DISTRIBUTION AND CHARACTERISTICS OF PU-239,PU-240 AND CS-137 IN THE SOIL OF KOREA

The concentrations of Pu-239,Pu-240 and Cs-137 were determined in undi stributed surface soil (0-4 cm) in Korea. They were in the range of 0. 24 similar to 1.1 Bq kg(-1) and 12.4 similar to 55.6 Bq kg(-1), respec tively. The mean activity ratio of Pu-239,Pu-240/Cs-137 in soil was 0. 0224, which is very similar to the estimated value (0.0211) commonly a ttributed the atmospheric nuclear test. The influence of rainfall on t he deposition of Pu-239,Pu-240 and Cs-137, and the effect of organic m atter content, clay content and pH on the relative adsorption of the t wo radionuclides on the surface soil were studied using the field meth od. Among parameters affecting the cumulative deposition of the radion uclides, the organic matter content plays the most important role in t he retention and relative mobility of Pu-239,Pu-240 and (137)cs in the soil. The other parameters such as rainfall, clay content and pH were of less significance. (C) 1997 Elsevier Science Ltd.