Erosional Behavior of Cesium-137

Movement of 137Cs by runoff, erosion, and infiltration on a silt-loam soil in Tennessee is reported. A summary of a 2-yr study is given, and a model for the nuclide erosional loss is suggested. It was found that, although an empirical parabolic equation adequately describes the radionuclide loss, an exponential model, based on the nuclide distribution in a soil profile, appears to give more general results. The results show that a 60% reduction in the radiation dose due to surface-deposited 137Cs occurred during the first 7 months following the application. Most of the applied radiocesium was found in the 0- to 3-cm layer or had been eroded away. It appears that the specific loss of 137Cs reflects the seasonal variation in the magnitude of the erosion index and the extent of vegetative cover for a particular location.