Design considerations for access to Tokamak fusion reactors

Abstract

A concept providing for access to the outside of a Tokamak fusion reactor to perform contact maintenance and for access to the interior of the reactor using locally controlled reactor-mounted remote handling machines is presented. By heavily shielding the reactor blanket and field-shaping coils, the activation of the toroidal field coils and other external components can be limited to acceptable doses. The use of low activity shielding materials, such as lead and boron carbide, result in minimal shield activity. An in-chamber remote handling machine for removing and replacing the linear and blanket modules is provided. Additional remote handling machines mounted on the outside of the reactor are conceived for gaining access to the field-shaping coils and outside of the blanket and to the poloidal bore. A preliminary assessment of the savings in the down time through the use of the proposed concept is made, and the potential impact of these savings identified.