Distribution of oceanic 137Cs from the Fukushima Dai-ichi Nuclear Power Plant simulated numerically by a regional ocean model

Title: Distribution of oceanic ¹³⁷Cs from the Fukushima Dai-ichi Nuclear Power Plant simulated numerically by a regional ocean model

Author: Daisuke Tsumune, Takaki Tsubono, Michio Aoyama, Katsumi Hirose

Reference: Journal of Environmental Radioactivity, Volume 111, September 2012, Pages 100–108

DOI: http://dx.doi.org/10.1016/j.jenvrad.2011.10.007

Keywords: Fukushima reactor accident; Regional ocean model; Release rate; ¹³⁷Cs; ¹³¹I/¹³⁷Cs activity ratio

Abstract: Radioactive materials were released to the environment from the Fukushima Dai-ichi Nuclear Power Plant as a result of the reactor accident after the Tohoku earthquake and tsunami of 11 March 2011. The measured ¹³⁷Cs concentration in a seawater sample near the Fukushima Dai-ichi Nuclear Power Plant site reached 68 kBq L⁻¹ (6.8 × 10⁴ Bq L⁻¹) on 6 April. The two major likely pathways from the accident site to the ocean existed: direct release of high radioactive liquid wastes to the ocean and the deposition of airborne radioactivity to the ocean surface. By analysis of the ¹³¹I/¹³⁷Cs activity ratio, we determined that direct release from the site contributed more to the measured ¹³⁷Cs concentration than atmospheric deposition did.

URL: http://www.sciencedirect.com/science/article/pii/S0265931X11002463