Direct Pressing: A New Method of Fabricating MX Fuel Pellets

For fabrication of MX-type (M = actinides; X = carbon and/or nitrogen) advanced fuels, for example, uranium-plutonium carbides for the fast breeder, the carbothermic reduction process of oxides, with subsequent crushing and ballmilling of the reaction product, pressing, and sintering has been generally adopted. A new fabrication procedure, the direct pressing (DP) method, based on the carbothermic reduction process, is presented, however, without intermediate comminution. The fuel is directly processed to pellets. MX powder handling and dust generation within the working area are avoided. The principle and advantages of the new fabrication procedure are reported. The feasibility of the DP method has been demonstrated in laboratory scale on (U,Pu)C fuel pellet preparation. Fuel data compared with the conventional method are given.