title: Multiscale Speciation of U and Pu at Chernobyl, Hanford, Los Alamos, McGuire AFB, Mayak, and Rocky Flats.
abstract: The speciation of U and Pu in soil and concrete from Rocky Flats and in particles from soils from Chernobyl, Hanford, Los Alamos, and McGuire Air Force Base and bottom sediments from Mayak was determined by a combination of X-ray absorption fine structure (XAFS) spectroscopy and X-ray fluorescence (XRF) element maps. These experiments identify four types of speciation that sometimes may and other times do not exhibit an association with the source terms and histories of these samples: relatively well ordered PuO2+x and UO2+x that had equilibrated with O2 and H2O under both ambient conditions and in fires or explosions; instances of small, isolated particles of U as UO2+x, U3O8, and U(VI) species coexisting in close proximity after decades in the environment; alteration phases of uranyl with other elements including ones that would not have come from soils; and mononuclear Pu-O species and novel PuO2+x-type compounds incorporating additional elements that may have occurred because the Pu was exposed to extreme chemical conditions such as acidic solutions released directly into soil or concrete. Our results therefore directly demonstrate instances of novel complexity in the Å and μm-scale chemical speciation and reactivity of U and Pu in their initial formation and after environmental exposure as well as occasions of unexpected behavior in the reaction pathways over short geological but significant sociological times. They also show that incorporating the actual disposal and site conditions and resultant novel materials such as those reported here may be necessary to develop the most accurate predictive models for Pu and U in the environment.
authors: ‡Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
authors: Olga N
authors: ON
authors: Batuk
authors: †Synchrotron-SOLEIL, L'Orme des Merisiers, Saint-Aubin - BP48, 91192, France.|‡Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
authors: Steven D
authors: SD
authors: Conradson
authors: §Ural Federal University, Mira Street 19, Ekaterinburg 620002 Russia.
authors: Olga N
authors: ON
authors: Aleksandrova
authors: ‡Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
authors: Hakim
authors: H
authors: Boukhalfa
authors: ∥V.G. Khlopin Radium Institute, 28, 2-nd Murinskiy Ave., St. Petersburg 194021, Russia.
authors: Boris E
authors: BE
authors: Burakov
authors: ‡Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
authors: David L
authors: DL
authors: Clark
authors: ⊥University of Nevada, MSM 245, 4505 S. Maryland Pkwy, Las Vegas, Nevada 89154, United States.
authors: Ken R
authors: KR
authors: Czerwinski
authors: #Pacific Northwest National Laboratory, PO Box 999 MSIN: K8-96, Richland, Washington 99352, United States.
authors: Andrew R
authors: AR
authors: Felmy
authors: ∇Environmental Earth System Sciences Department, 473 Via Ortega, Stanford University, Stanford California 94305-4216, United States.
authors: Juan S
authors: JS
authors: Lezama-Pacheco
authors: ○Radiochemistry Division, Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia.|◆Frumkin Institute of Physical Chemistry and Electrochemistry of RAS, Leninsky av. 31, Moscow 119071, Russia.
authors: Stepan N
authors: SN
authors: Kalmykov
authors: #Pacific Northwest National Laboratory, PO Box 999 MSIN: K8-96, Richland, Washington 99352, United States.
authors: Dean A
authors: DA
authors: Moore
authors: ◆Frumkin Institute of Physical Chemistry and Electrochemistry of RAS, Leninsky av. 31, Moscow 119071, Russia.
authors: Boris F
authors: BF
authors: Myasoedov
authors: ‡Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
authors: Donald T
authors: DT
authors: Reed
authors: #Pacific Northwest National Laboratory, PO Box 999 MSIN: K8-96, Richland, Washington 99352, United States.
authors: Dallas D
authors: DD
authors: Reilly
authors: ‡Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
authors: Robert C
authors: RC
authors: Roback
authors: ○Radiochemistry Division, Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia.
authors: Irina E
authors: IE
authors: Vlasova
authors: ¶SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States.
authors: Samuel M
authors: SM
authors: Webb
authors: ‡Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
authors: Marianne P
authors: MP
authors: Wilkerson
mesh_terms: D047852:Chernobyl Nuclear Accident; D003120:Colorado; D009515:New Jersey; D009516:New Mexico; D011005:Plutonium / Q000032:analysis* / Q000737:chemistry; D012426:Russia; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013052:Spectrometry, X-Ray Emission; D014455:Ukraine; D014501:Uranium / Q000032:analysis* / Q000737:chemistry; D014861:Washington
chemical_list: D012990:Soil Pollutants, Radioactive; D014501:Uranium; D011005:Plutonium