Neutronic investigation of the application of certain plutonium-mixed fluids in a fusion–fission hybrid reactor

Highlights: • We investigated the effect on nuclear parameters of spent fuel-grade Pu mixed with some fluids in the hybrid reactor system. • We used the MCNPX-2.7.0 Monte Carlo code for three-dimensional calculations. • It was found that neutron flux, heating, fission reaction rate had desirable values for 5% SFG-PuO2 in the fluid. - Abstract: In this study, the fluids that were investigated were contained increased mole fractions of the mixtures molten salt 99–95% Li20Sn80 and, the heavy metals 1–5% SFG-Pu, SFG-PuF4, SFG-PuO2. The fluids were used in the liquid first wall, blanket and shield zones of the designed hybrid reactor system. Beryllium (Be) zone with the width of 3 cm was used for the neutron multiplicity between liquid first wall and blanket. Four centimeter thick 9Cr2WVTa ferritic steel was used as the structural material. The nuclear parameters of a fusion–fission hybrid reactor such as neutron flux, heating, fission reaction rate were investigated according to the mixture components, radial energy spectrum in the designed system. In this study, the effect of spent fuel-grade Pu content in the designed system on these nuclear parameters were calculated by using the three-dimensional Monte Carlo code MCNPX-2.7.0 and nuclear data library ENDF/B-VII.0