  Antineutrinos have been proposed as a means of reactor safeguards for more
than 30 years and there has been impressive experimental progress in neutrino
detection. In this paper we conduct, for the first time, a case study of the
application of antineutrino safeguards to a real-world scenario - the North
Korean nuclear crisis in 1994. We derive detection limits to a partial or full
core discharge in 1989 based on actual IAEA safeguards access and find that two
independent methods would have yielded positive evidence for a second core with
very high confidence. To generalize our results, we provide detailed estimates
for the sensitivity to the plutonium content of various types of reactors,
including most types of plutonium production reactors, based on detailed
reactor simulations. A key finding of this study is that a wide class of
reactors with a thermal power of less than 0.1-1 GWth can be safeguarded
achieving IAEA goals for quantitative sensitivity and timeliness with detectors
right outside the reactor building. This type of safeguards does not rely on
the continuity of knowledge and provides information about core inventory and
power status in real-time.
