A Dedicated Detector for the Verification of Highly Enriched Uranium in Naval Reactors

One of the requirements of a future Fissile Material Cutoff Treaty is that fissile material used in naval reactor fuel must not be diverted for weapons purposes. This could become relevant for both weapon and non-weapon states of the NPT because, in both cases, the geometry of the fuel and core may be considered sensitive information. Inspections and measurements would therefore have to rely on non- intrusive methods to determine the accuracy of the declared inventory in a reactor core. This talk will present MCNP-PoliMi simulations of a dedicated detector system to determine the amount of HEU present in various naval reactor core configurations. To test the viability of the method simulations have been done of interrogating a notional Russian icebreaker core. In this study we have found that many hypothetical diversion scenarios are detectable. We have also found that changing the reactor fuel configuration such as a smeared core, pin-type core or plate fuel all give similar results for the average enrichment.