STP681: Effect of β-Phase Heat Treatment on the Subsequent α-Phase Ballooning Behavior of Zircaloy-4 Fuel Sheaths

    Hunt, CEL
    Research engineer and technician, Fuel Engineering Branch, Atomic Energy of Canada Limited, Chalk River Nuclear Laboratories, Fuel Engineering Branch, Chalk River, Ontario

    Newell, WG
    Research engineer and technician, Fuel Engineering Branch, Atomic Energy of Canada Limited, Chalk River Nuclear Laboratories, Fuel Engineering Branch, Chalk River, Ontario

    Pages: 18    Published: Jan 1979


    Abstract

    During certain postulated transients, a fuel sheath could experience a thermal spike into the β-phase followed by a prolonged period under stress in the α-phase temperature region. This thermal cycle would alter the metallurgical structure and the mechanical behavior. Ballooning tests were done on β heat-treated tubes to compare with previous work on as-received fuel sheaths. Comparisons were made at fixed internal pressures. Two heating rates were used—0.5 and 25°Cs-1—and the temperature range covered was 600 to 900°C. For both heating rates, in the α-phase temperature region the β heat-treated tubes strained less than as-received material at the same temperature and pressure. At temperatures in the (α + β)-phase region, there was no difference between the behavior of the two material conditions.

    Keywords:

    Zircaloy, mechanical properties, heat treatment, nuclear fuel cladding


    Paper ID: STP36695S

    Committee/Subcommittee: B10.02

    DOI: 10.1520/STP36695S


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