DEPTH DISTRIBUTION OF PU-239,PU-240 AND CS-137 IN SOILS OF SOUTH-KOREA

Depth distribution of Pu-239,Pu-240 and Cs-137 in the soils of South K orea have been studied. The average accumulated depositions were estim ated roughly to be 54.8+/-32.1 Bq . m(-2) for Pu-239,Pu-240 1.6 +/- 1. 0 Bq . . m(-2) for Pu-238 and 1982.8+/-929.1 Bq . m(-2) for Cs-137. Th e activity ratios of Pu-239,Pu-240/Cs-137 in soils were found to be in the narrow range of 0.0153 to 0.0361 with a mean value of 0.0230+/-0. 006. The concentrations of Pu-239,Pu-240 and Cs-137 in soils decrease exponentially with increasing the soil depth. A significant correlatio n was found between the concentration of Pu-239,Pu-240 and that of Cs- 137. The activity ratios of Pu-239,Pu-240/Cs-137 tend to increase slig htly with increasing soil depth.