2019-09-03 
Breslaujos g. 3, Kaunas. AK-202 kab. Author, Institution: Andrius Tidikas, Lithuanian Energy Institute
Dissertation title: Investigation of neutron transport and radioactive processes in Nuclear Fusion devices
Science area, field of science: Technological Sciences – Energy and Power Engineering, T006
Defense of the dissertation: 2019-09-03, 13:00, Lithuanian Energy Institute (Meeting Hall – AK-202 a.), Breslaujos st. 3, Kaunas, Lithuania.
Scientific Supervisor: – Dr. Gediminas Stankūnas (Lithuanian Energy Institute, Technological Sciences – Energetics and Power Engineering, T006)
Dissertation Defense Board of Energetics and Power Engineering Science Field:
- Chairperson – Prof. Dr. Habil. Eugenijus Ušpuras (Lithuanian Energy Institute, Technological Sciences – Energetics and Power Engineering, T006);
- Prof. Dr. Habil. Juozas Augutis (Vytautas Magnus University, Technological Sciences – Energetics and Power Engineering, T006);
- Dr. Artūras Plukis (Center for Physical Sciences and Technology, Nature Sciences – Physics, N002);
- Dr. Ion E. Stamatelatos (National Centre for Scientific Research “Demokritos” (Greece), Nature Sciences – Physics, N002);
- Dr. Egidijus Urbonavičius (Lithuanian Energy Institute, Technological Sciences – Energetics and Power Engineering, T006).
The doctoral dissertation is available on the internet and at the library of Kaunas University of Technology (K. Donelaičio st. 20, Kaunas) and Lithuanian Energy Institute (Breslaujos st. 3, Kaunas, Lithuania).
Annotation:
Increasing demand for sustainable energy source with low carbon emissions drives the research interest in nuclear fusion. During the operation of nuclear fusion device, structural and functional materials are exposed to tangible neutron irradiation. Neutron interactions with matter result not only in heat transfer but also in a significant material activation which leads to the production of radioactive nuclides. These radionuclides are the source of ionizing radiation and decay heat affecting nuclear fusion device operation, decommissioning and waste management. In this work neutron transport and material activation calculations were employed in order to assess the production of radionuclides in nuclear fusion devices suitable for electricity production.
Investigation of material activation was performed by combining calculation results for three nuclear fusion relevant research devices: Joint European Torus, Fusion Materials Irradiation Facility – Demo Oriented Neutron Source and Demonstration Power Station. Differences and dependences in activities, dose rates and decay heats due to different fusion reactions, irradiation scenarios, material compositions, volumetric vacuum vessel and fusion power changes were obtained with application of extended material activation calculation methodology. A novel sensitivity analysis based method was also suggested for neutron spectra evaluation. It is expected that this conducted research will result in betterment of nuclear fusion experimental and technological development.
- Summary of the dissertation (in Lithuanian)
- Dissertation