摘要

Anodic behavior of U-Zr or U-Pu-Zr alloys during electrorefining in molten chloride electrolyte was modeled on the basis of recent findings from the observation of anode residues after a number of electrorefining tests, such as the formation of an intermediate region that has a composition corresponding to the 5 phase. Simulation of anodic dissolution of the U-Zr alloy during the engineering-scale electrorefining tests using the model showed that the calculated dissolution ratios of uranium and zirconium were in agreement with the experimental results when the alloy pin was chopped to as short as 5 mm. Three runs of laboratory-scale electrorefining tests with uncladded U-Pu-Zr ternary alloy were also simulated. The characteristic change of the anode potential during these tests was well reproduced in the calculation using the fitting parameters for uranium activity in the porous zirconium layer. The results of some predictive calculations showed that the required period to attain a certain uranium dissolution ratio is drastically increased with the increase in pin length, and that the zirconium dissolution ratio is largely increased when a higher anodic current density is applied to improve the electrorefining processing rate.

  • 出版日期2010-12