Root Uptake of ¹⁴C Leached from the Low-Level Radioactive Waste for Sub-Surface Disposal with Engineered Barriers by Oryza sativa L. (2)

-Distribution of ¹⁴C in Rice Plant on the Case Using Acetic Acid as ¹⁴C-Source-

Abstract

The behavior of ¹⁴C from radioactive waste in paddy rice (Oryza sativa L.) at different stages of plant development was studied using the hydroponic and acetic acid as ¹⁴C-source. For ¹⁴C-application, plant root was soaked for 2 hours in a nutrient solution containing ¹⁴C-acetic acid at the vegetative growth stage (Aug. 2, 2007), heading (flowering) stage (Aug. 30, 2007) and milk-ripe stage (Sep. 13, 2007). In final sampling day (Mar. 5, 2008), 0.88-1.96% of the applied radioactivity was recovered from whole plant, however, the ratio of recovered radioactivity was not different at the growth stage. The distribution of ¹⁴C absorbed at each stage to each organ was noted to be highest in the submersed root through all the stages. Therefore the mixing of the root residue at the time of plowing would result in enhancement of the soil persistence of ¹⁴C.