Abstract
As part of research on the vibratory compaction method of fabricating UO2 fuel elements, the effect of vibration character (frequency, acceleration and so on) on the compaction density was studied with sinusoidal wave vibration generated by an electrodynamic-shaker, with the view to optimization of vibration conditions for obtaining high compaction densities. Fused UO2 with a particle size distribution of -6, +12 mesh: 67.5 w/o, -40, +70 mesh: 20.0 w/o, -200 mesh: 12.5 w/o (mesh: US. Unit) was compacted into 40" long, 0.5" outer diameter and 0.035" wall 304 stainless steel tubes. Optimum results (88 % of theoretical density) were obtained with the following stepwise acceleration increase procedure:
(1) Powder blend is poured into the tube while it is vibrating at 8 G's and 300 cps.
(2) After the tube is filled, acceleration is increased to 20 G's at the same frequency of 300 cps and vibration is maintained for 2 min.
(3) Then, acceleration is increased to 40 G's and sweeping of frequencies between 300 and 3, 000 cps is initiated at the rapid speed of 4.4 decades/min, while maintaining a constraining load of 4 kg on the powder.
(4) After 2 min vibration at 40 G's, acceleration is increased to 60 G's and sweeping vibration is kept for 10-15 min.
