Peculiarities of radionuclide transfer to plants

Abstract

The biosphere and its interacting components (air, soil, bottom sediments, flora, fauna, human beings) are constantly affected by ionizing radiation. One of the ionizing radiation sources is noble radioactive gas that is continually released into the environment because of the normal operation of nuclear power plants (NPP) (shortlived and longlived noble gas) and nuclear fuelreprocessing plants (NFRP) (longlived noble gas). Another source is related to nuclear tests and the Chernobyl NPP accident, when longlived gaseous and aerosol radionuclides (85Kr, transuranics, 137Cs, 90Sr, etc) were spread in all environmental systems. In order to evaluate the mechanism of radionuclide transfer to plants, model experimental investigation using gaseous 85Kr and ionic state 137Cs was undertaken. For this purpose specific chambers with defined physical parameters were applied. The gained tentative results show the importance of these experiments for the estimation of radionuclide transfer to plants and for the prognosis of human internal irradiation.

Kaupimosi koeficiento vertės, priklausomai nuo laiko, kai maitinančioje terpėje yra jonų formos l37Cs, kito nuo (5,2±0,5)-10-3 iki (53,0±7,0)-1CH m2/kg. Tuo atveju, kai maitinančioje terpėje yra mineraliniu elementų, I37Cs kaupimosi kviečių daiguose koeficientas kinta nuo (1,1±0,2)-10~2 iki (37,0±7,0)-10-3 m2/kg. Gautieji preliminarūs rezultatai parodė tokių tyrimų svarbą įvertinant radionuklidų pernašos į augalus mechanizmą bei prognozuojant vidinės žmogaus apšvitos dydžius.