Patent Number: 041522052
Section: summary

The invention relates to a spacer or spacer support, especially for water-cooled nuclear reactor fuel assemblies formed of a grid of edgewise disposed sheetmetal webs of material having minimal neutron absorption, preferably a zirconium alloy, and of resilient or springy contact elements of other materials which are applied therein and extend in the axial or longitudinal direction of the mesh of the grid. Such spacers have become known, heretofore, for example, from the German Published Prosecuted Application DT-AS 1,489,632, wherein use was made of the principle, known also from considerably earlier publications, of making the spacer grid per se of a material that absorbs as few neutrons as possible and to fabricate the resilient contact elements of a correspondingly harder material which can have a considerably higher absorption cross section. Since it is difficult to join such different materials metallurgically, a simple plug connection was proposed, the loosening of which was supposed to be prevented by a bent-over end of the resilient contact strip. This construction, however, posed great difficulties in assembly as well as in accurately establishing the radial insertion location as seen from the fuel rod, not to mention that also the axial support of the contact springs during the operation of the reactor might be very unreliable. The problem therefore arose of finding a spacer construction with parts of different materials, with which these difficulties are circumvented, and which furthermore permits the use of the generally known "three-point support" (note the German Published Non-Prosecuted Application DT-OS 1,589,051). It is accordingly an object of the invention to provide a spacer or spacer support for nuclear reactor fuel assemblies which meets the latter requirements. With the foregoing and other objects in view, there is provided, in accordance with the invention, in a nuclear reactor fuel element, a spacer comprising a grid formed of edgewise disposed sheetmetal webs of material having minimal neutron absorption, and resilient contact elements of different material applied to the grid and extending in axial direction of the mesh of the grid, the mesh of the grid being defined by mesh walls formed with rectangular openings extending in longitudinal direction of the fuel element, the resilient contact elements comprising respective resilient strips self-lockingly snapped into the openings and including a wave-shaped part thereof extending from one to the other side of the mesh walls and respective parts that are not wave-shaped connected to opposite ends of the wave-shaped part thereof and contacting respective webs of the grid. In accordance with other features of the invention, the fuel element is for a water-cooled nuclear reactor and the material having minimal neutron absorption is formed of zirconium alloy. In accordance with additional features of the invention, at least one of the parts that are not wave-shaped is bent about the edge of the respective web or is suspended therefrom. In accordance with a concomitant feature of the invention, the parts that are not wave-shaped and contact the respective webs of the grid are formed with rigid contact projections i.e. either provided therewith or constructed therewith. Other features which are considered as characteristic for the invention are set forth in the appended claims. Although the invention is illustrated and described herein as spacer support for water-cooled nuclear reactor fuel elements, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.