Physical and chemical characteristics of plutonium in existing contaminated soils and sediments

Plutonium from three sites was studied to provide information necessary in understanding its behavior and fate under prevailing conditions. Plutonium in soils from the Nevada Test Site (NTS) was predominantly associated (50 to 75 percent) with the coarse silt (53 to 20 $mu$m) fraction. The plutonium in samples from Oak Ridge National Laboratory (ORNL) and Mound Laboratory (ML) was predominantly in the clay size (less than 2 $mu$m). The solubility in citric acid was about 20 to 25 percent in the ORNL sample and 40 to 50 percent in the ML sample. Density gradient segregation of the clay size fraction of the ML sample showed the activity distribution to be directly related to the weight of the recovered fraction with enhanced contribution by the very light organic fraction. Approximately 71 percent was found in the 2.3 to 2.4 g/cm$sup 3$ fraction which contained 65 weight percent of the clay and 16 percent in the less than 1.8 g/ cm$sup 3$ fraction (organic fraction) which contained 6 percent of the weight fraction. (auth