Examination of diversion and misuse detection for a generalized sodium-cooled fast test reactor

Research into diversion and misuse detection in sodium-cooled fast reactors (SFRs) has not typically involved full-core, high-fidelity neutronic analysis, focusing instead on a broad systems-analysis approach for determining the likelihood of materials diversion. We present here the exploration of a detailed neutronics analysis for a generalized SFR to highlight three diversion and misuse scenarios (i. e., insertion of fertile targets) and determine their effects on reactor neutronics. The initial scenarios provide evidence that using global and local plant instrumentation techniques—including measuring the control rod (CR) height, cycle length, and various fuel assembly powers—allows for the detection of clandestine plutonium generation. We conclude by examining optimal placements for fertile target assemblies, utilizing a multi-agent blackboard optimization algorithm. The optimization algorithm shows where fertile targets are likely to be placed in order to produce one significant quantity of plutonium in one year. Utilizing the multi-agent blackboard optimization algorithm provides plutonium producing core configurations which would be difficult to detect using existing plant instrumentation. However, the optimization algorithm allows us to determine which locations in the core most likely to contain a fertile target if the reactor is indeed proliferating plutonium. Using this information, we can inform safeguards inspectors which core-location(s) require intensified inspection.