Advancing Methods for Providing Attribution for the HEU Used in a Terrorist Nuclear Weapon

An algorithm was developed that uses measured isotopic ratios from fission product residue following the detonation of a high-enriched uranium nuclear weapon to compute the original attributes of the nuclear material used in the device. The specific attributes assessed are the uranium isotopics (considering U, U, U, and U) and the type of enrichment process used to create the material (e.g., gaseous diffusion, gas centrifuge, etc.). Using the original material attributes of the weapon significantly increases the probability of identifying the perpetrator of the attack. In this study, research was conducted to perform sensitivity analysis of the calculated values, analyze alternate methods of enrichment, determine the source (uranium mine) from which the feed material was taken and assess potential “spoofing” techniques. The purpose of this research was to verify that the analytical method developed would remain valid for a multitude of conceivable variations that could potentially be used to disguise the origin of the original nuclear material used in the device. It is envisioned that this methodology could serve as a preprocessing step to a more computationally intensive and more accurate system in the event of a nuclear terrorist attack.