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Radiation detection, shielding and identification in public safety.
Kumičák, Ivan ; Šťastný, Ondřej (referee) ; Varmuža, Jan (advisor)
A problem of ionizing radiation is considered in this thesis. The work consists of few chapters, where types of ionizing radiation and its interaction with material environment, also separate measures, which characterize both a source of ionizing radiation and influence of ionizing radiation on a life form are describes. Kinds of detectors of ionizing radiation and principles of their running are taken up as well.
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Ionizing Radiation Measurement
Podolský, Ondřej ; Pikula, Stanislav (referee) ; Beneš, Petr (advisor)
The bachelor’s thesis deals with measuring of ionizing radiation. The aim is to verify the measurement methods for measuring statistical parameters of ionizing radiation sources and verification of attenuation coefficient depending on density. The first contains characteristic of ionizing radiation, shielding, detection and interaction with the environment. The thesis also focuses on the description and testing of selected statistical distributions. In conclusion deals with the practical verifications of measuring methods which may be used as a laboratory exercises in the future.
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Design modification of the collimator for RAW measuring system
Svoboda, Štěpán ; Lisý, Martin (referee) ; Šen, Hugo (advisor)
This thesis deals with structural design of collimator. Collimator is important component of radioactivity measuring device. This apparatus is made by Envinet. Collimator is part of device, which makes good conditions for measuring radioactivity, protects detector and tries avoid overload detector. In this thesis is dealt simplification of collimator. It supposed, that simplified collimator will be more reliable. This proposal saves more money, because company will not have to send employee of Envinet to service their measuring devices in a very distant countries, such as Russia, Ukraine etc.
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Nuclear fission reactions
Michal, Jakub ; Lachman, Jakub (referee) ; Sitek, Tomáš (advisor)
Understanding of physical principles of nuclear fission and nuclear reactions is crucial for operation of a nuclear power plant. Both, light nuclides, and heavy nuclides, are fissionable, but retrieve enough energy is possible only for the heavy ones such as uranium and plutonium. There are many possible ways how the nuclear fission of the same nuclide can take place, however the energetic balance remains almost the same. Another important factor is the yield of the different isotopes. After fission they are usually in an excited state and decay by one of the decay modes. The nuclear fuels are normally based on the fissile nuclides mainly of the uranium and minorly on the plutonium. Despite the plutonium is originally in the fuel, it is one of the main sources of the released energy from nuclear fission. Problems of nuclear fission are then connected with the nuclear waste and possible proliferation of nuclear weapons.
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Historical use of waste from the Jáchymov uranium factory as a building material
Voháňková, Michaela ; Goliáš, Viktor (advisor) ; Šálek, Ondřej (referee)
Between 1853 and 1939, colourful and highly sought-after uranium paints were produced on an industrial scale in Jáchymov. Until the discovery of radium by Marie Curie Skłodowska in 1898, the waste from production was considered essentially worthless. In the 1970s, the use of materials with increased radioactivity was detected in buildings in Jáchymov. Some of the most affected buildings were demolished. In the 1990s, remediation interventions took place during which these building materials (plaster and mortar) were removed from most of the buildings. During this period, gamma radiation doses as well as radioactivity and uranium were measured in the laboratory. The mineralogical and phase character of the material was not investigated, which was the main objective for this bachelor thesis. The presumption of preservation of at least some of the surviving houses was minimal. Nevertheless, a few unique cases have been found. A total of 11 buildings were found along a 12 km tour whose plaster showed elevated radioactivity ranging from 3.2 to 28.4 μGy/h. Sampling was carried out at 6 of them. Determination of 226 Ra mass activities was performed by laboratory gamma spectrometry, uranium contents were determined by instrumental neutron activation analysis. In the study set, the radium activities reached...
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Optical fibres for ionising radiation measurements
Zbožínek, Tadeáš ; Jelínek, Michal (referee) ; Mikel, Břetislav (advisor)
The work focuses on studying methods of measuring ionizing radiation using optical fibres. More attention is paid to their use, together with scintillation materials. The proposed method allows the connection of an electronic detector with a scintillation sensor by optical means. The interconnection provides the possibility of shielding the detector from the effects of high ionizing radiation activities. The shielded detector will thus not be subject to the adverse effects of this radiation and can be used even for long-term measurements of high activities. First experimental measurements of reference sources verify the principle of the proposed method and help to select the best choice for the type of optical fibre.
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Materials shielding properties measurement
Michal, Martin ; Burian, Jiří (referee) ; Katovský, Karel (advisor)
This thesis deals with the issue of ionizing radiation, specifically gamma radiation and its shielding. This radiation is produced, for example, during a fission reaction in a nuclear reactor. Materials such as lead, or concrete are most often used to shield gamma radiation. This is due to their low cost and high density. The task of new trends is to try to replace these existing materials with more efficient, lighter, and non-toxic materials. The aim of the practical part was the calculation of linear attenuation coefficients. For the calculation, the values of the thickness of the shielding sheets, the intensity of the unattenuated beam and the attenuated beam were needed. These values were determined from measurements. For more accurate calculations, the background value was also measured, which was then subtracted from the intensity values of the undamped beam. The resulting values were compared with each other.
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Composite materials with enhanced coefficient of linear attenuation of ionizing radiation
Novotný, Kamil ; Petruš, Josef (referee) ; Kučera, František (advisor)
Ionizing radiation has many useful applications in the fields of healthcare, food industry, nuclear energy and others but poses a hazard to human health in higher doses. In this work, composite materials with enhanced ionizing radiation attenuation properties were prepared. Unsaturated polyester resin was reinforced with inorganic fillers containing elements such as bismuth or barium. Morphology of the samples was studied using scanning electron microscopy. Theoretical values of mass attenuation coefficients were obtained for photon energies 662 keV and 1253 keV using the XCOM software. The attenuation of ionizing gamma radiation was experimentally measured using radioactive sources 137Cs and 60Co. Linear attenuation coefficients and half value layers of the materials were determined using the obtained data. Addition of the fillers improved the shielding properties of the matrix. Composite containing bismuth oxide achieved the highest values of linear and mass attenuation coefficients. The experimental results were found to be in good agreement with theoretical values. Moreover, influence of the fillers on impact toughness has been evaluated.
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The level of population knowledge about selected radiation accidents in South Bohemian region
TŘEŠNIČKOVÁ, Tereza
This diploma thesis deals with the level of population knowledge about selected radiation accidents in South Bohemian region. The goal is to determine the level of population knowledge about selected radiation accidents and then compare the knowledge about disaster in Chernobyl, Fukushima and the others selected radiation accidents. In the thesis were set two hypotheses: H1: The level of population knowledge about selected radiation accidents in South Bohemian region will reach at least 70 % and H2: The level of population knowledge about disasters in Chernobyl and Fukushima will be statistically significantly higher than the knowledge about the others selected radiation accidents. To achieve the stated goals and to test the hypotheses, a questionnaire was compiled, and a survey was made. The results of the survey were evaluated by methods of descriptive and mathematical statistics. The questionnaire consisted of 16 questions. The first part of questionnaire was about disasters in Chernobyl and Fukushima, the second part was about the others selected radiation accidents. The survey consisted of 126 people living in South Bohemian region. The results of the survey show that the overall percentage of correctly answered questions was 55 %, which can be considered as an average result. 72 % of people answered the questions correctly in first part of questionnaire and 37 % in the second part. The set goals were achieved, first hypothesis was refuted and the second was confirmed. The benefit of this diploma thesis is to obtain a summary of level of population knowledge about selected radiation accident in South Bohemian region. The results can be used as information material.
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