Congruent and Incongruent Radionuclide Release During Matrix Dissolution of Partly Oxidized High Burnup Spent Fuel


With respect to the assessment of the long-term behavior of the waste form spent fuel it is of high importance to study in particular the UO2 matrix dissolution behavior and the associated release/retention of radionuclides in contact with groundwater. During long term fuel storage, fuel oxidation may not be avoided. Main issue of this work is to identify the impact on the corrosion of partly oxidized fuel of environmental conditions such as (1) the nature of solution contacting the matrix, the (2) presence/absence of CO2, (3) fixed pH values within a range between pH 7- pH 11, and (4) the presence/absence of corroding container material (Fe-powder). Dissolution tests with powdered oxidized spent fuel in various granite waters, and NaCl-brine resulted in matrix dissolution rates in the same order of magnitude for all investigated media (ca.5×10−4/d). The presence of CO2 and fixed pH values (pH 5–11) was without a distinct effect. The independence of the dissolution rate of the oxidized fuel matrix upon the nature of solution, pCO2, fixed pH values (5-11) can probably be explained by a masking effect of radiolysis. In presence of Fe powder the matrix dissolution rate was found to be slowed down by a factor of ca. 20, associated with strong retention effects of radionuclides.

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  1. 1.

    J.I. Kim, B. Grambow, Geochemical assessment of actinide isolation in a German salt repository environment. Engineering Geology. 52, 221–230, (1999)

    Google Scholar 

  2. 2.

    B. Grambow, A. Loida, P. Dressler, H. Geckeis, J. Gago, I. Casas, J. de Pablo, J. Gimenez, M.E. Torrero, M.E. Long-Term Safety of Radioactive Waste Disposal: Chemical Reaction of Fabricated and High Burnup Spent UO2 Fuel with Saline Brines, Forschungszentrum Karlsruhe Wissenschaftliche Berichte FZKA 5702, März 1996

    Google Scholar 

  3. 3.

    P. Toulhouat, Personal communication: Composition calculated for equilibrium of deep granite water with granite and fracture filling materials (CEA specification), (1995)

    Google Scholar 

  4. 4.

    B. Martinez, A. Melón, J. Valladares, Personal communication: Preparation of a synthetic bentonite-granitic water. Madrid, Spain; CIEMAT Geological Division (1996)

    Google Scholar 

  5. 5.

    B. Grambow, R. Müller (Mater. Res. Soc. Symp.Proc. 176 (1990) 229

    CAS  Article  Google Scholar 

  6. 6.

    A. Loida, B. Grambow, H. Geckeis, Anoxic corrosion of various high burnup spent fuel samples, Journal of Nuclear Materials 238 (1996) 11–22

    CAS  Google Scholar 

  7. 7.

    H. Geckeis, B. Grambow, A. Loida, B. Luckscheiter, E. Smailos, J. Quinones, Formation and Stability of Colloids under Simulated Near Field Conditions, Radiochim.Acta 82, 123–128 (1998)

    CAS  Article  Google Scholar 

  8. 8.

    W. Gray, C. Wilson, Spent Fuel Dissolution Studies FY1991 to 1994, PNL-10540 Pacific Northwest Laboratory (1995)

    Google Scholar 

  9. 9.

    J. de Pablo, I. Casas, J. Giménez, M. Molera, M.E. Torrero, Effect of Temperature and Bicarbonate Concentration on the Kinetics of UO2(s) Dissolution under Oxidizing Conditions. Mat. Res.Soc. Symp.Proc. 465 535–542 (1997)

    Article  Google Scholar 

  10. 10.

    B. Grambow, A. Loida, A. Martinez-Esparza, P. Diaz-Arocas, J. de Pablo, J.L. Paul, G. Marx, J.P. Glatz, K. Lemmens, K. Ollila, H. Christensen, Source Term for Performance Assessment of Spent Fuel as aWaste Form, Final Report, Forschungszentrum Karlsruhe Wissenschaftliche Berichte FZKA 6420, Februar 2000

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Loida, A., Grambow, B. & Geckeis, H. Congruent and Incongruent Radionuclide Release During Matrix Dissolution of Partly Oxidized High Burnup Spent Fuel. MRS Online Proceedings Library 663, 417 (2000).

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