Tagging and Fissile Material Verification Concepts for Nuclear Warhead Dismantlement

Arms control treaties that reduce the number of deployable nuclear-warhead delivery systems might also lead to provisions for the verified dismantlement of nuclear weapons. Based on public information and very simple conceptual models of nuclear warheads, one can visualize a set of procedural and technological requirements to account for warheads removed from deployed sites and ultimately dismantled. To accomplish the accounting function, verification-quality tags and/or seals might be needed in order that the warheads taken out of storage can be tracked to the dismantlement site. These tags/seals would represent an overlay on the existing chain of custody. The verified dismantlement of the warheads poses special problems in confirming their identity and in avoiding the loss of sensitive information. A central factor is the publicly recognized need for some minimum quantity of fissile material to constitute a nuclear warhead. A measurement system that could make such a determination without giving away unnecessary information would be desired. Some approaches based on existing fissile assay methods are discussed.