Investigation of radiation damage in structural material of APEX reactor by using Monte Carlo method

► In this study was calculated effects of the radiation damage on the selected fluid rates and thicknesses of liquid second wall. ► MCNPX-2.5.0 Monte Carlo code was used for three-dimensional calculations. ► The heavy metal was found as appropriate 10% ThF4 for DPA and 10% UO2 for gas production. ► DPA in the structural material was calculated as appropriate for 40-50 cm thickness of the liquid second wall.