System for controlling thrust in steam turbine

A system (102) controls net thrust of a steam turbine system (90) having a stepped rotating shaft (98). A first leak off line (120) fluidly couples a first stage (122) of a turbine section to a packing (112) upstream of a stepped portion (110) on the rotating shaft (98). A second leak off line (130) fluidly couples a second stage (132) of the turbine section that is subsequent to the first stage (122) to a step area (134) upstream of the stepped portion (110), and a connection line (140) fluidly couples the first leak off line (120) to the second leak off line (130). The lines include control valves such that a controller (150) can actively control the net thrust by regulating thrust pressure on the stepped portion (110) using steam from the first and second stages of the turbine section. The controller (150) may also prevent damage to an active retractable seal (114) using the control valves.