Role of Clay Minerals in Controlling the Fate and Transport of Radioactive Cs in the Soils of Fukushima.

The widespread radioactive contamination of the soils of Fukushima and vicinity prefectures resulting from the Fukushima Daiichi Nuclear Power Plant accident 2011 has resulted in widespread soil contamination by ¹³⁷Cs over an expansive area.  It has been estimated that 1.3 x 10¹⁶ Bq of ¹³⁷Cs were released into the atmosphere between March 12 and April 6^th of 2011 and about 20% of this was deposited on land.  The selectivity of clay minerals for Cs⁺ is typically much greater than that of other cations resulting in strong and often irreversible binding of Cs⁺ to clay minerals. The fate and transport of ¹³⁷Cs in the soils of Nagasaki over the past 70 years attest to the slow mobility of ¹³⁷Cs⁺  in soils. The negative consequences are that the strong interaction of Cs⁺  with clay minerals results in its accumulation in the surface soils of Fukushima.  At the same time, however, clay science initiatives in Japan seek to exploit this selectivity as a tool to enhance cleanup of contaminated soils.