The performance of a muon radiography system designed to image the inner structure of a nuclear plant located at a distance of 64 m was evaluated. We concluded absence of the fuel in the pressure vessel during the measurement period and succeeded in
profiling the fuel material placed in the storage pool. The obtained data also demonstrated the sensitivity of the system to water level changes in the reactor well and the dryer-separator pool. It is expected that the system could reconstruct a 2 m cubic fuel object easily. By operating multiple systems, typically four identical systems, viewing the reactor from different directions simultaneously, detection of a 1 m cubic object should also be achievable within a few month period.
In this note, we compile results of various simulation studies for the upgrade of the Belle detector. Based on these studies, we propose a set of optimum or appropriate parameters of the detector.
