Shadow Corrosion Mechanism of Zircaloy

    Volume 2, Issue 6 (June 2005)

    ISSN: 1546-962X


    Published Online: 1 June 2005

    Page Count: 17

    Lysell, G
    Studsvik Nuclear AB, Nyköping,

    Nystrand, A-C
    Studsvik Nuclear AB, Nyköping,

    Ullberg, M
    Studsvik Nuclear AB, Nyköping,

    (Received 5 April 2004; accepted 23 November 2004)


    The mechanism of Zircaloy shadow corrosion was studied theoretically and experimentally. The theoretical study showed shadow corrosion, with a few exceptions, to be remarkably consistent with a galvanic corrosion mechanism. The exceptions may be explained as radiation effects. An experiment was therefore devised to test the galvanic hypothesis, based on the fact that galvanic corrosion requires a closed current loop. Three pieces of Zircaloy cladding with stainless steel counter electrodes were exposed in-pile. Two of the claddings were galvanically coupled to the counters. The third cladding was well insulated by fitting it to a 100 mm sapphire tube. The claddings were irradiated together in oxidizing water chemistry for one reactor period. The galvanically coupled claddings developed shadow corrosion, but not the well insulated cladding.

    Paper ID: JAI12374

    DOI: 10.1520/JAI12374

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    Title Shadow Corrosion Mechanism of Zircaloy
    Symposium Zirconium in the Nuclear Industry: Fourteenth International Symposium, 2004-06-15
    Committee B10