Radiocesium in the swash zones off the coast of the Japan Sea

Hyoe Takata; Mutsuo Inoue; Yuhei Shirotani; Natsumi Kudo

doi:10.1016/j.apradiso.2018.08.012

Radiocesium in the swash zones off the coast of the Japan Sea

Appl Radiat Isot. 2018 Nov:141:64-67. doi: 10.1016/j.apradiso.2018.08.012. Epub 2018 Aug 17.

Authors

Hyoe Takata¹, Mutsuo Inoue², Yuhei Shirotani³, Natsumi Kudo⁴

Affiliations

¹ Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba 299-5105, Japan. Electronic address: takata@kaiseiken.or.jp.
² Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Nomi, Ishikawa 923-1224, Japan.
³ Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba 299-5105, Japan; Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Nomi, Ishikawa 923-1224, Japan.
⁴ Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba 299-5105, Japan.

PMID: 30179770
DOI: 10.1016/j.apradiso.2018.08.012

Abstract

Radiocesium concentrations were measured in seawater and sediment samples collected in the swash zones in Ishikawa and Niigata prefectures, off the coast of Japan Sea opposite to the side where TEPCO Fukushima dai-ichi Nuclear Power Plant (FDNPP) is located in September 2016 and August 2017, five to six years after the accident. Cs-134 in the seawater samples was detected, suggesting the intrusion of FDNPP-derived radiocesium in both swash zones. FDNPP-derived radiocesium was appeared to be transported by the Tsushima Warm Current. In the surface sediments only ¹³⁷Cs was detected during the sampling period. We could not find out the presence of the FDNPP-derived radiocesium in the corresponding sediment on the swash zones; however, detected radiocesium in those sediments was assumed to be influenced by ¹³⁷Cs of FDNPP-derived radiocesium little for Ishikawa area and some for Niigata area.

Keywords: Cs-134; Fukushima Dai-ichi Nuclear Power Plant; Global fallout; Swash Zone.