End closure for a fuel element of a nuclear reactor with a tendency to store the fission products of a defective element

摘要

In order to increase the detection sensitivity of measurements for locating a fuel rod that has become defective, the present invention proposes to provide the upper end plugs for fuel rods in liquid cooled nuclear reactors with an enhanced tendency to deposit washouts, entrained by coolant, of fission products from rod defects through the configuration or nature of the shape and/or the surface of said plugs. As special measures to increase the deposits, changes in shape are proposed which cause separation vortices, thus e.g. separation edges (11, 12) or concave regions (13), or else the roughening or coating of parts (14) on the fuel rod plugs. In particular, it is proposed to coat with a getter for specific isotopes. Roughening, coating or flattening of the plug tips can also be carried out subsequently on already existing fuel rods. IMAGE