An advanced conceptual tokamak fusion power reactor utilizing closed cycle helium gas turbines

Abstract

UWMAK-III is a conceptual Tokamak reactor designed to study the potential and the problems associated with an advanced version of Tokamaks as power reactors. Design choices have been made which represent reasonable extrapolations of present technology. The major features are the noncircular plasma cross section, the use of TZM, a molybdenum based alloy, as the primary structural material, and the incorporation of a closed-cycle helium gas turbine power conversion system. The blanket design is unique in that tritium breeding is accomplished in the liquid lithium coolant of the outer blanket only. The inner blanket zone nearest the torus centerline is a hot shield cooled with helium. The reactor is designed to generate 4735 MW(th) and 1985 MW(e) continuously. The reference design for the power conversion system was selected based on trade-off considerations and an examination of interface problems. Three loops with turbomachinery rated at 585 MW(e) have been incorporated and the helium inlet temperature is 1600°F (871°C). A conceptual design of the turbomachinery is given together with a preliminary heat exchanger analysis that results in relatively compact designs for the regenerator, precooler, and intercooler. This paper contains a general description of the UWMAK-III system and a discussion of those aspects of the reactor, such as the burn cycle, the blanket design, and the heat transfer analysis, which are required to form the basis for discussing the power conversion system. We concentrate on the power conversion system and include a parametric performance analysis, an interface and trade-off study and a description of the reference conceptual design of the closed-cycle helium gas turbine power conversion system.