Technical development to remove radionuclides from agricultural soils by plants (Joint research)

Yamada, Satoshi*; Sakoda, Akihiro   ; Ishimori, Yuu  

Tottori University and Japan Atomic Energy Agency started a joint study to develop an environmental remediation technique for agricultural soil. Nine plants were water-cultured and examined for screening. A few were selected as candidates for demonstrations in fields. Preselected plants were mainly halophytes. Easily cultivated and harvested plants without harmful effect on new agriculture were also considered. Seedings prepared were first grown for a certain term. Additive-free, Cs and Sr groups, which are both stable isotopes, were then made. Stems, leaves and roots were harvested, in principle, two weeks after the addition, to measure K, Ca, Mg, Sr and Cs concentrations in them. It was concluded that New Zealand spinach and ice plant were most adequate for removing contaminants from surface soil. The two accumulate Cs and Sr mostly in the shoots, are prostrate, and spread the roots shallowly. For valid application, growth-phase dependences of absorption and distribution, growth property and root distribution should be elucidated. Finally, the application study plan was developed based on screening test results.