Patent Number: 
Section: abstract

The present invention relates to a process for sintering a compacted powder of at least one oxide of a metal selected from an actinide and a lanthanide, this process comprising the following successive steps, carried out in a furnace and under an atmosphere comprising an inert gas, dihydrogen and water:                (a) a temperature increase from an initial temperature TI up to a hold temperature TP,        (b) maintaining the temperature at the hold temperature TP, and        (c) a temperature decrease from the hold temperature TP down to a final temperature TF,        in which the P(H2)/P(H2O) ratio is such that:                    500<P(H2)/P(H2O)≤50 000, during step (a), from TI until a first intermediate temperature Ti1 between 1000° C. and TP is reached, and            P(H2)/P(H2O)≤500, at least during step (c), from a second intermediate temperature Ti2 between TP and 1000° C., until TF is reached.