In this study the thermal-hydraulic analysis of the SCWR reactor with a new geometric design is discussed. In the new design, coolant and moderator circuits are separated and nanofluid has been used as coolant of the reactor core. In the performed sub-channel analysis, the conservation equations of mass, momentum and energy are solved numerically. Since in the new geometry the coolant and moderator circuits are separated, compared to previous plans, using the nanofluids with higher mass fraction of nanoparticles is applicable. In this article, the thermal-hydraulic analysis is performed for various mass fractions of Al2O3 nanoparticle and moderator velocities. Calculations show that the core outlet temperature grows up with increasing nanoparticle mass fraction. As it was expected, by increasing the nanoparticle mass fraction the core pressure drop will be raised, but in the proposed design this pressure drop is much lower.