Grizzi Vitor F, Lee Shao-Chun, Z Y
Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.
Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States.
J Phys Chem B. 2024 Jun 13;128(23):5676-5684. doi: 10.1021/acs.jpcb.4c01243. Epub 2024 Jun 4.
An in-depth understanding and characterization of molten salt properties are necessary for the optimized design, efficient operation, and safety assurance of molten salt reactors (MSRs). Investigating molten salt properties in experimental settings can be challenging and time-consuming due to the high temperatures of interest, the salt's corrosiveness, purity and composition control, and health and safety concerns. Therefore, it is beneficial to perform computational screening to assist in the ultimate experimental measurements. Herein, we used first-principles molecular dynamics simulations to calculate several thermophysical, structural, and dynamic properties of eutectic LiF-NaF with fuel additives UF and ThF. We found that with the incorporation of uranium or thorium, a prepeak appears in the structure factor, indicative of a medium-range structural ordering. Furthermore, we explore the mechanism through which these structural changes enhance shear stress correlations, thereby increasing the salt's viscosity. This work highlights the importance of studying the atomic-scale structure of molten salts and how the addition of fuel elements can substantially affect it.
深入了解和表征熔盐特性对于熔盐反应堆（MSR）的优化设计、高效运行和安全保障至关重要。由于感兴趣的温度较高、盐的腐蚀性、纯度和成分控制以及健康和安全问题，在实验环境中研究熔盐特性可能具有挑战性且耗时。因此，进行计算筛选以协助最终的实验测量是有益的。在此，我们使用第一性原理分子动力学模拟来计算含有燃料添加剂UF和ThF的共晶LiF-NaF的几种热物理、结构和动力学性质。我们发现，随着铀或钍的加入，结构因子中出现一个预峰，这表明存在中程结构有序。此外，我们探讨了这些结构变化增强剪切应力相关性从而增加盐粘度的机制。这项工作突出了研究熔盐原子尺度结构的重要性以及燃料元素的添加如何对其产生重大影响。
