STP955: Gas-Bubble Growth Mechanisms in the Analysis of Metal Fuel Swelling

    Gruber, EE
    Metallurgist and mechanical engineer, Argonne National Laboratory, Argonne, IL

    Kramer, JM
    Metallurgist and mechanical engineer, Argonne National Laboratory, Argonne, IL

    Pages: 13    Published: Jan 1987


    Abstract

    Under steady state conditions, irradiation resorption of fission gas from bubbles limits the swelling rates of metallic fast-reactor fuels to relatively small values. During transient thermal excursions, however, resorption effects diminish relative to thermal kinetics. Various bubble-growth mechanisms then become important components of the swelling These mechanisms include growth by diffusion, for bubbles within grains and on grain boundaries; dislocation nucleation at the bubble surface, or “punchout”; and bubble growth by creep. Analyses of these mechanisms are presented and applied to provide information on the conditions and the relative time scales for which the various processes should dominate fuel swelling. The results are compared to a series of experiments in which the swelling of irradiated metal fuel was determined after annealing at various temperatures and pressures. The diffusive growth of bubbles on grain boundaries is concluded to be dominant in these experiments.

    Keywords:

    irradiation, fission gas, swelling, bubble growth, metal fuel, dislocation nucleation, diffusion-controlled growth, creep (swelling), grain boundaries


    Paper ID: STP33834S

    Committee/Subcommittee: E10.02

    DOI: 10.1520/STP33834S


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