Year
2019
Abstract
The goal of this project is to address the nuclear safeguards need for near real-time detection of a potentialreconfiguration of a gas centrifuge enrichment plant (GCEP) for the unauthorized production of highlyenriched uranium. Such misuse at these facilities requires changes in the uranium hexafluoride (UF6) massflow rates, which currently could go undetected for a significant amount of time with existing technologyand protocols. Our work demonstrates a noninvasive tool that will measure the mass flow rate of UF6 gasin GCEP pipes using a modified thermal mass flow meter concept. The device is applied to the outside ofthe pipe and injects heat onto the surface of the pipe, which thus eliminates the need to make anymodifications to the pipe itself. The measurement of the change in temperature under the heating strip andthe resulting temperature profile correlates to the mass flow rate in the pipe. This enables near real-timeverification that a GCEP is operating as designed and declared, and ensures the detection of facilityreconfiguration in a timely manner.Computational fluid dynamics (CFD) simulations were used to investigate the sensitivity of the mass flowmeter at flow conditions relevant to common GCEP scenarios on feed, product and tail header gas lines. Inaddition, CFD was used to establish a correlation between the instrument’s performance with both UF6 andair. Using this correlation, relevant experiments were preformed using air at corresponding mass flow rateson a much simplified apparatus than would be required for UF6 experimentation. The results from initialexperiments indicate that the simplest configuration of the device displays an equivalent UF6 mass flowresolution of better than 10%, and approaching 3% for some conditions.