Recycle of thorium is an essential process in the thorium‐uranium closed fuel cycle of molten salt reactor (MSR). Pyrochemical treatment of spent nuclear fuel using chloride molten salts as medium has been considered as a promising method. In this article, we performed molecular dynamics simulations on the ThCl4LiCl molten salts using a polarizable force field parameterized by us from first‐principles calculations. The microscopic structures and macroscopic properties at different compositions were investigated using the developed force field to understand the structure/property relationship in the mixture. The differences between ThCl4LiCl and ThF4LiF MSs are compared to understand the behaviors of Th4+ in the fluoride‐chloride mixed media. In the molten fluorides, the coordination number of Th4+ is larger, and the resulting more shared anions lead to lower ThF dissociation barrier and shorter lifetime of the Th4+ first solvation shell. Our results also indicate the Pauling's structural rules for crystals can be used to rationalize the local structures in molten salts. © 2018 Wiley Periodicals, Inc.

中文翻译：

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ThCl4-LiCl熔盐的极化力场参数化和理论模拟

钍的回收是熔盐堆（MSR）钍-铀闭式燃料循环中必不可少的过程。使用氯化物熔盐作为介质对乏核燃料进行热化学处理已被认为是一种很有前途的方法。在本文中，我们使用由我们根据第一性原理计算参数化的极化力场对 ThCl4LiCl 熔盐进行了分子动力学模拟。使用开发的力场研究了不同成分的微观结构和宏观性质，以了解混合物中的结构/性质关系。比较 ThCl4LiCl 和 ThF4LiF MSs 之间的差异，以了解 Th4+ 在氟化物-氯化物混合介质中的行为。在熔融氟化物中，Th4+的配位数较大，并且由此产生的更多共享阴离子导致更低的 ThF 解离势垒和更短的 Th4+ 第一溶剂化壳的寿命。我们的结果还表明鲍林的晶体结构规则可用于使熔盐中的局部结构合理化。© 2018 Wiley Periodicals, Inc.