| The economic utilization of high assay low enrichment fuels and closing the nuclear fuel
cycle depend heavily on the recycling of used nuclear fuel. A large obstacle in nuclear fuel
recycling is safeguards and non-proliferation. The development of high intensity mono-energetic
gamma-ray sources using laser Compton scattering may allow for the rapid non-destructive assay
of highly radioactive materials, such as used nuclear fuel. A detection system based on nuclear
resonance fluorescence using a laser Compton scattering source was simulated using MCNP6 to
evaluate its potential to detect U-235 and Pu-239 within used nuclear fuel. Initially, the system was
found to require ~5,900 and ~130,000 seconds to achieve 1% uncertainty measurements in U-235
and Pu-239 densities, respectively, in a used sodium fast reactor fuel element. After system
parameters were studied and improved, the detection time was lowered to ~3,200 and ~27,000
seconds for U-235 and Pu-239, respectively. Using fuel element grouping, the detection time was
further lowered to ~110 and ~740 seconds for U-235 and Pu-239 respectively. Following the
improvements made to the detection system, it has become competitive with other assay methods
and can significantly improve material tracking and safeguards within a pyroprocessing facility.
Keywords: Safeguards, non-proliferation, nuclear, reprocessing, non-destructive assay |