Blanket concept of water-cooled lithium lead with beryllium for the SlimCS fusion DEMO reactor

Uto, Hiroyasu; Tobita, Kenji; Someya, Yoji; Takase, Haruhiko; Asakura, Nobuyuki

In this study, as an advanced option for SlimCS blanket, conceptual design study of water-cooled lithium lead (WCLL) blanket was performed. Compared with solid breeder, liquid lithium-lead (LiPb) breeder seems to have advantages of the sustainment of a design value of TBR independent of lithium burn-up and of a reduction of radioactive waste. However, in SlimCS, the net TBR supplied from WCLL blanket is not enough because the thickness of blanket in SlimCS is limited to 45 cm by conducting shell position for high beta access. Therefore, the beryllium (Be) pebble bed was adopted as additional multiplier. Considering of temperature of blanket materials, a double pipe structure was adopted. The Be pebble was separated by SiC/SiC composite tube, and was cooled by coolant on center. The local TBR of WCLL with Be blanket was similar to that of solid breeder blanket on the neutron wall load Pn = 5 MW/m. Several concepts on WCLL blanket and their engineering problems are presented.