| abstract |
FIELD: chemistry.SUBSTANCE: present invention relates to a method for sintering a pressed powder of at least one metal oxide selected from actinides and lanthanides to produce nuclear fuel granules. Said method includes the following successive steps carried out in furnace in atmosphere containing inert gas, hydrogen and water: (a) increasing temperature from initial temperature Tto temperature Tholding, which is at level of 1400–1800 °C, (b) holding temperature at temperature Tholding and (c) temperature reduction from temperature Tholding to final temperature T. During step (a) of temperature T, until intermediate temperature Tis achieved between 1000 °C and T, ratio of partial pressures P (H)/P(HO) is such that 500 < P(H)/P (HO) ≤ 50,000. During step (c) of second intermediate temperature Tbetween Tand 1000 °C until temperature Tis reached, P (H)/P (HO) ≤ 500. Firing mode may include lowering temperature after holding at Tto level of 20–500 °C with further temperature increase to T,holding and cooling.EFFECT: technical result of invention is increase in specific weight to a level greater than or equal to 94,5 % of theoretical and higher thermal stability of this specific weight.18 cl, 2 ex, 2 tbl, 7 dwg |