The competitive interaction of plutonium and americium with water-soluble components of FA and with insoluble components of HA which are specific sorbents of radionuclides considerably influences their mobility

Humus influence on mobility of plutonium and amend urn in soil has been investigated. To do (his the entrance of radionuclides into soil water solutions with different organic matter concentration and the distribution of 2 3 9 , 2 4 0 P u and 2 4 1 Am between humus fractions o f soil has been analyzed.. The mineral and organic sods with distinct quantitative and qualitative composition of humus, contaminated by radionuclides of Chernobyl origin have been studied. The groups of fill vie 07A) and mimic acids (HA) which differ in their composition and solubility in water were extracted from soils and the content of m 3 4 0 P u and M I A m in these organic fractions was detected. It was established that humus substances (HS) mainly promote the fixation of 2 3 9 2 4 0 Pu and M 1 Am in solid phase of soil. The humus o f organic soils promotes the fixation of plutonium and americium to a greater extent than HS of mineral soils. That is one o f the reasons of lower mobility of 2 3 9 2 4 0 p u and 2 4 1 Am in organic soils. A higher ability of plutonium to form the difficultly soluble complexes with HS compare to americium may be a factor of higher mobility of americium in soil.