Overview of 13 years of research on radionuclide behavior in Brazilian soils

Instituto de Radioproteção e Dosimetria/CNEN. Av. Salvador Allende s/n°, 22780-160 Recreio, Rio de Janeiro, RJ, Brasil

Abstract

Since the Goiânia Accident in 1987, the Environmental Impact Assessment Service of the Institute of Radioprotection and Dosimetry started developing studies aiming to improve response for nuclear and radiological accidents. In 1993 radioecological studies for determining transfer factors adequate to main types of agricultural soils and crops cultivated in Brazil. While the studies proceeded, it was felt that mechanisms involved in soil-plant processes should be better understood. Sequential extraction was seen as an important tool to understand radionuclide behavior in the soil-plant system. After 15 years studying different types of tropical soils and several radionuclides, such as ¹³⁷Cs, ⁹⁰Sr and ⁶⁰Co, it could be seen the relevance of site specific data to be used for environmental impact assessments and to the decision making process after an accidental contamination, and that these assessments need to be based on the knowledge of environmental processes governing the long term behavior of radionuclides at a specific type of environment.