Advancing The On-Line Enrichment Monitor (OLEM) Capability

The International Atomic Energy Agency (IAEA) has deployed the On-Line Enrichment Monitor (OLEM) to monitor the enrichment levels of UF6 gas flowing in header pipes in gaseous centrifuge enrichment plants. A challenge of the measurement is the UF6 and uranium deposits in the pipe both emit 186 keV gamma-rays from the decay of uranium-235 which is the primary signature for the enrichment measurement. The deposits are therefore an interference in the measurement that is not distinguishable by the gamma-ray signature. For an accurate measurement of the enrichment, the deposit contribution must be estimated and accounted for, typically performed in a post-analysis process. Research is ongoing to explore an approach using the well-known ‘dual collimator’ approach to measure both the gas and deposits in the same measurement using arrays of cadmium-zinc-telluride (CZT) gamma-ray detectors. This presentation will provide the research status and the modeling and simulation results of this effort. If successful, this approach could provide increased precision and reduced analysis time with a smaller and lighter collection node compared to the current OLEM.