Numerical simulations of liquid metal (LM) magnetohydrodynamic (MHD) flows in a prototypical dual coolant lead lithium (DCLL) blanket module have been performed under conditions relevant to a real LM blanket system, i.e. strong magnetic field of 5 T (Hartmann number Ha ∼ 104) and poloidal flow velocity of 0.1 m s−1 (Reynolds number Re ∼ 105). The proposed blanket model includes all essential sub-components of a real LM blanket: radial supply ducts, inlet and outlet manifolds, multiple poloidal ducts and a U-turn zone. The computations were performed using a DNS-like finite-volume code on a very fine mesh of ∼ 320 × 106 cells to accurately capture all flow features. Four cases have been simulated, including: Case 1 for electrically conducting walls, Case 4 for non-conducting walls, and Cases 2 and 3 with partial SiC FCIs electrical insulation of the blanket conduits using silicon carbide flow channel inserts placed at selected locations. In these four cases, the computed MHD flows were analyzed for: (1) MHD pressure drop, (2) flow distribution, (3) flows in particular blanket components, (4) 3D and flow development effects, and (5) unsteady flows. Many important conclusions have been made, regarding effectiveness of the FCI to reduce the MHD pressure drop, flow balancing in the parallel channels, characteristic flow patterns in all blanket sub-components, electromagnetic coupling between the flows, 3D MHD effects, flow development length, and unsteady effects. This study is limited to purely MHD flows. Next study will focus on a DCLL blanket with a volumetric heating.