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Ionizing Radiation, Residual Heat Generation, and Inventory of Spent Nuclear Fuel
Hájková, Barbora ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
This bachelor's thesis deals with ionizing radiation, residual heat generation, and inventory of spent nuclear fuel. It introduces types of ionizing radiation and half-life of isotopes, which are contained in the nuclear fuel. Furthermore, using code UwB1, a simulation of the burning of nuclear fuel used at the Dukovany Nuclear Power Plant from the introduction of fuel into the reactor to its storage in deep repositories in 2065, is carried out.
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New Trends in Ionizing Radiation Shielding Research and Development
Vláčil, Martin ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
This thesis deals with the problem of shielding ionizing radiation which is a beam that has enough energy to ionize an atom or a molecule of an irradiated substance. This radiation can occur in nuclear facilities such as a nuclear power plant, a particle accelerator, or in X-rays in healthcare. Until now, standard shielding materials, most often lead or concrete, have been used to protect against ionizing radiation. New trends are therefore trying to replace these materials with lighter, more effective and harmless materials. The practical part is focused on measure the data to obtain the basic properties of shielding materials, such as the attenuation factor and the buildup factor. A measuring platform is described here, which can be used to measure the data needed to calculate the attenuation factor and the buildup factor. The measurement results are compared with tabular values to determine the accuracy of the measurements. Furthermore, the results of measurements of five concrete materials from the company MICo, spol. s r.o. To obtain theoretical values, the simulation program MCNP6 was used, in which it is possible to create a model of the measuring platform, which was used in practical measurements. Next the shielding material, source and detector are defined. The result lead again to the data needed to determine the attenuation factor. The results of measurement and simulation data in MCNP6 are evaluated and graphically processed into such a form that it is possible to compare the properties of shielding materials with each other.
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Simulation and measurement of neutron field by Bonner spheres
Arbeit, Vít ; Šťastný, Ondřej (referee) ; Mičian, Peter (advisor)
The objective of this master’s thesis is introduction, explanation and practical demonstration of simulations conducted in program PHITS. The first part analyses neutrons and related issues regarding their detection as well as neutron sources. Next part is focused on program PHITS, both on it’s basic and advanced functions. Practical part of this thesis deals with the simulations of Bonner spheres and their responses to neutrons of different energies under different conditions. It also compares the results obtained through simulations with measured data.
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Study of alternative ending of nuclear fuel cycle in the Czech Republic
Michalica, Jaroslav ; Radil, Lukáš (referee) ; Šťastný, Ondřej (advisor)
This bachelor thesis deals with the alternative end of the nuclear fuel cycle in the Czech Republic. At the beginning of the work, the nuclear fuel cycle is explained, then the radioactive waste, how it is produced, and how we divide it. This is followed by a chapter that deals with the removal of the used nuclear fuel, from its extraction from the reactor through its temporary storage until its final disposal in an underground waste repository. The work then explains the alternative of direct disposal of used nuclear fuel, namely reprocessing of used nuclear fuel. It explains the existing methods for the reprocessing of used nuclear fuel which are currently being used, and where the used nuclear fuel reprocessing plants are located. The conclusion of the thesis deals with the economic comparison of direct final disposal of used nuclear fuel with reprocessing and final disposal of radioactive waste.
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The temperature field analysis of the subcritical accelerator-driven reactors
Majer, Šimon ; Šťastný, Ondřej (referee) ; Svoboda, Josef (advisor)
The aim of the bachelor thesis is to discuss the problems of accelerator driven system, to describe the possibilities of temperature measurement, to create model of the spallation target QUINTA target in the program Inventor and to perform the simulation by using the Ansys software. The theoretical part is focused on nuclear energy and its potential for the future and continues smoothly to the issue of accelerator driven system (ADS), where it discusses the possibilities of using mentioned system. The thesis is processed from the point of view of electrical energy, focusing on generation issues and the possibility of heat monitoring. The possibilities of temperature measurement are discussed here for calculation and simulation of heat transfer. The practical part of the bachelor’s thesis is processed with the help of the Joint Institute for Nuclear Research in Dubna, where the ADS research is in process. The input data and the size of the geometry were provided by the JINR research team and were used to simulate heat transfer by using the Ansys program. The results of the simulation are processed graphically in the last chapter of the bachelor thesis.
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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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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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Shielding and detection of neutrons
Černý, Tomáš ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
The master’s thesis provides an overview of available neutron sources in terms of neutron yields and energy spectrum of emitted neutrons. Reactions of neutrons with matter, especially neutron scattering and radiation capture, are described. The possibilities neutron neutron detection and spectrometry are also described. The following experiment deals with a design of suitable shielding materials and the analysis of the moderated energy spectrum of neutron flux. The properties of the neutron field were measured using detection by activation. Subsequently, a simulation of the problem was performer in the MCNP program. In the end, the achieved results are compared and evaluated.
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Accelerator driven nuclear reactor neutron field parameters determination
Zemčíková, Kristína ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
The master thesis deals with calculation of neutron field parameters in systems controlled by an accelerator called the Accelerator Driven System (ADS). Firstly physical principle is described, along with its parts as well as the history and present of ADS projects worldwide. Subsequently, neutron activation analysis and gamma spectrometry are described in more detail. The experiment on AmBe neutron source and on Microtron MT25 is presented in the experimental part. Lastly, the reaction rates are calculated.
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Proofs of settlement buldings from the late bronze age until La téne period in the region of Lomský and Loučenský streams in northwestern Bohemia
ŠŤASTNÝ, Ondřej
The main focus of this thesis are proofs of buildings from urnfield period to La T?ne period and the development of the buildings during these periods. The main source of information is a research of archeological data gained from published or unpublished archeological excavations where these structures were detected. The main region on which this thesis if focus on is a microregion of Lomský and Loučenský streams in the northwestern Bohemia. With the help of these documented structures we can trace possible continuity of settlement between periods. Part of the paper is a rewier research of object 3/84 from Jenišův Újezd where the excavations were held during 1984-85 and 1989.
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