*Yuko Itoh1, Masahiro Kobayashi1, Akihiro Imaya1
(1.Forestry and Forest Products Research Institute, Japan)
Keywords:radioactive Cs, rainfall monitoring, forested area
To clarify the actual status of radioactive Cs inflow after the Fukushima Daiichi nuclear power plant (FDNPP) accident in March 2011 in 15 forest areas in the Kanto region, radioactive Cs concentration of preserved rainfall monitoring samples (bulk precipitation and throughfall) were measured. The initial influx of radioactive Cs through bulk precipitation and throughfall at the same location from after the accident to May 2011 has already been reported (Itoh et al., 2015). In this study, we subsequently measured for radioactive Cs in preserved samples from June 2011 to December 2013. At the intensive monitoring site, radioactive Cs in preserved samples from 2011 until 2020 were measured.
Although more 10 years have passed since the FDNPP accident, the analysis of the preserved samples could reproduce the radioactive Cs inflow at each forest site. At the intensive monitoring site, radioactive Cs inflow through bulk precipitation was detected even in 2020.