Separations and Safeguards Performance Modeling for Advanced Reprocessing Facility Design

The long-standing goal of domestic safeguards for reprocessingplants is the ability to track all nuclear material within a plantin real time, with high quality, and with minimal impact to costand plant operations. In reality, this goal is hampered by thelimitations and cost of deployment of plant-wide measurementtechnologies. Thus advanced safeguards systems rely on an optimizationof measurement uncertainty, timeliness of detection,cost, and impact to operations. The Separations and SafeguardsPerformance Model, developed at Sandia National Laboratories,provides a platform for both evaluating and demonstratingthese advanced systems. This transient model tracks elementalmass flow rates and bulk chemicals through a reprocessing plantand simulates materials accountancy and process control measurements.The model was used to evaluate the effectiveness ofimproved measurements and near real time accountability. Theresults of the modeling effort suggest that adding additional measurementsto every vessel or component processing plutoniumprovides only marginal benefit to the safeguards system due toadditional error buildup. Future work will need to examine ifthe costs are worth the benefit or if other techniques may providemore improvement.