Performance of a remotely located muon radiography system to identify the inner structure of a nuclear plant

Fujii, Hirofumi*; Hara, Kazuhiko*; Hashimoto, Shugo*; Ito, Fumiaki*; Kakuno, Hidekazu*; Kim, S.*; Kochiyama, Mami ; Nagamine, Kanetada*; Suzuki, Atsuto*; Takada, Yoshihisa*; Takahashi, Yu*; Takasaki, Fumihiko*; Yamashita, Satoru*

The performance of a muon radiography system designed to image the inner structure of a nuclear plant located at a distance of 64 m is evaluated. We conclude that there is an absence of fuel in the pressure vessel during the measurement period and profile the fuel material placed in the storage pool. The obtained data also demonstrate 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 easily reconstruct a 2 m cubic fuel object. By operating multiple systems, typically four identical systems, viewing the reactor form different directions simultaneously, detection of a 1 m cubic object should be achievable within a period of a few months.