Conceptual designs of tokamak fusion reactors

Tokamak fusion reactor design studies conducted in JAERI with support from national laboratories, universities and industries in the fifteen years since 1973 to the present are described. These studies gave considerable impact on the national and international fusion programs. From the proposal of He-cooled Li2O blanket for fusion power reactor in 1973 to the most recent proposal of easily replaceable guard limiter concept to the ITER project, a number of unique proposals that have influenced the world wide fusion reactor design studies are introduced. They are described in the context of major fusion reactor design efforts and design methodology developments of the past fifteen years. (author)