The CFAR (compact fusion advanced Rankine) cycle concept for an advanced tokamak reactor consists of a high temperature blanket cooled by evaporating mercury, microwave superheaters and magnetohydrodynamic generators for direct electric power generation. The vanadium alloy blanket is designed to minimize the MHD pressure losses in the front section where the mercury is evaporating. A passive concept for condensing the mercury vapor in the event of a LOCA (loss of coolant accident) is described. It is shown that an active cooling system is required to keep the vanadium alloy structure and the front part of the blanket at acceptable temperatures during cool-down after a LOCA.