Investigation on dose rate reduction at Fukushima University Junior High School and Kindergarten

Kurikami, Hiroshi  ; Yoshikawa, Hideki; Sasamoto, Hiroshi   ; Iijima, Kazuki  ; Zaima, Naoki; Munakata, Masahiro ; Tokizawa, Takayuki; Nakayama, Shinichi 

This report shows the records of JAEA's investigation on dose rate reduction at the Fukushima University Junior High School and Kindergarten. The main outcomes are as follows. (1) experiments were performed to investigate intrusion depth of radiocesium in the soil. Based on the experiment, we proposed a countermeasure to reduce air dose rates. (2) The action we proposed allowed dose rate reduction to about one tenth to one twentieth at playgrounds. (3) Follow-up monitoring was performed after one year, and shows no obvious evidence of recontamination at the playgrounds. (4) Decontamination of a tree was tested. Radiocesium was accumulated around the root. By removing the soil, the air dose rate at about one-meter distance from the tree was decreased.