  This letter presents the physics and feasibility of reactor antineutrino
monitoring to verify the burnup of plutonium loaded in the reactor as a Mixed
Oxide (MOX) fuel. It examines the magnitude and temporal variation in the
antineutrino signals expected for different MOX fuels, for the purposes of
nuclear accountability and safeguards. The antineutrino signals from
reactor-grade and weapons-grade MOX are shown to be distinct from those from
burning low enriched uranium. Thus, antineutrino monitoring could be used to
verify the destruction of plutonium in reactors, though verifying the grade of
the plutonium being burned is found to be more challenging.
