Particle flowability test using a vibrating tube with a tapered end was carried out to evaluate the applicability of this method to the analysis of MOX particles for nuclear fuel pellet fabrication. In this experiment, zirconia particles were used as model particles, which are smaller than several hundred micrometers in diameter. The sample particles were prepared by mixing the particles with different sizes, whose shape and surface state were changed by a mechanical treatment. The experimental results showed that the removal of smaller particles is more effective than the mechanical surface treatment in improving the flowability. Furthermore, it was found that the vibrating tube method can identify the difference in the particle flowability more easily and clearly than the method based on Carr's flowability index.
