Technical considerations on tritium breeding blanket systems for a fusion power reactor

Design studies of five candidate tritium breeding blankets for a fusion power reactor have been performed. The concept of a breeder outside of the coolant tubes (BOCT) was adopted for Li 2 O blankets in which the breeder is indirectly cooled by water or helium. For LiAlO 2 , a breeder inside the coolant tubes (BICT) concept was adopted on the basis of the chemical stability of LiAlO 2 . In this blanket the breeder is directly cooled by helium coolant. These solid breeders are fabricated in the form of small spheres to prevent thermal cracking and to ease in filling them in the blanket. A liquid lithium breeder employs a self-cooling concept and also a BOCT concept with helium indirect cooling of stagnant liquid lithium. In addition to evaluations of each blanket performance, technological problems and R&D issues for power reactor blanket development have been also identified.