Development of advanced controlled-potential coulometry system for accountability analysis of plutonium in reprocessing facility

A controlled-potential coulometry system (CPC) has been developed to analyze the accountability of plutonium products at the Tokai Reprocessing Plant (TRP). There has been demand to standardize CPC as highly accurate analysis method because, since 1995, the International organization for Standards (ISO) has been advocating ISO12183. To increase TRP's CPC system efficiency, a high performance potentiostat and a high performance coulometer (the principal measuring instruments used in the CPC system) were designed and constructed in collaboration with Westinghouse Savannah River Company (WSRC). Also, the optimization of the procedure was examined. As a results of these efforts, the latest CPC system (complying with ISO12183) has demonstrated long-term measurement reliability of up to 0.1% for 20 mg of plutonium. (author)