Simulation and Analysis of Plutonium Reprocessing Plant Data*

It will be difficult for large-throughput reprocessing plants to meet International Atomic Energy Agency (IAEA) detection goals for protracted diversion of plutonium by materials accounting alone. Therefore, the IAEA is considering supplementing traditional material balance analysis with analysis of solution monitoring data (frequent snapshots of such solution parameters as level, density, and temperature for all major process vessels). Analysis of solution monitoring data will enhance safeguards by improving anomaly detection and resolution, maintaining continuity of knowledge, and validating and improving measurement error models. However, there are costs associated with accessing and analyzing the data. To minimize these costs, analysis methods should be as complete as possible, simple to implement, and require little human effort. As a step toward that goal, we have implemented simple analysis methods for use in an “off-line” situation. These methods use solution level to recognize major tank activities, such as tank-to-tank transfers and sampling. In this paper, we describe their application to realistic simulated data (the methods were developed by using both real and simulated data), and we present some quantifiable benefits of solution monitoring.