Helium-Cooled Solid Breeder Blanket for ITER

This paper summarizes the latest results of a design study of a helium-cooled solid breeder blanket for ITER. Attractive features of this design include the following : 1) There is a significant design margin since only part of the allowable solid breeder temperature window needs to be used. 2) There is an expanding data base available from solid breeder experiments carried out internationally. 3) The solid breeder can be designed to operate at high reactor-relevant temperature, while the helium is kept at moderate temperature and pressure for safety and reliability. In addition, since helium is a gas, it can be run so as to optimize the structure temperature and accommodate long term power variation without incurring any substantial pressure penalty. 4) The use of helium, an inert gas minimizing any chemical reaction and corrosion, in combination with a low activation solid breeder, is a safety advantage. An extensive list of the blanket operating parameters is provided and key factors are discussed.