日本地球惑星科学連合2018年大会

講演情報

[EJ] Eveningポスター発表

セッション記号 M (領域外・複数領域) » M-AG 応用地球科学

[M-AG33] 福島原発事故により放出された放射性核種の環境動態

2018年5月20日(日) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:北 和之(茨城大学理学部)、恩田 裕一(筑波大学アイソトープ環境動態研究センター)、篠原 厚(大阪大学、共同)、津旨 大輔(一般財団法人 電力中央研究所)

[MAG33-P03] Temporal variations in radiocesium concentration in suspended sediment in Tochigi prefecture after the Fukushima Dai-ichi Nuclear Power Plant accident

*坂下 渉1恩田 裕一2加藤 弘亮2Nam Sooyoun3五味 高志3 (1.筑波大学 生命環境系、2.筑波大学 アイソトープ環境動態研究センター、3.東京農工大学)

キーワード:Fukushima Dai-ichi Nuclear Power Plant、Cesium-137、Suspended sediments

Released radionuclides have been transported to the Japanese terrestrial ecosystems after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on March 2011. Previous studies have reported the temporal changes in dissolved radiocesium concentrations in Fukushima prefecture from their intensive collecting of various water samples. Their results from June 2011 to July 2013 indicate the two components of exponential decline of 137Cs concentration after the FDNPP accident. Our previous works also monitored the radiocesium concentrations in suspended sediments in the same regions. However, the early trend of declined 137Cs concentrations is still unclear because the samplings are conducted from 1-3 year after the FDNPP accident. In this study, we report new temporal variations in radiocesium concentrations in suspended sediments in Tochigi prefecture from July 2010 to October 2013. Our samplings are conducted in Mt. Karasawa, Tochigi prefecture, in central Japan. Our results indicate that the first exponential declines are found until around September 2011. In this paper, we report the parameters describing the trend of radiocesium concentrations in the suspended sediments based on the two-component exponential model.