EXPERIMENTAL INVESTIGATION OF FLOW TRANSIENT CRITICAL HEAT-FLUX AT LIGHT-WATER REACTOR CONDITIONS

An experimental investigation of flow transient critical heat flux (CH F) for water at pressures 6.9 and 15.5 MPa is conducted under the simu lation of both Boiling Water Reactor (BWR) and Pressurized Water Re-ac tor (PWR) conditions. The influence of flow decay rates on local mass velocity and quality at CHF is explored to ensure the adequacy of loca l-condition approach in the CHF predictions. The assessment of transie nt upstream correction factor to modify the predictions of steady-stat e CHF correlations during the BWR flow transients are presented. A mec hanistic CHF model based on the dryout of a sublayer and CHF correlati ons are evaluated in the predictions of PWR flow transient CHF.