The measurement of uranium dioxide (UO2) enrichment in simulated pressurized water reactor fuel pellets has been performed using the infinite thickness technique. The use of this technique is well established on large volumes of uranium compounds, however new advanced reactor fuels require the enrichment assessment of individual UO2 fuel pellets. Monte Carlo GEANT4 simulations and experimental measurements were performed to collect energy and count data for sintered UO2 sim fuel pellet slices. Results indicate that the infinite thickness technique can be used on individual fuel pellets for determination of enrichment, by confirming the infinite thickness of sintered UO2 (4.9 mm), and that the count rate form the characteristic 185.6 keV 235U photopeak increases linearly with fuel pellet enrichment. Working is ongoing to refine the simulated datasets and improve experimental measurements.