Simulation of long-term behaviour of Cs and Pu in the Japan Sea

Nakano, Masanao ; Takeishi, Minoru ; Furuta, Sadaaki

In order to assess the worldwide and long-term effects from nuclear facilities, LAMER (Long-term Assessment ModEl for Radioactivity in the oceans) has been developed. As a part of LAMER, an advection-diffusion-scavenging model incorporated into the OGCM concerned the Japan Sea has been developed and validated by calculating Cs and Pu water profiles in the Japan Sea and comparing them with experimental data. The concentrations of Cs and Pu have generally shown reasonable agreement between calculated and observed data. The best agreement between the experimental and calculated water profiles in the Japan Sea was obtained with the horizontal and vertical diffusion coefficients of 310 cm s and 0.3 cm s, respectively. The simulation in this study make them sure the quantitative origins and behaviours of Cs and Pu in the Japan Sea. The behaviours of Cs and Pu in the Japan Sea have been much different from the behaviours in the Pacific Ocean.