Development of new technology using nuclear reactor for the research of agricultural environment and expanding of its use

Direct labeling of heavy metals in humus soil by thermal neutron irradiation was studied. The water elution rate of each element was measured under the various neutron irradiation conditions. The water elution rate of elements were changed by the neutron irradiation time. However, the state of element in soil was not changed by short irradiation time (less than 10 min), so that, the elution rate was the same value as that without irradiation. Six elements (Sc46, Cr51, Fe59, Co60, Zn55 and Eu152) were specified. The direct labeling of elements in agricultural materials (sludge compost) made clear that the elution rate of Fe, Co, Cr and Sc decreased with decreasing the dosage of sludge compost in soil. (S.Y.)