Impeller rotor seal runner with anti-rotation feature

An apparatus for an aircraft powerplant, comprising:

• an impeller rotor configured to rotate about an axis, the impeller rotor including a plurality of fluid circuits arranged circumferentially about the axis within the impeller rotor, and each of the plurality of fluid circuits including a first outlet passage, a second outlet passage and an inlet passage fluidly coupled to the first outlet passage and the second outlet passage in parallel;
• and
• a seal runner mechanically fastened to the impeller rotor, the seal runner including a bore, a plurality of ports, a sidewall and a protrusion, each of the plurality of ports extending radially through the sidewall, each of the plurality of ports fluidly coupling the first outlet passage of at least one of the plurality of fluid circuits to the bore, the sidewall extending axially along, circumscribing and forming a radial outer peripheral boundary of the bore, and the protrusion projecting radially out from the sidewall and into a recess in the impeller rotor;
• wherein the protrusion is configured to plug axially into the recess during assembly of the seal runner with the impeller rotor, and an interface between the protrusion and the impeller rotor rotationally fixes the seal runner to the impeller rotor.