[en] The report consists of eight chapters. The first chapter outlines studies on high-temperature engineering testing methods which were carried out in the Japan Atomic Energy Research Institute, and studies for development of high-temperature gas furnace conducted in overseas countries. The second chapter deals with design of furnaces to be used for research on high-temperature engineering testing. The third chapter addresses studies on fuels and graphite material. The fourth chapter outlines studies on metallic materials including heat-resistant alloys and pressure-resistant low-alloy steel. The fifth chapter addresses furnace engineering studies dealing with furnace physics, reactor monitoring, reactor control, FP deposition and heat engineering. The sixth chapter describes tests and studies of equipment and structures used at high temperatures. In particular, the chapter addresses demonstration tests of large equipment, and high-temperature structure engineering. The seventh chapter deals with high-temperature irradiation techniques and after irradiation testing techniques. The eighth chapter outlines studies on nuclear heat utilization systems. (N.K.)