A disposable blood separation set and a centrifugal blood processing system comprising a blood processing chamber adapted to be mounted on a rotor of a centrifuge； a frustro-conical cell separation chamber in fluid communication with the processing chamber, the cell separation chamber having an inlet, and outlet and a side tap outlet adjacent the inlet. The inlet may protrude into the cell separation chamber forming a circumferential well surrounding the protruding inlet. The side tap outlet may connect to the well. The set and system comprise means for selectively drawing fluid from either the outlet or the side tap outlet.
