Position:     Assistant Professor
Degree:       Ph.D.
Laboratory: Energy and Environmental Materials
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Evaluation of the Physical Properties of Severe Accident Products

Ensuring preparedness for severe accidents in nuclear power plants is a critical aspect of safety. Both light water reactors and fast reactors are expected to produce specific chemical species depending on the accident scenario. However, the formation mechanisms and physical properties of many of these reaction products remain unclear, posing challenges to the development of effective countermeasures. To address this issue, our research conducts a comprehensive investigation—from the identification of possible reaction products to the synthesis of simulated materials and the measurement of their physical properties. Through this work, we aim to generate fundamental data that will contribute to enhancing the safety of nuclear power systems.

Characterization of Materials at High Temperatures

Measuring the physical properties of materials at high temperatures is essential for understanding material fabrication processes and degradation behavior. However, due to the limitation that both the sample and measurement equipment may react or melt in high-temperature environments, conducting tests is challenging, and there is a lack of data in this area. To obtain precise data even in such conditions, we employ non-contact heating methods, such as lasers, and innovative container designs, alongside techniques to minimize reaction effects by shortening measurement times as much as possible. Our goal is to better understand the changes occurring in materials at high temperatures.

Publications

1. Toshiki Kondo, Taro Toda, Junichi Takeuchi, Florian Kargl, Hiroaki Muta and Yuji Ohishi. “Thermophysical properties of molten (Fe₂O₃)_0.95-(SiO₂)_0.05 measured by aerodynamic levitation”, High temp. – High press., Old city publishing, 52, 3-4, pp 307-321 (2023).
2. Toshiki Kondo, Hiroaki Muta, Ken Kurosaki, Florian Kargl, Akifumi Yamaji, Masahiro Furuya, and Yuji Ohishi. “Density and viscosity of liquid ZrO₂ measured by aerodynamic levitation technique”, Heliyon, ELSEVIER, 5, 7 (2019).
3. Toshiki Kondo, Yuji Ohishi, Hiroaki Muta, Ken Kurosaki, and Shinsuke Yamanaka. “Thermal conductivity and electrical resistivity of liquid Ag–In alloy”, J. Nucl. Sci. Tech., Taylor & Francis, 55, 5, pp 568-574 (2018).