  Cubic-meter-sized antineutrino detectors can be used to non-intrusively,
robustly and automatically monitor and safeguard a wide variety of nuclear
reactor types, including power reactors, research reactors, and plutonium
production reactors. Since the antineutrino spectra and relative yields of
fissioning isotopes depend on the isotopic composition of the core, changes in
composition can be observed without ever directly accessing the core itself.
Information from a modest-sized antineutrino detector, coupled with the
well-understood principles that govern the core's evolution in time, can be
used to determine whether the reactor is being operated in an illegitimate way.
A group at Sandia is currently constructing a one cubic meter antineutrino
detector at the San Onofre reactor site in California to demonstrate these
principles.
