角運動量を保存する粒子法を用いた相変化を伴う高温・高粘性流体の 拡散・凝固挙動評価
概要
For predicting the fuel debris distribution in Fukushima Daiichi Nuclear Power Plants (1FNPPs), it is essential to figure out the melt spreading behavior on primary containment vessel (PCV) floor. In this paper, we analyzed VULCANO spreading experiment programs using a particle method called “Moving Particle Full-Implicit method (MPFI)” which conserves an angular momentum. Phase change model was installed into MPFI method. two experiments having different corium characteristics were analyzed to confirm the corium composition effect for the influence of the spreading and the solidification behaviors. As a result, the molten corium drastically spread up to 10 seconds and rapidly solidified after 10 seconds. The free surface particles were solidified by the radiation. Besides, the corium in VE-U9 spread rather than that in VE-U7 due to the low viscous corium effect. It was confirmed that this method has a potential to utilize to simulate corium spreading in Fukushima.
