Migration of 239Pu in soluble and insoluble forms in soil

A field experiment study was performed at the rural site of South-East Lithuania. The main tasks of the study included an evaluation of the peculiarities of partition of 239Pu in soluble (239Pu(NO3)4, 239PuCl3) and insoluble (239PuO2) forms in soddy and forest soil horizons. The results of durable experiments (418 and 326 days) have shown that from 44.1% to 92.2% of 239Pu of investigated chemical forms were accumulated in the top (0-5 cm) soil layer. Some share (5.7-39.2%) of plutonium from studied chemical forms was found in the 5-20 cm layers of studied soil samples (columns). Obtained distribution of plutonium in soil layers may be attributed to the consideration that the migration rate to the soil depth for plutonium is 0.1-1.0 cm x y-1 but for some part of plutonium 10 times higher migration rate is characteristic as well. Plutonium transfer factor (TF) to the grassland plants was calculated, the values ranged from 10-2 to 10-1. (author)