The project concentrates on the processes governing the availability to biota of long-lived radionuclides present in soil. An analysis of the distribution of radionuclides between solid and liquid phase and of their accumulation from the liquid phase by biota is of special interest to predict the leaching of radionuclides from the soil as time passes by and to interpret effects of remedial measures against transfer into the foodchain.
In this project the availability of radionuclides is studied in artificial as well as in natural systems at different levels of organization. The study includes the chemical characterization of binding properties of the soil, the determination of distribution functions and the description of the uptake and release processes by different organisms plants, microorganisms and soil invertebrates). Integration of the results and a mathematical description of the processes studied are part of the project. Most of the subprojects have been carried out with the radionuclides caesium-134/caesium-137 and strontium-90. A variety of techniques quantify and interpret the solid-liquid distribution and a number of practical advises have been proposed to evaluate the effectiveness of countermeasures.
The participating institutes will study the relation between chemical speciation of radionuclides in soil systems and their bioavailability. The parameters which mainly determine the relation between the compartments soil and plant will be investigated for a number of elements, caesium and strontium being the most important ones. The aspects which determine solid/ liquid distribution and the aspects which affect uptake and accumulation by the plant will be studied separately and in combination, under controlled conditions. These data will be evaluated against available field observations and data collected during the forthcoming growing season. The final goal will be a generalized description of the relationship between the solid phase, the liquid phase and biota.
The results will benefit in judging the sensitivity of soils with respect to a potential contamination and the effectiveness of soil treatments and crop selection to inhibit contamination of the foodchain.
Funding SchemeCSC - Cost-sharing contracts
OX11 0RQ Didcot,harwell,chilton