Automated Safeguards System Design for a LEU Enrichment Plant

The objective of this work is to safeguard a declared, low-enrichment plant against the illicit production of highly enriched uranium (HEU). We used an analysis that is an extension of the Distributed Source Term Analysis (DSTA) method developed by Los Alamos National Laboratory for uranium holdup measurements in the Rokkasho enrichment cascade.1, 2 This publication presents the detector design work which is to be used in future DTSA. These detectors will be a part of a unique system that will provide near-real time measurement and analysis of the singles neutron count rate from a fixed network of detectors (near-isotropic detectors positioned near the ceiling) that will automatically indicate if HEU is being produced.3 Because all the geometric effects can be quantified using the Monte Carlo radiation transport code MCNPX4, we can ascertain the amount and enrichment of the uranium with a resolution determined by the details of how the detector array is setup; this final stage of the work will be published in the future. This model is significant in that an array of simple, inexpensive, identical, and somewhat remote detectors can provide a direct, automated indication of illicit HEU production over the entire cascade hall.