プールスクラビング時のエアロゾル移行モデルの評価

抄録

In severe accidents of nuclear power plants, large amounts of gas containing radioactive particles are generated. It is extremely important to analyze the pool scrubbing effect in evaluating the influence to the environment. However, study on its principle is not carried out sufficiently, and we do not have enough experimental data to analyze the effect. The purpose of this study is to clarify the gas-liquid two-phase flow behavior which is important in elucidating the mechanism of pool scrubbing. We evaluate the aerosol transfer behavior using MELCOR code and compare the gas phase jet which was experimentally measured with the MELCOR code. Bubble behavior was observed via a high-speed camera. The bubble rising speed, bubble distribution and void fraction were measured by a wire mesh sensor. As a result, it is confirmed that bubbles in the nozzle tip have a shape closer to the true sphere than bubbles evaluated with MELCOR. From the comparison of swarm rise velocity measured experimentally and calculated from MECLOR code, experimental results showed faster speed than the calculated results of MELCOR code. Finally, we discuss the validity of the analysis code by comparing the model in the analysis code with the experiment data.