Project Number: 3096-13000-010-003-N
Project Type: Non-Funded Cooperative Agreement
Start Date: Aug 1, 2020
End Date: Jul 31, 2025
Estimation of soil redistribution rates using the anthropogenic radioisotope (AR) 137Cs has served the scientific community well for over 5 decades, but as natural decay of this AR and industrial accidents releasing it have resulted in a time in which it is no longer reliable. Other AR that are not biologically active, are strongly adsorbed to the soil matrix, and have very long half lives such as 239Pu and 240Pu should be investigated to determine if they are reliable surrogates for 137Cs. Our objective is to investigate soil profile inventories of 239Pu and 240Pu and compare their relationship of their relative inventory regarding soil degradation to the relationship between 137Cs relative inventories and soil degradation by erosion.
Discrete samples from soil profile depths have been dry ashed and extracted with nitric acid. These extracts will be reacted with ion exchange resin and sodium nitrite and a small aliquot of 242Pu is added as a yield tracer. The samples are agitated on an orbital shaker allowing good contact between the solution and the exchange resin. The equilibrated samples are pured through a pipette tip with a glass fiber plug to collect the exchange resin. The resin plug is subsequently rinsed with nitric acid to remove uranium. The exchange resin plugs are then rinsed with hydrochloric acid to remove thorium. After two more nitric acid rinses, the pipette columns containing the exchange resin are eluted with ammonium oxalate and a water rinse. The eluted samples are analyzed using an Inductively Coupled Plasma Mass Spectrometer.