High-Temperature Gas Reactors is the fifth volume in the JSME Series on Thermal and Nuclear Power Generation. Series Editor Yasuo Koizumi and his Volume editors Tetsuaki Takeda and Yoshiyuki Inagaki present the latest research on High-Temperature Gas Reactor (HTGR) development and utilization, beginning with an analysis of the history of HTGRs. A detailed analysis of HTGR design features, including reactor core design, cooling tower design, pressure vessel design, I&C factors and safety design, provides readers with a solid understanding of how to develop efficient and safe HTGR within a nuclear power plant. The authors combine their knowledge to present a guide on the safety of HTGRs throughout the entire reactor system, drawing on their unique experience to pass on lessons learned and best practices to support professionals and researchers in their design and operation of these advanced reactor types. Case studies of critical testing carried out by the authors provide the reader with firsthand information on how to conduct tests safely and effectively and an understanding of which responses are required in unexpected incidents to achieve their research objectives. An analysis of technologies and systems in development and testing stages offer the reader a look to the future of HTGRs and help to direct and inform their further research in heat transfer, fluid-dynamics, fuel options and advanced reactor facility selection. This volume is of interest for nuclear and thermal energy engineers and researchers focusing on HTGRs, HTGR plant designers and operators, regulators, post graduate students of nuclear engineering, national labs, government officials and agencies in power and energy policy and regulations.