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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.
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Small-punch test of structural steels at low temperatures
Němčíková, Eva ; Hůlka, Jiří (referee) ; Hadraba, Hynek (advisor)
Diploma thesis is focused on comparison of small punch test results and tensile test results. For experiments were chosen steel P91, 10Ch2MFA, 20CrNi2MoV, 11 416 and 42 2707. These steel are used in nuclear power engineering, or they were developed for this purpose. Basic mechanical characteristics, namely ultimate tensile stress and yield stress, were evaluated from small punch test records of observed materials. This is done via convenient correlation relationships. Obtained values were compared with values obtained by conventional tensile tests. There are mentioned own suggested correlation relationships and comparison of temperature curves gained from small punch test and tensile test in the thesis. Assessment of microstructure of observed materials and analysis of fracture surfaces was provided as well. It was found out, that for assessing basic mechanical characteristics (ultimate tensile stress and yield stress) is the best to suggest own correlation relationships, instead of using universal relationships from literature. The fracture mechanism of all types of assessed steel was ductile in entire temperature range (up to -40 °C).
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Small Punch Test - assessment of the possibilities of the methodology and its limitations
Závodský, Peter ; Němec, Karel (referee) ; Válka, Libor (advisor)
The Bachelor’s thesis is aimed to sum up and consider actual state of knowledge about a relatively new method used for testing materials called Small Punch Test. There are pros and cons of the method with troubles at the application process stated in the thesis. We can read something about the basic idea of small punch testing. A big effort was spent to sort many types of tests according to used configurations of testing machines and another testing parameters. There are stated techniques used for determination some basic material properties from small punch testing also with methods of correlation to results obtained from standard material tests in the thesis.
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Data processing from fibre optic temperature sensors
Carboch, David ; Tomašov, Adrián (referee) ; Dejdar, Petr (advisor)
The bachelor thesis is dealing with fiber optic sensor systems, their division and properties. Furthermore, the thesis discusses the possibilities of fiber optic measurements in the nuclear power environment. Then the thesis contains possible methods of temperature measurement and their comparison. The thesis deals with the design of the sensing probe. Through the probe, the mechanical resistance of the sensing fiber and the handling of the sensing fiber have been improved. Furthermore, the thesis deals with the creation of an interactive chart of the relative temperature of a nuclear reactor in real time. In the chart, the dependence of reactor temperature change on reactor power and air temperature change can be observed. The measured results can be exported from the chart.
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Small-punch test of structural steels at low temperatures
Němčíková, Eva ; Hůlka, Jiří (referee) ; Hadraba, Hynek (advisor)
Diploma thesis is focused on comparison of small punch test results and tensile test results. For experiments were chosen steel P91, 10Ch2MFA, 20CrNi2MoV, 11 416 and 42 2707. These steel are used in nuclear power engineering, or they were developed for this purpose. Basic mechanical characteristics, namely ultimate tensile stress and yield stress, were evaluated from small punch test records of observed materials. This is done via convenient correlation relationships. Obtained values were compared with values obtained by conventional tensile tests. There are mentioned own suggested correlation relationships and comparison of temperature curves gained from small punch test and tensile test in the thesis. Assessment of microstructure of observed materials and analysis of fracture surfaces was provided as well. It was found out, that for assessing basic mechanical characteristics (ultimate tensile stress and yield stress) is the best to suggest own correlation relationships, instead of using universal relationships from literature. The fracture mechanism of all types of assessed steel was ductile in entire temperature range (up to -40 °C).
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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.
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|
|
Small Punch Test - assessment of the possibilities of the methodology and its limitations
Závodský, Peter ; Němec, Karel (referee) ; Válka, Libor (advisor)
The Bachelor’s thesis is aimed to sum up and consider actual state of knowledge about a relatively new method used for testing materials called Small Punch Test. There are pros and cons of the method with troubles at the application process stated in the thesis. We can read something about the basic idea of small punch testing. A big effort was spent to sort many types of tests according to used configurations of testing machines and another testing parameters. There are stated techniques used for determination some basic material properties from small punch testing also with methods of correlation to results obtained from standard material tests in the thesis.
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