Thermal hydraulic modelling of a high temperature nuclear reactor

Abstract

In the last years, the interest in the innovative LS-VHTR (Liquid-Salt-Cooled Very High-Temperature Reactor) has been growing. The advantages of using liquid salt as coolant is mainly related with its high efficiency of heat transfer, operation at low pressures, high volumetric heat capacity compared with gas and sodium, possible optical inspection and low corrosion rate. The LS-VHTR is a reactor of 2400 MWt cooled by liquid Li2BeF4 (Flibe) salt. The main aim was to verify the model capability comparing the calculation results with the available data. A thermal modeling of this reactor has been developed using the RELAP5-3D code using a point kinetic model. The core inlet and outlet coolant temperatures, the coolant mass flow, pressure drop and the temperatures along the core were simulated. The results have been compared with the available data. The developed model demonstrated that the RELAP5-3D is capable of reproduce the thermal behavior of the LS-VHTR in steady state operation.