Systems and methods for manufacturing metal fuel are described. Methods for fabricating a metal-fuel-matrix cermet nuclear fuel may include crushed ceramic particles combined with metallic fast reactor fuel via bottom pour casting or injection casting, or a powdered metallurgical process. A maximum quantity of crushed ceramic particles added to the metallic fuel must not exceed that which would fail to yield a continuous matrix of metal fuel. After a short irradiation period, the microstructure of the fuel may be substantially identical to that of injection cast fuel, without crushed ceramic particles, irrespective of the fabrication process. Thus, the extensive existing database for injection cast fuel, without crushed ceramic particles, may be an excellent indicator of expected irradiation performance. Each of the processes may contribute to a solution of the spent nuclear fuel problem and may denature Pu239 during the process.