Transfer of Radionuclides to Crop Plants through Roots

—Radiocesium and strontium—

Abstract

Cesium-137 and strontium-90 are important radionuclides for dose assessment in accidental and/or routine release of radionuclides from nuclear facilities including ground disposal facilities to the environments. Because both nuclides have relatively long half lives (30 years and 28.8 years, respectively) and relatively higher quantity in the fission product.
This study was carried out to estimate the amount of these nuclides transferred from culture solution to crop plants, particularly the edible parts of the plants. Rice plant (Oryza sativa L, cv. koshihikari), spinach (Spinacea oleracea L.), soybeans (Glycine max Merr.), and the other four kinds of crop plant were transplanted in culture solution containing ¹³⁷CsCl and ⁸⁵SrCl₂, and the transfer rates of ¹³⁷Cs and ⁸⁵Sr were obtained. The transfer rate is defined by the following equation; Transfer rate=the activity of plant sample/day/the mean activity of culture solution
The differences by the nuclides, by the organs of each plant and by plant species were discussed in this paper. And temporal critical crop plants for ¹³⁷Cs and ⁹⁰Sr were also selected.