Mavrik Zavarin

Portrait of  Mavrik Zavarin

  • Title
    Director, Glenn T. Seaborg Institute
  • Email
  • Phone
    (925) 424-6491
  • Organization
    Not Available

Research Interests

Environmental radiochemistry, Actinide chemistry, Surface complexation modeling of contaminant-mineral interactions, and Reactive transport modeling.

Professional Experience

Director, Glenn T. Seaborg Institute, LLNL, 2016–

Lawrence Livermore National Laboratory, 2018–, Science Focus Area Manager

Clemson University, 2012– , Adjunct Professor

Las Positas Community College, 2007– , Adjunct Professor

Lawrence Livermore National Laboratory, 2009–2018, Science Focus Area Lead Scientist

Helmholtz Zentrum Dresden Rossendorf (Dresden, Germany), 2012, Visiting Scientist

Lawrence Livermore National Laboratory, 2005–2010, Project Manager, Chemical Sciences Division

Lawrence Livermore National Laboratory, 1998–2005, Geochemist

University of California at Berkeley, 1993–98, Ph.D. Student

Gump Research Station, 1996, Summer Researcher


UC Berkeley, Nuclear Science and Security Consortium, External Board Member, 2019–

Notre Dame Actinide Center of Excellence, External Science Review Panel, 2018–

Seaborg Institute, Idaho National Laboratory, Review board member, 2017–

Nuclear Forensics Summer Internship, Director, LLNL, 2016–

Nuclear Forensics Undergraduate Summer School, Lecturer, W.S.U., 2011

Biological and Environmental Research Advisory Committee, Member, Dept. of  Energy, 2006–2010

Technical Working Group, Member, UGTA project, 2003–

Review Team, Member, Environmental Molecular Sciences Laboratory (2005, 2006, 2011)


  • American Chemical Society

  • Glenn T. Seaborg Institute

  • Sigma Xi, Livermore Chapter

Recent Students and Postdocs

Naomi Wasserman (post-doc, 2020–)

Teresa Baumer (post-doc, 2020–)

Nick Parham (undergraduate intern, Military Academy Research Associates (MARA) program, 2020)

Dinesh Adhikari (post-doc, 2019–2020)

Gauthier Deblonde (post-doc, 2019–2020)

Kurt Smith (LBNL post-doc, 2019–2020)

Nancy Merino (post-doc, 2019–)

Silvina DiPietro (graduate intern, Florida International University)

Emily Maulden (graduate intern, Washington State University)

Chao Pan (post-doc, 2018–2020)

Stefan Hellebrandt (post-doc, 2018–2019)

Keith Morrison (post-doc, 2015–2018)

Enrica Balboni (post-doc, 2016–2019)

Katie Hoffman (U. of Cincinnati, SCGSR fellow, 2017)

Mitchell Friend (Washington State University, intern, 2017–2018)

Carolyn Crow (post-doc, 2015–2017)

Merritt Earle (summer intern, Clemson Univ., 2015)

Claudia Joseph (post-doc, 2013–2016)

Mark Boggs (post-doc, 2012–2015)

Chad Durrant (graduate student, Penn State, 2013–2017)

Adele Panasci (graduate student, UC Davis, 2011–2014)

Corey Pilgrim (graduate student, UC Davis, 2013–present)

Nathan Conroy (graduate student, Clemson Univ., 2012–2017)

James Begg (post-doc, 2010–2014)

Ruth M. Tinnacher (post-doc, 2008–2011)

Brian A. Powell (post-doc, 2006–2008)

Jennifer Wong (graduate student, Clemson University, 2012–2016)

Sandra Fernando (summer intern, University of Michigan, 2011)

Mathew Snow (summer intern, Washington state University, 2010)

Mathilde Bourbin (intern, Ecole Nationale Superieure de Chimie de Paris, France, 2007, 2008)

Guillermo Atilio Blasiyh Numo (intern, IAEA Fellow, National Atomic Energy Commission of Argentina, 2006)

John Clements (summer intern, Clemson University, 2006

Justin Walensky (intern, The New college of Florida, 2004–2005)

Amanda Rainer (summer intern, 2003)


(ratemyprofessor overall score:  4.6)

2018                Introductory Organic Chemistry (30B), Las Positas Community College

2016                Introductory Inorganic Chemistry (30A), Las Positas Community College

2015                Introductory Inorganic Chemistry (30A), Las Positas Community College

2014                Introductory and Applied Chemistry (31), Las Positas Community College

2013                Introductory Inorganic Chemistry (30A), Las Positas Community College

2007–2010       Introductory Inorganic Chemistry (30A), Las Positas Community College

2008                Introductory Organic Chemistry (30B), Las Positas Community College

2003, 2005       Environmental Detectives, workshop presenter with E. Zavarin, Tri-Valley Expanding Your Horizons in Science and Mathematics

1996                Chemistry (1A) with Environmental Chemistry Lab Focus, Teaching Assistant, U.C. Berkeley

1995–1997       Introduction to Soils (ESPM 125), Teaching Assistant, U.C. Berkeley

Ph.D., University of California at Berkeley, 1999, Soil Chemistry

B.S., University of California at Berkeley, 1993, Chemistry


Books and Monographs

Geckeis, H., M. Zavarin, B. Salbu, O.C. Lind, and L. Skipperud. 2019. Chapter 25: Environmental Chemistry of Plutonium, In Plutonium Handbook, 2nd edition (D. L. Clark, D.A. Geeson R.J. Hanrahan, Jr, Eds.) American Nuclear Society. ISBN: 978-0-89448-201-4

Kersting, A.B., and Zavarin, M. (2011) Colloid Facilitated Transport of Plutonium at the Nevada Test Site, in Actinide Nanoparticle Research, Springer-Verlag, Berlin.

Doner, H.E., and Zavarin, M. (1997) The Role of Soil Carbonates in Trace and Minor Element Chemistry in Soils and Environment – Soil Processes from Mineral to Landscape Scale, in Advances in GeoEcology 30.

Refereed Journal Publications

Damerow, J., et al. Accepted. Sample Identifiers and Metadata to Support Data Management and Reuse in Multidisciplinary Ecosystem Sciences, Data Science Journal.

Emerson, H.P., Pearce, C.I., Delegard, C.H., Cantrell, K.J., Snyder, M.M.V., Thomas, M.L., Gartman, B.G., Miller, M.D., Resch, C.T., Heald, S.M., Plymale, A.E., Reilly, D.D., Saslow, S.A., Neilson, W., Murphy, S., Zavarin, M., Kersting., A.B., Freedman, V.L., 2021, Influences on Subsurface Plutonium and Americium Migration, ACS Earth Space Chem. Accepted.

Deblonde, G., Kersting, A., and Zavarin, M. 2020. Open questions on the environmental chemistry of radionuclides, Commun Chem 3: 167,

Morrison, K.D., Zavarin, M., Kersting, A.B., Begg, J., Mason, H.E., Balboni, E., Jiao, Y. 2021. The influence of uranium concentration and pH on U-phosphate biomineralization by Caulobacter OR37, Environ. Sci. Technol.,

Tran, E., Zavarin, M., Kersting, A.B., Klein-BenDavid, O., Teutsch, N., Weisbrod, N. 2021. Colloid-facilitated transport of 238Pu, 233U and 137Cs through fractured chalk: Laboratory experiments, modelling, and implications for nuclear waste disposal, Science Tot. Environment, 757: 143818,

Balboni, E., Smith, K.F., Moreau, L., Li, T.T., Booth, C., Maloubier, M., Kersting, A.B., Zavarin, M. 2020. Plutonium fate during ferrihydrite to goethite recrystallization. ACS Earth Space Chem., 4(11): 1993–2006,

Pan, C., Jiao, Y., Kersting, A.B., Zavarin, M. 2021. Plutonium redox transformation in the presence of iron, organic matter and hydroxyl radicals: Implications for transient plutonium mobilization in water, Environ. Sci. Technol.,

Tran, E., Reimus, P., Klein-BenDavid, O., Teutsch, N., Zavarin, M., Kersting, A.B., Weisbrod, N. 2020. Mobility of Radionuclides in Fractured Carbonate Rocks: Lessons from a Field-Scale Transport Experiment, Environ. Sci. Technol., 54(18): 11249–11257,

Zhao, P., Zavarin, M., Dai, Z., and Kersting, A.B. 2020. Stability of plutonium oxide nanoparticles in the presence of montmorillonite and implications to colloid facilitated transport, Applied Geochemistry. 122: 104725,

Maloubier, M., Emerson, H., Peruski, K., Kersting, A.B., Zavarin, M., Almond, P.M., Kaplan, D.I., Powell, B.A. 2020. Impact of Natural Organic Matter on Plutonium Vadose Zone Migration from an NH4Pu(V)O2CO3(s) Source, Environ. Sci. Technol. 2020, 54, 2688−2697.

Tran, E., Teutsch, N. Klein-BenDavid, O., Kersting, A., Zavarin, M., Weisbrod, N. 2019. Radionuclide transport in brackish water through chalk fractures. Water Research, 163: 114886.

Hamilton-Brehm, S.D., Stewart, L.E., Zavarin, M. Caldwell, M., Lawson, P., Onstott, T.C., Grzymski, J., Neveux, I., Sherwood Lollar, B., Russell, C.E., and Moser, D.P. 2019. Thermoanaerosceptrum fracticalcis gen. nov. sp. nov., a novel fumarate-fermenting organism from a deep fractured carbonate aquifer of the US Great Basin. Front. Microbiol. 10:2224.

Joseph, C., Balboni, E., Baumer, T., Treinen, K., Kersting, A.B., and Zavarin, M. 2019. Plutonium desorption from nuclear melt glass-derived colloids and implications for migration at the Nevada National Security Site, USA, Environ. Sci. Technol., 53, 12238−12246.

Zavarin, M., Zhao, P., Joseph, C., Begg, J.D., Boggs, M.A., Dai, Z., and Kersting, A.B. 2019. Hydrothermal alteration of nuclear melt glass, colloid formation, and plutonium mobilization at the Nevada National Security Site, U.S.A., Environ. Sci. Technol., 53, 13, 7363-7370.

Friend, M.T., Zhao, P., Zavarin, M., and Wall, N.A. 2019. Complexation of Plutonium(IV) with trans-1,2-Diaminocyclohexane-N,N,N′,N′-tetraacetic Acid (CDTA) in Acidic Solution, Journal of Solution Chemistry 4 (2), 212–233, doi: 10.1007/s10953-019-00859-1

Morrison, K.D., Jiao, Y., Kersting, A.B., and Zavarin, M. 2018. Reduction of Plutonium(VI) to (V) by Hydroxamate Compounds at Environmentally Relevant pH, Environ. Sci. Technol., 52:6448−6456.

Begg, J.D., Edelman, C., Zavarin, M., Kersting, A.B. 2018. Sorption kinetics of plutonium (V) to three montmorillonite clays, Applied Geochemistry, 96: 131–137.

Pilgrim, C.D., Mason, H.E., Zavarin, M., Casey, W.H. 2018. Rates of ligand exchange around the bis-oxalato complex NpO2(C2O4)23- measured using multinuclear NMR at neutral to semi-alkaline conditions, ChemPlusChem 10.1002/cplu.201800025, 83:1-8,

Durrant, C.B., Begg, J.D., Kersting, A.B., Zavarin, M. 2018. Cesium sorption reversibility and kinetics on illite, montmorillonite, and kaolinite, Sci. Tot. Env., 610/611: 511–520,

Pilgrim, C.D., Zavarin, M. and Casey, W.H. 2017. The pressure dependence of carbonate exchange with [NpO2(CO3)3]4- in aqueous solutions. Inorg. Chem, 56: 661−666

Begg, J., Zavarin, M., and Kersting, A.B. 2017. Desorption of plutonium from montmorillonite: An experimental and modeling study, Geochim. Cosmochim. Acta, 197: 278-293.

Conroy, N.A., Zavarin, M., Kersting, A.B., and Powell, B.A. 2017. The Effect of Natural Organic Matter on Plutonium Sorption to Goethite, Environ. Sci. Technol., 51: 699-708.

Joseph, C., Mibus, J., Trepte, P., Müller, C., Brendler, V., Park, D.M., Jiao, Y., Kersting, A.B., Zavarin, M. 2017. Long-term diffusion of U(VI) in bentonite: Dependence on density. In press Science Total Environment, 575: 207-218.

Boggs, M.A., Jiao,Y., Dai, Z., Zavarin, M., and Kersting, A.B. 2016. Plutonium Reaction with Pseudomonas sp. and its Extracellular Polymeric Substances, Applied and Environmental Microbiology, 82: 7093-7101.

Romanchuk, A Yu, Kalmykov, S N, Kersting, A B, Zavarin, M. 2016. Behavior of plutonium in the environment. Russian. Chem. Rev., 85: 995-1010. DOI: 10.1070/RCR4602

Zhao, P., Begg, J.D., Zavarin, M., Tumey, S.J., Williams, R., Dai, Z.R., Kips, R., and Kersting, A.B. 2016. Plutonium(IV) and (V) Sorption to Goethite at Sub-Femtomolar to Micromolar Concentrations: Redox Transformations and Surface Precipitation. Environ. Sci. Technol., 50: 6948-6956. DOI: 10.1021/acs.est.6b00605.

Mason, H.E., Begg, J.D, Maxwell, R.S., Kersting, A.B., Zavarin, M., 2016. A novel NMR method for the investigation of trivalent lanthanide sorption on amorphous silica at low surface loadings, Envir. Sci. Process. Impact, 18: 802-809.

Wong, J., Zavarin, M., Begg, J.D., Kersting, A.B., and Powell, B.A. 2015 Effect of equilibration time on Pu desorption from goethite, Radiochim. Acta, 103:695-705. DOI: 10.1515/ract-2015-2404.

Tinnacher, R.M., Begg, J.D., Mason, H., Ranville, J., Powell, B.A., Wong, J.C., Kersting, A.B., and Zavarin, M. 2015. Effect of fulvic acid surface coatings on plutonium sorption and desorption kinetics on goethite, Environ. Sci. Technol., 49(5):2776-2785, doi: 10.1021/es505120s.

Begg, J.D., Zavarin, M., Tumey, S.J., and Kersting, A.B. 2015. Plutonium sorption and desorption behavior on bentonite, J. Environ. Radioact., 141:106-114, doi: 10.1016/j.jenvrad.2014.12.002.

Boggs, M.A., Dai, Z., Zavarin, M., and Kersting, A.B. 2015. Plutonium(IV) sorption to montmorillonite in the presence of organic matter, J. Environ. Radioact., 141:90-96, doi: 10.1016/j.jenvrad.2014.12.005.

Shusterman, J., Mason, H., Bruchet, A., Zavarin, M., Kersting, A.B., and Nitsche, H. 2014. Analysis of trivalent cation complexation to functionalized mesoporous silica using solid-state NMR spectroscopy, Dalton Trans., 43:16649-16658, doi: 10.1039/c4dt02380c.

Panasci, A.F., Harley, S.J., Zavarin, M., and Casey, W.H. 2014. Kinetic studies of the [NpO2(CO3)3]4− ion at alkaline conditions using 13C NMR, Inorg. Chem., 53:4202−4208, doi: 10.1021/ic500314v (cover).

Boggs, M.A., Mason, H.E., Arai, Y., Powell,A., Kersting, A.B., and Zavarin, M. 2014. Nuclear magnetic resonance spectroscopy of aqueous plutonium(IV) desferrioxamine B complexes. Eur. J. Inorg. Chem., 21:3312-3321, doi: 10.1002/ejic.201402105.

Begg, J.D., Zavarin, M., and Kersting, A.B. 2014. Plutonium desorption from mineral surfaces at environmental concentrations of hydrogen peroxide. Environ. Sci. Technol., 48:6201–6210, doi:10.1021/es500984w.

Zhao, P., Tinnacher, R. M., Zavarin, M., and Kersting, A. B. 2014. Analysis of trace neptunium in the vicinity of underground nuclear tests at the Nevada National Security Site, J. Environ. Radioact., 137:163-172, doi: 10.1016/j.jenvrad.2014.07.011.

Benedicto, A., Begg, J.D., Zhao, P., Kersting, A.B., Missana, T., and Zavarin, M. 2014. Effect of major cation water composition on the ion exchange of Np(V) on montmorillonite: NpO2+-Na+-K+-Ca2+-Mg2+ selectivity coefficients, Appl. Geochem., 47:177-185, doi: 10.1016/j.apgeochem.2014.06.003.

Zavarin, M., Zhao, P., Dai, Z.R., and Kersting, A.B. 2014. Plutonium sorption and precipitation in the presence of goethite at 25 and 80°C, Radiochim. Acta, 102:983-997.

Parsons-Moss, T., Wang, J., Jones, S., May, E. Olive, D., Dai, Z., Zavarin, M., Kersting, A.B., Zhao, D., and Nitsche, H. 2014. Sorption interactions of plutonium and europium with ordered mesoporous carbon, J. Mater. Chem. A, 2:11209-11221, doi: 10.1039/C4TA01740D.

Zimmerman, T., Zavarin, M., and Powell, B. A. 2014. Influence of humic acid on plutonium sorption to gibbsite: Determination of pu-humic acid complexation constants and ternary sorption studies, Radiochim. Acta, 102:629-643, doi: 10.1515/ract-2014-2163.

Begg, J.D., Zavarin, M. Zhao, P., Tumey, S.J., Powell, B.A., and Kersting, A.B. 2013. Pu(V) and Pu(IV) sorption to montmorillonite, Environ. Sci. Technol., 47:5146-5153, doi: 10.1021/es305257s.

Snow, M.S., Zhao, P., Dai, Z., Kersting, A.B., and Zavarin, M. 2013. Neptunium(V) sorption to goethite at attomolar to micromolar concentrations, J. Colloid Interface Sci., 390:176-182, doi:10.1016/j.jcis.2012.08.058.

Huang, P., Zavarin, M., and Kersting, A.B. 2012. Ab initio structure and energetics of Pu(OH)4 and Pu(OH)4(H2O)n clusters: Comparison between density functional and multi-reference theories, Chem. Phys. Lett., 543:193–198, doi:10.1016/j.cplett.2012.06.033.

Zavarin, M., Powell, B.A., Bourbin, M. Zhao, P., and Kersting, A.B. 2012. Np(V) and Pu(V) ion exchange and surface-mediated reduction mechanisms on montmorillonite, Environ. Sci. Technol., 46:2692–2698, doi: 10.1021/es203505g.

Tinnacher, R. M., Powell, B. A., Kersting, A. B., and Zavarin, M. 2011. Kinetics of neptunium(V) sorption and desorption reactions on goethite: Experiment and modeling, Geochim. et Cosmochim. Acta, 75:6854-6599.

Powell, B. A., Dai, Z., Zavarin, M. Z., Zhao, P., and Kersting, A. B. 2011. Stabilization of plutonium nano-colloids by epitaxial distortion on mineral surfaces, Environ. Sci. Tech., 45:2698-2703.

Zhao, P., Zavarin, M., Leif, R.N., Powell, B.A., Singleton, M.J., Lindvall, R.E., and Kersting, A.B. 2011. Mobilization of actinides by dissolved organic compounds at the Nevada Test Site, Applied Geochemistry, 26:308-318.

Hu, Q., Zavarin, M. and Rose, T.P. 2008. Effect of reducing groundwater on the retardation of redox-sensitive radionuclides, Geochemical Trans., 9:12.

Hu, Q., Rose, T.P., Zavarin, M., Smith, D.K., Moran, J.E., and Zhao, P. 2008. Assessing field-scale migration of radionuclides at the Nevada Test Site: Mobile species. J. Environ. Radioactivity, 99:1617-1630.

Zhao, P., Hu, Q., Rose, T.P., Nimz, G.L., and Zavarin, M. 2008. Distribution of 99 Tc and 129I in the vicinity of underground nuclear tests at the Nevada Test Site, J. Radioanal. Nucl. Chem., 276(3):755-761.

Zavarin, M. and Doner, H.E. 2005. Effect of P and Se(IV) on calcite precipitation inhibition, Soil Sci., 170(8):612-623.

Zavarin, M., Roberts, S.K., Hakem, N., Kersting, A., and Sawvel, A.M. 2005. Eu(III),Sm(III), Np(V), Pu(V), and Pu(IV) sorption to calcite, Radiochim. Acta, 93:93-102.

Strawn, D., Doner, H., Zavarin, M., and McHugo, S. 2002. Microscale investigation into the  geochemistry of arsenic, selenium, and iron in soil developed in pyritic shale materials, Geoderma, 108(3-4):237-257.

Zavarin, M. and Doner, H.E. 2002. Interpretation of heterogeneity effects in synchrotron x-ray fluorescence microprobe data, Geochemical Trans., 3(7):51-55.

Dubbin, W., Sposito, G. and Zavarin, M. 2000. X-ray absorption spectroscopic study of Cu glyphosate adsorbed by microcrystalline gibbsite, Soil Sci., 165:699-707.

Sun, X. Doner, H.E., and Zavarin, M. 1999. Spectroscopy investigation of arsenite (As(III)) oxidation on Mn-substituted goethite, Clays and Clay Mins., 47(4):474-480.

Zawislanski, P.T. and Zavarin, M. 1996. Nature and rates of selenium trans-formations:  A laboratory study of Kesterson Reservoir soils, Soil Sci. Soc. Am. J., 60(3):791-800.

Conference Proceedings

Birkholzer, J., Asahina, D., Chen, F., Gardner, P., Houseworth, J., Jove-Colon, C., Kersting, A.B., Nair, P., Li, L., Liu, H., Painter, S., Reimus, P., Rutqvist, J., Steefel, C., Tynan, M., Wang, Y., and Zavarin, M. An overview of US disposal research activities linked to international URLs, Proceedings of the IHLRWMC 2013, American Nuclear Society, Albuquerque, NM, April 28-May 2, 2013, 1047-1054.

Zavarin, M., Zhao, P., Dai, Z.R., Carroll, S.A., and Kersting, A.B. Morphology of plutonium precipitates in the presence of goethite at 25 and 80°C, Proceedings of the IHLRWMC 2013, American Nuclear Society, Albuquerque, NM, April 28-May 2, 2013, 816-821.

Carle, S.F., Zavarin, M., Shumaker, D.E., Tompson, A.F.B., Maxwell, R.M., and Pawloski, G.A. Simulating effects of non-isothermal flow on reactive transport of radionuclides originating from an underground nuclear test, Proceedings of the XVI International Conference on Computational Methods in Water Resources, Copenhagen, Denmark (2006).

Maxwell, R.M., Tompson, A.F.B., Carle, S.F., Zavarin, M., and Kollet, S.J. A serendipitous long-term infiltration experiment:  water and radionuclide circulation beneath CAMBRIC trench at the Nevada Test Site, Proceedings of the XVI International Conference on Computational Methods in Water Resources, Copenhagen, Denmark (2006).

Zavarin, M. and Doner, H.E. Selenium, Nickel, and Manganese interaction with calcite, Fourth International Conference on the Biogeochemistry of Trace Elements, Berkeley, CA (June 1997).

Conference Proceedings (Unreviewed)

Farnham, I., Rehfeldt, K., Zavarin, M. 2020. The Nature and State of Groundwater Contamination at the Nevada National Security Site: What Have We Learned from Decades of Groundwater Analysis?, Waste Management Conference, Phoenix, AZ.

Begg, J.D., Zavarin, M., and Kersting, A.B. Probing the stability of Pu on montmorillonite, Pu Futures-The Science, Las Vegas, NV (September 2014).

Boggs, M.A., Zavarin, M., Jiao, Y., and Kersting, A.B. Influence of extracellular polymeric substances on plutonium sorption to bacteria, Pu Futures-The Science, Las Vegas, NV (September 2014).

Zhao, P., Kersting, A.B., Dai, Z., and Zavarin, M. Stability of intrinsic pu colloids in the presence of montmorillonite at 25 and 80 °C: High-fired and solution precipitated PuO2, Pu Futures-The Science, Las Vegas, NV (September 2014).

Zhao, P., Zavarin, M., Tumey, S., Williams, R., Dai, Z., Kips, R., and Kersting, A.B. Pu sorption to goethite at micromolar to attomolar concentrations, Pu Futures-The Science, Keystone, CO (September 2010).

Tinnacher, R.M., Zhao, P., Williams, R.W., Zavarin, M., and Kersting, A.B., Neptunium-237 concentrations in groundwater from Nevada Test Site wells, Pu Futures-The Science, Keystone, CO (September 2010).

Zavarin, M., Zhao, P., Hu, Q., Rose, T.P., and Kersting, A.B., Radionuclide distribution in debris from underground nuclear tests detonated in silicate and carbonate rocks, Pu Futures-The Science, Pacific Grove, CA (July 2006).

Zavarin, M., Maxwell, R.M., Kersting, A.B., Zhao, P., Sylvester, E.R., Allen, P.G., and Williams, R.W. Plutonium colloid-facilitated transport in the environment-Experimental and transport modeling evidence for plutonium migration mechanism, Pu Futures 2003 – The Science (2003).