Detecting Nuclear Material Diversion At The State-level - Challenges And Opportunities

INFCIRC/153 (Corrected) designates nuclear material accountancy as a safeguards measure of fundamental importance in detecting the diversion of nuclear material and describes the technical conclusion of the Agency’s related verification activities in terms of the conclusions of material balance evaluation (MBE), i.e. the periodic evaluation for each material balance area (MBA) of the declared material unaccounted for (MUF). However, the basic undertaking stipulates that the State should accept safeguards, in accordance with the terms of the Agreement, on all source or special fissionable material in all peaceful nuclear activities within its territory, under its jurisdiction or carried out under its control any­ where, for the exclusive purpose of verifying that such material is not diverted to nuclear weapons or other nuclear explosive devices. MBE procedures which were developed several decades ago to support safeguards implementation under CSAs are rooted in a facility-based structure with conclusions drawn for each material category, i.e. plutonium, enriched uranium, natural and depleted uranium etc., each MBA and each material balance period (MBP). The evolution of safeguards concepts to the State-level posed the question of how to draw a meaningful conclusion on the absence of diversion of nuclear material for the whole State. Since attempts to tackle methodological challenges associated, inter alia, with non-synchronized MBP proved ineffective, a more promising approach was explored, based on a holistic analysis of nuclear material flow and inventories in the framework of the State’s declared nuclear fuel cycle and against the results of its acquisition path analysis. The purpose of this paper is to discuss the initial experience gained from applying this method and to present prospective developments.