A method of producing a nuclear fuel product is provided. The method includes the steps of providing a core comprising aluminum and low-enriched uranium; and sealing said core in a cladding. The low-enriched uranium has a proportion of U235 below 20 wt %. The core includes more than 80 wt % of a mixture of UAl3 phase and UAl4 phase, and the mixture has a weight fraction of UAl3 phase higher than or equal to 50%, or the core includes more than 50 wt % of UAl2 phase. The core has a low-enriched uranium loading higher than 3.0 gU/cm3. The core includes less than 10 wt % in total of one or several material(s) taken from the list consisting of aluminum phase and aluminum compounds other than UAl2 phase, than UAl3 phase, and than UAl4 phase. A corresponding nuclear fuel product is also provided.