  This paper explores the use of cosmic ray muons to image the contents of
shielded containers and detect high-Z special nuclear materials inside them.
Cosmic ray muons are a naturally occurring form of radiation, are highly
penetrating and exhibit large scattering angles on high Z materials.
Specifically, we investigated how radiographic and tomographic techniques can
be effective for non-invasive nuclear waste characterization and for nuclear
material accountancy of spent fuel inside dry storage containers. We show that
the tracking of individual muons, as they enter and exit a structure, can
potentially improve the accuracy and availability of data on nuclear waste and
the contents of Dry Storage Containers (DSC) used for spent fuel storage at
CANDU plants. This could be achieved in near real time, with the potential for
unattended and remotely monitored operations. We show that the expected
sensitivity, in the case of the DSC, exceeds the IAEA detection target for
nuclear material accountancy.
