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INVESTIGATION OF PU-239 TRANSMUTATION FOR ACCELERATOR DRIVEN SUBCRITICAL REACTORS
Tanchak, Anhelina ; Parlag,, Oleg (referee) ; Krása, Antonín (referee) ; Nečas, Vladimír (referee) ; Katovský, Karel (advisor)
Tato disertační práce je zaměřena na stanovení průřezů radionuklidů vznikajících v důsledku spalační reakce v terči z plutonia (239PuO2) ozářeného protonovým svazkem o energii 660 MeV. Kromě toho byly vzniklé nuklidy zkoumány pomocí různých nástrojů za účelem zjištění jejich vlastností. K ozáření terče byl použit fázotronový urychlovač Spojeného ústavu jaderných výzkumů v Dubně jako generátor protonového svazku. Experiment byl zaměřen na hledání krátce žijících radionuklidů. Pro měření spekter gama byly použity detektory HPGe. Spektra , získaná během tohoto experimentu, byla zpracována pomocí softwaru DEIMOS32. Pro identifikaci jader vzniklých v terči 239PuO2 byl použit kód AD4HEL. Komplexní analýza těchto zbytkových produktů a jejich charakteristik významně přispívá k pochopení spalace a štěpných reakcí mezi protony a 239Pu v oblasti vysokých energií. Experimentální údaje o průřezech jaderných reakcí mohou sloužit jako referenční údaje pro teoretické simulace ke studiu reakcí a mohou být použity k doplnění jaderných databází. V komplexní analýze byly experimentální výsledky porovnány se simulacemi provedenými pomocí kódů Monte Carlo pro přenos částic, jako jsou MCNP v.6.1. a FLUKA. Výstupem z experimentálních dat je, že získaná data celkově odpovídají očekávání, přičemž mají podobné oblasti koncentrací nuklidů, analogické grafy a mírné odchylky v rozsahu hodnot. Odchylka je pravděpodobně způsobena normalizačním faktorem z důvodu omezení různých softwarových nástrojů.
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Determination of radionuclides in water and sediments
Bílek, Jiří ; Holubová, Zuzana (referee) ; Komendová, Renata (advisor)
This thesis has been prepared for DIAMO, Branch GEAM Dolní Rožínka. Literature research includes a description of the ionizing radiation, natural radionuclides, mining of uranium ore and mineral deposits; Běstvina and Licoměřice. The experimental part includes sampling, analysis and evaluation of the content of selected radionuclides in the two selected locations. The content of uranium and radium in sludge from mine water treatment plant is determined annually by an external laboratory, using of semiconductor gamma-spectrometric analysis (GSA). Determination of both radionuclides in waters in these areas is carried out in the Centre of testing laboratories (SZLAB) in Dolní Rožínka. Uranium and radium activity is below the detection limit. Sludges from Běstvina, according to the results of external laboratories, routinely show activity of both radionuclides. But activity in the waters from this locality is below the detection limit. The goal of this diploma thesis is to verify the radionuclide content in sludge from CDV Běstvina by another method. As a comparative method was chosen determination of uranium using the UV-VIS spectrophotometry with separation on silicagel. Location Licoměřice was chosen as a reference. Like a supplementary method for determining the concentration of uranium was chosen ICP-MS. For the determination of the radium was chosen radiochemical method scintillator ZnS (Ag).
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Setup and testing of alpha beta counter NA6201
RÖSZLER, Tomáš
This diploma thesis was focused on the Setup and testing of alpha beta counter NA6201 for measuring alpha and beta activity, which is located in the dosimetric laboratoriy of the Faculty of Health and Social Studies. Since the laboratory was moved to wing H, the equipment has been used for practical education or research sporadically. The theoretical part of this diploma thesis studies aspects of physics related to alpha and beta radiation, its dosimetry, monitoring and the working of detectors. The legal framework of this topic and the research system, resp. monitoring in the Czech Republic is also examined. In the practical part, this diploma thesis focuses on the set up of the NA6201 counter, its setting and measurement of samples. It also includes an assessment of the usability of the device in education and further research. In the practical part, it was found by comparative measurements that the NA6201 device is not able to reliably measure beta activity. The comparative measurement consisted of water samples collection from springs, their processing and determining the total beta volume activity. The Alpha-beta EMPOS EMS 3 automat was used for comparison. Further use of the NA6201 counter is possible only if the identified shortcomings of the current situation are solved, especially the absence of a chemical laboratory with the necessary equipment for sample processing and the absence of a methane cylinder. Proposed possible solutions are moving the device to more suitable premises or retrofitting the laboratory with necessary equipment.
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Vertikální migrace Cs-137 v půdním profilu do hloubky 1m
NOVÁČKOVÁ, Jana
From the point of view of long-term environmental contamination, cesium-137 is the most important element because it is absorbed into the human body, but also into the root system of plants, mosses, fungi, wild berries and wild game meat. Above all, however, it remains in different layers of the soil. Several main factors affect the distribution of radionuclides in the soil, namely rainfall, water entry into the soil, diffusion, migration through root systems, human, animal activity, etc. Monitoring its occurrence in the environment is important and involves the interference of cesium-137 with potassium. It in absorbed in the human body (about 80%) and excreted in the urine. It remains most in soft tissues and its biological half-life is 110 days. We are exposed to ionizing radiation from natural sources and human activities. Human activity causes artificial radioactivity, which is relatively small, compared to natural radioactivity, but the impact on human health can be huge. The first part of the bachelor thesis relates to the issue with the use of theoretical and scientific information, standards, law. The next part includes the methodology and results of practical measurement of soil samples. The aim was to find out which layer of soil deposits the most radioactive cesium, because it is assumed that it is still a part of it. Soil samples were taken in the protected landscape area of Šumava, in the 2nd zone of the National Park, in the Železnorudsko area, locality Nová Hůrka (Kuchyně). The site choice presented the distribution of radioactive fallout in our territory. Soil samples were take in 1 cm increments to a depth of 1 m, dried, cleaned and prepared for measurement. The samples taken were measured in the standard way at the Regional Center of the State Office for Nuclear Safety (SÚJB) in České Budějovice. The spectra obtained by measurement were evaluated using GAMWIN software. In the practical part, soil layers with a thickness of 1 cm to a depth of 1 m were taken and after their processing and preparation for measurement, the activity of cesium-137 in soil samples was measured by semiconductor gamma spectrometry. The measured results were compared with the results of previous soil samples and they were evaluated and interpreted in the bachelor's thesis. The results of the measurements showed the depth to which the maximum of cesium-137, which comes from nuclear weapons testing, and especially from the radiation accident at Chernobyl, is currently located. The aim of the work was to find out what is the depth distribution of cesium-137 in uncultivated soils and whether its migration through the soil profile is still ongoing and to confirm or refute the hypothesis of what maximum amount still occurs in the range of plant root system.
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Adsorption of radionuclides in granite pores and micropores
Šindelář, Jakub ; Mls, Jiří (advisor) ; Šantrůček, Jaromír (referee)
Adsorption of radionuclides in granite pores and micropores ABSTRACT This graduation thesis deals with laboratory determination of adsorption isotherms parameters. Granite from the central moldanubian pluton, site Panské Dubenky, Czech Republic, was chosen to the experiment. The place is one of the candidate sites to build a deep nuclear waste disposal. A batch experiment was performed in two modes, differing in the way of addition of radioactive nuclide 90 Sr. From this experiment, distribution coefficients for a linear isotherm or parameters for Langmuir isotherm were obtained. Beside this, a through-diffusion experiment was performed. The objective of this experiment was to identify whether some of the radionuclides used (137 Cs, 90 Sr, 125 I) is able to penetrate through the pores of a granite slice barrier between two solutions of different concentrations. During the period of the experiment no radionuclide was detected reliably.
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The impact of the nuclear accident at Chernobyl on the environment
Dvořáková, Markéta ; Přibil, Rudolf (advisor) ; Braniš, Martin (referee)
Modern civilization is dependent on the production of energy. But there are only two energy sources that can cover our energy needs: the energy produced by burning fossil fuels and the energy produced by nuclear fission. People are afraid of nuclear accidents and storage of radioactive waste in relation with the use of nuclear energy. My work focuses on the risk of a nuclear accident, which is demonstrated on the Chernobyl nuclear accident. There were obsolete types of nuclear reactors at Chernobyl. The staff, which serviced the power plant, was inadequately prepared for the experiment. A lot of radionuclides released into atmosphere after the explosion at Chernobyl. They affected mainly the near area from the power plant. There was announced the thirty kilometers large Zone of Alienation. My work deals with the consequences of the accident at Chernobyl for environment - health effects for people and the exposure to animals and plants in the near but also in farther area from the Chernobyl nuclear power plant.
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Data Acquisition from the Deep Horizons of the Rožná Mine - Final Report (Technical report SÚRAO č. 464/2020)
Bukovská, Z. ; Švagera, O. ; Chabr, T. ; Leichmann, J. ; Sosna, K. ; Souček, Kamil ; Vavro, Martin ; Zuna, M. ; Navrátil, P. ; Bohdálek, P. ; Bošková, M. ; Dobeš, P. ; Filipský, D. ; Franěk, J. ; Galeková, E. ; Georgiovská, Lucie ; Hanák, J. ; Havlová, V. ; Hlisnikovský, K. ; Holéczy, D. ; Jankovský, F. ; Jaroš, M. ; Jelínek, J. ; Knésl, I. ; Koucká, L. ; Kryl, J. ; Kříbek, B. ; Kubeš, M. ; Kubina, Lukáš ; Kučera, R. ; Kukutsch, Radovan ; Laufek, F. ; Mixa, P. ; Mozola, J. ; Násir, M. M. ; Palát, J. ; Patočka, M. ; Pořádek, P. ; Rosendorf, T. ; Soejono, I. ; Staš, Lubomír ; Vavro, Leona ; Veselovský, F. ; Vorel, J. ; Waclawik, Petr ; Wertich, V. ; Zajícová, Vendula ; Zelinková, T.
Final Report of the Project „Data Acquisition from the Deep Horizons of the Rožná Mine“ presents the results of the study of rock mass properties with respect to the presence of a significant tectonic zone. The study focused on the change of properties in the vicinity of the so-called first zone of the Rožná deposit, but also on the change of these properties with a depth of 12–24. floor of the former mine, 550-1200 m below the surface. Realized works included geological, petrographic, geochemical description of the rock environment, geophysical work (esp. seismics), study of physico-mechanical properties of rocks, transport experiments and deposit revalidation of the Rožná deposit. All work was carried out for the purpose of describing the studied zone and its manifestation with an emphasis on ensuring the safety of the potential location of the deep geological repository.
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The preparation of porous materials for radionuclide capture
Bajzíková, Anna ; Smrček, Stanislav (advisor) ; Hrubý, Martin (referee)
Title: The Preparation of Porous Materials for Radionuclide Capture Author: Bc. Anna Bajzíková Curriculum: Teaching of Chemistry and Biology for Secondary Schools Type of thesis: Master's Department: Department of Teaching and Didactics of Chemistry, Faculty of Science, Charles University in Prague Elaborated: Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Psysical Engineering, Czech Technical University in Prague Advisor: Doc. Ing. Stanislav Smrček, CSc. Consultant: RNDr. Ján Kozempel, Ph.D. Abstract: The use of radionuclides is still increasing and with it also increases the amount of radioactive waste and this waste have to be processed. This thesis is focused on the preparation, characterization and testing of porous materials which could be used for the process of this waste. There were prepared and characterized materials based on silica and zirkonia with a modified surface. For the modification were used styren with divinilbenzene, polyacrilonitrile and diglycolamides at different configurations of these materials. Furthermore, there were prepared materials based on hydroxyapatite and its modifications. Prepared sorbents were tested for radionuclide capture - flow through the column and also in the static experiments. The capture of 227Ac and its daughter's radionuclides...
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The preparation of porous materials for radionuclide capture
Bajzíková, Anna ; Smrček, Stanislav (advisor) ; Čuba, Václav (referee)
This thesis is focused on the preparation of porous materials which may be usable for radionuclide uptake. These characteristics can be found at nanoporous materials (size of pores 1 - 100 nm) or at polymers. Nanoporous metal oxides and silica gel with styrene-divinylbenzene-TODGA modified surface were prepared and characterized for this purposes. All new prepared substances were tested for the efficiency of radionuclides capture. These measurements were done in Ústav jaderného výzkumu in Řež or in our laboratory.
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