Impact of the Fukushima Daiichi Nuclear Power Station Accident on the Sea of Japan and the Sea of Okhotsk.

Abstract

The Japan Coast Guard has been investigating radioactivity in the waters around Japan since 1959. The 2011 Tohoku Earthquake that occurred off the Pacific coast caused a tsunami. The TEPCO Fukushima Daiichi Nuclear Power Station was severely damaged and a radioactive accident occurred. Radioactive materials were released into the environment, flowed out from the coastlines of Niigata and Yamagata prefectures to the ocean, and transferred to the Notsuke Strait by ocean currents. By utilizing the half-lives of 134Cs and 137Cs, 137Cs of seafloor sediment could be separated into the concentration due to the global fallout and the concentration due to three accidents at TEPCOʼs Fukushima Daiichi Nuclear Power Station. It was suggested that silt clay in the seafloor sediments selectively adsorb radioactive cesium.