THE CONCEPTUAL DESIGN OF THE DOUBLE-PIN TYPE BLANKET WITH HOLLOW CERAMIC BREEDER PELLETS FOR FUSION EXPERIMENTAL REACTORS

Several ceramic breeder blanket concepts for fusion experimental react ors have been proposed. Satisfying the allowable temperature ranges of each material and enhancing the tritium breeding ratio (TBR) are indi spensable to development of any blanket concept. The present paper pro poses a ceramic breeder blanket concept which realizes these points. L ithium zirconate (Li2ZrO3) is adopted as the breeder along with double -cladding pins having hollow pellets. The pellets are placed in the co -axial center tubes, while beryllium pebbles fill the outer tubes and serve not only as a neutron multiplier but also as a thermal barrier b etween the breeder and coolant, which flows outside the pins. The pins can be shortened and straightened by setting them in the toroidal dir ection. Hollow pellets are used to unify the radii of the outer clad, and to reduce the volume fraction of stainless steel by making baffle plates unnecessary between the pin rows. The optimum ratio of the Li2Z rO3 volume fraction to the beryllium plus Li2ZrO3 one is investigated to maximize the TBR, and the pin radii and pin arrangement are determi ned. The proposed blanket concert is seen to satisfy the temperature r anges and enhance the local TBR to 1.3.