Patent Number: 039765423
Section: summary

This invention relates to gas cooled nuclear reactors and, more particularly, to an improved fuel element for use in a gas cooled nuclear reactor. One problem encountered in the design of gas cooled nuclear reactors is in the control of the flow of gaseous coolant over the clad fuel containers. Various arrangements have been devised to enable control of the flow of gaseous coolant over the fuel containers. Many of these prior art structures or orificing devices have been subject to the difficulty of unduly impeding coolant flow or producing undesired perturbation therein. Frequently, the accuracy of adjustment has been limited and the distribution of the flow pattern within the fuel element may vary with the amount the orificing device is opened. Finally, control over such prior art orificing devices has often been difficult and unwieldy to effect, and such devices have often offered too high a resistance to coolant flow when in the open position. An object of the invention is to provide an improved fuel element for use in a gas cooled nuclear reactor. A further object of the invention is to provide a fuel element having an adjustable orifice which, in the maximum flow or open position, presents a minimum resistance to coolant flow. It is another object of the invention to provide a fuel element having an adjustable orifice therein which is readily adjustable from the exterior of a reactor core.