SEDL / STP / STP1207-EB / STP13704S

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

Download this paper for $25 PDF (288K)          View License Agreement
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 J^c(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.