The omni-directional planetary wheel type mobile robot (KAEROT/ml) has been developed on the concepts of the modularity, reliability, and stability. Manipulator system is designed in order to be able to install on mobile system and to upgrade operating capability. Control system consists of 68030 processor board, servo motor controller and I/O board. The 6 DOFs hydraulic manipulator is designed for nozzle dam installation and removal. The reachable length of manipulator is 1.7 m with the wrist configuration of pitch-yaw-roll. For the easy installation of manipulator from outside steam generator, specially designed guider is considered. Also master manipulator is designed for force feedback control. RCP (Remote Control Part) is constructed with Sparc processor boards and servo control boards. Graphic simulation has done for the evaluation of manipulator performance of nozzle dam works. (Author).