Analyses on importance of iodine chemistry models in AnCheBi code for a severe accident of nuclear power plant

Abstract

In this paper, with the experimental data on the chemical behavior of iodine under the conditions of severe accident in nuclear power plant, first, we perform numerical analyses on the iodine chemistry model in AnCheBi (Analysis on Chemical Behavior of Iodine Species in the Containment) code for validation. Then, we perform analyses on the importance of the iodine chemistry models in AnCheBi code. In the analyses, the reaction coefficients are randomly sampled via Latin Hypercube sampling. The correlation coefficients, then, are calculated via the results of sensitivity analyses of AnCheBi with the randomly sampled reaction coefficients. In the calculations of correlation coefficients, concentrations of the iodine species are selected as figure of merits. From the correlation coefficients, we provide the reaction coefficients which are related with the dominant phenomena among the various chemical behaviors of iodine. Hence, they are the most important to evaluate the source term of nuclear accident in terms of regulatory view.