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Graphical processing of VVER 1000 simulation results
Kiš Bandi, Peter ; Novotný, Filip (referee) ; Vojáčková, Jitka (advisor)
This bachelor thesis describes core design of nuclear reactor VVER 1000 and deals with processing of results calculated by neutronics code PARCS in SNAP application suite. Nowadays, while designing or modifying nuclear reactor, it is very important to verify behavior of newly designed or modified parts in anticipation. For this purpose there are various computing programmes designed especially for these computations. However, to work with them is necessary to be familiar with the construction of the reactor core, because it is important to understand the results of the calculations. These can be shown either in form of text files or or processed into form of graphs and animations using various applications, in this case in SNAP application suite.
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Security of VoIP protocols
Novotný, František ; Číka, Petr (referee) ; Krajsa, Ondřej (advisor)
This bachelor dissertation deals with the VoIP (Voice over Internet Protocol) safety. The most used transport and signal protocols employing this technology are presented first. Two extended protocols, SIP (Session Initiation Protocol) and IAX (Inter-Asterisk eXchange Protocol), as well as open source Asterisk, which is closely connected with these protocols, are shown in detail. After that, methods, attacks and threats able to assure secure transfer in the use of VoIP among users are described. Afterwards the practical part of this essay, divided into two parts, is presented. In the first part, a passive attack in the form of tapping is demonstrated, and in the second, active attacks are described which take the form of forced cancellations and forwarded calls between two communicating users. With both attacks, safety measures that could effectively prevent against their potential attacking are proposed. In the closing part, the VoIP safety is evaluated for securing a quality connection between users communicating through it.
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Research and Development of Generation IV. reactors with an Emphasis on Molten Salt Reactors
Slančík, Tomáš ; Novotný, Filip (referee) ; Katovský, Karel (advisor)
The bachelor thesis reviews the particular generations of nuclear reactors from the first prototypes to nowadays advanced reactors. It also provides an overview of projects supporting development of IV. generation of nuclear reactors. The main part describes the selected reactors of generation IV by the Generation IV International Forum, focusing on molten salt reactors. The last chapter is devoted to a practical part of bachelor thesis focused on simulated calculation of neutron flux in various salts using MCNP program.
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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.
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Crosstalk analysis and modelling
Novotný, František ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
The thesis concerns the problem of interference modelling for xDSL technologies and Ethernet. The introduction describes the origin of crosstalk, that arise during the operation of the systems and the physical properties of the lines, therefore, the next section describes the properties of the primary and secondary parameters of the homogenous line and their modelling. In order to achieve higher data rates on the metallic line, systems with larger frequency spectrum are applied, resulting in a greater attenuation of the line. This issue and the characteristics determination of the transmission systems are subjects of the mathematical models, which are divided according to the modelling of primary or secondary parameters. The main goal of this work is to describe the effects which influence the performance of data transfer via xDSL and Ethernet technology focusing on internal and external disturbances acting on the cable lines. This is the crosstalk at the near and far end, adaptive white noise, radio frequency interference RFI and impulse noise. Following part of the thesis deals with the properties of xDSL technologies, specifically ADSL2+ and VDSL2 and Ethernet. Another aim is to design applications which enable to test the performance of xDSL and Ethernet transmission systems with its own award simulations interference. The conclusion describes the design and implementation of laboratory experiments for measuring of the efficiency and spectral properties of xDSL. The proposed laboratory protocols are annexed to this thesis, including the measured waveforms.
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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 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.
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Mandatory access control policies of operating system
Novotný, Filip ; Lattenberg, Ivo (referee) ; Pelka, Tomáš (advisor)
The subject of this paper is data protection by means access control. It compares the difference between DAC and MAC access control and describes the progress of MAC due to user requierements. Next part is dedicated to SELinux, what offers more system safeness. SELinux is based on mandatory access control. Making own policy is dedicated to SELinux editor, which is composed of Simplified Policy and is easy to use for ordinary user.
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Computational analysis of pressurized water reactor core behaviour using PARCS code
Novotný, Filip ; Ing. Jan Frýbort, Ph.D., KJR FJFI ČVUT v Praze (referee) ; Katovský, Karel (advisor)
The Master Thesis performs search concerning advanced small and medium power light-water reactors’ designs, including different possibilities to gain a license for their development and operation. The work covers the principal theory about the area of neutronics calculations, principal equations and simplifications. There are several different methods for solution of neutronics calculations. The thesis gives an overview of two principal groups of codes – deterministic methods and Monte Carlo method. The survey shows computational codes examples based on mentioned methods. The computational code PARCS is chosen for further study, which contained description of the input and output file, process of the model creation and conditions for neutronics calculation the of selected reactor design. Based on these facts, the transient calculation has been prepared within the thesis. Thee analyses are described – reactor emergency shutdown, reactor shutdown with stuck group of control and emergency shutdown rods and reactor shutdown with faulty reaction of emergency shutdown rods.
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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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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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