National Repository of Grey Literature 5 records found  Search took 0.01 seconds. 
Design of the internal circuit of the system for long-term heat removal from NPP hermetic zone
Zemanová, Silvie ; Baláš, Marek (referee) ; Milčák, Pavel (advisor)
The diploma thesis deals with the safety of nuclear power plants and the design of a system for long-term heat removal from the hermetic envelope of the WWER 440 model 213 NPP intended for severe accident management. The thesis contains a description of the course of selected severe accidents and the causes of their occurrence and presents approaches (the concept of defence in depth) and measures (implementation of new systems) by which operators aim to prevent and prepare for their management. The practical part of the diploma thesis is devoted to the design of the piping route of the long-term heat removal system (dimensions, material, wall thickness, layout) and the calculation of the hydraulic losses of this route, it also deals with the conceptual design of the heat exchanger for the above-mentioned emergency system and its thermal calculation.
Accident Tolerant Fuel simulation loaded in advanced nuclear reactor during severe accident conditions
Hamřík, Lukáš ; Foral, Štěpán (referee) ; Mičian, Peter (advisor)
Tato diplomová práce se zaměřuje na paliva se zvýšenou tolerancí vůči haváriím, jež jsou považována za další krok ke zvyšování bezpečnosti provozu jaderných elektráren. Zpočátku jsou odhaleny slabiny v současnosti provozovaného palivového systému. Jsou popsány možnosti pokročilých paliv a jejich kategorizace, v návaznosti na jejich stav vývoje a problémy, kterým čelí před svým nasazením. Je zmíněna elektrárna APR1400 se svými systémy pro zmírnění následků havárie. Model APR1400 je využit k posouzení vlivu pokročilých materiálů pokrytí při těžké havárii. Stručně jsou představeny možnosti a schopnosti kódu MELCOR, který je schopen simulovat danou problematiku těžkých havárií. Je popsána implementace pokročilých materiálů pokrytí do programu MELCOR, společně se simulovanými scénáři. Na závěr jsou diskutovány výsledky získané ze simulací.
Project of nuclear power unit secure emergency power supply for design basis accident as well as for extension conditions
Žák, Tomáš ; Šťastný, Jiří (referee) ; Katovský, Karel (advisor)
The present Master´s thesis aims at designing an evolutionary scheme of secured power supply at nuclear power plants with VVER 440 reactors during design basis accidents as well as design extension conditions. In the first part of this thesis, concepts relating to the defence in depth of nuclear reactors, operating modes of the blocks as well as types and possibilities of electrical power supply and electric circuits of the block are defined. Although the present thesis deals with PWR 440 in general, special emphasis is put on the Czech NPP in Dukovany, where there are four PWR 440 reactors in operation, and on the possibilities for enhancing the defence in depth in this area. The second part of the thesis deals with the difference in station blackout definitions before and after Fukushima; not only the differences in situation evaluation are dealt with, but a solution is also proposed to make the system of secured power supply system during design basis accidents as well as design extension conditions more robust. This option has been selected out of a number of possibilities based on the evaluation of reliability, availability and cost-effectiveness of the proposal.
Severe accidents of third generation pressurized water reactors
Nečas, Karel ; Foral, Štěpán (referee) ; Černý, Tomáš (advisor)
The bachelor thesis focuses on the development of global nuclear energy. It clearly describes the development and division of nuclear facilities used for electricity production. The theoretical part of the thesis describes the division of nuclear facilities according to the development generations, the types are discussed in terms of technology and principle of operation. The operating conditions of nuclear reactors are described in detail, with emphasis on emergency conditions. The next part of the thesis focuses on the LOCA accident type for third generation pressurized water reactors. This thesis also includes an analysis of different approaches od the computation codes used for modelling various conditions of the nuclear power plants. The practical part of the bachelor thesis describes nuclear reactor APR1400. It provides its elementary parameters. The calculation code MELCOR was used for modelling this type of the nuclear reactor. The sensitivity analysis of the severe accident was performed using selected parameters. This analysis describes the influence of these parameters on the hydrogen production, the process of damaging of the active zone, and the reactor vessel melting time.
Project of nuclear power unit secure emergency power supply for design basis accident as well as for extension conditions
Žák, Tomáš ; Šťastný, Jiří (referee) ; Katovský, Karel (advisor)
The present Master´s thesis aims at designing an evolutionary scheme of secured power supply at nuclear power plants with VVER 440 reactors during design basis accidents as well as design extension conditions. In the first part of this thesis, concepts relating to the defence in depth of nuclear reactors, operating modes of the blocks as well as types and possibilities of electrical power supply and electric circuits of the block are defined. Although the present thesis deals with PWR 440 in general, special emphasis is put on the Czech NPP in Dukovany, where there are four PWR 440 reactors in operation, and on the possibilities for enhancing the defence in depth in this area. The second part of the thesis deals with the difference in station blackout definitions before and after Fukushima; not only the differences in situation evaluation are dealt with, but a solution is also proposed to make the system of secured power supply system during design basis accidents as well as design extension conditions more robust. This option has been selected out of a number of possibilities based on the evaluation of reliability, availability and cost-effectiveness of the proposal.

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