Modelling of Full-Scale Pressure Tube Rupture Experiments

Abstract

The paper describes an integrated model.developed at Ontario Hydro, to provide a physical basis for the transient phenomena that occur following pressure tube rupture in a CANDU fuel channel. The model predictions are compared to fundamental results obtained from the first two tests in the Full-scale pressure Tube Rupture Program being carried out at Westinghouse Canada, Inc. under CANDU funding. The model shows that the degree of coolant subcooling is a dominant parameter affecting the annulus pressure transient, and that there-is a feedback effect of calandria tube strain. These effects are observed in the experiments.Measurements of the peak annulus pressure and calandria tube permanent hoop strain obtained from the first two tests compare favourably with the model predictions. Other measured parameters.such as annulus pressurization and bellow rupture times are well predicted. Potential areas in which the model can be improved are discussed.