Plutonium and Neptunium Speciation and Mobility in Soils and the Subsurface

Stout, Stephen A. ; Reilly, Sean D. ; Neu, Mary P.

Los Alamos National Laboratory

关键词: Public Lands;    Attenuation;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Sediments;    Neptunium;   

DOI  :  10.2172/896427
RP-ID  :  ERSD-90254-2006
RP-ID  :  AC52-06NA25396
RP-ID  :  896427

美国|英语

来源: UNT Digital Library

【 摘 要 】

The DOE is conducting cleanup and stabilization activities at its nuclear weapons development sites, many of which have accumulated plutonium in soils for 60 years. To properly control Pu migration in soils and groundwaters within Federal sites and onto public lands, better evaluate the public risk, and design effective remediation strategies, a fundamental understanding of Pu speciation and environmental transport is needed. The DOE is increasingly relying on monitored natural attenuation (MNA) for site stewardship. While this is practical, and defensible based on fundamental actinide chemistry and most environmental data, there are significant gaps in the foundation of the approach. Key among them is the inability to project migration rates and redistribution of actinide contaminants, particularly given the diversity and heterogeneity of sites. Matrix sorption/desorption processes are the main factors that determine contaminant transport, but little data of this type are available for Pu or Np with minerals and sediments. To support MNA and predictive geochemical models we conducted the following research: (1) Studied environmentally relevant Pu and Np species. (2) Determined the mechanisms and thermodynamics of interactions of Pu and Np species with Mn and Fe (oxy)hydroxides and with sediments, including actinide sorption/desorption during mineral formation and redox cycling.