PERFECCIONAMIENTOS INTRODUCIDOS EN UN CONJUNTO DE COMBUSTI- BLE PARA UN REACTOR NUCLEAR.

摘要

This invention relates to long nuclear fuel bundles which employ grids to support the fuel elements at intermediate points. More particularly it relates to a grid assembly feature to provide a long fuel bundle with variable rigidity. A structure for attaching grids to a cage of tie rods which enables the rigidity of the whole assembly to be adjusted to give a wide variation from very stiff to relatively flexible. the grids are joined to the tie rod cage by several straps of such a length and cross section so as to have a predetermined torsional rigidity and thereby provide the complete fuel bundle with the desired amount of flexability to cope with the out of straightness deviations of an actual fuel channel. The tie rods are attached to the grid by the flexible straps so as to prevent relative axial movement between the tie rods and grid. This invention provides the maximum stiffness at the point furtherest away from the axis of rotation which enables the fuel to be designated to fill the channel to the maximum possible extent, without the fuel bundle jamming in the fuel channel.