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Assessment of the thermomechanical behaviour of perspective nuclear fuel for reactivity insertion accidents
Halabuk, Dávid ; Suk, Ladislav (referee) ; Martinec, Jiří (advisor)
The objective of this master’s thesis is to simulate thermo-mechanical behaviour of nuclear fuel in a pressurized water reactor during a reactivity initiated accident. An important part of this work is focused on examination of processes which occur during such accident and on creation of a detailed overview of material properties of nuclear fuel and fuel cladding which are necessary for simulations that closely reflect reality. Simulations in this thesis examine cases of fresh or irradiated nuclear fuel for two types of fuel cladding, Zircaloy-4, a material that is currently used in nuclear reactors, and ceramic matrix composite material made of SiC. The thesis also presents comparison of results with a corresponding international benchmark and an assessment of the influence of selected input parameters on obtained results.
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Fuel element characterization
Halabuk, Dávid ; Suk, Ladislav (referee) ; Martinec, Jiří (advisor)
This bachelor thesis describes the fuel rods of VVER reactors. In addition to general description of fuel rod, there is also overview of the nuclear fuel used in the past and at present in Czech and Slovak nuclear power plants, as well as overview of the new trends in development of nuclear fuel. Big part of the thesis is focused on description of nuclear fuel and fuel cladding properties and the individual processes affecting fuel rod during fuel burnup. Next part describes in detail the causes of fuel failures occurring in VVER reactors. The last part of the thesis includes calculation of changes of deformations and stresses occurred in fuel cladding during pellet-cladding interaction. Calculation is done for four different shapes of fuel pellets and in addition to deformation and stress analysis, there are also calculated axial dilatations of fuel column and radial temperature distributions in fuel rod.
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Nuclear Fuel Innovation
Mičian, Peter ; Zeman, Miroslav (referee) ; Katovský, Karel (advisor)
This bachelor thesis deals with the latest findings about nuclear fuel, especially fuels for pressurized water reactors. The thesis provides an overview of the latest research in the field of fuel cladding, which separates the fuel from coolant. Part is focused on burnable absorbers, which helps to reduce neutron flux during the first year of new fuel assembly. Furthermore, the thesis briefly discusses transmutation fuel cycles. the main empahsis is focused on ATF fuels, in the form of fuels with enhanced thermal conductivity. Develompment in this field could increase the safety and usage of the nuclear energy. The latest part is focused on applications of computational program FEMAXI-6 and analyze its outputs. This program deals with calculations of behavior of high-burnup fuel elements. As data for inputs were used real data from the nuclear power plant Dukovany.
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Experimental and calculational analyses of new generation nuclear fuels
Tioka, Jakub ; Mičian, Peter (referee) ; Števanka, Kamil (advisor)
The search for Accident tolerant fuels (ATF) which is the first part of this thesis is currently one of the most actual topics in the field of nuclear fuels. These fuels must be first successfully tested in operational and also accident conditions for their possible inclusion in commercial use. Following part of the thesis specifically focuses on the boiling crisis in nuclear reactors which can damage the nuclear fuel cladding. Therefore, it is necessary to know the critical heat flux value and the departure from nuclear boiling ratio. Calculations which determine critical heal flux value are placed in the practical part of the thesis. Calculations are compared with the data obtained during experiments. The ALTHAMC12 and the other correlations which are based on the previous measurements are used for the computational analysis.
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Experimental and calculational analyses of new generation nuclear fuels
Tioka, Jakub ; Mičian, Peter (referee) ; Števanka, Kamil (advisor)
The search for Accident tolerant fuels (ATF) which is the first part of this thesis is currently one of the most actual topics in the field of nuclear fuels. These fuels must be first successfully tested in operational and also accident conditions for their possible inclusion in commercial use. Following part of the thesis specifically focuses on the boiling crisis in nuclear reactors which can damage the nuclear fuel cladding. Therefore, it is necessary to know the critical heat flux value and the departure from nuclear boiling ratio. Calculations which determine critical heal flux value are placed in the practical part of the thesis. Calculations are compared with the data obtained during experiments. The ALTHAMC12 and the other correlations which are based on the previous measurements are used for the computational analysis.
|
|
| |
|
|
Assessment of the thermomechanical behaviour of perspective nuclear fuel for reactivity insertion accidents
Halabuk, Dávid ; Suk, Ladislav (referee) ; Martinec, Jiří (advisor)
The objective of this master’s thesis is to simulate thermo-mechanical behaviour of nuclear fuel in a pressurized water reactor during a reactivity initiated accident. An important part of this work is focused on examination of processes which occur during such accident and on creation of a detailed overview of material properties of nuclear fuel and fuel cladding which are necessary for simulations that closely reflect reality. Simulations in this thesis examine cases of fresh or irradiated nuclear fuel for two types of fuel cladding, Zircaloy-4, a material that is currently used in nuclear reactors, and ceramic matrix composite material made of SiC. The thesis also presents comparison of results with a corresponding international benchmark and an assessment of the influence of selected input parameters on obtained results.
|
|
|
Nuclear Fuel Innovation
Mičian, Peter ; Zeman, Miroslav (referee) ; Katovský, Karel (advisor)
This bachelor thesis deals with the latest findings about nuclear fuel, especially fuels for pressurized water reactors. The thesis provides an overview of the latest research in the field of fuel cladding, which separates the fuel from coolant. Part is focused on burnable absorbers, which helps to reduce neutron flux during the first year of new fuel assembly. Furthermore, the thesis briefly discusses transmutation fuel cycles. the main empahsis is focused on ATF fuels, in the form of fuels with enhanced thermal conductivity. Develompment in this field could increase the safety and usage of the nuclear energy. The latest part is focused on applications of computational program FEMAXI-6 and analyze its outputs. This program deals with calculations of behavior of high-burnup fuel elements. As data for inputs were used real data from the nuclear power plant Dukovany.
|
|
|
Fuel element characterization
Halabuk, Dávid ; Suk, Ladislav (referee) ; Martinec, Jiří (advisor)
This bachelor thesis describes the fuel rods of VVER reactors. In addition to general description of fuel rod, there is also overview of the nuclear fuel used in the past and at present in Czech and Slovak nuclear power plants, as well as overview of the new trends in development of nuclear fuel. Big part of the thesis is focused on description of nuclear fuel and fuel cladding properties and the individual processes affecting fuel rod during fuel burnup. Next part describes in detail the causes of fuel failures occurring in VVER reactors. The last part of the thesis includes calculation of changes of deformations and stresses occurred in fuel cladding during pellet-cladding interaction. Calculation is done for four different shapes of fuel pellets and in addition to deformation and stress analysis, there are also calculated axial dilatations of fuel column and radial temperature distributions in fuel rod.
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