A study of the bioavailability of ⁹⁰Sr, ¹³⁷Cs, and ^239+240Pu in soils at two locations of Spain affected by different radionuclide contamination events

¹ University of Extremadura, Department of Physics, Avda. de la Universidad s/n, 10071 Cáceres, Spain, e-mail: ymiralle@unex.es
² Centro de Investigaciones Energéticas Medioambientales y Tecnológicas, Madrid, Spain

Abstract

It is well known that the bioavailability of artifical radionuclides such as ⁹⁰Sr, ¹³⁷Cs and ^239+240Pu in contaminated soils depends on the source term origin of the contamination. Altough the behaviour of the mentioned radionuclides in the soil is also influenced by the time passed from the contamination event and the characteristics of the contamination receiving soils. The objective of the present work is to analyse the different bioavailability and possible chemical-physical associations of ⁹⁰Sr, ¹³⁷Cs, and ^239+240Pu in soils located in different Spanish ecosystems (Almeria and Cáceres provinces) by application of a sequential extraction procedure based on the NIST standard sequential extraction protocol. The resulting fractions obtained are: a) water soluble and exchangeable, b) associated to organic matter, and c) residual fraction. They will be studied jointly with the polluting sources (deposit of nuclear fallout-50s and 60s, Palomares accident in 1966 and the cesium release by Acerinox in 1998) in each ecosystem to interpret the observed behaviour of radionuclides.