Fig. 10.

Photographs of the U–Nb samples received and processed at LANL. (a) The largest two subsample fragments of Alloy-1 were combined and digested together to create one sample solution for the purposes of the interlaboratory comparison study. (b) A white Nb precipitate forms when an aliquot of the U–Nb sample is dissolved in HNO₃ or HCl acid (see bottom of centrifuge tube). Part of LANL’s method for Pa purifications involved physically separating this precipitate by centrifuging and decanting the supernatant