The aging of the US nuclear stockpile presents a number of challenges, incl
uding the increasing radioactivity of plutonium residues due to the in grow
th of Am-241 from the beta -decay of Pu-241. We investigated parameters tha
t affect the sorption of Am onto anion-exchange resins from concentrated ef
fluents derived from nitric acid processing of plutonium residues. These po
stevaporator wastes are nearly saturated solutions of acidic nitrate salts,
and americium removal is complicated by physical factors, such as solution
viscosity and particulates, as well as by the presence of large quantities
of competing metals and acid. Single- and double-contact batch distributio
n coefficients for americium and neodymium from simple and complex surrogat
e solutions are presented. Varied parameters include the nitrate salt conce
ntration and composition and the nitric acid concentration. We find that un
der these extremely concentrated conditions, Am(III) removal efficiencies c
an surpass 50% per contact. Distribution coefficients for both neodymium. a
nd americium are insensitive to solution acidity and appear to be driven pr
imarily by low water activities of the solutions.