Study of space-dependent fast-neutron spectra and tritium breeding ratio in different assemblies of Li, Li and natural Li

Using diffusion theory and the eigenfunction expansion method, a detailed space-dependent study of fast neutron spectra has been carried out in ⁷Li, ⁶Li and natural Li assemblies of dimensions 100 × 60 × 60 cm³ and 30 × 60 × 60 cm³. Values of total (space-averaged) tritium breeding ratio (TBR) have been obtained for these assemblies. BARC-892, a 27-group data-set was used for these calculations.

The results of TBR for the smaller assembly have been compared with the corresponding experimental and calculated values of Takahashi et al. (1984). We find that the present values of TBR are in reasonably good agreement with the above experimental results.