Determining Reactor Fuel Type from Continuous Antineutrino Monitoring

Abstract

We investigate the ability of an antineutrino detector to determine the fuel type of a reactor. A hypothetical 5t antineutrino detector is placed 25m from the core and measures the spectral shape and rate of antineutrinos emitted by fission fragments in the core for a number of 90 day periods. Our results indicate that four major fuel types can be differentiated from the variation of fission fractions over the irradiation time with a true positive probability of detection at 95%. In addition, we demonstrate that antineutrinos can identify the burn-up at which weapons-grade mixed-oxide (MOX) fuel would be reduced to reactor-grade MOX on average, providing assurance that plutonium disposition goals are met. In addition, we investigate removal scenarios where plutonium is purposefully diverted from a mixture of MOX and low-enriched uranium (LEU) fuel. Finally, we discuss how our analysis is impacted by a spectral distortion around 6MeV observed in the antineutrino spectrum measured from commercial power reactors.