Neptunium and Americium Speciation in Selected Basalt, Granite, Shale, and Tuff Ground Waters

See allHide authors and affiliations

Science  15 Jul 1983:
Vol. 221, Issue 4607, pp. 271-273
DOI: 10.1126/science.221.4607.271


Neptunium and americium are relatively insoluble in ground waters containing high sulfate concentrations, particularly at 90°C. The insoluble neptunium species is Np(IV); hence reducing waters should enhance its formation. Americium can exist only in the trivalent state under these conditions, and its solubility also should be representative of that of curium.