| Autor: |
Zink, Peter A., Jan-Fong Jue, Serrano, Brenda E., Fredrickson, Guy L., Cowan, Ben F., Herrmann, Steven D., Li, Shelly X. |
| Předmět: |
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| Zdroj: |
Proceedings of the Institute of Nuclear Materials Management Annual Meeting; 2010, p1-10, 10p, 2 Black and White Photographs, 1 Chart, 3 Graphs |
| Abstrakt: |
Electrorefining of metallic spent nuclear fuel in high temperature molten salt systems is a core technology in pyroprocessing, which in turn plays a critical role in advanced fuel cycle technologies. In electrorefining, spent nuclear fuel is electrochemically processed to separate uranium, noble metals, and active metals, which include the transuranics. The accumulation of the active metals in a LiCl-KCl eutectic molten salt electrolyte occurs at the expense of the UCl3- oxidant concentration in the electrolyte, which must be periodically replenished. Our interests lie in the accumulation of active metals in the molten salt electrolyte. The real-time monitoring of actinide concentrations in the molten salt electrolyte is highly desirable for controlling electrochemical operations and assuring material safeguards. However, real-time monitoring is not possible with current methods for sampling and chemical analysis. A new solid-state electrochemical sensor is being developed for real-time monitoring of actinide ion concentrations in a molten salt electrorefiner. The ultimate function of the sensor is to monitor plutonium and other actinide concentrations during electrorefining operations. In this work gadolinium was employed as a surrogate material for plutonium. In a parametric study, polycrystalline Na-β''-alumina precursor discs and tubes were subject to vapor-phase exchange with Gd3+ using a GdCl3- containing salt to produce exchanged Gd-β''-alumina samples. Electrochemical impedance spectroscopy and microstructural analysis were performed on the ion-exchanged discs to determine the relationship between ion exchange and Gd3+ ion conductivity. A sensor design and model are proposed for configuring the ion-exchanged tubes as potentiometric sensors in order to monitor real-time Gd3+ ion concentrations in mixtures of GdCl3 and LiCl-KCl eutectic molten salts through measurement of the potential difference between a reference and working electrode. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
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