| 摘要 |
<p>1277638 UO 2 optionally with ThO 2 COMITATO NAZIONALE PER L'ENERGIA NUCLEARE 10 June 1969 [26 June 1968] 29369/69 Heading C1A High density -particles of -stoichiometric uranium dioxide are -produced from a powder of a non-stoichiometric uranium dioxide, optionally mixed with one or more other actinide oxides (e.g. thorium oxide), by (a) obtaining a paste by mixing the starting powder with a solvent (e.g. water), (b) drying the paste, (c) granulating to obtain particles, (d) sieving, and (e) heating the sieved particles to 1100-1300‹ C. e.g. under dynamic vacuum or in an inert gas, keeping them at this temperature for 2-10 hours and then cooling, the thermal gradient of the heating and cooling steps being not more than 600‹ C. per hour. The solvent may include an organic binder (e.g. polyvinyl alcohol) present in an amount 0À3-1À5% by weight of the oxides; a pause of about 2 hours in the heating step at 600‹ C. is then necessary to remove the -binder.</p> |
