Make sure that the cesium concentration in the ice significantly reduces the 1/25.

Where you made ​​the icicles and frozen radioactive cesium containing contaminated water , that the cesium concentration in the ice significantly reduces the 1/25 , it was found in the experiments of Toyama . Frost crystals that freeze to clean among the mud became hint . The good concentration has continued to decrease further and repeat the experiment , it is expected to " help in the treatment of contaminated water TEPCO Fukushima Daiichi nuclear power plant ." I reported in the Atomic Energy Society of Japan on the 27th .
Matsuyama and university professor of Hydrogen Isotope Research Center , Tsushima Emeritus Prof. of university research has been in the country guru of snow and ice studies .
In the experiment , were placed in a freezing container dedicated simulated contaminated water 10 liters , including the cesium of 1500 Bq per liter , and the icicles made ​​of 5.4 kg weight chilled to 4 degrees below zero . Result of the measurement of the cesium concentration of ice , it was reduced to 61 becquerels per kilogram . Became 1/270 up to the outer peripheral portion of the ice in particular . On the other hand , 98% of the cesium collect to 4.5 kg contaminated water remaining after freezing , it was concentrated to approximately 2 -fold .
The frozen water is slowly frost crystals to allow , when making ice direction of the crystal are aligned in the "single crystal" , it becomes ice free of impurities . By repeating the freezing treatment using this property , cuts down the amount of contaminated water .
There is a contaminated water (266 million copies drums equivalent) about 530,000 tons of March , the prospect of full-scale operation can not stand " ALPS ( Alps ) " also removal device of radioactive material on the grounds of the Fukushima Daiichi nuclear power plant I have surpassed in the expansion tank to . There is a problem such as the size of the freezing equipment , but Matsuyama Professor talk to be " or not can complement the role of . Alps was effective to remember the frost crystals , if you experiment with dubious " . It will be freezing container , such as a dedicated large- scale is required , but worth trying in fact it is likely . Run up I want to promote something .


放射性セシウム入り汚染水を凍らせて氷柱を作ったところ、氷の中のセシウム濃度が２５分の１と大幅に減ることが、富山大の実験で分かった。泥の中でもきれいに凍る霜柱がヒントになった。実験を繰り返すと濃度がさらに減り続けたといい、「東京電力福島第１原発の汚染水処理の一助に」と期待する。２７日に日本原子力学会で報告する。
　同大水素同位体科学研究センターの松山教授と、雪氷学の国内第一人者で同大の対馬名誉教授らが研究した。
　実験では、１リットル当たり１５００ベクレルのセシウムを含む模擬汚染水１０リットルを専用の凍結容器に入れ、氷点下４度まで冷やして重さ５・４キロの氷柱を作製。氷のセシウム濃度を測定した結果、１キロ当たり６１ベクレルに減った。特に氷の外周部では最大２７０分の１になった。一方、凍らずに残った汚染水４・５キロにはセシウムの９８％がたまり、約２倍に濃縮されていた。
　霜柱ができるように水をゆっくりと凍らせ、結晶の方向がそろう「単結晶」の氷を作ると、不純物を含まない氷になる。この性質を使って凍結処理を繰り返せば、汚染水の量を減らせる。
　福島第１原発の敷地内には３月時点で約５３万トン（ドラム缶換算で２６６万本）の汚染水があり、放射性物質の除去装置「ＡＬＰＳ（アルプス）」も本格運転のめどが立たずにタンク増設でしのいでいる。凍結装置の大型化など課題もあるが、松山教授は「霜柱を思い出し、半信半疑で実験したら効果があった。アルプスの役割を補完できるのではないか」と話す。大規模な専用の凍結容器等が必要になることでしょうが実際にやってみる価値はありそうですね。何とか実行まで進めてほしいですね。