Environmental radiation monitoring after the Fukushima NPP accident, 3; Sediment discharge from river to coastal area

Misono, Toshiharu   ; Funaki, Hironori ; Nakanishi, Takahiro   ; Tsuruta, Tadahiko  ; Shiribiki, Takehiko; Sanada, Yukihisa   

Typhoon Hagibis (on 11-12 October 2019) and the subsequent typhoon Bualoi (on 24-25 October 2019) caused considerable flood damage in Fukushima region. The Ukedo River has a catchment with a high Cs inventory due to the FDNPP accident. Thus, there was concern about re-contamination of the seabed sediment in the coastal area due to the deposition of particulate Cs discharged from river. The results showed that the Cs concentration in the seabed sediment two years after the large-scale discharge was higher than that before the river flood. We plan to clarify the details of the mechanism through continuous monitoring.