STP1207: Application of J-Q Fracture Methodology to the Analysis of Pressurized Thermal Shock in Reactor Pressure Vessels

    Shum, DKM
    Senior research engineer, Saint-Gobain/Norton Industrial Ceramics Corp., Northboro, MA

    Theiss, TJ
    Development engineers, Oak Ridge National Laboratory, Oak Ridge, TN

    Rolfe, ST
    Professor and head, University of Kansas, Lawrence, KS

    Pages: 17    Published: Jan 1994


    Abstract

    Detailed two-dimensional plane strain analysis results for a reactor pressure vessel (RPV) with a shallow inner-surface axial flaw subject to a postulated pressurized thermal shock (PTS) transient are presented. The PTS transient simulates the pressure-fluid temperature history of an RPV in a pressurized water reactor (PWR) under postulated “small break loss of coolant accident” (SBLOCA) conditions. Analysis results appear to support the utility of the J-Q approach and interpretation method to characterize the crack-tip fields in an RPV under PTS conditions. Specifically, the (Q-stress parameter can be defined, for the assumed RPV and flaw geometries and transient conditions, up to maximum loading as characterized by the value of the J-integral during the transient. A method that incorporates small-specimen Jc(Q, T) toughness locus data in the safety-margin assessment of an RPV is presented. Analysis results suggest that the predicted margin of safety in RPVs under PTS conditions is greater based on the J-Q approach than that based on the conventional single-parameter J approach.

    Keywords:

    pressurized thermal shock, J-Q, theory, fracture mechanics, crack-tip fields, shallow flaw


    Paper ID: STP13704S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP13704S


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