Transfer and translocation of ²⁴¹Am, ²³⁹Pu, ¹³⁷Cs and ⁸⁵Sr after partial foliar contamination of bean plants

Laboratoire de Radioécologie et d'Écotoxicologie, Institut de Radioprotection et de Sûreté Nucléaire, DEI/SECRE/LRE, Cadarache, Bât. 186, BP. 3, 13115 St-Paul-lez-Durance Cedex, France

Abstract

Foliar transfer of transuranium elements had not received the same attention as other long-lived radionuclides, such as the well-known classical fission products Cs and Sr. Thus, the aim of this study was to compare the foliar transfer parameters of ²⁴¹Am and Pu with those of ¹³⁷Cs and ⁸⁵Sr. Bean plants (Phaseolus vulgaris) at flowering development stage were contaminated by soaking their first two trifoliate leaves for 3 hours in a solution containing ²⁴¹Am, Pu, or ¹³⁷Cs and ⁸⁵Sr. Results showed that transuranium elements were more retained by leaves than Cs or Sr. The mean leave-to-pod translocation factor of Am was of the same order as that of Sr, showing that the behaviour of Am was close to the behaviour of Sr. Translocation of Pu was significantly lower than for Cs, Sr or Am and occurred preferentially in leaves. Differential mobility of Am, Pu, Cs and Sr were compared to those used in related studies. Comparison showed that, when specific values of representative radioecological parameters are lacking, the behaviour of Am and Pu towards foliar transfer may be conservatively described as “Sr-like".