[en] Currently, there is interest in fissioning weapons-grade plutonium in nuclear reactors, making use of its valuable energy while at the same time reducing certain dangers associated with its potential for nuclear weapons proliferation. In the process of dismantling nuclear weapons, the US intends to convert much of the Pu metal to oxide. This process yields a PuO_2-x powder that potentially can be incorporated into mixed oxide nuclear fuel (MOX), a mixture of PuO₂ and UO₂. This paper describes the process of gallium removal from Ga₂O₃-doped CeO_2-x, a surrogate for weapons-grade PuO_2-x. Gallium is removed from the surrogate feedstock material using thermal techniques. An Ar-6% H₂ gas was used in order to reduce the oxide to gaseous Ga₂O. Experimental results were shown in the temperature range of 600 C to 1,200 C as a function of time and sample geometry. The results to date have shown that CeO_2-x is a very good surrogate for PuO_2-x