National Repository of Grey Literature 14 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Experimental Investigation of Accelerator Driven Nuclear Reactors for Thorium Based Nuclear Power
Zeman, Miroslav ; ČR,, Milan Štefánik, UJF AV (referee) ; Katovský, Karel (advisor)
The Master Thesis deals with the use of thorium nuclear fuel in accelerator driven systems. Basic principle of ADS, present situation and future possibilities are described in this work. The main goal of the work is determination of neutron flux in spallation target QUINTA. In December 2013, an experiment was performed at Joint Institute for Nuclear Research, Dubna. Samples of cobalt, situated at different positions in QUINTA target, were irradiated in secondary neutron field generated by deuteron beam of energies 2 AGeV and 4 AGeV and beam of C-12 with energy 2 AGeV. The samples were measured with the use of germanium semiconductor detectors and analysed using gamma-ray spectrometry. Reaction rates of Co-59 products were determined. Neutron flux was determined in setup QUINTA on the base of experimental reaction rates. Experimental reaction rates were compared with calcula1tion of MCNPX code.
Simulation of Accelerator Driven Nuclear Reactor for Spent Nuclear Fuel Transmutation
Jarchovský, Petr ; Ing. Antonín Krása, Ph.D., SCK.CEN Mol (referee) ; Katovský, Karel (advisor)
This master’s thesis deals with usage of burn-up (spent) nuclear fuel in nuclear power plants of next generation – accelerator driven transmutation plants which is produced in current nuclear power plants. This system could significantly reduce the volume of dangerous long-lived radioisotopes and moreover they would be able to take advantage of its great energy potential due to fast neutron spectrum. In the introduction are listed basic knowledge and aspects of spent nuclear fuel along with its reprocessing and the possibility of further use while minimizing environmental impact. As another point detailed description of accelerator driven systems is described together with its basic components. In addition this search is followed by individual chronological enumeration of projects of global significance concerning their current development. Emphasis is placed on SAD and MYRRHA projects, which are used like base for calculations. This last, computational part, deals with the creation of the geometry of subcritical transmutation reactor driven by accelerator and subsequent evaluation which assembly is the most effective for transmutation and energy purposes along with changing of target, nuclear fuel and coolant/moderator.
Investigation of Thorium Utilization in Accelerator Driven Nuclear Reactors
Král, Dušan ; ČR, Petr Chudoba, ÚJF AV (referee) ; Zeman, Miroslav (advisor)
This thesis deals with the idea of using accelerator driven systems for thorium transmutation into the fissile material, which can be utilized in the accelerator driven systems and in thermal nuclear reactors. Thorium occurs on Earth only in fertile isotope Th-232. It can be converted to fissile U-233 by neutron capture and subsequent beta decay. The experimental part handles the data measured by the irradiation of four thorium samples by the secondary neutrons in the QUINTA spallation target, which was irradiated with 660~MeV protons. Reaction rates for the fission and spallation products were estimated using gamma spectroscopy and activation techniques. Furthermore, Pa-233 production rates were also determined in all experimental samples. Pa-233 and fission production rates were calculated in all experimental samples using the MCNPX transport code and evaluated nuclear data for high-energy reactions. The experimental results are of a great importance for the future investigation of thorium in the accelerator driven system concept, validation of Monte-Carlo based calculation codes and validation of high-energy nuclear models.
The temperature field analysis of the subcritical accelerator-driven reactors
Majer, Šimon ; Šťastný, Ondřej (referee) ; Svoboda, Josef (advisor)
The aim of the bachelor thesis is to discuss the problems of accelerator driven system, to describe the possibilities of temperature measurement, to create model of the spallation target QUINTA target in the program Inventor and to perform the simulation by using the Ansys software. The theoretical part is focused on nuclear energy and its potential for the future and continues smoothly to the issue of accelerator driven system (ADS), where it discusses the possibilities of using mentioned system. The thesis is processed from the point of view of electrical energy, focusing on generation issues and the possibility of heat monitoring. The possibilities of temperature measurement are discussed here for calculation and simulation of heat transfer. The practical part of the bachelor’s thesis is processed with the help of the Joint Institute for Nuclear Research in Dubna, where the ADS research is in process. The input data and the size of the geometry were provided by the JINR research team and were used to simulate heat transfer by using the Ansys program. The results of the simulation are processed graphically in the last chapter of the bachelor thesis.
Use of activation detectors for neutron field measurement in models of ADTS
Chudoba, Petr
Accelerator driven transmutation systems could be a solution to the problem with long-lived nuclear waste and opening the way to thorium fuel cycle. Due to intensive neutron source based on spallation reaction are these systems very litle dependent on the arrangement of the core and fuel quality. These systems can transmute the spent fuel, eventually 232Th or 238U without affecting maintenance of fission reaction. Additionally subcritical blanket ensures high safety. For these systems it is necessary to know the cross sections of reactions of fast neutrons produced in the spallation reaction with different materials. This data is necessary not only for the selection of appropriate construction materials, but also for creation of programs simulating accelerator driven transmutation systems. This thesis is focused on the experimental determination of cross sections of reactions 89Y(n,2n)88Y and 89Y(n,3n)87Y with neutron energies from 17,6 to 33,6 MeV. Yttrium is analyzed for its (n,xn) threshold reactions, which makes it appropriet activation detector for study of the neutron fields in model configurations of accelerator driven transmutation systems. The obtained cross sections are unique, in that so far there are no experimental data for used neutron energies. Powered by TCPDF (www.tcpdf.org)
Cross-Sections Of Nuclear Isomers In The Interaction Of Protons On Thin Thorium Target
Golomb, Robert
The paper shows the results of experimental gamma spectra obtained with thorium 232Th target, and an aluminum collector irradiation with protons at an energy JINR Synchrocyclotron 100 and 660 MeV. For Th232, identified 258 and 222 gamma lines that belong to 45 and 55 nuclides. For Al - 238, 330 lines and 81, 119 nuclides respectively. The cross sections of fragmentation of the 232Th and Al nuclei under the interaction of protons 100 and 660 MeV were determined. A comparison of the obtained cross sections of the reaction with theoretical calculations was made.
Use of activation detectors for neutron field measurement in models of ADTS
Chudoba, Petr
Accelerator driven transmutation systems could be a solution to the problem with long-lived nuclear waste and opening the way to thorium fuel cycle. Due to intensive neutron source based on spallation reaction are these systems very litle dependent on the arrangement of the core and fuel quality. These systems can transmute the spent fuel, eventually 232Th or 238U without affecting maintenance of fission reaction. Additionally subcritical blanket ensures high safety. For these systems it is necessary to know the cross sections of reactions of fast neutrons produced in the spallation reaction with different materials. This data is necessary not only for the selection of appropriate construction materials, but also for creation of programs simulating accelerator driven transmutation systems. This thesis is focused on the experimental determination of cross sections of reactions 89Y(n,2n)88Y and 89Y(n,3n)87Y with neutron energies from 17,6 to 33,6 MeV. Yttrium is analyzed for its (n,xn) threshold reactions, which makes it appropriet activation detector for study of the neutron fields in model configurations of accelerator driven transmutation systems. The obtained cross sections are unique, in that so far there are no experimental data for used neutron energies. Powered by TCPDF (www.tcpdf.org)
Use of activation detectors for neutron field measurement in models of ADTS
Chudoba, Petr ; Wagner, Vladimír (advisor) ; Krtička, Milan (referee)
Accelerator driven transmutation systems could be a solution to the problem with long-lived nuclear waste and opening the way to thorium fuel cycle. Due to intensive neutron source based on spallation reaction are these systems very litle dependent on the arrangement of the core and fuel quality. These systems can transmute the spent fuel, eventually 232Th or 238U without affecting maintenance of fission reaction. Additionally subcritical blanket ensures high safety. For these systems it is necessary to know the cross sections of reactions of fast neutrons produced in the spallation reaction with different materials. This data is necessary not only for the selection of appropriate construction materials, but also for creation of programs simulating accelerator driven transmutation systems. This thesis is focused on the experimental determination of cross sections of reactions 89Y(n,2n)88Y and 89Y(n,3n)87Y with neutron energies from 17,6 to 33,6 MeV. Yttrium is analyzed for its (n,xn) threshold reactions, which makes it appropriet activation detector for study of the neutron fields in model configurations of accelerator driven transmutation systems. The obtained cross sections are unique, in that so far there are no experimental data for used neutron energies.
The temperature field analysis of the subcritical accelerator-driven reactors
Majer, Šimon ; Šťastný, Ondřej (referee) ; Svoboda, Josef (advisor)
The aim of the bachelor thesis is to discuss the problems of accelerator driven system, to describe the possibilities of temperature measurement, to create model of the spallation target QUINTA target in the program Inventor and to perform the simulation by using the Ansys software. The theoretical part is focused on nuclear energy and its potential for the future and continues smoothly to the issue of accelerator driven system (ADS), where it discusses the possibilities of using mentioned system. The thesis is processed from the point of view of electrical energy, focusing on generation issues and the possibility of heat monitoring. The possibilities of temperature measurement are discussed here for calculation and simulation of heat transfer. The practical part of the bachelor’s thesis is processed with the help of the Joint Institute for Nuclear Research in Dubna, where the ADS research is in process. The input data and the size of the geometry were provided by the JINR research team and were used to simulate heat transfer by using the Ansys program. The results of the simulation are processed graphically in the last chapter of the bachelor thesis.
Investigation of Thorium Utilization in Accelerator Driven Nuclear Reactors
Král, Dušan ; ČR, Petr Chudoba, ÚJF AV (referee) ; Zeman, Miroslav (advisor)
This thesis deals with the idea of using accelerator driven systems for thorium transmutation into the fissile material, which can be utilized in the accelerator driven systems and in thermal nuclear reactors. Thorium occurs on Earth only in fertile isotope Th-232. It can be converted to fissile U-233 by neutron capture and subsequent beta decay. The experimental part handles the data measured by the irradiation of four thorium samples by the secondary neutrons in the QUINTA spallation target, which was irradiated with 660~MeV protons. Reaction rates for the fission and spallation products were estimated using gamma spectroscopy and activation techniques. Furthermore, Pa-233 production rates were also determined in all experimental samples. Pa-233 and fission production rates were calculated in all experimental samples using the MCNPX transport code and evaluated nuclear data for high-energy reactions. The experimental results are of a great importance for the future investigation of thorium in the accelerator driven system concept, validation of Monte-Carlo based calculation codes and validation of high-energy nuclear models.

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