Growth method of grain refinement of mixed fuel sintered body using lithium oxide

摘要

The present invention relates to a mixture or the like when the valence of +3 cation compound containing Ga element _{CeO 2, PuO 2, Gd 2} O 3, Er 2 O 3 to promote sintering of the mixed powder material in a reducing sintering conditions and UO ₂ When Li ₂ O is used and pure UO ₂ is sintered under ordinary sintering conditions to obtain a sintered body having an average grain size of 100 μm or more, Li ₂ O is used as a sintering accelerator.;In the preparation of mixed fuel sintered body, 0.1wt% Li ₂ O is added to the mixed powder. When the sintered density is rather low at 1580 ℃ or more and the coarse sintered body is desired, sintering is performed in a mixed gas atmosphere of hydrogen and argon. And sintered body having a grain size slightly smaller than that is sintered in a pure hydrogen atmosphere, a desired sintered body can be obtained.