A method for fabricating a nuclear fuel, comprising: providing a nuclear fuel material, the nuclear fuel material consolidated into a solid cylindrically shaped 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: an elongated grain structure for the plurality of grains, with a length along a shortest dimension smaller than or equal to a selected distance, wherein said plurality of grains are arranged such that the shortest dimension is substantially parallel with a radial thermal gradient of the cylindrically shaped volume of the nuclear fuel material, 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 a diffusion level of a fission product from a grain interior to at least one grain boundary in the grains to maintain a fission product concentration within the volume of a nuclear fuel material at or below a concentration required for nucleation of the fission product. providing a nuclear fuel material, the nuclear fuel material consolidated into a solid cylindrically shaped 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: an elongated grain structure for the plurality of grains, with a length along a shortest dimension smaller than or equal to a selected distance, wherein said plurality of grains are arranged such that the shortest dimension is substantially parallel with a radial thermal gradient of the cylindrically shaped volume of the nuclear fuel material, 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 a diffusion level of a fission product from a grain interior to at least one grain boundary in the grains to maintain a fission product concentration within the volume of a nuclear fuel material at or below a concentration required for nucleation of the fission product. an elongated grain structure for the plurality of grains, with a length along a shortest dimension smaller than or equal to a selected distance, wherein said plurality of grains are arranged such that the shortest dimension is substantially parallel with a radial thermal gradient of the cylindrically shaped volume of the nuclear fuel material, and a boundary network configured to transport a fission product from at least wherein said plurality of grains are arranged such that the shortest dimension is substantially parallel with a radial thermal gradient of the cylindrically shaped volume of the nuclear fuel material, 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 a diffusion level of a fission product from a grain interior to at least one grain boundary in the grains to maintain a fission product concentration within the volume of a nuclear fuel material at or below a concentration required for nucleation of the fission product. wherein the selected distance is suitable for maintaining a diffusion level of a fission product from a grain interior to at least one grain boundary in the grains to maintain a fission product concentration within the volume of a nuclear fuel material at or below a concentration required for nucleation of the fission product.