Transfer parameters are key inputs for modeling radionuclide transfer in the environment and estimating risk to humans and wildlife. However, there are no data for many radionuclide-foodstuff/wildlife species combinations. The use of parameters derived from stable element data when data for radionuclides are lacking is increasingly common. But, do radionuclides and stable elements behave in a sufficiently similar way in the environment? To answer this question, at least for soil to plant transfer, sampling was conducted in four different countries (England, Kazakhstan, Spain and Ukraine) affected by different anthropogenic radionuclide source terms (in chronological order: global fallout, Semipalatinsk Test Site, the 1957 Windscale accident and the 1986 Chernobyl accident) together with a bibliographical review. Soil to grass transfer parameters (ratio between dry matter concentrations in plant and soil), Fᵥ, for ¹³⁷Cs and ⁹⁰Sr were significantly higher than those for stable elements, suggesting that the use of the latter could lead to underestimating radionuclide concentrations in plant samples Transfer parameters for ¹³⁷Cs and stable Cs were linearly correlated, with a slope of 1.54. No such correlation was observed for ⁹⁰Sr and stable Sr, the mean value of the ⁹⁰Sr:Sr ratio was 35 ranging (0.33–126); few data were available for the Sr comparison. The use of radionuclide transfer parameters, whenever possible, is recommended over derivation from stable element concentrations. However, we acknowledge that for many radionuclides there will be few or no radionuclide data from environmental studies. From analyses of the data collated there is evidence of a decreasing trend in the Fᵥ(¹³⁷Cs)/Fᵥ(Cs) ratio with time from the Chernobyl accident.

A Lagrangian model which simulates the dispersion of 137Cs in the North Atlantic has been developed. The model includes water/sediment interactions. It has been tested comparing calculated and measured 137Cs concentrations in water and sediments of the European Shelf resulting after the releases from the nuclear fuel reprocessing plants of Sellafield and La Hague. Some additional numerical experiments have been carried out. First, the redissolution of 137Cs from contaminated sediments after the reduction in releases from the reprocessing plants has been studied. This allowed to calculate effective half-lives of 137Cs in several sub-basins. Later, potential leakage of 137Cs from dumped nuclear wastes in several locations of the Atlantic has been investigated. Even in worst-case scenarios, these leakages should not lead to any radiological implications.