Rapid removal of cesium-137 from urban area after the Fukushima Dai-ichi Nuclear Power Plant Accident

Yoshimura, Kazuya  

This study evaluated Cs-137 inventories for 11 buildings in the evacuation zone in 2015 and 2016. Additionally, the results were analyzed with the data obtained in the model decontamination project to evaluate temporal trend in the distribution during the initial five years after the accident. The inventory on paved ground accounted for 20% of that on permeable field, and other building components such as roof, wall and window showed low inventory (less than 4%). These values indicate the limited contamination of urban area. The inventories of paved ground, roof and wall in 2011 and 2012 showed similar values with those obtained in this study, suggesting that initial run-off and the following wash-off effects during the first year after the accident largely defined the distribution of Cs-137 in urban area.