Water-cooled solid breeding blanket design for DEMO

Tobita, Kenji; Saito, Ai*; Nishio, Satoshi; Enoeda, Mikio; Tanigawa, Hisashi; Sato, Satoshi; Tsuru, Daigo; Hirose, Takanori; Seki, Yohji; Yamada, Masao*

Self-sufficiency of tritium fuel is an indispensable requirement in a fusion reactor. In this sense, the blanket design ensuring the self-sufficiency of fuel should be considered with importance and higher priority in fusion reactor design. Generally speaking, however, it is difficult to envisage a self-consistent blanket design satisfying various requirements such as robustness to an enormous electromagnetic forces and excellent heat removal performance other than fuel self-sufficiency with matured candidate materials. This paper presents a concept study on torus configuration with water-cooled solid breeder blanket satisfying these functions. The result indicates that (1) the conducting shell should be arranged at the position of r/a =1.34 or farther, and (2) when blanket is installed behind the divertor, the increment of tritium breeding ratio is as low as 0.01-0.02. In addition, promising blanket concepts in the presently studied DEMO reactor are proposed.