Figure 4
From: The nature of Pu-bearing particles from the Maralinga nuclear testing site, Australia
Details of the composition of Bruce. (a,b) FIB-SEM EDX line scans across the Pu–U-Fe(Al)-rich spheroid shown in (c); both profiles were measured at the same location, but at 20 and 5 kV respectively. These line scans demonstrate that the outer phase (labelled Al-oxide-rich matrix) consists predominantly of Al-O, and contains low levels of Pu–U, both in the background (site labelled ‘A’) and in particulate form (‘E’). The large, light grey, lath-shaped phase A grains (sites ‘B’, ‘C’, ‘D’) are Pu–U–C with minor Fe–Al. The matrix within the spherical area contains variable amounts of Fe–Al: the lighter areas contain more Fe than Al, i.e. between B and C, compared to the darker area that contains more Al than Fe, i.e. between C and D. This Fe(Al) alloy matrix also contains low levels of Pu–U. (d) Detail of (c); location in (c) is marked by a white rectangle. The Fe(Al) matrix of the this Pu–U–Fe(Al)-rich spheroid has broken down into an assemblage of two Fe(Al) alloys with different Fe:Al ratios (dark- and medium grey), and Pu–U rich nanoparticles (white). (e) Another Pu–U–Fe(Al)-rich sphere that contains phase A and B inclusions; note vapor bubbles associated with phase B. Vertical curtailing is an artifact of FIB polishing. (f) A detail of phase A, showing local compositional variation and porosity.
