Nuclear fuel and method of fabricating the same

A method for fabricating a nuclear fuel, comprising:

• providing a nuclear fuel material, the nuclear fuel material consolidated into a solid volume of nuclear fuel material having a surface, the consolidated nuclear fuel material including a plurality of grains;
• and
• performing one or more processes on the consolidated volume of nuclear fuel material in order to obtain a characteristic length along at least one dimension of some of the grains smaller than or equal to a selected distance and a boundary network configured to transport a fission product from at least one grain boundary of some of the grains to the surface of the volume of the nuclear fuel material, wherein the selected distance is suitable for maintaining adequate diffusion of a fission product from a grain interior to at least one grain boundary in some of the grains.