Impact of molybdenum on iodine chemistry during fission product transport phenomenology

Abstract

The release of iodine in a case of severe nuclear accident is directly linked to short-term radiological consequences. This concern raises issues in understanding the chemical forms of the transported iodine to devise proper accident management measures/strategies. In contributing to such efforts, this work presents experimental and theoretical approaches to defining the impact of molybdenum as a semi-volatile fission product toward iodine speciation in the gas phase. Given humid atmospheric conditions with different oxygen potentials, the interactions were revealed through the reaction products consisting of both gas and aerosols upon their transport and condensation in the temperature range of 1150–450 K. Through thermodynamic equilibrium calculations where new thermodynamic data of cesium molybdates have been incorporated, the experimental observation was reproduced, hence general interaction mechanism was proposed in this work.