Radioactivity decontamination in and around school facilities in Fukushima

Saegusa, Jun; Tagawa, Akihiro ; Kurikami, Hiroshi  ; Iijima, Kazuki  ; Yoshikawa, Hideki; Tokizawa, Takayuki; Nakayama, Shinichi ; Ishida, Junichiro

After the Fukushima nuclear accident, JAEA lead off demonstration tests to find out effective decontamination methods for various school facilities in Fukushima. It included (1) dose reduction measures at schoolyards, (2) purification of swimming pool water and (3) removal of surface contamination of playground equipments. Through these tests, they established practical methods suitable for each situation; (1) At school yards, dose rates were drastically reduced by removing topsoil which was then placed in trenches of 1 m deep; (2) For the purification of pool water, the flocculation-coagulation treatment was found to be effective for collecting radiocesium dissolved in the water; (3) Demonstration tests for playground equipments, such as horizontal bars and a sandbox wood frame, suggested that effectiveness of decontamination considerably varied depending on the material, paint or coating condition. This paper reviews these demonstrations.