[en] Calculations and analysis on the fusion-driven sub-critical system FDS have been performed. Neutronics calculations have been done with the multi-functional code VisualBUS1.0 and the data library HENDL1.0/MG to obtain the neutron spectra of different regions of the blanket of FDS-I. Then activation calculations of structural steel CLAM, tritium breeding material/coolant LiPb etc. and the impurities controlling level for CLAM and LiPb were carried out with the code FISPACT and the IAEA activation data library FENDL/A-2.0. (authors)