Abstract: A spacer pad for a nuclear control rod includes first and second halves each including a head and a shank. The shanks are configured for joining together the pad first and second halves, and the shanks are independently locked together for preventing the disassembly thereof. In an exemplary embodiment, the first and second shanks are threadingly joined together, and then independently locked together using a complementary hook and ledge respectively supported by the pad halves which allows assembly together of the pad halves but prevents disassembly thereof.

Abstract: An assembly for servicing a cruciform control blade includes a carriage having first and second crossarms each containing a generally U-shaped slot for receiving the top of the control blade. The first crossarm includes a clamping actuator to rigidly clamp the carriage to the blade top. The second crossarm includes a tool positionable adjacent to a roller aperture in a selected one of the four panels of the control blade. The tool is positioned on the second crossarm at a predetermined depth, and at a predetermined lateral span from the first crossarm so that upon mounting of the carriage on the blade top and actuation of the clamping actuator, the tool is vertically and laterally aligned with a center of the panel roller aperture. In one embodiment, the tool is effective to sever the roller from the panel aperture without damaging the panel, and in another embodiment the tool is effective for installing a replacement spacer pad in the aperture.