A simulation of spent nuclear fuel imaging using cosmic radiation for verification and accountancy

Muon Scattering Tomography (MST) relies on multiple Coulomb scattering (MCS) of high energy cosmic ray muons in dense materials to reconstruct 2D and 3D images of targets of interest. Targets, such as containers for spent nuclear fuel, are difficult or impossible to image using conventional X-ray techniques due to the presence of shielding and the high density/high-Z nature of the materials involved. MST is a modern non-destructive technique using naturally occurring radiation to assay the contents of such containers. This technique is particularly well suited for applications in spent nuclear fuel management and nuclear non-proliferation. The GEANT4 simulation of the Cosmic Ray Inspection and Passive Tomography (CRIPT) detector was used for this investigation. The GEANT4 CRIPT simulation has been tuned using real detector data to produce results consistent with real experiments. As such, the results of simulation can reliably be used to predict the performance of such a system under particular constraints. The CRIPT detector also exploits direct muon momentum measurements making CRIPT a unique MST apparatus. The simulation modelled the geometry of a single Modular Air-Cooled Storage (MACSTOR) basket, containing a number of CANDU-type/Pressurized Heavy Water Reactor (PHWR) fuel bundles. Using two well established techniques, MST can identify a defect of a single missing bundle from a MACSTOR basket with > 99% confidence in 3.7 hours. (author)