Identification of statistical invariance for anodic signals of Mk-IV electrorefiner

A statistical invariance technique is proposed for an analysis of anodic signals from the Mk-IV electrorefiner (ER) currently used for treating spent EBR-II fuel. Voltage and applied current signals obtained from the Data Archival Software System (DASS) were used in this study. In general, the plots of these signals from different experimental runs present complex patterns to analyze - the currents were adjusted and shut-off due to limited ampere-hr or cut-off cell voltage: the voltage would increase showing a sign that uranium in the fuel elements had been depleted. Rather than directly analyzing these sets of time-series signals, a simple nonlinear function of these signal sequences and division were observed, which returned resistance series information. The primary idea deriving the methodology presented in this paper is that "anodic resistance time series should show intrinsic kinetic progress of anodic ER process." A simple histogram-based analysis reveals notable statistical information, which may be invariant under ideal ER operating conditions. For instance, the results suggest that mostly uranium dissolution would be preferentially transferred around 0.00217 - 0.00354 ohm and other minor distribution peaks may possibly represent other transfers of fission species in the system.