|
|
Simulation of nuclear fuel burn-up during whole fuel cycle
Smola, Luděk ; ČEZ,, Ondřej Zlámal, (referee) ; Katovský, Karel (advisor)
The main goal of this Bachelor’s thesis is to create a long-term kinetics model of a nuclear reactor – model, which simulates changes in nuclear fuel inside the reactor core during reactor operation. As the term long-term suggests, primarily the changes in whole five-year fuel cycle horizon are studied, which stands for changes in concentration of elements contained within fresh fuel as well as origination of new ones (with special focus on higher actinides and plutonium). This mathematical model is created using the MAPLE 14 software. Outputs from the model are displayed graphically and thoroughly analysed, so that comprehensive conclusions of problems can be made. Furthermore, the thesis contains theoretical and informational background that is necessary for understanding all the aspects of the model – historical development of nuclear reactors, their basic types, nuclear fuel description focusing on fuel for pressurized light-water reactors VVER (for which the model is primarily designed), MOX fuel and possibilities of its utilization, and last but not least – selected topics from nuclear physics.
|
|
|
Sensitivy analysis of the influence of manufacturing inaccuracies on the nuclear fuel reactivity
Sedlák, Martin ; Katovský, Karel (referee) ; Novotný, Filip (advisor)
This thesis deals with a sensitivity analysis of the influence of manufacturing inaccuracies on the reactivity of nuclear fuel. Sensitivity analysis has been done for fuel assembly TVSA-T, for nuclear reactors VVER-1000. Particularly, for fuel rod of type tvel - without burnable absorbers. Thirty three combinations of maximal and minimal of manufacturing parameters were simulated in SCALE environment. Changes of multiplication coefficient in dependence on burnup for 5 combinations have been also studied. It has been found that the most significant influence on the reactivity has the accuracy of enrichment and outer diameter of cladding. It has also been found that influence of manufacturing inaccuracies is not constant during burnup. The benefit of the thesis is determining the effects of individual inaccuracies on the reactivity and the fact that their influence is not constant during burnup.
|
|
|
Radiation damage of VVER-440 based Dukovany NPP reactor pressure vessel investigation
Říha, Tomáš ; Martinec, Jiří (referee) ; Šen, Hugo (advisor)
This master‘s thesis deals with radiation damage of reactor pressure vessels, specifically of NPP Dukovany Unit No. 3. In general damage mechanisms of reactor steels are described and possibilities of monitoring of material degradation and its recovery used at NPP’s all over the world are mentioned as well. A practical part of the thesis is focused on interpretation of analyses carried out with the assistance of MOBY DICK code. The ground of these analyses is a neutron fluence value development on different locations of RPV for the whole life of operation up to 24th cycle. The analyses results are put into context with performed in-service inspections. The thesis follows up with neutron fluence computation for the future cycles containing new types of nuclear fuel up to 34th cycle. The outcome of practical part of the master‘s thesis is a comparison between new types of nuclear fuel with respect to radiation damage of RPV’s.
|
|
|
Front and Back End of the Nuclear Fuel Cycle
Winterová, Radka ; Mastný, Petr (referee) ; Katovský, Karel (advisor)
In this bachelor thesis author deals with the topic of nuclear power fuel cycle and the particular differences that are typical for each nuclear reactor types. The author aims to describe in detail both - the front and especially the back end of the nuclear fuel cycle, fuel fabrication for light water nuclear reactors, fuel reprocessing and recycling, and consequently fuel production based on REPU and MOX. Thesis should also get familiar with global approaches to fuel cycle, especially the back end.
|
|
|
Nuclear Fuel in Operational Conditions
Konopová, Tamara ; Novotný, Filip (referee) ; Katovský, Karel (advisor)
This thesis deals with the issue of nuclear fuel. Firstly, the problem of nuclear fuel in the implementation for certain reactors is presented. Production of nuclear fuel is introduced, which includes the performance of companies engaged in the production of this fuel. Secondly, the phenomena in the fuel burnup are discussed. Lastly, the burnable absorbers are mentioned and the analysis of burnable absorbers is carried out.
|
|
| |
|
|
The state-of-of-art of research and design of nuclear fuel
Bílý, Lukáš ; Mičian, Peter (referee) ; Katovský, Karel (advisor)
This bachelor’s thesis deals with advanced nuclear fuels resistant to accidents. It focuses primarily on fuel cladding innovation. The aim was to select several concepts and then test them using the UwB1 program. The UwB1 program shows us how the multiplication factor changes during the nuclear fuel combustion process in the reactor. Based on the results, one concept was then selected.
|
|
|
Nuclear Fuel in Operational Conditions
Konopová, Tamara ; Novotný, Filip (referee) ; Katovský, Karel (advisor)
This thesis deals with the issue of nuclear fuel. Firstly, the problem of nuclear fuel in the implementation for pressurized water reactors is presented. Production of nuclear fuel is introduced, which includes the performance of companies engaged in the production of this fuel. Secondly, problems of nuclear fuel during operation, focusing on burnable absorbers and phenomena in the fuel burnup are discussed. Lastly, the calculation is carried out and gadolinium as a burnable absorber is compared with erbium as a burnable absorber.
|
|
|
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.
|
|
|
Current Status of Nuclear Fuel Assemblies Inspections at Nuclear Power Plants World-Wide
Fendrychová, Michaela ; Temelín, Elektrárna (referee) ; Katovský, Karel (advisor)
This bachelor thesis deals with post irradiation examination (PIE) of spent nuclear fuel. The document briefly introduces basic light water reactor types (BWR, PWR, VVER) and construction of nuclear fuel for these reactors. Typical fuel failure types are described as well as methods for detection of such defects or failures. Consequently inspection methods suitable for commercial nuclear power plants are described. The primary goal of this thesis was to analyze existing inspection methods and to propose improvement of existing PIE at Temelín nuclear power plant. Therefore part of this thesis is devoted to description of fuel used at Temelín power plant, inspection methods currently applied at Temelín power plant and discussion of possible improvements of PIE.
|
guest ::
