Detecting low levels of transuranics with electron energy loss spectroscopy

With the second difference electron energy loss spectroscopy (EELS) technique, transuranic (TRU) and rare-earth (RE) elements have been detected at low concentration levels (<200 ppm) in alteration phases formed during the laboratory corrosion of nuclear waste glass. Use of the high-energy M-4,M-5 edges to detect TRU elements is the only method available to positively identify them because the weaker lower-energy N-4,N-5 edges overlap with the more intense M-4,M-5 edges of the trace levels of REs that may be present in the same alteration phases. The position and intensity of the M-4,M-5 absorption edges of the TRU were confirmed with samples of transuranic contaminated soils and data from the literature, The M-4:M-5 ratio for the actinide absorption edges was used, in combination with crystal chemical considerations to determine chemical state.