Study of Deposit Cesium-137 (137Cs) Activity as a Result of Fission Product From the Fukushima Daiichi Nuclear Power Plant at Japan After Earthquake and Tsunami in 2011

Study of deposit Cesium-137 (137Cs) activity as a result of the fission product of Fukushima Daiichi Nuclear Power Plant after earthquake and tsunami in 2011 has been done. The purpose of the present research is to study the deposit 137Cs activity on the land and the Sea of Japan and then to estimate a model of 137Cs distribution on the earth's surface of Japan. The stability of nuclei decay equation is used to obtain a deposit 137Cs activity depending on time, theoretically. The Pasquill-Gifford equation is used to estimate a distribution of 137Cs activity on the earth surface from the original source. The results suggested that Hatachinaka city, the largest measurement point, for about 60 years forward, 137Cs activity levels reach about 54 Bq. In the Sea of Japan at the point of sensor C47, which it has the largest value, the accumulation of deposit 137Cs activity gives about 0.69 Bq at the time of the next 60 years. For the distribution of 137Cs activity, the concentration values at a distance of 200 m from the original source obtained maximum for all case