Thermal hydraulic model validation for HOR mixed core fuel management Original Research Article

A thermal-hydraulic core model has been developed for the Hoger Onderwijsreactor (HOR), a 2 MW pool-type research reactor. The model was adopted for safety analysis purposes in the framework of HEU/LEU (highly enriched uranium/low enriched uranium) core conversion studies. It is applied in the thermal-hydraulic computer code SHORT (Steady-state HOR Thermal-hydraulics) which is presently in use in designing core configurations and in-core fuel management. An elaborate measurement program was performed for establishing the core hydraulic characteristics for a variety of conditions. The hydraulic data were obtained with a dummy fuel element with special equipment allowing a.o. direct measurement of the true core coolant flow rate. Using these data the thermal-hydraulic model was validated experimentally. The model, experimental tests, including calibration of the measurement device, and model validation are discussed.