50L規模の雑固体廃棄物溶融固化体の性能と放射能分布の均一性評価

Characterization of 50L-scale solidified products yielded by melting treatment of miscellaneous solid wastes and evaluation of radioisotope tracer distribution

中塩 信行; 中島 幹雄; 平林 孝圀*

Nakashio, Nobuyuki; Nakashima, Mikio; Hirabayashi, Takakuni*

高周波誘導加熱とプラズマ加熱を併用するハイブリッド加熱方式及び導電性るつぼを用いる高周波誘導加熱方式の2つの溶融方式によって50Lドラム缶スケールの溶融固化体を製作した。長期浸出試験前後の溶融固化体を解体し、固化体の固型化材(モルタル)充填状況,固化体性状の変化,固化体の化学組成及び放射性核種分布の均一性を調べるとともに、溶融固化体加熱方式の違いが放射性核種の金属層・スラグ層への分布に与える影響を調べた。いずれの溶融方式においても、均質で放射性核種が均一に分布した溶融固化体が製作できることを示すとともに、長期浸出試験後も固化体性状の劣化はなく健全な状態が保たれていることを明らかにした。

Large-scale melting tests of simulated miscellaneous solid wastes were conducted to characterize solidified products (50L-drum size). Two heating modes were adopted in the tests: hybrid heating and induction heating modes. In the former, wastes were heated with both an induction furnace and a plasma torch, and in the latter, an electrically-conductive crucible was used with the induction furnace. Visual observation, chemical analysis and radioactivity measurements were conducted to the solidified products. It was found that the radioisotope distribution of solidified products was almost homogeneous. There was no remarkable deterioration in the solidified products subsequent to the leaching test.