Xa9745829 Environmental Radioactivity in the Soil of the Republic of Korea One Decade after the Chernobyl Accident

During Chernobyl accident a large amount of radionuclides were released into atmosphere and added to atmospheric nuclide inventory from weapons tests. In early May of 1986 in South Korea, radioactivities such as 1-131 and Cs-137 were detected in surface air and rain water. That indicated that Chernobyl debris spreaded to far eastern Asia. In the present time, the long-lived radionuclides have been deposited on the soil of Korean peninsular resulted from Chernobyl accident as well as from atmospheric nuclear weapon tests. Meanwhile, it has been reported that isotopic properties in fallout differ significantly, depending on their origin. Several studies have reported that plutonium isotopic ratio, Pu-238 to Pu-239,240 in particular, in fallout originated from Chernobyl accident was quite different from the ratio in global fallout from nuclear tests and bum-up of SNAP-9A satellite using Pu-238 as energy source[l]. As soil, in terrestrial environment, is a principal reservoir of man-made radionuclides, a study on isotopic characteristic in soil can give some information on howChernobyl accident is effecting on Korean environment In this study, the vertical inventory of radionuclides, Pu-238, Pu-239,240 and Cs-137, and their isotopic ratios in soils were investigated to estimate the contribution of Chernobyl derived-nuclides to Korean environment.