Patent ID: 8666016

Claim:
A fuel exchange apparatus, comprising: a traveling carriage moving horizontally in one direction; a traversing carriage moving horizontally on said traveling carriage in a direction orthogonal to the one direction in which said traveling carriage moves; and a nuclear fuel holding unit attached to said traversing carriage, and including a telescopic tube having telescopic portions which extend and contract with respect to one another, a holding tool which holds a nuclear fuel assembly and which enables release of said held nuclear fuel assembly, and a lifter for raising and lowering said holding tool which holds and releases the nuclear fuel assembly by winding and running out linear members for suspending and supporting the holding tool from said traversing carriage; wherein said holding tool has a clamp mechanism that is selectively placed in a constrained state in which said holding tool is subject to a constraint by said clamp mechanism pressed on an inner surface of said telescopic tube and in a freely suspended state in which said holding tool is released from the constraint by said clamp mechanism which is kept away from the inner surface of said telescopic tube and is freely suspended by said linear members; wherein said clamp mechanism has at least one clamp body disposed in said holding tool, and a clamp driving apparatus for placing selectively said at least one clamp body in a pressed state, in which said at least one clamp body is pressed against the inner surface of said telescopic tube, and the freely suspended state which is a non-pressed state, in which said at least one clamp body is away from said inner surface, so that said holding tool is in said constrained state when said at least one clamp body is in said pressed state, and is in said freely suspended state when said at least one clamp body is in said non-pressed state; wherein said clamp driving apparatus has at least one top formed in a cone shape, a screw member vertically passed through and engaged with said at least one top, and a motor for rotating said screw member; and wherein forward and backward motion of said at least one top caused in the vertical direction by rotating said screw member by said motor moves horizontally said at least one clamp body in order to generate said pressed state and said non-pressed state.