Electrochemical studies and analysis of 1-10 wt% UCl3 concentrations in molten LiCl-KCl eutectic
Electrochemical studies and analysis of 1-10 wt% UCl3 concentrations in molten LiCl-KCl eutectic
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DOI：
10.1016/j.jnucmat.2014.05.057
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发表时间：
2014-09-01
影响因子：
3.1
通讯作者：
Phongikaroon, Supathorn
中科院分区：
文献类型：
--
作者：
Hoover, Robert O.;Shaltry, Michael R.;Phongikaroon, Supathorn
三种电化学方法-循环伏安法（CV），计时电位法（CP），和阳极溶出伏安法（ASV）-被施加到高达10重量%的UCl 3在熔融LiCl-的溶液。KCl低共熔盐在500摄氏度，以确定电化学性能和行为，并帮助提供一个科学依据，为发展一个在现场电化学探针，以确定浓度的铀在用过的核燃料电解精炼机。UCl 4和UCl 3的扩散系数计算值分别为（6.72 +/- 0.360）x 10（-6）cm（2）/s和（1.04 +/- 0.17）x 10（-5）cm 2/s。U（IV）/U（III）和U（III）/U氧化还原对的表观标准还原电位分别为（-0.381 +/- 0.013）V和（-1.502 +/- 0.076）V vs. 5 mol% Ag/AgCl或（-1.448 +/- 0.013）V和（-2.568 +/- 0.076）V vs. Cl-2/Cl。在将该数据与过冷热力学数据进行比较以确定活度系数时，所使用的热力学数据库很重要，得到的活度系数范围为UCl 4的2.34 x 10（-3）至1.08 x 10（-2）和UCl 3的4.94 x 10（-5）至4.50 x 10（-4）。在阳极溶出伏安法和循环伏安法的阳极或阴极峰中，CV阴极峰高除以扫描速率的平方根被证明是测定熔融盐中UCl 3浓度的最可靠的方法。(C)2014年爱思唯尔B。V.保留所有权利。
Three electrochemical methods - cyclic voltammetry (CV), chronopotentiometry (CP), and anodic stripping voltammetry (ASV) - were applied to solutions of up to 10 wt% UCl3 in the molten LiCl-KCl eutectic salt at 500 degrees C to determine electrochemical properties and behaviors and to help provide a scientific basis for the development of an in situ electrochemical probe for determining the concentration of uranium in a used nuclear fuel electrorefiner. Diffusion coefficients of UCl4 and UCl3 were calculated to be (6.72 +/- 0.360) x 10(-6) cm(2)/s and (1.04 +/- 0.17) x 10(-5) cm2/s, respectively. Apparent standard reduction potentials were determined to be (-0.381 +/- 0.013) V and (-1.502 +/- 0.076) V vs. 5 mol% Ag/AgCl or (-1.448 +/- 0.013) V and (-2.568 +/- 0.076) V vs. Cl-2/Cl for the U(IV)/U(III) and U(III)/U redox couples, respectively. In comparing this data with supercooled thermodynamic data to determine activity coefficients, the thermodynamic database used was important with resulting activity coefficients ranging from 2.34 x 10(-3) to 1.08 x 10(-2) for UCl4 and 4.94 x 10(-5) to 4.50 x 10(-4) for UCl3. Of anodic stripping voltammetry and cyclic voltammetry anodic or cathodic peaks, the CV cathodic peak height divided by square root of scan rate was shown to be the most reliable method of determining UCl3 concentration in the molten salt. (C) 2014 Elsevier B. V. All rights reserved.