  Cosmic-ray muons can be used for the non-destructive imaging of spent nuclear
fuel in sealed dry storage casks. The scattering data of the muons after
traversing provides information on the thereby penetrated materials. Based on
these properties, we investigate and discuss the theoretical feasibility of
detecting single missing fuel rods in a sealed cask for the first time. We
perform simulations of a vertically standing generic cask model loaded with
fuel assemblies from a pressurized water reactor and muon detectors placed
above and below the cask. By analysing the scattering angles and applying a
significance ratio based on the Kolmogorov-Smirnov test statistic we conclude
that missing rods can be reliably identified in a reasonable measuring time
period depending on their position in the assembly and cask, and on the angular
acceptance criterion of the primary, incoming muons.
