  Nuclear materials accountability and nonproliferation are among the critical
tasks to be addressed for the advancement of nuclear energy in the United
States. Monitoring spent nuclear fuel is important to continue reliable
stewardship of SNF storage. Cosmic ray muons have been acknowledged a promising
radiographic tool for monitoring SNF due to their highly penetrative nature and
high energy. Cosmic ray muons are more suitable and have been used for imaging
large and dense objects. Despite their potential in various applications, the
wide application of cosmic ray muons is limited by the naturally low intensity
at sea level. To efficiently utilize cosmic ray muons in engineering
applications, trajectory and momentum must be measured. Although various
studies demonstrate that there is significant potential for measuring momentum
in muon applications, it is still difficult to measure both muon scattering
angle and momentum in the field. To fill this critical gap, a muon spectrometer
using multilayer pressurized gas Cherenkov radiators was proposed. However,
existing muon tomographic algorithms were developed assuming monoenergetic muon
scattering and are not optimized for a measured polyenergetic momentum
spectrum. In this work, we develop and evaluate a momentum integrated muon
scattering tomography algorithm. We evaluate the algorithm on its capability to
identify a missing fuel assembly from a SNF dry cask. Our results demonstrate
that image resolution using MMST is significantly improved when measuring muon
momentum and it can reduce monitoring time by a factor of 10 when compared to
that of a conventional muon imaging technique in terms of systematically
finding a missing FA.
