Plutonium Uptake by Beans at Different Stages of Vegetation

The process of plutonium uptake by plants is influenced by many factors, which leads to very variable quantitative indices of its uptake. In the vegetation experiment, the uptake of plutonium in the system "soil — agricultural plant" was studied in different vegetation periods of beans (Fabaceae) of the Yantarnye variety. The analysis of the specific activity of plutonium in the soil and plants was carried out using radiochemical isolation by the method of ion-exchange chromatography. The activity of plutonium isotopes was measured in alpha spectrometers Alpha Duo, ORTEC. The Concentration Ratio was used to estimate the absorption of plutonium. The values of Concentration Ratio obtained during the study indicate its unequal uptake in different periods of plant growth and development. The Concentration Ratio were as follows: on day 14 — (4.5 ± 0.7) × 10 in the "first pair of true trifoliate leaves" phase, on day 22 — (3.5 ± 0.5) × 10 in the "stem branching" phase, on day 33 — (4.5 ± 0.6) × 10 in the "stem branching" phase, on day 47 — (1.8 ± 0.3) × 10 in the "budding" phase, on day 52 — (4.5 ± 0.7) × 10 in the "flowering" phase, on day 63 — (7.7 ± 1.2) × 10 in the "bean formation" phase. The results of the conducted vegetation experiment indicate that the most intensive uptake of plutonium by beans occurs during the transition to generative development at the budding stage.