Spatial distribution of radionuclides in seabed sediments off Ibaraki coast after the Fukushima Daiichi Nuclear Power Plant accident
Fifty-one seabed sediments were collected to estimate the influence of the Fukushima Daiichi Nuclear Power Plant accident on the area offshore from Ibaraki. The 134Cs and 137Cs radioactivity levels were 3.8–206.7 and 6.1–296 Bq/kg (dry wt), respectively, and the activity ratios of 134Cs/137Cs were 0.48–0.77. The 90Sr and 239,240Pu activity levels were ND–0.26 and 0.170–0.78 Bq/kg (dry wt), respectively. The ratios of 238Pu/239,240Pu activity were 0.014–0.019. The 90Sr radioactivity was increased by the accident and Pu isotopes radioactivity was not changed.
KeywordsSeabed sediment Ibaraki coast Fukushima Daiichi Nuclear Power Plant accident Cesium Strontium Plutonium isotopes
We would like to thank the grateful discussion and measurement of TOC with Koarashi (Japan Atomic Energy Agency). We also thank the staff members of Seikai for their support in collecting samples.
- 1.Sumiya S, WatanabE H, Nakano M, TAkeyasu M, Nakada A, Fujita H, Isozaki T, Morisawa M, MizutanI T, Kokubun Y, Nagaoka M, Kato C, Onuma T, Nemoto M, Inoue H, Murakami M, Fujii J, Watanabe H, Kaminaga M, Sato Y, Sugai M, Tadokoro S, Sagawa F, Maejima K (2012) Annual report on the environmental radiation monitoring around the Tokai Reprocessing Plant FY 2010. JAEA-Review 2012–015 (in Japanese) http://www.jolissrch-inter.tokai-sc.jaea.go.jp/pdfdata/JAEA-Review-2012-015.pdf. Accessed 22 Sept 2014
- 2.Kawamura H, Kobayashi T, Furuno A, In T, Ishikawa Y, Nakayama T, Shima S, Awaji T (2011) Preliminary numerical experiments on oceanic dispersion of 131I and 137Cs discharged into the ocean because of the Fukushima Daiichi Nuclear Power Plant Disaster. J Nucl Sci Technol 48:1349–1356CrossRefGoogle Scholar
- 4.Otosaka S, Kobayashi T (2012) Sedimentation and remobilization of radiocesium in the coastal area of Ibaraki, 70 km south of the Fukushima Dai-ichi Nuclear Power Plant. Environ Monit Assess 184:5419–5433Google Scholar
- 5.MEXT (2011) Readings of sea area monitoring at offshore of Miyagi, Fukushima and Ibaraki Prefecture (marine soil) http://www.radioactivity.nsr.go.jp/ja/contents/6000/5703/24/229_so_0710.pdf. Accessed 26 Nov. 2013
- 7.UNSCEAR (1982) Reports (1982) ionizing radiation: sources and biological effects. Scientific Committee on the Effects of Atomic Radiation, United NationsGoogle Scholar