Development of Mechanistic Entrainment Correlation in Accident of Evaporation to Dryness by Boiling of Reprocessed High-Level Liquid Waste

Abstract

An accident of evaporation to dryness by boiling of high-level liquid waste (HLLW) is postulated to be one of the severe accidents that may occur as a result of the loss of cooling function at a fuel reprocessing plant. In this case, some amount of nonvolatile fission products (FPs) will be transferred in the form of mist to the vapor phase in the tank, and could be released to the environment. Therefore, the quantitative estimation of the transfer rate is one of the key issues in the assessment of the accident consequences. To resolve this issue, a mechanistic correlation of the entrainment rate with upward vapor flow has been developed based on the data obtained from the experiments using simulated and actual HLLW.