Patent Number: 053135075
Section: claims

1. An apparatus for attaching a key member to a nuclear fuel assembly grid and detaching the same therefrom, said key member having a longitudinal axis and being adapted to be detachably attached to the grid by rotating the same about the longitudinal axis, said apparatus comprising: (a) supply and recovery means for supplying the key member to a prescribed position adjacent to the grid and recovering the same;  (b) inserting and removing means disposed between said supply and recovery means and said grid for inserting the key member supplied from said supply and recovery means into the grid and removing the key member from the grid to recover the same to said supply and recovery means; and  (c) rotating means disposed adjacent to said inserting and removing means for rotating the key member inserted in the grid in a prescribed direction about said longitudinal axis to attach the same to the grid and rotating the same in a direction opposite to said prescribed direction to detach the same from the grid. 2. An apparatus according to claim 1, wherein said inserting and removing means includes an opposed pair of rollers disposed parallel to each other so as to define a space therebetween, and drive means operably connected to said rollers for rotating the rollers in reverse directions, said space between said rollers being such that when said rollers are rotated, said rollers engage the key member to move the same toward and away from the grid. 3. An apparatus according to claim 2, wherein said inserting and removing means further includes discharging means for moving the key member to bring the same into the space between said rollers. 4. An apparatus according to claim 2, wherein said rollers are disposed movable toward and away from each other between a proximity position, in which the rollers engage the key member to move the same, and a distal position in which the rollers do not engage the key member. 5. An apparatus according to claim 4, wherein said inserting and removing means further includes drive means connected to said rollers for moving said rollers between said proximity position and said distal position. 6. An apparatus according to claim 1, wherein said rotating means includes a worm wheel having an aperture formed therethrough for receiving the key member, a worm gear held in engaged with said worm wheel, and an actuator for rotating said worm gear. 7. An apparatus according to claim 1, wherein said rotating means includes a holding member having an aperture formed therethrough for receiving the key member, a link mechanism connected to said holding member, and an actuator for rotating said holding member through said link mechanism.