(A) numerical assessment of reflood phenomena in PWRs

Abstract

As an extension work of computer codes QUEN1D, KREWET and BEAR developed by previous workers at KAIST has been performed. This study is based on a signle flow channel, and separated two phase flow. The heat transfer selection logic is developed and the heat transfer coefficients are calculated as a function of the local flow conditions. The wall temperataure history is calculated by solving the time-dependent radial conduction equation. Comparison between predictions and PWR-FLECHT experiment data shows a relatively good agreement, but further improvement seems to be necessary for low pressure and low flloding rate conditions.