Reactor charge machine fuel grab lifting mechanism - is hydraulic ram giving reduced height and weight

摘要

A lifting mechanism for the grab of a nuclear reactor charge machine for handling fuel elements or control rods comprises a hydraulic piston-cylinder unit with piston rod. one or other moving component (cylinder or piston rod) engages into the hollow top of the grab by a coupling device, while the other component is mounted on a support attached to the charge machine carriage. In the preferred arrangement, the piston rod is connected to the charge machine support member by a two directional pivoting hinge, and comprises a duct for fluid communicating with the space inside the cylinder and outside the piston rod; the lower end of the cylinder is connected by a two directional hinge to the grab. The preferred hydraulic fluid is water. This water pref. circulates in a closed system consisting of the cylinder space, the duct through the cylinder rod, a connecting line and a displacement chamber of the piston-cylinder type, in which the piston is itself actuated by a different pressure fluid on the opposite side. As compared with a hoisting mechanism comprising cables pulleys etc., the hydraulic arrangement results in a more compact system, a lower centre of gravity, reduced weight and smaller space requirement. It is not possible for contaminated water from the reactor to drip onto the platform of the charge machine.