Source Term Identification of Environmental Radioactive Pu/U Particles by their Characterisation with Non-Destructive Analytical Techniques

Six radioactive particles stemming from Thule area (NW-Greenland) were investigated by gamma-ray and L X-ray spectrometry based on radioactive disintegration, scanning electron microscopy coupled with energy-dispersive and wavelength-dispersive X-ray spectrometer, synchrotron radiation based techniques as microscopic X-ray fluorescence, microscopic X-ray absorption near-edge structure (A-XANES) as well as combined X-ray absorption and fluorescence microtomography. Additionally, one particle from Mururoa atoll was examined by microtomography. From the results obtained, it was found out that the U and Pu were mixed in the particles. The U:Pu intensity ratios in the Thule particles varied between 0.05 and 0.36. The results from the microtomography showed that U:Pu ratio was not homogeneously distributed. The 241Am:238 239 240Pu activity ratios varied between 0.13 and 0.17, indicating that the particles originate from different source terms. The oxidation states of U and Pu as determined by A-XANES showed that U(IV) is the preponderant species and for Pu, two types of particles could be evidenced. One set had about 90 Pu(IV) while in the other the ratio Pu(IV):Pu(VI) was about one third.

ERIKSSON Mats;  OSAN Janos;  JERNSTROEM Jussi;  WEGRZYNEK D.;  SIMON R.;  CHINEA-CANO E.;  MARKOWICZ A.;  BAMFORD S.;  TAMBORINI Gabriele;  TOEROEK S.;  FALKENBERG G.;  ALSECZ A.;  DAAHLGARD H.;  WOBRAUSCHEK P.;  STRELI C.;  ZOEGER N.;  BETTI Maria; 

2005-09-15

PERGAMON-ELSEVIER SCIENCE LTD

JRC30459

http://www.sciencedirect.com/science/article/pii/S0584854705000248,    https://publications.jrc.ec.europa.eu/repository/handle/JRC30459,   

10.1016/j.sab.2005.02.023,