CALCULATION OF GAS PARAMETERS IN A NPP CONTAINMENT TAKING INTO ACCOUNT THE ADIABATIC ISOCHORIC COMPLETE COMBUSTION OF HYDROGEN BY THE KUPOL-M CODE

An important factor for the analysis of hydrogen safety is to take into account the effect of possible hydrogen combustion on the parameters of NPP containment atmosphere. In order to evaluate this effect a model of adiabatic isochoric complete combustion (AICC) of hydrogen was developed and implemented in the KUPOL-M containment code. With the model of adiabatic isochoric complete combustion of hydrogen included in the KUPOL-M code, this code will become applicable for the VVER NPP safety analysis performed with the aim to estimate possible thermal mechanical loads on the containment in case of hydrogen burning. This model is simple, conservative and based on the laws of conservation of mass and energy. The following assumptions are made in the model of adiabatic isochoric complete combustion of hydrogen: the volume in which burning takes place is constant; there is no heat transfer; the limiting component (in most cases it is hydrogen) burns down completely; intermediate stages of chemical transformations are not considered. The test results of this model on experimental data are presented in the article. There is a good agreement between the data of calculations and experiments in a wide range of hydrogen concentrations in gas mixtures. Based on the test results it can be concluded that implementation of AICC model in the KUPOL-M code allows conservatively evaluating the parameters in the containment atmosphere without significantly increasing the calculation time.