In this study, the effect of (n,gamma) reactions in spent fuel-grade (SFG)-PuO2, UO2, NpO2 and UCO contents was investigated in a designed hybrid reactor system. In this system, the molten salt-heavy metal mixtures 93-85 % Li20Sn80 + 5 % SFG-PuO2 and 2-10% UO2, 93-85 % Li20Sn80 + 5 % SFG-PuO2 and 2-10 % NpO2, 93-85 % Li20Sn80 + 5 % SFG-PuO2 and 2 10 % UCO were used as fluids. Beryllium (Be) is used as neutron multiplier by (n,2n) reactions. Thence, a Be zone with a width of 3 cm was used in order to contribute on fissile fuel breeding between the liquid first wall and blanket. (n,gamma) reactions were calculated in the liquid first wall, blanket and shield zones, which SFG-PuO2, UO2, NpO2 and UCO contents. 9Cr2WVTa ferritic steel with the width of 4 cm was used as the structural material. Three-dimensional nucleonic calculations were performed using the most recent version MCNPX-2.7.0 the Monte Carlo code and nuclear data library ENDF/B-VII.0.