二酸化ウラン分散-黒鉛系燃料の再処理, (I)

機械的分離方法による二酸化ウランの回収

抄録

An approach to recover UO₂ mechanically from the UO₂-graphite fuel specimen was investigated. After disintegrating an unirradiated specimen by a pulverizer, ball mill, or micron mill, the obtained powder was separated into the UO₂ and graphite phases by a heavy-media-separation method in which a zinc-bromide solution was used as the heavy medium.
The disintegration of the specimen into fine powder was essential for the mechanical separation of UO₂.
Additional treatments such as preoxidation of the sample, addition of dispersion agent to the zinc-bromide solution, and irradiation of the solution with the ultrasonic waves, were not effective in improving the UO₂ recovery.
However, it seemed that the grinding method coupled with continuous removal of the ground particles with fluid flowing would be effective in obtaining a high UO₂ recovery.