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Experimental analysis focused on the effect of chloride salt on neutron flux with different energy levels
Slančík, Tomáš ; Števanka, Kamil (referee) ; Katovský, Karel (advisor)
Master’s thesis focuses on the history and current progress in research of molten salt reactors around the world, with an emphasis placed on the properties of molten salts and the problems associated with their use. In relation to the practical part, one chapter is devoted to the creation of input file in the MCNP software. The practical part deals with neutron activation analysis of graphite prism experiment, which is filled with powder NaCl salt. This experiment is focused on the effect of salt on neutron flux with different energy levels. The whole problem was also simulated in the MCNP environment along with the experiment. At the end of the thesis, the individual methods are compared and evaluated.
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Analysis of thermal power plants environmental impacts using radioanalytical methods
Král, Dušan ; Ing. Ondřej Huml, Ph.D., KJR FJFI ČVUT v Praze (referee) ; Katovský, Karel (advisor)
Operation of classical power sources, like coal fueled thermal power plants, causes more or less strong impact on surrounded environment. Beside to the generally discussed CO2 emissions, there are CO, SOx, NOx too; and also fly ash emissions containing various trace elements depending on coal quality. Heavy trace elements carried by fly ash generate locally distributed fallout and contaminate soil in the power plant neighborhood for many years. These elements may be detected in soil samples as well as in biomass. Objectives of this work are to find and quantify trace elements in soil samples near Oslavany hard coal fueled thermal plant, which was in operation from 1913 to 1993. Power plant did not use any advanced fly ash filters. Hard coal was used as a fuel for power plant and it was mined locally in Rosice-Oslavany coal district in very deep mines (up to 1428 m). Coal contained a lot of trace elements. A mine as well as power plant is for more than 20 year closed, but trace elements can be still find in the environment. Main goal is to find these elements using activation analysis and gamma-ray spectrometry methodology. We have assembled thirty six soil samples in square lattice drawn around Oslavany power plant brownfield. On behalf of cooperation with colleagues from the Czech Technical University in Prague and their Open-Access project, we irradiated samples in three vertical channels of VR-1 research nuclear reactor. Irradiated samples were transported to gamma spectroscopy & activation analysis laboratory and measured by HPGe detector. Gamma spectra were analyzed and some trace elements identified. We have determine relative and absolute concentration of found elements. We observe and determine activity and weight of As, U, Ba, La, Eu, Mn, K, V, Mg and Na only. Results show a real suspicion for increase of trace elements in soil samples of hard coal power plant surroundings.
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Ionizing radiation shielding simulation using MCNP code
Konček, Róbert ; Košťál,, Michal (referee) ; Katovský, Karel (advisor)
Radiation is defined as ionizing if it has enough energy to remove electrons from atoms or molecules when it passes through or collides with matter. This ability implies potentially detrimental effects on living tissue. Ionizing radiation shielding is therefore a discipline of great practical importance. The thesis builds upon the author's previous work on the topic and widens the scope of discussion with theoretical and practical issues of advanced shielding calculations. The theoretical part of the thesis describes several approaches to calculating fluence or absorbed dose at an arbitrary point in space. Point-kernel methods provide sufficiently accurate results for simpler shielding problems. In many practical cases, however, calculations based on the transport theory are necessary. There are two basic types of transport calculations: deterministic transport calculations in which the linear Boltzmann equation is solved numerically, and Monte Carlo calculations in which a simulation is made of how particles migrate stochastically through the problem geometry. Advantages and disadvantages of both methods are discussed. In the practical part are the results of radiation shielding calculations performed with a major Monte Carlo code - MCNP6, compared with those obtained in the experiments, which were carried out at the Ionizing Radiation Laboratory at Department of Electrical Power Engeneering, FEEC BUT. The experiments consisted of placing a cobalt-60 radioisotope source at three different positions inside a lead collimator, and counting pulses with two different scintillation detectors positioned in front of the opening of the collimator, alternately with or without lead shield located between the source and the used detector. Agreement of the calculations and the data from the measurements is reasonable, given the inherent uncertainties of the experimental set-up. Performed sensitivity analysis shows relative importances of different parameters used as inputs in simulations, such as densities of materials, or dimensions of the scintillation crystals. Annotated MCNP input files used for simulation are also part of the thesis.
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Experimental and calculational salts' properties investigation for MSR reactors from nuclear data point-of-view
Burian, Jiří ; Ing. Miroslav Zeman, PhD., SÚJB RC Brno (referee) ; Katovský, Karel (advisor)
Nowadays there is research into molten salt reactors. The use of chlorine-based salts, which would be more available than known fluoride salts, is envisaged. The subject of research is not only the chemical and physical properties of chloride salts, but also their behavior in the neutron field and the influence of neutron balance inside the reactor. Many properties can also be determined using calculations that draw information from scientific nuclear libraries (endf). The purpose of this work is to compare important nuclear libraries with each other, and also to compare the reaction rates calculated from the library data with the reaction rates obtained by self-measurement. The preview will include a description of the necessary activities associated with the preparation of measurements, instructions for compiling the computer program NJOY and the process of the measurement itself. At the end of the work will be summarized the results and statements of which nuclear library is the closest in its values to the results of experiments.
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Characterization of the neutron AmBe source using threshold activation detectors
Burian, Jiří ; Zeman, Miroslav (referee) ; Král, Dušan (advisor)
Neutron activation analysis is used to characterize an unknown neutron field source or material of unknown composition. Using known reactions that take place in the activation detector due to the action of the neutron field, their measurement and evaluation, we can describe the composition of the source if we know the material composition of the activation detector, or, conversely, if we do not know the materials from which the activation detector is made, we can find out if we put this detector of unknown composition into the action of neutron radiation of known origin.
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Determination of nuclear reactions' microscopic cross-sections using an accelerator-driven neutron source
Filová, Vendula ; Šťastný, Ondřej (referee) ; Král, Dušan (advisor)
Tato práce se věnuje určení mikroskopických účinných průřezů interakcí neutronů s indiem. Teoretická část shrnuje neutronové zdroje používané ve vědě i průmyslu, popisuje princip jejich fungování a představuje příklady jejich aplikací. Praktická část obsahuje postup vyhodnocování velikostí účinných průřezů včetně jednotlivých provedených korekcí. Byly vyhodnocována data celkem ze tří experimentů, při kterých byly produkovány neutrony interakcí protonů s tenkým lithiovým terčem. Kvazi monoenergetickým neutronům byly vystaveny sendviče folií včetně foile z india, produkty interakcí byly měřeny pomocí gamma spektrometrie. Výsledné mikroskopické účinné průřezy jsou porovnány s daty z knihoven evaluovaných dat a z knihovny EXFOR.
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Determination of nuclear reactions' microscopic cross-sections using an accelerator-driven neutron source
Filová, Vendula ; Šťastný, Ondřej (referee) ; Král, Dušan (advisor)
Tato práce se věnuje určení mikroskopických účinných průřezů interakcí neutronů s indiem. Teoretická část shrnuje neutronové zdroje používané ve vědě i průmyslu, popisuje princip jejich fungování a představuje příklady jejich aplikací. Praktická část obsahuje postup vyhodnocování velikostí účinných průřezů včetně jednotlivých provedených korekcí. Byly vyhodnocována data celkem ze tří experimentů, při kterých byly produkovány neutrony interakcí protonů s tenkým lithiovým terčem. Kvazi monoenergetickým neutronům byly vystaveny sendviče folií včetně foile z india, produkty interakcí byly měřeny pomocí gamma spektrometrie. Výsledné mikroskopické účinné průřezy jsou porovnány s daty z knihoven evaluovaných dat a z knihovny EXFOR.
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Zdroj monoenergetických elektronů pro monitorování spektrometru v neutrinovém experimentu KATRIN
Slezák, Martin ; Vénos, Drahoslav (advisor) ; Vorobel, Vít (referee)
The international project KATRIN (KArlsruhe TRItium Neutrino experiment) is a next- generation tritium beta decay experiment. It is designed to measure the electron antineutrino mass by means of a unique electron spectrometer with sensitivity of 0.2 eV/c2 . This is an improvement of one order of magnitude over the last results. Important part of the measurement will rest in continuous precise monitoring of high voltage of the KATRIN main spectrometer. The monitoring will be done by means of conversion electrons emitted from a solid source based on 83 Rb decay. Properties of several of these sources are studied in this thesis by means of the semiconductor gamma-ray spectroscopy. Firstly, measurement of precise energy of the 9.4 keV nuclear transition observed in 83 Rb decay, from which the energy of conversion electrons is derived, is reported. Secondly, measurement of activity distribution of the solid sources by means of the Timepix detector is described. Finally, a report on measurement of retention of 83 Rb decay product, the isomeric state 83m Kr, in the solid sources is given.
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Experimental and calculational salts' properties investigation for MSR reactors from nuclear data point-of-view
Burian, Jiří ; Ing. Miroslav Zeman, PhD., SÚJB RC Brno (referee) ; Katovský, Karel (advisor)
Nowadays there is research into molten salt reactors. The use of chlorine-based salts, which would be more available than known fluoride salts, is envisaged. The subject of research is not only the chemical and physical properties of chloride salts, but also their behavior in the neutron field and the influence of neutron balance inside the reactor. Many properties can also be determined using calculations that draw information from scientific nuclear libraries (endf). The purpose of this work is to compare important nuclear libraries with each other, and also to compare the reaction rates calculated from the library data with the reaction rates obtained by self-measurement. The preview will include a description of the necessary activities associated with the preparation of measurements, instructions for compiling the computer program NJOY and the process of the measurement itself. At the end of the work will be summarized the results and statements of which nuclear library is the closest in its values to the results of experiments.
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Characterization of the neutron AmBe source using threshold activation detectors
Burian, Jiří ; Zeman, Miroslav (referee) ; Král, Dušan (advisor)
Neutron activation analysis is used to characterize an unknown neutron field source or material of unknown composition. Using known reactions that take place in the activation detector due to the action of the neutron field, their measurement and evaluation, we can describe the composition of the source if we know the material composition of the activation detector, or, conversely, if we do not know the materials from which the activation detector is made, we can find out if we put this detector of unknown composition into the action of neutron radiation of known origin.
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