological bedrock, 2/ in uranium-polluted area in vicinity of Příbram (Central Bohemia, Czech Republic). Furthermore, selected trace elements were determined also in underlying soils by use of the both analytical methods. For investigation of trace elements mobility, the BCR sequential extraction was applied.
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Studium magnetických kvantově kritických jevů na uranových sloučeninách
Opletal, Petr ; Pospíšil, Jiří (advisor) ; Javorský, Pavel (referee)
Motivation of this thesis is a study of magnetic phase diagram of the pseu- doternary system UCoxRu1−xAl. Three single crystals UCo0.19Ru0.81Al, UCo0.27Ru0.73Al and UCo0.40Ru0.60Al have been successfully prepared by Czochralski method. Composition was confirmed by EDX analysis and quality of single crystals was checked by Laue method. Crystallographic parameters and occupancies were de- termined by X-ray powder diffraction. Data analysis confirmed strong uniaxial magnetocrystalline anisotropy (c is the easy magnetization axis) and existence of hard and soft ferromagnetic phase. Curie temperature TC = 41 K was determined for UCo0.40Ru0.60Al and phase transition from the soft ferromagnetic phase to the hard one takes place at 35 K. UCo0.27Ru0.73Al becomes ferromagnetic at TC = 18 K and the transition from the soft to the hard ferromagnetic phase takes place somewhere around 7 K. UCo0.19Ru0.81Al is paramagnetic down to 2 K. Analysis of the temperature dependence of resistivity and heat capacity reveals signatures of non-Fermi liquid behaviour due to proximity of quantum critical point. 1
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Factors affecting uptake and distribution of uranium in plants.
Krejčová, Daniela ; Lhotáková, Zuzana (advisor) ; Tylová, Edita (referee)
Uranium is a radionuclide, which naturally occurs in Earth's soil in rather an insignificant amount. It is not very dangerous in such small concentration; however, this concentration is rising due to anthropogenic activity, therefore an estimation of its increase is at hand. It is necessary to research possibilities of not only effective, but also ecological extermination of this contamination. Phytoremediation could be an appropriate solution, but this method is still in its beginning stages when it comes to uranium contaminations. That's why we need to study influences of uranium on plants and find out to what extent are they suitable for phytoremediation of areas contaminated by uranium. Phytoremediation methods are based on the abilities of plants to receive and accumulate certain pollutants. The factors that influence the amount of uranium received by a plant can be divided into four groups: plant species, uranium's oxidation levels, pH of of the medium or the substrate and ligand, which is attached to the uranium (Mitchell, 2013). Transportation of uranium to the aboveground part of the plant is also a factor here. Plants need to deal with the accepted uranium; aside from the radiological risks resulting from the characteristics of radioisotope, uranium is also a heavy metal. Chemical...
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Radioactive accessory minerals in granitoids and its changes during metamorphosis and alteration.
Tuhý, Marek ; Goliáš, Viktor (advisor) ; Matějka, Dobroslav (referee)
This paper is focused on gathering information about alterations of radioactive accessory minerals in granitic rocks. These minerals become unstable during the influence of fluids and increased temperature and pressure conditions. Allanite is usually metamict therefore it is more easily altered than others. Alteration of monazite is described as decomposing original grains which leads to the formation of secondary minerals such as allanite, apatite, minerals of thorium and epidote. Zircon is the most durable mineral mentioned in this paper. Zircon is altered mainly if it is metamict. Majority of authors agree that during alteration uranium is mobilized into fluids and thorium with REE is incorporate into the secondary minerals.
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Uranium mineralisation of the Lugian orthogneiss as a precursor of the radioactive springs genesis
Fatková, Karolína ; Goliáš, Viktor (advisor) ; Škoda, Radek (referee)
The Lugian area is known for the occurrence of springs of radioactive radon mineral waters in areas formed by orthogneisses. Samples of mineralized orthogneisses (Sněžník, Krkonoše and Jizera) found by field radiometry were examined. By the laboratory gamma spectrometry of 28 samples, it was discovered that K and Th have background concentrations, in contrast U-Ra is increased up to 108,5 ppm. The distribution of radionuclides was determined by the alpha autoradiography method in eight selected samples with the highest uranium concentrations. According to optical and electron microscopy with ED analysis, radionuclides are present in the following mineralization stages: Common accessory minerals (zircon, monazite, xenotime, apatite, thorite) occur in the primary magmatic association. The primary magmatic uraninite s.s., associated with zircon, was found in two samples. Its presence is probably the main reason for the high fertility of lugian orthogneisses. Uraninite s.s. also occurs in the form of inclusions in pyrite in the metamorphic (syndeformative) period. Symptoms of greisenization (fluorite, fluorine-rich zircon) can be observed in the Jizera orthogneiss. The hydrothermal stage with comb-like quartz and hematite in the cavities and veinlets is evident in the Krkonoše orthogneiss. The...
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Everyday life of employees in the Uranium Mines Příbram during the so-called normalization
Fechtnerová, Tereza ; Krátká, Lenka (advisor) ; Hlaváček, Jiří (referee)
This diploma thesis is focused on everyday life of employees working in the uranium mines in Příbram during the so-called normalization. Using the method of oral history, I try to capture the ordinary lives of ordinary people against the background of one historical period, with regard to the work benefits which were provided to them by their employer. The thesis is anchored in a rich source base, which primarily constists of interviews conducted directly with witnesses of the time, secondarily of archival material and relevant literature. The main goal of the thesis is to find out why young men decided to pursue the hard work of a miner, how the company took care of them, what contributions the employer offered to them and, in general, how the people involved see uranium life today.
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Superconductivity and Magnetism of Uranium Compounds
Vališka, Michal
This thesis studies the UCo1−xRuxGe system on the border of magnetic instabil- ity. Proper study of magnetic and transport properties of poly crystals with dif- ferent ruthenium content revealed complex change of these parameters through the series. UCoGe is a weak ferromagnet with TC ∼ 3 K and low magnetic moment 0.035 µB/f.u.. We observed rapid increase of these two quantities up to the con- centration of ruthenium of xmax ≈ 0.1. Background of this increase was studied on the single crystal grown by oating zone method. Polarized neutron diraction experiment performed on this single crystal with composition of UCo0.88Ru0.12Ge ex- plained strengthening of magnetism with a change of mutual orientation of magnetic moments on the uranium and cobalt site. Previously reported antiparallel alignment for the UCoGe is changed to the parallel orientation for the doped UCo0.88Ru0.12Ge when cobalt moment is reoriented. Strong anisotropy of the UCo0.88Ru0.12Ge projects to the temperature dependence of resistivity and to the thermal expansion proper- ties. This primal increase of TC and magnetic moment is followed by decrease when approaching the concentration xcr ≈ 0.31 where magnetic order disappears. Closer study of the critical exponents of temperature dependencies of resistivity, specic heat and the...
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