Patent Number: 
Section: claims

1. A nuclear fuel rod end distance adjusting device, the device comprising:an insertion rod including nuclear fuel rod tongs and configured to linearly move forward and backward;a housing having a hollow space;insertion power means installed inside the housing and configured to move in a longitudinal direction of the housing by converting a rotational motion into a linear motion;a connector connected between the insertion power means and the insertion rod; andan anti-rotation tool installed between the insertion power means and the connector, being capable of moving in the longitudinal direction of the housing by being interlocked with the linear motion of the insertion power means, but preventing rotational force of the insertion power means from being transmitted to the connector. 2. The device of claim 1, wherein the insertion power means comprises a ball screw,a rotation space provided at an end portion of the anti-rotation tool, wherein an end portion of a male screw of the ball screw is idle in the rotation space, andthe connector is fixed to an opposite end portion of the anti-rotation tool. 3. The device of claim 1, wherein a guide long-hole is provided in the longitudinal direction of the housing in the housing, and a moving pin guided along the guide long-hole is installed in the anti-rotation tool. 4. The device of claim 1, wherein the nuclear fuel rod tongs are screwed to the insertion rod, and the insertion rod is screwed to the connector,wherein the nuclear fuel rod tongs are configured to be screwed to the connector. 5. The device of claim 2, wherein a guide long-hole is provided in the longitudinal direction of the housing in the housing, and a moving pin guided along the guide long-hole is installed in the anti-rotation tool. 6. The device of claim 2, wherein the nuclear fuel rod tongs are screwed to the insertion rod, and the insertion rod is screwed to the connector,wherein the nuclear fuel rod tongs are configured to be screwed to the connector.