Conversion technique of salt wastes generated in pyrochemical reprocessing into oxide

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佐藤 史紀 ; 明珍 宗孝; 照沼 仁*; 新井 修*

Sato, Fuminori; Myochin, Munetaka; Terunuma, Hitoshi*; Arai, Osamu*

乾式再処理より発生する核分裂生成物を含む溶融塩廃棄物を、適切に安定化処理する手法について検討した。検討では、既存手法に対して熱力学計算コードを用いた詳細な考察を行い、より性能の高い改良型の処理方法を提案した。続いて、提案に基づき模擬溶融塩廃棄物を用いた基礎試験を実施し、処理後の廃棄物生成物量を低減できることを確認した。

Oxide conversion of molten salt wastes in pyrochemical reprocessing was studied as a pre-treatment of vitrification. A new method using boron oxide and water vapor was suggested from consideration of a conventional method using boric acid (H3BO3) by chemical equilibrium calculation. Applying the new method for NaCl-CsCl salt in a small-scale experiment, it was confirmed that the most of the salt was converted to oxide and the amount of the oxide wastes after the treatment could be reduced by 20% compared with the conventional method.