the invention relates to a process for the treatment of a metal oxide powder , particularly a uo 2 or puo 2 powder , with a view to its fritting . this process consists of oxidizing the powder , so as to form on its surface a hydrated oxide layer of the same metal . when the oxide is uo 2 or puo 2 and mixtures thereof , as well as those prepared with tho 2 , the treated powder can be used for producing nuclear fuel pellets by cold compression , followed by fritting .