Plutonium oxidation and subsequent reduction by Mn(IV) Minerals in Yucca Mountain tuff Article

Powell, BA, Duff, MC, Kaplan, DI et al. (2006). Plutonium oxidation and subsequent reduction by Mn(IV) Minerals in Yucca Mountain tuff . Environmental Science and Technology, 40(11), 3508-3514. 10.1021/es052353+

cited authors

  • Powell, BA; Duff, MC; Kaplan, DI; Fjeld, RA; Newville, M; Hunter, DB; Bertsch, PM; Coates, JT; Eng, P; Rivers, ML; Serkiz, SM; Sutton, SR; Triay, IR; Vaniman, DT

abstract

  • Plutonium oxidation state distribution on Yucca Mountain tuff and synthetic pyrolusite (β-MnO2) suspensions was measured using synchrotron X-ray micro-spectroscopy and microimaging techniques as well as ultrafiltration/solvent-extraction techniques. Plutonium sorbed to the tuff was preferentially associated with manganese oxides. For both Yucca Mountain tuff and synthetic pyrolusite, Pu(IV) or Pu(V) was initially oxidized to more mobile Pu(V/VI), but over time, the less mobile Pu(IV) became the predominant oxidation state of the sorbed Pu. The observed stability of Pu(IV) on oxidizing surfaces (e.g., pyrolusite), is proposed to be due to the formation of a stable hydrolyzed Pu(IV) surface species. These findings have important implications in estimating the risk associated with the geological burial of radiological waste in areas containing Mn-bearing minerals, such as at the Yucca Mountain or the Hanford Sites, because plutonium will be predominantly in a much less mobile oxidation state (i.e., Pu(IV)) than previously suggested (i.e., Pu(V/VI). © 2006 American Chemical Society.

authors

publication date

  • June 1, 2006

published in

Digital Object Identifier (DOI)

start page

  • 3508

end page

  • 3514

volume

  • 40

issue

  • 11