High efficient power generation by HTGRs, (1). Power generation by high-temperature helium-gas turbine cycle

The development of High-Temperature Gas-cooled Reactors (HTGRs) has a long history, and originated from the Dragon Project in 1959. After the achievement of the Dragon Reactor's criticality in 1964, the Fort-Saint Vrain Reactor in the U.S. and the THTR-300 in Germany were constructed and successfully operated. In Japan the High-Temperature engineering Test Reactor (HTTR) with a thermal output of 30MW is now under construction. Its main objectives are : fundamental or basic studies for high-temperature engineering, development for future HTGR's technology, and research on heat application to industrial purposes. In addition to this widely envisaged use of high-temperature heat, HTGRs with excellent safety and easy operation features have a possibility of obtaining higher thermal efficiency, because of its high outlet temperature. In this sense, an HTGR system with a high-temperature helium-gas turbine is most promising. The maximum thermal efficiency of this system under the same operational condition of HTTR is expected to be about 45% or more. (author)