Year
2006
Abstract
Efforts have been under way at Lawrence Livermore National Laboratory (LLNL) to develop detailed analytical models that simulate enrichment and conversion facilities for the purpose of aiding in the identification of possible areas where material diversion could occur as part of an overall safeguards strategy. Operation of an enrichment process for manufacturing commercial reactor fuel presents proliferation concerns including both diversion and the potential for undeclared enrichment to make weapons grade material. Inspections by the International Atomic Energy Agency (IAEA) are designed to provide assurance that such diversion is not occurring through, among other things, visual examination of the facility and taking specific measurements such as the radiation fields outside of various process lines. Our current effort is aimed at developing algorithms that would be incorporated into the current process models that would provide estimates of both neutron and gamma radiation fields outside any process line for the purpose of determining the most effective locations for placing in-plant monitoring equipment. These algorithms, while providing dose and spectral information, could also be designed to provide detector responses that could be physically measured at various points on the process line. Such information could be used to optimize detector locations in support of real-time on- site monitoring to determine the enrichment levels within a process stream. The results of parametric analyses to establish expected variations for several different process streams and configurations are presented. Based upon these results, the capability of a sodium iodide (NaI(Tl)), high-purity germanium (HPGe), or neutron detection system is being investigated from the standpoint of their viability in quantitatively measuring and discerning the enrichment of in-process material. The benefits and issues associated with both passive and active interrogation measurement techniques are also discussed.