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The AmBe Laboratory Neutron Source Field Determination Using Experimental Stend
Jelínek, Martin ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
This master’s thesis provides a comprehensive overview of the conventional neutron sources from the perspective of reactions which lead to the production of neutrons, advantages, disadvantages, properties and their possible utilization. In the relation to the assembly of the laboratory neutron source and the unique experimental stand “Candle” basic methods of the neutron field analysis are outlined and two of them, the neutron activation analysis and the calculation using the MCNP software code are discussed in depth to apply and compare these methods. The experimental part deals with the realization of neutron activation analysis from its design itself, through gamma spectrometry to the cadmium ratio calculation. In compliance with the measurements, a calculation with MCNP code was run and both methods were evaluated and compared. The computation is complemented with the analysis of radiation situation on the borders of the supervised area, which is compared to the legal limit.
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Alternative sources of nuclear energy
Svoboda, Josef ; Zlámal, Ondřej (referee) ; Katovský, Karel (advisor)
In places where it is not possible to use conventional production and distribution of energy, autonomous sources take over. Most of autonomous sources use solar energy, wind energy and other renewable resources. For applications such as special missions into outer space the usage of conventional sources is not possible. Except for powering special satellites, unconventional nuclear sources are also used in autonomous unmanned objects located in distanced areas with extreme natural conditions. It is also used in unusual propulsions of ground, water and air machine. These vehicles are for example pacemaker powered by radioisotope source, submarines, aircrafts and other vehicles supplied by nuclear reactor of unconventional conception. In this bachelor thesis there are globally summarized questions connected with unconventional sources of nuclear energy with detailed description of chosen parts. This work is concerned with finding more efficient machinery for conversion of heat energy supplied by radioisotope decay to electric energy.
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Nuclear reactors for new units in the Czech Republic
Brunčiaková, Miriama ; Martinec, Jiří (referee) ; Katovský, Karel (advisor)
This bachelor thesis is concerned with nuclear reactors in operation, in construction and in project plans. Because of that it is a very actual theme. Czech Republic tries to solve the question about building two new reactors for Temelín-3,4. There are two competitors in this tender. First of them is the CzechRussian consortium MIR.1200 with the alike named project MIR.1200, and the second one is Westinghouse company with the project AP 1000. Both of these projects belong to III.+ generation of nuclear reactors. In comparison with the previous generations, this generation brings evolution changes and uses much more passive security elements. The project AP 1000 solves heavy accidents by passive security systems solely. The project MIR.1200 uses combination of both active and passive security systems.
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Investigation of Ionizing Radiation Infuence to the Communication Systems of Satellites
Golubev, Martin ; Hobst, Leonard (referee) ; Katovský, Karel (advisor)
This master thesis discuss about ionizing radiation, interaction with matter and effects on her. In the work is discussed differend types of interactions of directly ionizing radiation and indirectly ionizing radiation. Below is an overview of methods of shielding from all of types of ionizing radiation. Second part of this thesis discuss about single event effects in semiconductors which are cause by ionizing radiation. At the end is described design of measuring instrument included FPGA chips. This design is discused both from point of wiew hardware and software too.
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Advanced nuclear reactors’ promising fuels
Kadlec, Miroslav ; Varmuža, Jan (referee) ; Katovský, Karel (advisor)
This bachelor thesis focuses on the development of nuclear reactors and the fuel burned them. Thesis describes the various types of nuclear fuel, including the ways they are treated either before or after use in a nuclear power plant. Also included is a description of the situation of nuclear power plants in the Czech Republic and the Slovak Republic. In conclusion focuses on the state of some upcoming projects of the future.
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Experimental Investigation of the Neutron Field in an Accelerator Driven Subcritical Reactor
Zeman, Miroslav ; Janda,, Jiří (referee) ; Chudoba,, Petr (referee) ; Katovský, Karel (advisor)
This dissertation focuses on irradiations of a spallation set-up consisting of more than half a ton of natural uranium that were executed by a 660 MeV proton beam at the Joint Institute for Nuclear Reserch in Dubna. Two types of irradiations were arranged: with and without lead shielding. Both types were arranged with threshold activation detectors (Al-27, Mn-55, Co-59, and In-nat) located throughout the whole set-up both in horizontal and vertical positions and activated by secondary neutrons produced by spallation reaction. The threshold activation detectors were analysed by the method of gamma-ray spectroscopy. Radionuclides found in the threshold detectors were analysed and reaction rates were determined for each radionuclide. Ratios of the reaction rates were determined from irradiation of the set-up with and without lead shielding. Subsequently, the neutron spectra generated inside the spallation target at different positions were calculated using Co-59 detector. The experimental results were compared with Monte Carlo simulations performed using MCNPX 2.7.0.
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Monitoring and Simulation of ADS Experimental Target Behaviour, Heat Generation, and Neutron Leakage
Svoboda, Josef ; Kliman,, Ján (referee) ; Wagner,, Vladimír (referee) ; Katovský, Karel (advisor)
Urychlovačem řízené podkritické systémy (ADS) se schopností transmutovat dlouhodobě žijící radionuklidy mohou vyřešit problematiku použitého jaderného paliva z aktuálních jaderných reaktorů. Stejně tak i potenciální problém s nedostatkem dnes používaného paliva, U-235, jelikož jsou schopny energeticky využít U-238 nebo i hojný izotop thoria Th-232. Tato disertační práce se v rámci základního ADS výzkumu zabývá spalačními reakcemi a produkcí tepla různých experimentálních terčů. Experimentální měření bylo provedeno ve Spojeném ústavu jaderných výzkumů v Dubně v Ruské federaci. V rámci doktorského studia bylo v průběhu let 2015-2019 provedeno 13 experimentů. Během výzkumu byly na urychlovači Fázotron ozařovány různé terče protony s energií 660 MeV. Nejdříve spalační terč QUINTA složený z 512 kg přírodního uranu, následně pak experimentální terče z olova a uhlíku nebo terč složený z olověných cihel. Byl proveden také speciální experiment zaměřený na detailní výzkum dvou protony ozařovaných uranových válečků, z nichž je složen spalační terč QUINTA. Výzkum byl především zaměřen na monitorování uvolňovaného tepla ze zpomalovaných protonů, spalační reakce a štěpení, způsobeného neutrony produkovanými spalační reakcí. Dále se na uvolňování tepla podílely piony a fotony. Teplota byla experimentálně měřena pomocí přesných termočlánků se speciální kalibrací. Rozdíly teplot byly monitorovány jak na povrchu, tak uvnitř terčů. Další výzkum byl zaměřený na monitorování unikajících neutronů z terče porovnávací metodou mezi dvěma detektory. První obsahoval malé množství štěpného materiálu s teplotním čidlem. Druhý byl složený z neštěpného materiálu (W nebo Ta), avšak s podobnými materiálovými vlastnostmi se stejnými rozměry. Unik neutronů (resp. neutronový tok mimo experimentální terč) byl detekován uvolněnou energií ze štěpné reakce. Tato práce se zabývá přesným měřením změny teploty pomocí termočlánků, s využitím elekroniky od National Instrument a softwaru LabView pro sběr dat. Pro práci s daty, analýzu a vizualizaci dat byl použit skriptovací jazyk Python 3.7. (s využitím několika knihoven). Přenos částic by simulován pomocí MCNPX 2.7.0., a konečně simulace přenosu tepla a určení povrchové teploty simulovaného modelu bylo provedeno v programu ANSYS Fluent (pro jednodušší výpočty ANSYS Transient Thermal).
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Nuclear Fuel and its Behavior during Burn-up
Matocha, Vítězslav ; Foral, Štěpán (referee) ; Katovský, Karel (advisor)
The point of this bachelor’s thesis is to characterize different types of nuclear fuels and their behaviour during the process of burning-up. Futher, basic types of nuclear reactors are mentioned, as well as their history and different kinds of nuclear fuels used in these reactors. Then there are pieces of information about fuel cycles and fuel burning-up. Furthermore, the thesis concentrates on the changes, which happen in the nuclear fuel during the process of burning-up, such as swelling and cracking. In its other parts, this bachelor’s thesis deals with fission products, mainly gas fission products are mentioned here. At the end of this thesis, a simple model of nuclear fuel burning-up is created. This model follows concentration of izotopes of uranium and plutonium during fuel burning-up.
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Fusion systems and their shielding
Roubal, Michal ; Katovský, Karel (referee) ; Král, Dušan (advisor)
This thesis is concerned with nuclear fusion and its use as a source of energy for humanity. In the first part of my thesis, I will briefly explore the research history of nuclear fusion. Next, I will investigate the various possible issues connected with achieving and sustaining nuclear fusion. I will briefly discuss the importance of mastering it. I will talk about existing and anticipated risks of radiation damage which can occur during nuclear fusion. Lastly, i will discuss the principles of tritium breeding.
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Nuclear Fuel Cycle of Temelin NPP
Ježek, Martin ; Zlámal, Ondřej (referee) ; Katovský, Karel (advisor)
This bachelor's thesis deals with the central part of a fuel cycle in the power plant of Temelín. It describes generally the whole fuel cycle, from the process of uranium mining up to permanent storage of burned-up material and it shortly mentiones possibilities of its remaking. Neverthless, the main point is the middle part of the fuel cycle. In the next parts, the thesis concentrates on the power plant of Temelín. It describes shortly the WER-1000 reactor, which is being used there, and the active zone as well. There is a further description of both fuels used there, a fuel form a Russian corporation of TVEL, which is used nowadays, as well as a fuel from an American corporation of Westinghouse used in the past. The thesis then deals with the development of a fuel cycle from the moment of launching the power plant up to the present. The problems with the fuel from the American corporation are mentioned here as well. Then it concentrates on more-than-year long cycles and tries to quantify their contribution. The thesis contains a very simple project of an elongated fuel cycle and his evaluation from the point of working economy and organisation of shutdowns.
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