Since the first observation of antineutrinos from beta decay of the fission products inside a nuclear reactor in 1956, the design and operating
experience of antineutrino detectors near reactors has increased to the point where monitoring the reactor’s power level and progression through its
burnup cycle has become possible. With the expected increase in world nuclear energy capacity, including the dissemination of reactor technologies
to non-nuclear states, the need for safeguards measures which are able to provide continuous, near-real-time information about the state of the core,
including its isotopic composition, in a tamper- and spoof-resistant manner is evident. Near-field (~20 m from the core) antineutrino detectors are
able to fulfill this demand without perturbing normal reactor operation, without requiring instrumentation which penetrates the reactor vessel, and
without displacing other plant structures.
Two sodium-cooled long-life fast reactors that are characteristic of next-generation reactors which are attractive for installation in non-nuclear states,
one large and one small power rating, have been modeled throughout their reference burnup cycles using MCC-3 and REBUS-3. Various diversions
of fissile material from the core, additions of blanket material, and other malicious activities designed to produce weapons-usable material for the
purpose of nuclear proliferation will be studied as perturbed core states. The difference in detector event rates between the reference and perturbed
cores states will be subjected to statistical analysis in order to determine the probability that a particular diversionary activity would be apparent before
the material could be weaponized. A substantial part of the analysis entails quantification of the various uncertainties resulting from the reactor
modeling, detector attributes, measured yield and energy of the fission products, etc. These data will indicate which types of diversion antineutrino
safeguards are particularly strong at counteracting and how the technology might be implemented in current and future international policies
concerning nuclear proliferation.