Canada is developing a next generation (Gen IV) reactor, the Canadian Super-Critical Water-cooled Reactor (SCWR), which has the potential of meeting all design goals of the Gen IV International Forum (GIF). These design goals include enhanced safety features (inherent safe operation and deploying passive safety features), improved economic and resource utilization (similar to 40% more efficient than current nuclear power generating stations, sustainable fuel cycle (will burn thorium, which is three times more abundant than uranium), enhanced sustainability, and greater proliferation resistance compared to the current fleets (i.e., Gen III and Gen III+) of reactors. The Canadian SCWR concept is a pressure-tube type reactor that uses supercritical water as a coolant, a separate low-pressure heavy water moderator, a high efficiency fuel channel that includes a zirconium alloy pressure and a ceramic zirconia insulator, and a direct steam power cycle. This paper presents the evolution of the Canadian SCWR core design, simplifications introduced in the design to deal with design challenges, and ongoing design activities.