Detecting and Quantifying Diversion in an Experimental Aqueous Reprocessing Loop

Bulk material handling facilities face unique safeguards challenges due to their continuous operation, high throughput, high radiation fields, large measurement uncertainties and variations in facility design. We have re-designed an experiment, the Next Generation Loop (NGL), to simulate movement of nuclear material in a generic aqueous reprocessing facility using water and commercially available radiotracers. The NGL can operate in a variety of configurations and boasts higher control of individual process streams compared to its predecessor, while employing both radiation and non-radiation sensors to observe and detect off-normal behavior. Off-normal behavior that can be simulated may include material holdup and diversion, which can correspond to plant inefficiencies, faults such as blockages or leaks, or unknown/unauthorized nuclear material streams. A model network was utilized to detect and quantity off-normal behavior. These results may help better safeguard existing bulk handling facilities and encourage the implementation of these methods in the safeguards by design approach for future facilities.