Journal Article
Radiochimica Acta, vol. 102, iss. 12, pp. 1059-1068, 2014
Authors
Edgar C. Buck, Dean A. Moore, Kenneth R. Czerwinski, Steven D. Conradson, Olga N. Batuk, Andrew R. Felmy
Abstract
Abstract
The occurrence of plutonium dioxide (PuO2) either from direct
deposition or from the precipitation of plutonium-bearing solutions in
contaminated soils and sediments is well described, particularly for the
Hanford site in Washington State. However, past research has suggested that
plutonium at the Hanford site may exist in chemical forms in addition to
PuO2. Although the majority of the plutonium is present as oxide, we
present evidence for the formation of nano-sized mixed plutonium- iron
phosphate hydroxide structurally related to the rhabdophane group minerals
in 216-Z9 crib sediments from Hanford using both transmission electron
microscopy (TEM) and X-ray absorption spectroscopy (XAS). The iron-plutonium
phosphate formation may depend on the local microenvironment in the
sediments, availability of phosphate, and hence the distribution of these
minerals may control long-term migration of plutonium in the soil.
