A turbine section comprises a rotor, blade and rim seal. The rotor comprises a rim defining an outer diameter surface, and a slot in the outer diameter surface. The blade comprises an airfoil, a platform surrounding the airfoil, a shank extending from the platform, a root extending from the shank for connecting to the slot, and a nub extending from the shank beneath the platform. The rim seal is disposed between the outer diameter surface and the nub. A method for cooling an outer diameter of a rotor disk comprises bleeding cooling air in a gas turbine engine, passing the flow of cooling air through a cover plate that retains a seal plate against the rotor disk, leaking the cooing air between a rotor disk rim and the seal plate, and guiding the cooling air across an outer diameter surface of the rotor disk rim utilizing a rim seal.