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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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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.
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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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Warming and Starting Nuclear Unit up of the Dukovany NPP after the Outage
Ludvík, Lubomír ; Suk, Ladislav (referee) ; Katovský, Karel (advisor)
This thesis deals with the analysis of warming and starting up the nuclear unit of Dukovany NPP after the outage. First part explains the various operating modes of nuclear power plants, specifically operating modes of Dukovany NPP. The following part contains the analysis of heat sources in the primary circuit and also the individual production and consumption of steam by the NPP. The next part deals with division into several points of the warming of the Dukovany NPP. The analysis of warming nuclear unit after a outage is made on the basis of the industry based data, measured in December 2015. The result of the analysis is determination the amount of steam passing from a another nuclear unit, which is following by the own proposal of the external steam source.
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Power and Temperature Coefficient During Nuclear Power Unit Operation
Smetana, Jan ; Vojáčková, Jitka (referee) ; Katovský, Karel (advisor)
This master thesis deals with the possibilities of traffic of nuclear power unit at thermal and power effect at the end of the campaign, focusing on VVER reactors. For a better idea of the reader the design of key components of the unit in terms of performance is analysed. Parameters of relevant components for Dukovany NPP are presented briefly. The possibilities of traffic of nuclear power unit on thermal and power effect at the end of the campaign are particularly demonstrated on the example of the Dukovany NPP. Furthermore the program Moby-Dick is introduced and the basic possibilities for its use to calculate the course of the campaign are described. At the end of the thesis, we conducted sample calculations for the duration of the campaign on the fourth block of the nuclear power plant.
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Power and Temperature Distribution in Nuclear Fuel Assemblies of VVER-440 reactor at Dukovany NPP
Smola, Luděk ; Novotný, Filip (referee) ; Katovský, Karel (advisor)
This Master’s thesis focuses on calculation of power and temperature distribution in fuel assemblies of VVER-440 reactor at Dukovany Nuclear Power Plant. Theoretical section contains a brief description of VVER-440 technology, fuel and its development at Dukovany Nuclear Power Plant, basics of heat generation in nuclear reactors as well as an overview and categorization of computer codes, used for core calculations. Of these codes, the MOBY-DICK computer code is then described in depth, including its input and output files. The MOBY-DICK code is later on used for pinwise calculating power distribution of selected fuel cycles of defined units at Dukovany Nuclear Power Plant, with vizualization of output values for characteristic fuel assemblies. Results of this computation are then used for analysis, whether uneven power distribution in the core and heat generation gradient within fuel assemblies have any influence on measuring channel output temperatures, which is the pivotal part of this thesis.
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Grid Node Operation after Large Nuclear Unit Connection to the Grid
Prokop, Ondřej ; Varmuža, Jan (referee) ; Katovský, Karel (advisor)
The thesis deals with the analysis of the grid node operation after the connection the nuclear unit. The aim of the master´s thesis is to describe the influence of network´s faults to a nuclear unit. Thesis is dealing with three fundamental problems. An influence of short circuits and power imbalance on the synchronous generator of nuclear power plant and its operation of the island network. The thesis is focused especially on the nuclear unit. However, in the case of any failure in the network, it´s necessary to check other units and their protections in the test system because unit failure could cause the disintegration of the power network. For the purposes of the simulation a test system of the power network has been developed. The test system was optimized in the LUG software, which is used to calculate the power network. Transient simulations are performed in the MODES software. Single faults are configured with scenarios. Results are generated into output files. Analysis of influence network´s faults on the synchronous generator of nuclear power plants. The ability of the synchronous generator to restore the primary steady state or hold the new steady state during changes in operating parameters of the network is one of the important parts of the safe and reliable operation of the power network. During the short circuit the damped transient actions occur. With the extension of the short circuit duration, the amplitude of the transient action increases. The risk of the stability loss of a synchronous generator increases. Therefore, the critical clearing time of a short circuit is being defined, which is the time when there is not any loss of stability. Critical clearing time of research generator is sufficient to turn off the short circuit with the help of its protection (the worst case is 0,8 s). For example, by comparison with the hydroelectric power plant, the critical clearing time is much longer. Models of other power plants have been designed with high reliability so in the case of these faults, it doesn’t cause the disintegration of the power network. Creation of island grid is characterized by strong current surges. Units must be resistant to these surges. In the island grid fast changes of the electrical parameters often occurs. Therefore, units must respond to these changes as quickly as possible and in the broadest limits. For this purpose an island operation regulator is being used. In the case of surplus island grid in steam power plants a dump condenser can be used. This is an important ability of steam power plants because the units are able to react quickly to changes of electrical parameters in island grid. The main result of this thesis is the behavior of the nuclear power plant during various faults in the power network. Researched generator of the nuclear power plant is highly stable against faults in the power network based on the findings. The results allow to continue in this topic with real network and real unit of nuclear power plant.
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Depletion calculation of VVER 1000 reactor fuel using KENO code
Janošek, Radek ; Katovský, Karel (referee) ; Novotný, Filip (advisor)
The introduction to operational nuclear reactors focusing on light-water pressurized reactor VVER 1000 is in the beginning of this Master´s thesis. This thesis covers basic technology of VVER 1000 reactor with focus on reactor core and nuclear fuel TVSA-T. A significant part of the thesis deal with basic concepts of nuclear safety and its methods. The main goal is to create a model of VVER 1000 reactor, which can be used in nuclear burn-up calculations using KENO code. Therefore a part of this thesis deals with explanation of statistical Monte Carlo method and the KENO code.
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Evaluation of Industrial Pollution of the Environment in the Moravian-Silesian Region Using Radioanalytical Methods
Brunčiaková, Miriama ; Varmuža, Jan (referee) ; Katovský, Karel (advisor)
Moravian-Silesian Region is a part of an area so called „small black triangle". It is an area of higher pollution caused by some kind of industrial zone. This region belongs to the most polluted atmosphere in the Czech Republic. The pollution is caused by various factors but the most negative one is metallurgic industry but also mine-mining, transport, and small local furnaces. To analyze pollution, the instrumental neutron activation analysis with analyzing of moss samples were used. The moss has rudimentary root system so it takes nutrients as well as heavy metals from the atmosphere. All irradiation has performed in the Joint Institute for Nuclear Research (JINR) in the Frank Laboratory of Neutron Physics (FLNP) at the reactor IBR-2M. Two kinds of irradiation have been performed as short-term irradiation as long-term irradiation. Short-term irradiation took about 3 mins and then short-lived isotopes were measured for about 15 mins. The long-lived isotopes were measured twice after about 4 days for 30 mins and after 23 days for 90 mins after 3 days of irradiation. For long term irradiation, the cadmium-screened irradiation channel was used. For analyzation and data processing the software Genie 2000 as well as software developed at FLNP JINR were used. In sum, 43 samples of the terrestrial mosses (Hypnum cupressiforme, Pleurozium schreberi and Brachythecium rutabulum) were collected in autumn of 2015 in which the concentration of 38 elements were determined, including heavy metals. As a result, the factor analysis have been performed as well as maps analyzation.
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Description and Utilization of Small and Medium Sized Nuclear Reactors
Novotný, Filip ; Sklenka,, Ľubomír (referee) ; Katovský, Karel (advisor)
This Bachelor’s thesis examines the area of small- and medium-sized nuclear reactors and their roles in the early development of nuclear energy. The work covers current small- and medium-sized reactors in operation and considers future developments in this area. Included is an analysis of the possibilities for their use and applications in various areas of human activity. The work focuses on new projects of small- and medium-sized reactors, especially on projects considered for the near future. They are evaluated for nuclear weapons proliferation resistance, as well as their economic and technical advantages. Furthermore, an analysis was carried out of the possible uses of small reactors in propulsion of spaceships, and their use in various geographic areas. Knowledge acquired from this analysis applies to the situation in the Czech Republic. Both unrealized projects, and projects which may be realized in the future, have been described.
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