Tetsuaki Takeda has been a professor of Graduate Faculty of Interdisciplinary Research, Research Faculty of Engineering, Department of Mechanical Engineering, University of Yamanashi since 2008. He was graduated from Kobe University, majored in nuclear engineering in 1982, and received his doctoral degree at The University of Tokyo in 1997. He stayed at University of California Los Angeles (UCLA) as a visiting researcher from 1993 to 1994. He has transferred his field of academic goal from Japan Atomic Energy Agency to University of Yamanashi in 2008. His research field is the thermo-hydraulics related in not only nuclear energy but also renewable energy. During his service in JAEA, he performed the experiments and analyses of the safety studies regarding the VHTR systems and the nuclear hydrogen production systems developments. Afterward, he has also performed experiment and analysis regarding a ground source heat pump system, solar thermal collector system, heat utilization system using thermoelectric devices, and so on. He served Chairman of Power and Energy Systems Division of Japan Society of Mechanical Engineers (JSME). Yoshiyuki Inagaki is Researcher of Department of Hydrogen and Heat Application Research and Development, HTGR Research and Development Center, Oarai Research and Development Institute, Sector of Fast Reactor and Advanced Reactor Research and Development in JAEA. He received his PhD degree from Kyushu University in 1996. He started his research career at JAERI in 1981 for the HTGR technology such as reactor internals and high temperature components. He then worked in Juelich Research Center in Germany from 1994 to 1995 for a hydrogen production process. He also researched HTGR heat application systems such as hydrogen production and nuclear steelmaking systems and the system integration technology for safe connection between a reactor and a hydrogen production system.