Abstract
We extended the first version of fission product (FP) chemistry database named ECUME (Effective Chemistry database of fission products Under Multiphase rEaction). The extended ECUME consists of three kinds of datasets: CRK (dataset for Chemical Reaction Kinetics), EM (Elemental Model set) and TD (ThermoDynamic dataset). The present ECUME is equipped with the CRK for the reaction of Cs-I-BMo-O-H system in gas phase, the EM for the Cs chemical reaction with stainless steel (SS) (Cs chemisorption onto SS) and the TD for CsBO2 vapor species and solid Cs2Si4O9 and CsFeSiO4. A FP chemical reaction calculation in gas phase with the CRK of Cs-I-B-O-H system has shown the necessity of consideration of chemical reaction kinetics in the temperature range below 1500 K. The EM for Cs chemisorption has successfully reproduced the effects of CsOH vapor concentration in gas phase and Si content in SS on the Cs chemisorption behavior which were not able to be considered by the existing model. The high quality vapor pressure data for CsBO2 vapor were evaluated based on the result of a high temperature mass spectrometry. Thermodynamic data for solid Cs2Si4O9 and CsFeSiO4 were successfully evaluated by the experiment and ab-initio based methodology, respectively. These results have shown the validity and importance of the ECUME application for the more accurate evaluation of FP chemistry during transportation in a reactor under a LWR severe accident.
