Component Design Considerations for Gas Turbine HTGR Power Plant

The gas turbine high-temperature gas-cooled reactor (HTGR) power plant combines the existing design HTGR core with a closed-cycle helium gas turbine power conversion system directly in the reactor primary circuit. The high density helium working fluid results in a very compact power conversion system. While the geometries of the helium turbomachinery, heat exchangers, and internal gas flow paths differ from air breathing gas turbines because of the nature of the working fluid and the high degree of pressurization, many of the aerodynamic, heat transfer and dynamic analytical procedures used in the design are identical to conventional open-cycle industrial gas turbine practice. This paper outlines some of the preliminary design considerations for the rotating machinery, heat exchangers, and other major primary system components for an integrated type of plant embodying multiple gas turbine loops. The high potential for further improvement in plant efficiency and capacity, for both advanced dry-cooled and waste heat power cycle versions of the direct-cycle nuclear gas turbine, is also discussed.