Embodiments of the present disclosure provide a cooling structure for a stationary blade. The cooling structure can include: an airfoil having a cooling circuit therein; an endwall coupled to a radial end of the airfoil; a chamber positioned within the endwall for receiving a cooling fluid from the cooling circuit, wherein the cooling fluid absorbs heat from the endwall, and a temperature of the cooling fluid in an upstream region is lower than a temperature of the cooling fluid in a downstream region; a first passage within the endwall fluidly connecting the upstream region of the chamber to a wheel space positioned between the endwall and the turbine wheel; and a second passage within the endwall fluidly connecting the downstream region of the chamber to the wheel space.