An Empirical Heat-Transfer Coefficient During Quenching

Abstract

Heat transfer coefficients (HTC) during quenching of a fuel channel are assessed to provide the boundary condition in the calculations of thermal stresses in the pressure tube. Of particular interest is the quenching of the fuel sheath and pressure tube during an IBIF (Intermittent Buoyancy Induced Flow) cycle. This information is required to determine whether the pressure tube can be returned to service following a channel flow stagnation. An empirical heat transfer coefficient based on the critical heat flux was used for the calculation of the fuel and pressure tube temperature during the quench. The prediction has been compared with measurements in a few selected Cold Water Injection Tests (CWIT) to quantify the conservatism.