Analysis of critical development issues towards advanced tokamak power plant CREST

A development scenario of the tokamak reactor in three stages (i.e. the experimental reactor ITER, a demonstration reactor and a commercial reactor) has been recently discussed. In order to construct a feasible development strategy, it is necessary to evaluate which component of reactor technologies and to what extent should be developed. From the viewpoint of the future electric supplier, we have proposed the conceptual design of a commercial power plant, compact reversed shear tokamak (CREST), and a demonstration power plant, Demo-CREST. On the other hand, the project of the experimental reactor ITER is underway, and its experimental plan and R&D activities are almost completed. Hence, it is most important and reasonable to investigate the demonstration power plant on the track of ITER in order to show a specific development scenario of the tokamak reactor. In this report, we discuss the engineering aspect in the Demo-CREST design and analyse the critical development issues towards an advanced tokamak CREST. The power flow and power plant system for Demo-CREST are investigated for improvement in the thermal efficiency of a single device, and the development goals for each reactor component and for each development step are quantitatively analysed.