Foliar uptake and translocation of Cs, Sr and I applied onto radish leaf surface

Radionuclides released into the atmosphere are deposited on the leaf surface of crop plants, taken up by the plants, and translocated to other parts. Part of the radionuclides deposited onto the leaves is removed from the surface by the environmental process called weathering, i.e. removal by rain, wind, etc. Although weathering, foliar uptake and translocation are important processes involved in the radiation dose assessment of radionuclides from plants, site-specific parameters to describe those processes have not yet been elucidated. We started to establish site-specific parameters for foliar uptake and translocation for Cs, Sr, and I using stable elements in a climate chamber in which meteorological conditions are controlled. Preliminary experiments of foliar uptake and translocation of Cs by applying droplets of Cs solution containing CsCI or CsNO₃ on a radish (Raphanus sativus L. cv. Redchim) leaf surface revealed that the uptake of Cs was strongly affected by counter anions of Cs in the applied solution. Approximately 80% of the Cs was absorbed for CsCI solution, while only 20% was absorbed for CsNO₃. The partition of absorbed Cs between leaf and root tuber was quite similar for both Cs compounds, which indicated that behavior of the absorbed Cs in radish was the same for both. (author)