Validation of the Numerical Model of the RVK-500 Hydrogen Recombiner

Abstract

If severe accidents occur at nuclear power plants with light water coolant, large quantities of hydrogen may be released as a result of the zirconium-steam reaction. In order to avoid explosive consequences, hydrogen passive autocatalytic recombiners (PAR) are installed in the containment to remove hydrogen flamelessly. To substantiate the hydrogen explosion safety of nuclear power plants using computer modeling, calculations of the state of the vapor-gas atmosphere inside the containment are performed, taking into account the presence of PAR. Experimental data are needed to validate computational models of recombiners. The article presents the results of a comparison of experimental and calculated data on the characteristics of the RVK-500 hydrogen recombiner. A brief description of the BM-P experimental stand is given, on which, for the first time in Russia, it was possible to study the operation of an industrial recombiner in abnormal operating modes (start modes and modes with leakage flow). To simulate abnormal operating modes of the recombiner, a CFD model is used, which describes the flow inside the recombiner in a simplified formulation (based on volumetric energy sources and the concentration of components of the vapor-gas medium). A description of the CFD model used to solve the problem of simulating the operation of the BM-P stand with the RVK-500 recombiner installed (inside the measuring chamber) is presented. For the experimental mode with leakage flow, a detailed comparison was carried out with the results of calculations performed for sensor placement points (temperature and concentration of components of the vapor-gas medium). In total, calculated and experimental data on the performance of the recombiner were compared for seven experimental modes, including the normal operation mode of the recombiner under conditions of a quiescent environment.