VAPEX-Code Analysis of a Melt-Coolant Interaction Experiment on the FARO Setup

The purpose of this work was to make a computational analysis using the VAPEX thermohydraulic code, developed at the Experimental Scientific-Research Center at the All-Russia Scientific-Research Institute of Nuclear Power Plants, of the L-33 experiment performed on the FARO setup to study the interaction of core melt with water. The calculation of the stage of mixing of the melt stream with water and subsequent cooling satisfactorily predicted experimental parameters such as the temperature of the water and gas in the vessel. The calculation of the formation and propagation of the thermodetonation wave agrees well with the experimental data. Analysis of the experiment showed that the VAPEX code can predict adequately the most important characteristics of melt-coolant interaction during a serious accident at a nuclear power plant in accordance with the out-of-vessel scenario of the development of the accident.