Numerical simulation of corium flow through rod bundle and/or debris bed geometries with a model based on Lattice Boltzmann method

IF 16.4 1区化学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Accounts of Chemical Research Pub Date : 2024-09-24 DOI:10.1016/j.nucengdes.2024.113603

J. Garcia Sarmiento , F. Fichot , V. Topin , P. Sagaut

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引用次数: 0

Abstract

A new model is proposed to investigate the relocation and the distribution of hot corium flows in different configurations (rod bundle, porous debris bed) representative of a severe accident in a Light Water Reactor (LWR). Our model relies on the coupling between a modified Lattice Boltzmann Method (LBM), called Free-Surface LBM, that solves hydrodynamics of unsaturated corium and a Finite Volume Method (FVM) that solves heat transfers. Corium solidification and melting are addressed by implementing a correlation between the temperature and the viscosity. Several simulations on representative elementary volumes were performed, varying configurations (debris bed, rod bundle with and without grid). From the results, it is possible to capture important details of the flow at a scale lower than the pore scale and, at the same time, it is possible to take into account the average effects at the scale of several pores. Presented as a proof of concept these preliminary studies show the interest of this kind of CFD approach to identify which parameters at microstructure scale can potentially govern the corium relocation kinetics at macroscopic scale. It will provide useful information that might improve core degradation models in severe accident codes, such as ASTEC.

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利用基于晶格玻尔兹曼法的模型，对流经棒束和/或碎片床几何形状的铈流进行数值模拟

我们提出了一个新模型，用于研究轻水反应堆（LWR）严重事故中不同配置（棒束、多孔碎片床）中热冕流的迁移和分布。我们的模型依赖于解决非饱和铈流体力学问题的改进型晶格玻尔兹曼法（LBM）（称为自由表面 LBM）和解决热传递问题的有限体积法（FVM）之间的耦合。通过实施温度与粘度之间的相关性，解决了铈凝固和熔化问题。对具有代表性的基本体积进行了多次模拟，并改变了配置（碎屑床、带网格和不带网格的棒束）。从结果来看，可以捕捉到低于孔隙尺度的流动的重要细节，同时也可以考虑到多个孔隙尺度的平均效应。作为概念验证，这些初步研究表明，这种 CFD 方法可以确定微观结构尺度上的哪些参数有可能在宏观尺度上控制铈的迁移动力学。它将提供有用的信息，从而改进严重事故代码（如 ASTEC）中的堆芯降解模型。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Accounts of Chemical Research 化学-化学综合

CiteScore

31.40

自引率

1.10%

发文量

312

审稿时长

2 months

期刊介绍： Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance. Accounts of Chemical Research replaces the traditional article abstract with an article "Conspectus." These entries synopsize the research affording the reader a closer look at the content and significance of an article. Through this provision of a more detailed description of the article contents, the Conspectus enhances the article's discoverability by search engines and the exposure for the research.