A cost minimized tokamak reactor using conservative coils/cooling technology

One attractive concept for future commercial reactors is one of low cost with minimum advanced technology. Cost-minimized reactors with different operating modes are compared to reveal the most cost-minimized reactor with impact of deign parameters on the cost of electricity (COE). Three kinds of operating modes are considered; i.e. first stability region (FS), second stability region (SS) and reversed shear (RS). Deuterium-tritium fueled, 1000 MW(e) reactors with conventional aspect ratio are assumed. Several criteria for the parameter survey are used; for example, (1) thermal-to-electricity conversion efficiency is assumed to be 34.5% with water as a coolant, (2) average neutron wall load must not exceed 5 MW m^-2 with a plasma major radius > 5 m, (3) 2 MeV neutral beam injector is applied. It is concluded that the RS operating mode is the most cost-minimized. The results indicated that attaining high β_N (the Troyon beta coefficient), low q₉₅ (safety-factor on the 95% flux surface), and high f_bs (fraction of bootstrap current) is the best way to obtain a cost-minimized reactor. This cost-minimized RS reactor is advantageous because it can be designed without using advanced coil technology nor an advanced cooling system.