RADIOISOTOPES

Radioactive materials were released to the ocean due to the Fukushima Dai-ichi Nuclear Power Plant Accident. Two main release pathways are atmospheric deposition and direct release from nuclear power plant sites. Release rates were estimated for each case, and at coastal and North Pacific scales, environmental dynamics model analysis was performed. In addition, analysis of the transfer process to marine sediments and marine organisms has been carried out, and studies on the role of particles enriched radiocesium at that time have also been started. The research results so far have been summarized, and future prospects including future forecasts have been described.