STP1354: The Effect of Microstructure on the Corrosion Behavior of Zircaloy-2 in BWRs

    Etoh, Y
    Senior researcher and researcher, Nippon Nuclear Fuel Development Co., Ltd., Ibaraki-ken,

    Nonaka, Y
    Senior researcher and researcher, Nippon Nuclear Fuel Development Co., Ltd., Ibaraki-ken,

    Kubo, T
    Senior engineer, Hitachi, Ltd., Ibaraki-ken,

    Nomata, T
    Senior specialist, Toshiba Corp., Kanagawa-ken,

    Hayashi, H
    Manager and chief engineer, Nuclear Power Engineering Corporation, Tokyo,

    Kitamura, M
    Manager and chief engineer, Nuclear Power Engineering Corporation, Tokyo,

    Pages: 20    Published: Jan 2000


    Abstract

    For improved Zircaloy-2 cladding tubes used in Japanese BWRs, α+β heat treatment is used on the outer surface of the tubeshell to suppress nodular corrosion. This treatment also provides superior uniform corrosion behavior up to 40 GWd/t. To investigate the effect of α+β heat treatment on corrosion behavior, the size distributions of second-phase particles in improved Zircaloy-2 cladding tubes and their changes during irradiation were observed and measured using an analytical transmission electron microscope. These cladding tubes were found to have smaller particles than previous ones. The dissolution rate of iron and nickel (Fe and Ni) was calculated as a function of particle size, chemical compositions of cladding tubes, and fast neutron flux. The relationship between corrosion behavior and the dissolution rate of Fe and Ni is described. Nodular corrosion occurred when the dissolution rate of Fe and Ni was slow.

    Keywords:

    Zircaloy-2, cladding tube, boiling water reactor, corrosion, hyrogen pickup, heat treatment, second-phase particle, irradiation-induced dissolution


    Paper ID: STP14322S

    Committee/Subcommittee: B10.02

    DOI: 10.1520/STP14322S


    CrossRef ASTM International is a member of CrossRef.