钍熔盐堆闭式循环在线后处理的探索设计及其化学问题研究

项目名称： 钍熔盐堆闭式循环在线后处理的探索设计及其化学问题研究

项目编号： No.91326113

项目类型： 重大研究计划

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 韩伟

作者单位： 哈尔滨工程大学

项目金额： 90万元

中文摘要： 鉴于法国提出的新型TMSR-NM后处理方案存在的安全性不够高、萃取率不高的缺憾，本项目提出了安全性更好的TMSR在线后处理新方案：以LiF-BeF2(CaF2)-LnF3-CeF4-ThF4为研究体系，采用高温熔盐/液态金属萃取、选择性电沉积及阳极溶解连续/交替的方式，实现Th/Ln的有效分离和钍循环。并对（1）高温熔盐/液态金属Bi-Li还原萃取Th过程的动力学和热力学、离子价态与萃取效果的关系及价态的电化学控制；（2）Th（Ⅳ）、Ln离子在液态阴极Bi还原的电化学行为、扩散行为及成核机理；进而探讨Th选择性电沉积的电化学机理；（3） Th选择性阳极溶解的电化学机理等化学问题进行研究，提高Th/Ln的分离效率，综合分析循环过程中Th、Ln的物料衡算及影响Th和Ln的分离因素，开发TMSR闭式燃料循环在线后处理的新概念流程，为我国具有自主知识产权的熔盐堆后处理技术提供可行性和基础数据。

中文关键词： 钍熔盐堆；在线检测；高温萃取；电沉积；阳极溶解

英文摘要： A new on-line reprocessing scheme in TMSR (thorium-based molten salt reactor) was proposed, in view of the innovative TMSR-NM reprocessing researched in French has the defects of safety and extraction efficiency. In order to achieve the effective separation between thorium and lanthanides and thorium fuel cycle, a reductive extraction in high temperature molten salts/liquid metal, a selective electrodeposition and anodic oxidation were employed in continuous/alternate way in LiF-BeF2(CaF2)-LnF3-CeF4-ThF4 molten salts. In order to improve the separation efficiency of Th/Ln, the key chemical issues were explored as follow: (1) The thermodynamics and kinetics of a reductive extraction of Th in high temperature molten salts/liquid Bi-Li, the relationship between ion valence state and extraction efficiency and valence state controlled by electrochemical method. (2) The electrochemical and diffusion behavior and nucleation mechanism of Th and Ln ions at a liquid Bi cathode; the electrochemical mechanism of selectivity electrodeposition of Th ions. (3) The electrochemical mechanism of selectivity anodic oxidation of Th at Bi-Th anode. A comprehensive analysis on the material balances of Th and Ln, and separation effects of Th/Ln were made during the whole cyclic processing. Based on the research results above, the inn

英文关键词： TMSR；on-line monitoring；high temperature extraction；electro-deposition；anodic dissolution