Nuclear Analysis of Blanket/Shield Design for D-D Tokamak Fusion Reactor

A study is made of the nuclear characteristics of blanket/shield design intended for the D-D tokamak reactor incorporating a cooperative effort by the University of Illinois, Brookhaven National Laboratory and Lawrence Livermore Laboratory. The reactor is characterized by high value of plasma beta (β=0.3) and low value of neutron wall loading (W n =0.436 MW/m 2 ). The 1 m-thick blanket is composed mainly of graphite, and the 1 m-thick shield is a combination of B 4 C, Al and H 2 O. Multi-dimensional calculations are carried out to confirm the results of one-dimensional calculation and to assess the problems inherent in the design. Compared to blankets constituted of other materials, the graphite blanket possesses the characteristics of much smaller residual radioactivity, afterheat and biological hazard potential, which could possibly more than offset the lower nuclear heating that can be provided. The design requirements for the magnet shield are satisfied by the present combination and thicknesses of blanket/shield materials.