Device for a nuclear reactor to inhibit the longitudinal movement of the fuel element within the reactor core

摘要

A typical embodiment of the invention provides a means for restraining the fuel elements within a nuclear reactor core from movement during reactor operation. Illustratively, within one of the fuel element end fittings a rectangular grid of torsion bars is positioned with the ends of each of the bars anchored in opposing parallel sides of the end fitting. Individual torsion arms fastened to the midportion of each of the respective torsion bars protrude above the end fitting to bear against the adjacent grid pads and thereby restrain motion in the direction of coolant flow. In the opposite fuel element end fitting a tube that extends through the length of the fuel element is connected to the center of a convex spring. The two ends of the spring are hinged to respective locking bars that are cammed to move in a direction that is transverse to the axis of the tube. As the fuel element moves in the direction of coolant flow, the tube presses the convex spring flat. The flattening spring, in turn, drives the locking bars into engagement with mating latches on the adjacent support grid to prevent further movement of the fuel element.