  The resurgence of interest in nuclear power around the world highlights the
importance of effective methods to safeguard against nuclear proliferation.
Many powerful safeguarding techniques have been developed and are currently
employed, but new approaches are needed to address proliferation challenges
from emerging advanced reactor designs and fuel cycles. Building on prior work
that demonstrated monitoring of nuclear reactor operation using neutrino
detectors, we develop and present a simple quantitative statistical test
suitable for analysis of measured reactor neutrino data and demonstrate its
efficacy in a semi-cooperative reactor monitoring scenario. In this approach, a
moderate-sized neutrino detector is placed near the reactor site to help
monitor possible MOX fuel diversion independent of inspection-based monitoring.
We take advantage of differing time-dependent neutrino count rates during the
operating cycle of a reactor core to monitor any deviations of measurements
from expectations given a declared fuel composition. For a five-ton idealized
detector placed 25m away from a hypothetical 3565 MWth reactor, the statistical
test is capable of detecting the diversion of ~80kg plutonium at the 95%
confidence level 90% of the time over a 540-day observation period.
