Evolution of cesium and strontium contamination deposited on vines

IPSN/DPRE/SERLAB, CE Cadarache, 13108 Saint-Paul-lez-Durance, France

Abstract

Vine plant contamination by means of dry aerosols (Cs-137 and Sr-90) was carried out on two large scale lysimeters taken from an on-site vine plantation (limestone silty loamy soil) in order to forecast, both short and long term consequences of an accident occurring at a pressurised water reactor on some common agricultural products. Initial contamination (of the soil and the plant) was performed at two vegetative stages : one at the "late flowering" stage for one lysimeter, the other at the "beginning of ripening" stage for the second lysimeter. A total but non-lethal defoliation test was carried out on one vine plant in order to estimate the efficiency of this countermeasure method in reducing contamination at harvest. The influence of rain during the vegetative stages was analysed. For the first 6 years following deposition, root absorption of two radionuclides was examined : the consequences of initial contamination on different parts of the plant (bunches, leaves and shoots) were assessed as a function of time after each harvest. Monitoring of migration in soil and bioavailability was also undertaken. Correlation tests between the activities found in the plants and the behaviour of radionuclides in soil (bio-availability of the stable and radioactive elements, migration of radio-nuclides) were performed.