A turbine of a gas turbine engine with a rotor and a stator forming a rim cavity, where the rotor includes a turbine rotor blade with a cooling air channel opening into the rim cavity, and a centrifugal impeller rotatably connected to the rotor in which the centrifugal impeller discharges pressurized cooling air into the rim cavity to improve the rim cavity seal and to supply pressurized cooling air to the rotor blade cooling air channel.