  Military and civilian applications of nuclear energy have left a significant
amount of spent nuclear fuel over the past 70 years. Currently, in many
countries world wide, the use of nuclear energy is on the rise. Therefore, the
management of highly radioactive nuclear waste is a pressing issue. In this
letter, we explore antineutrino detectors as a tool for monitoring and
safeguarding nuclear waste material. We compute the flux and spectrum of
antineutrinos emitted by spent nuclear fuel elements as a function of time, and
we illustrate the usefulness of antineutrino detectors in several benchmark
scenarios. In particular, we demonstrate how a measurement of the antineutrino
flux can help to re-verify the contents of a dry storage cask in case the
monitoring chain by conventional means gets disrupted. We then comment on the
usefulness of antineutrino detectors at long-term storage facilities such as
Yucca mountain. Finally, we put forward antineutrino detection as a tool in
locating underground "hot spots" in contaminated areas such as the Hanford site
in Washington state.
