Analysis of Pb-Bi Vessel Wall Ablation Experiment with High Temperature Liquid by MPS Method

Abstract

Abstract:In a severe accident of a light water reactor, ablation of the RPV (reactor pressure vessel) lower head by corium is a key phenomenon, which affects progression of the accident. The MPS (moving particle semi-implicit) method is one of particle methods that calculate behavior of incompressible fluid by semi-implicit method. In preceding studies, the MPS method has been extensively studied and developed for simulations of different phenomena involved in severe accident of nuclear reactors. This paper aims to investigate whether the MPS method is capable of analyzing the lower head ablation phenomenon. The small-scale experiment carried out at CRIEPI (Central Research Institute of Electric Power Industry) using Pb-Bi vessel and silicone oil was analyzed for the validation of the MPS method. The MPS analysis well reproduced the experimental phenomena qualitatively. However, with respect to some quantitative results, more investigation such as influence of the calculation particle size is necessary.

Numerical Study on Relocation Process of Al, Fe, and Pb by Using the Moving Particle Semi-Implicit Method During Severe Accident of Reactor

“…Regarding Pb-Al, there is an experiment of melting and solidification, however, it is for crystalline size (Grabaek and Bohr, 1965). In the case of the melting behavior of Pb-alloy with silicone oil, Masumura et al (2015) successfully validated the experiment with numerical simulation.…”

“…The Moving Particle Semi-Implicit (MPS) method introduced first by Koshizuka and Oka (1996) is one of the alternative mesh-free methods utilized to simulate the relocation process of some nuclear materials. This method has been applied successfully (Duan, Yamaji, and Sakai, 2022;Masumura, Yamaji, and Furuya 2015;Mustari et al, 2015;Li, Oka, and Furuya, 2014;Kawahara and Oka, 2012) as reviewed by Li et al (2020).…”