Mechanisms governing the release of radionuclides from spent nuclear fuel in geological repository: Major outcomes of the European project SFS

Christophe Poinssot, Cécile Ferry, Bernd Grambow, Manfred Kelm, Kastriot Spahiu, Aurora Martinez, Lawrence Johnson, Esther Cera, Joan De Pablo, Javier Quinones, Detlef Wegen, Karel Lemmens, Thomas McMenamin

    Research outputpeer-review

    Abstract

    European Commission supported a wide research project entitled "Spent Fuel Stability under repository conditions" (SFS) within the 5 th FWP, the aim of which was to develop a common understanding of the radionuclides release from spent nuclear fuel in geological disposal and build a RN release model in order to assess the fuel performance. This project achieved by the end of 2004 focuses both on the Instant Release Fraction (IRF) model and the Matrix Alteration Model (MAM). A new IRF model was developed based on the anticipated performances of the various fuel microstructures (gap, rim, grains boundaries) and the potential diffusion of RN before the canister breaching. However, this model lets the choice to the end-user about the degree of conservativeness to consider. In addition, fuel alteration has been demonstrated to be linked to the production of radiolytic oxidants by water radiolysis at the fuel interface, the oxidation of the fuel interface by radiolytic oxidants and the subsequent release of uranium under the influence of aqueous Uganda. A large set of experimental data was therefore acquired in order (i) to upgrade the current radiolytic kinetic scheme, (ii) to experimentally correlate the fuel alteration rate and the fuel specific alpha activity by performing experiments on alpha doped samples, (iii) to experimentally test the potential inhibitor effect of hydrogen on fuel dissolution. Based on these results, a new MAM was developed, which was also calibrated using the experiments on inactive UO2 samples. This model was finally applied to representative granitic, salt and clayey environment to predict spent fuel long-term fuel performance.

    Original languageEnglish
    Title of host publication29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX
    Place of PublicationWarrendale, United States
    PublisherMRS - Materials Research Society
    Pages421-432
    Number of pages12
    ISBN (Print)1558998896, 9781558998896
    DOIs
    StatePublished - 2006
    EventMRS 2005. Scientific Basis for Nuclear Waste Management XXIX - SCK•CEN, Gent
    Duration: 12 Sep 200516 Sep 2005

    Publication series

    NameMaterials Research Society Symposium Proceedings
    Volume932
    ISSN (Print)0272-9172

    Conference

    ConferenceMRS 2005. Scientific Basis for Nuclear Waste Management XXIX
    Country/TerritoryBelgium
    CityGent
    Period2005-09-122005-09-16

    ASJC Scopus subject areas

    • General Materials Science
    • Condensed Matter Physics
    • Mechanics of Materials
    • Mechanical Engineering

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