DESIGN STUDIES ON NUCLEAR PROPERTIES ON THE FLIBE BLANKET FOR HELICAL-TYPE FUSION-REACTOR FFHR

The Force-Free Helical Reactor, FFHR, is a demo-relevant heliotron-typ e D-T fusion reactor. The blanket design for FFHR is improved in nucle ar properties by using a one-dimensional neutron transport calculation . Nuclear properties, including tritium breeding ratio (TBR), nuclear heating and induced radioactivity, are evaluated. From the viewpoints of TBR and nuclear heating, the breeding zone is divided into three la yers. The first layer consists of a 100% Flibe layer for cooling the f irst wall and efficient transfer of thermal energy. The second layer i s filled up with Be pebbles in order to increase the TBR and the inter active surface area for reducing the amount of corrosive TF (tritiated fluorine) molecules. The third layer is a 100% Flibe layer. In the im proved blanket, the local TBR is 1.2 and the energy deposited in the F libe is calculated as 55% of the total nuclear heating. The effect of nuclear transmutation on Li, Be, F is also discussed. (C) 1998 Elsevie r Science S.A. All rights reserved.