Development of HLW vitrification off-gas treatment process

Basic and bench-scale experiments have been carried out in order to develop the vitrification off-gas process and equipment. Effects of process parameters on the decontamination factors of the melter and off-gas equipment and performance of the down stream adsorbents for Ruthenium and Iodine have been studied with a small scale experimental apparatus using the RI tracer. A full scale plastic model of the submerged bed scrubber has been developed. Its dynamic and decontamination performance of this scrubber have been studied and the results of experiments show the superiority of this scrubber. Water scrubbing of the volatile Ruthenium has been studied with the bench-scale apparatus and a high decontamination factor of the system has been reached. Results of these experiments are used in the construction of the PNC Tokai vitrification plant and the JNFS (Japan Nuclear Fuel Service Co. LTD.) Shimokita vitrification plant. (author)