[en] The fabrication of TRU containing fuel materials requires the development of new fabrication technologies because it is difficult to handle the highly radioactive TRUs by the traditional fuel fabrication process. In this paper, we propose sintering process of ceramic fuels by high-frequency induction heating. The specific housing apparatus was made and used as a pre-heater in order to directly induce the electric current on the ceramic specimens. When the heating rate and sample dimension were properly controlled, ceramic nuclear fuel pellets with a density of more than 95% TD could be produced within a few minutes. Induction heating process is simple, clean, energy-efficient and compatible with hot-cell technology so that it can be a potential candidate process for the rapid fabrication of TRU containing radioactive nuclear fuel materials. (authors)

[en] Fabrication methods of an annular pellet with highly precise diametric tolerances have been investigated. Three new approaches were applied in order to achieve a better diametric tolerance. First, we have tried to introduce a new compaction process which combined a usual double-act pressing and a cold isostatic pressing. Secondly, annular compacting mold with inclined inner and outer surfaces was designed by considering a difference in the diametric changes depending on the pellet height during sintering. Finally, a rigid rod inserted sintering process was applied in order to minimize a diametric tolerance. A green annular pellet was firstly compacted with a double-acting press and then sintered after a precisely-machined rigid rod was inserted. Sintered annular pellets which were fabricated by the above processes show better inner diametric tolerances without an inner surface grinding. (author)