Numerical simulation of propagation of radioactive pollution in the ocean from the Fukushima Dai-ichi nuclear power plant

Abstract

Numerical simulation of the large-scale horizontal mixing and transport of radioactive water from the Fukushima Dai-ichi nuclear power plant (NPP) (141°02′ E, 37°27′ N, east coast of Honshu Island, Japan) and the use of the satellite altimetric velocity field in the northwestern Pacific allowed us to obtain the following results. The patch of radioactive water dumped from the NPP propagated eastwards as jets of an extension of the Kuroshio Current. The discovered phenomenon of trapping the radionuclides by stable and unstable manifolds of local synoptic eddies may be harmful for living organisms. If one assumes that pollution of considerable areas of coastal waters near Honshu Island took place due to fallout of radioactive precipitation with rain, then a part of the radioactive water may be subjected to north-bound advection and is mixing under the impact of stable and unstable manifolds of the triple-eddy system to the north of the NPP. No radionuclide flux from the Tsugaru strait into the Sea of Japan has been found in the surface layer. Nevertheless, there is a small likelihood of their penetration there with a deep counter current and/or due to wind drift.