A turbine pump assembly includes a centrifugal pump including an inlet cavity with an inlet pressure, a control section having a turbine flow rate control spool valve, a shut off biasing mechanism located at a first end of the control section, and an inlet pressure piston located at a second end of the control section, and an inlet pressure fluid line fluidly connecting the inlet cavity with the inlet pressure piston. When the inlet pressure is above a predetermined threshold, the inlet pressure is configured to maintain the turbine flow rate control spool valve in an operational mode. When the inlet pressure is below the predetermined threshold, the shut off biasing mechanism is configured to apply a closing force to disable the turbine flow rate control spool valve thereby reducing a speed of a turbine of the turbine pump assembly.