Numerical study on noble metal particles behavior in glass melter of vitrification process

Solid particles of noble metals in the high-level liquid waste tend to accumulate on the bottom of the TVF glass melter of the Tokai reprocessing center. The sediments of the noble metals reduce the electric heating efficiency by forming short circuit of electric current. For the long-term steady operation of the glass melter, the accumulation mechanism should be investigated to improve outflow ratio of noble metal particles. In this study, a numerical simulation code for solid-liquid two-phase flow was employed to investigate the noble metal particles behavior in the melter. Effects of some parameters on the outflow ratio were evaluated as well as the accumulation mechanism. As a result, this simulation method could lead same accumulation and outflow profile tendencies with them in experimental results, so that the particle behaviors that created these tendencies became clear. In addition, we found that the outflow ratio reaches the maximum value at both certain outflow velocity of glass and the glass temperature near the bottom of melter. (author)