Characterization and distribution of Pu isotopes in marine sediments 30 km off Fukushima after the Fukushima DNPP accident

On March 11, 2011, a catastrophic earthquake (M 9.0) occurred in the northwest Pacific about 130 km off northeastern Japan, followed by a gigantic tsunami, which caused serious damage of the electric system of Fukushima Dai-ichi nuclear power plants (DNPP). As a result, the cooling system of nuclear reactors failed, resulting in hydrogen explosions in the reactors. In addition to the large amount of atmospheric releases caused by the hydrogen explosions, the cooling of the reactors with fresh water and seawater, and the release of highly contaminated water from the damaged reactor buildings resulted in the direct discharges of radionuclides into the sea. In this study, we investigate the isotopic composition of Pu in the marine sediments 30 km off Fukushima in the Pacific, and evaluate the possible Pu pollution in the marine environment after the Fukushima DNPP accident.2012年度日本海洋学会春季大