Electrochemical Reprocessing Safeguards Modeling

Electrochemical reprocessing of spent nuclear fuel has seen renewed interest in the U.S. and elsewhere as a potential alternative to building large and costly aqueous reprocessing plants. The simplified plant design and smaller footprint may reduce costs and the number of waste streams generated. However, little experience exists with safeguarding a commercial electrochemical facility, and the environment presents challenges for traditional materials accountancy. The goal of this work was to develop a model of an electrochemical reprocessing plant for safeguards system design and testing. Past experience on the development of a Separations and Safeguards Performance Model (SSPM) for aqueous processing was utilized to generate a SSPM-EChem (Electrochemical) version that would be representative of a potential future plant. This model was used to develop a preliminary materials accountability strategy, with a key goal to be able to achieve similar detection thresholds as compared to aqueous plants. The unique challenges for materials accountancy for this type of facility are described. Preliminary analysis has shown that some modifications to the plant operations may be required to improve the ability to safeguard this type of facility. This principle of Safeguards by Design is important to consider early to design future plants appropriately. This preliminary analysis has identified the following uncertainty goals for actinide measurements in a 100 metric ton per year plant: 0.5% for the electrorefiner inventory, 1% for input spent fuel measurements, and 1% for the U and U/TRU products.