Non-Destructive Analysis of Natural Uranium Pellet

As part of ongoing nuclear forensics research, samples of $^{\mathrm{nat}}$UO$_{\mathrm{2}}$ have been irradiated in a thermal neutron spectrum at the University of Missouri Research Reactor (MURR) with the goal of simulating a pressurized heavy water reactor. Non-destructive gamma ray analysis has been performed on the samples to assay various nuclides in order to determine the burnup and time since irradiation. The quantity of $^{\mathrm{137}}$Cs was used to determine the burnup directly, and a maximum likelihood method has been used to estimate both the burnup and the time since irradiation. This poster will discuss the most recent results of these analyses.