Abstract
Tokamak reactor system analysis code has been developed at KAERI (Korea Atomic Energy Research Institute) and it is used for the development of concept of DEMO reactor. The system code finds the design parameters which satisfies the plasma physics and engineering constraints or optimizes the design depending on the given figure of merits. Prospect in development of plasma physics and technology are included in the simple mathematical model, i.e., the overall plant power balance equation and the plasma power balance equation. The system analysis provides satisfactory results to select the operational region of a DEMO reactor concept, although the zero-dimensional model cannot precisely consider profile effects such as heating and current drive profile, bootstrap current fraction, advanced tokamak operation with negative shear, and so on. The parameters arising from the system studies will be used as a basis for further development of DEMO reactor concept and to identify necessary R&D areas, both in physics and technology for realization of the concept. As an application of the tokamak reactor system code, we investigate the performance of DEMO reactor in terms of the plasma physics and technology with main requirements for DEMO reactor selected as: 1) to demonstrate tritium self-sufficiency, 2) to generate net electricity, and 3) for steady-state operation. It is shown that to access operation space for high performance, main restrictions are given by the divertor heat load and the steady-state operation requirements. Developments in both plasma physics and technology are required to handle high heat load and to increase the current drive efficiency.