Approaching Acquisition Path Analysis Formally - Experiences So Far

In the past, IAEA's safeguards activities have been planned mainly based on the presence of nuclear material. However, resources should be spent where they are needed most. To overcome this issue, a new risk model was developed. This so called State-level concept (SLC) has changed the inspection system to a comprehen- sive, objective-driven approach where the State is considered as a whole. Acquisition Path Analysis (APA) is a key element of the SLC. By considering the State's nuclear prole, the APA generates a list of acquisition paths ranked by their attractiveness for the State. Currently, this process is mainly based on expert judgment. However, the IAEA's requirements state that APA must be objective, reproducible, transparent, standardized, documented and as a result non-discriminatory. A formal approach fullling the requirements was set up by the authors and presented at the 53rd INMM Annual Meeting [1]. The methodology is based on a three steps approach: network modeling, network analysis and strategic assessment. As a solu- tion of this process, a Nash-equilibrium can be found that provides an indicator on the eectiveness of the implemented safeguards system. Furthermore, it also reveals the potential behavior of both actors, i.e. the State and the IAEA. The given paper presents the rened methodology. Improvements were made in the interface denition between the three steps. Also, the general network model was updated and the automatic visualization of acquisition paths as well as strategic as- sessment were accomplished. A prototype implementation will be shown in this paper. Based on this methodology, we give an overview of the test cases developed so far. The cases cover a variety of State-specic characteristics such as the complexity of fuel cy- cles and the presence or absence of an Additional Protocol (AP). Moreover, an attempt is presented to apply the methodology to a nuclear weapon State (NWS). Using the examples, we analyze how the consideration of State factors would in uence the de- tection probabilities of illegal activities. As a consequence, the case studies indicate, where and when the IAEA better focuses activities and budget.