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Preconcentration Techniques for Determination of Uranium Using the Modified Sorbents.
Moos, Martin ; Řehůřková, Irena (referee) ; Kanický, Viktor (referee) ; Kráčmar, Stanislav (referee) ; Sommer, Lumír (advisor)
The work has been focused on the preconcentration techniques for determination of uranium on the modified sorbent, with the final use of ICP-OES and ICP-MS. First ICP-OES at a wavelength of 385.958 nm was used for determination of uranium. Parameters were optimized and the effect of mineral acids (HCl, HNO3), tensides (Septonex, Ajatin) and organic reagents like (4-(2-pyridylazo)resorcinol, ammonium pyrrolidinedithiocarbamate, 8-hydroxyquinoline-5-sulphonic acid and 1,2-dihydroxyanthraquinone-3-sulphonic acid) was observed. For ICP-MS an isotope 238U was chosen. As an internal standard 209Bi (200 ?g•l-1) was used. Modified silica gel was used (Silicagel tethered with C18, C8 alkyls and phenyl) and two types of Amberlite XAD 4 and XAD 16 for the preconcentration of uranium (VI). Commercially produced Amberlite was modified as follows: Drying at 100 °C (24 hours), milled, minced sorbent was selected and fractionated to particles size ranging from 0.32 to 0.63 ?m and finally activated in methanol. The deionised water and Septonex (5•10-3 mol•l-1) at pH 8 were used for Amberlite conditioning. The optimal sorption of uranium (VI) proceeded at pH 8 in the presence of 4-(2-pyridylazo)resorcinol or ammonium pyrrolidinedithiocarbamate with Amberlite XAD-16 moreover with 1,2-dihydroxyanthraquinone-3-sulphonic acid. All organic reagents have mass concentration five time larger than uranium . For the elution of uranium the mixture of 1 mol•l-1 HNO3 with acetone (ratio of 1:1) was used. Acetone was evaporated and the final analysis performed using ICP-OES. The preconcentration of uranium (VI) using Silicagel-C18 conditioning was performed with ethanol, deionised water and Zephyraminu (5•10-4 mol•l-1) at pH 8. For the Silica-C8 and Silicagel-Phenyl the same conditioning procedure without zephyramin was used. Silica-C18 had the highest sorption efficiency with 1,2-dihydroxyanthraquinone-3-sulphonic acid, Silicagel-C8 with ammonium pyrrolidinedithiocarbamate and Silicagel-Phenyl with 8-hydroxyquinoline-5-sulfonic acid, all organic reagents have mass concentration five time larger than uranium concentration. As an optimal elution mixture acetone and ethanol (ratio of 1:1) in the presence of 1 mol•l-1 HCl was evaluated. Acetone and ethanol was evaporated and the final analysis was performed using ICP-MS. Silicagel-C18 was evaluate as the most effective in the presence of zephyramin and 1,2-dihydroxyanthraquinone-3-sulphonic acid. Sorption was also tested in the presence of 20 ?g•l-1 microelements (Be, V, Co, Ni, Y, Pb, Th, Cd) and in the presence of a defined concentrations of K, Na, Ca, Mg, Al and Fe. Direct analysis of uranium was carried out on samples of water from the river Ploucnice and Turonian aquifers containing uranium, 3,5 and 19,3 ?g•l-1. Different type of water required preconcentration of uranium (VI) on Silica-C18 in the presence of 1,2-dihydroxyanthraquinone-3-sulphonic acid and zephyramin. The analysis results gave statistically satisfactory results, which were confirmed using standard addition of 20 ?g•l-1.
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Equipment for the enrichment of nuclear fuel
Ostrezi, Matěj ; Martinec, Jiří (referee) ; Suk, Ladislav (advisor)
The aim of this bachelor thesis is to review the current knowledge and possibilities dealing with an enrichment of the nuclear fuel and to describe particular methods of the enrichment. An attention is paid to basic principles, functions, technological and power requirements and efficiency of the discussed methods. In conclusion, a difficulty of the enrichment process is pointed out and a balance sheet of the economic impact is made.
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Statistical analysis of laser spectroscopy measurements
Slávik, Ľuboš ; Bednář, Josef (referee) ; Hübnerová, Zuzana (advisor)
Cieľom tejto bakalárskej práce je stručne vysvetliť metódu spektroskopie laserom indukovaného mikroplazmatu (LIBS) ako nástroj analýzy prvkového zloženia študovaných vzorkov. Výstupy z prvkovej analýzy (emisné spektrá) sú ďalej spracované pomocou matematických metód regresnej analýzy za účelom nájdenia vzťahov medzi nameranými chemickými prvkami. Tieto dve metódy sú použité na analýzu problému založeného na reálnych dátach, a to nájdenie špecifického vzťahu medzi prítomnosťou uránu a hydrozirkónu v študovanom vzorku uranonosného pieskovca.
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Sodium cooled fast reactors
Daňhel, Aleš ; Katovský, Karel (referee) ; Foral, Štěpán (advisor)
This bachelor’s thesis deals with the sodium-cooled fast reactors. It comprehensively describes the problem of sodium-cooled fast reactors. Attention was paid to the basic specifications and parameters of these reactors. There was briefly described nuclear reactions which are under way in core of sodium-cooled fast reactors but also chemical reactions which are linked to function of liquid sodium as a coolant and heat transfer substance. Attention was also paid to the differences in the reactor core configuration and to the machine device specific for sodium-cooled fast reactors. Further on this bachelor’s thesis puts on the overview of sodium-cooled fast reactors that have worked, are still working or are under construction in each country all over the world. There was briefly described generation IV nuclear reactors, particularly its history and reasons that originate generation IV. Under generation IV was also described nuclear reactor SFR and highlighted differences compared to existing sodium-cooled fast reactors. In the practical part of this bachelor’s thesis is easily made a calculation of the heat transfer from the fuel rod to the cooling sodium and there is also mentioned course of the heat transfer coefficient along the fuel rod. This calculation was made by computing program MATLAB.
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The current state of mining and uranium reserves
Vondra, Marek ; Nerud, Pavel (referee) ; Šnajdárek, Ladislav (advisor)
This bachelor thesis is engaged in current state of uranium mining. It describes development of uranium mining on the area of the Czech Republic from the beginning to current state of mining. There are summarized current uranium reserves in the world, with the most important mining areas included. The treatment of uranium ore is described, with its influence on the environment and the remediation of affected mining area. In the last section, the possible ways of uranium usage in the future are mentioned.
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Nuclear Fuel Cycle of Dukovany NPP
Dudáš, Michal ; Foral, Štěpán (referee) ; Katovský, Karel (advisor)
The goal of this bachelor’s thesis is to introduce the nuclear fuel cycle of nuclear power plant Dukovany focusing on its middle part. It describes the methods of loading fuel assemblies in-out and out-in, the differences between continual (on-load reactors) and campaign kind of fuel cycle. There are briefly described individual types of fuel used on nuclear power plant Dukovany from the start to recent days. It is further followed by the external fuel cycle. The front end describes more about mining, enrichment and fabrication. There are also few different separation methods of uranium described. The back end deals with different ways of spent fuel storage, spent fuel pools, and dry cask storage as well as ultimate disposal. The paper also contains brief overview among the most known nuclear reactors with the short descriptions of its own nuclear fuel cycles. It is further followed by description of fuel cycles with different length, focusing on different types of fuel and different loading methods. There is also a possible concept of outages for nuclear power plant Dukovany considering few different long lasting campaigns. The paper contains economic assessment considering the simplified conditions. It also deals with pros and cons of individual cycles focusing on organization operating and spent fuel storage.
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The topic of labor camps at uranium mines in the teaching of geography (using Jáchymov and Příbram as an example)
Zavřelová, Aneta ; Jelen, Jakub (advisor) ; Boudný, Zdeněk (referee)
This bachelor thesis focuses on geography teaching methods at elementary and high schools in Jáchymov and Příbram regions. Specifically, the research deals with a topic of uranium labor camps, between 1950s and 1960s. The first part of the thesis analyze how geography is being taught at elementary and high schools, based on the curriculum framework and textbook research. Next, there is a chapter with a focus on the labor camps from the point of view of geography. The thesis also contains analysis of the researched locations, especially their mining history. The next section of the bachelor thesis discusses the socio-historical context in the 1950s and 1960s, uranium as the key raw material of the Cold War, labor camps and their characteristics and the inmates' daily routine. The practical part of the thesis is represented by questionnaire research conducted at the elementary and high schools and its results. The final chapter contains worksheets designed for high school students which could be used during outdoor education sessions. Keywords Geography, framework educational program, Uranium, labor camps, Jáchymov, Příbram
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Dlouhodobé sukcesní změny vegetace na výsypkách po těžbě uranu
VEJVODOVÁ, Kateřina
Vegetation sampling was carried out on uranium post-mining spoil heaps to evaluate the changes of spontaneous vegetation development after 11 years. The study was conducted in Příbram region. The species composition, participation of vegetation groups, life forms and effect of selected enviromental fakctors were considered.
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The history and the present of nuclear weapons in the world and in The Czech Republic
TEJC, Michal
This bachelor thesis deals with the history and the present of nuclear weapons in the world and in the Czech Republic, from the first research in the area of the discovery of physical particles to the development and testing of nuclear weapons of individual states, the adoption of international treaties and agreements that reduce dangerous nuclear weapon abuses in the world. In the theoretical part, it contains historical references to discovering new elements, their research and practical use in nuclear weapons. The thesis also describes the clear history of the individual research programs of states that have now declared themselves or are expected to hold nuclear weapons or are currently developing nuclear weapons. The thesis continues with the analysis of international treaties and agreements on gradual banning of nuclear weapons testing, which resulted in the adoption of the Non-proliferation Treaty. The aim of this thesis was to: Analyze and compare the historical development and present of nuclear weapons in the world and in the Czech Republic. In order to meet this goal, it was necessary to address the persons who are oriented in the given issue and to use the processed questionnaires to characterize individual views of the respondents on the issue of nuclear weapons use or abuse, documenting accepted international treaties and possibilities of real nuclear weapons abuse by states that did not join international commitments. After responding people and analyzing their responses to nuclear weapons, materials that could be used to manufacture them, and controlling their non-proliferation, it was documented that all respondents agreed that international agreements led to lower international tensions and partial suspension of nuclear tests. In most countries, nuclear programs have either ended, or their nuclear program has been completely resolved beyond the guarantee system. By adopting current legal acts, the possibilities to illegally manufacture nuclear weapons have decreased. This does not apply to countries that support international terrorism and nuclear deterrence.
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