Preliminary results on transfer of radionuclides in soil and crops in the Chernobyl area

The IPSN is collaborating with IBRAE (INS: Institute of Nuclear Safety of Russia) in the fields of measurements and computer modelling, and of radiochemistry with EPFL (Swiss Federal Institute of Technology, Lausanne). The opportunity given by Russia to collect samples in a contaminated area inside the Chernobyl region gives us the possibility to combine the efforts of the three institutes to provide a complete chain: sampling, measurement, modelization and validation. An emphasis is made on the evolution, versus time, of the vertical distribution in different soils, mainly podzol, of cesium, measured by spectrometry gamma, and strontium, extracted by radiochemistry and measured by beta counting. This paper presents the objectives of the project, the progress of the work and the first results obtained. (author)