Radiation-Induced Densification Model of Uranium-Gadolinium Fuel

Abstract

In this paper, we have developed a model of radiation-induced densification of uranium-gadolinium fuel. The fuel is established to be in the brittle state under irradiation in the volume of uranium-gadolinium fuel pellet containing a burnable neutron absorber and in the plastic state out of this volume. The plastic zone volume increases during burnup of the neutron absorber. The relative change in a pellet volume or length of a fuel rod for uranium-gadolinium fuel is shown to be lower than that for uranium oxide nuclear fuel having the same microstructure and irradiated under the same conditions (the neutron flux).