Cosmic-ray muon radiography for reactor core observation

Takamatsu, Kuniyoshi  ; Takegami, Hiroaki ; Ito, Chikara   ; Suzuki, Keiichi*; Onuma, Hiroshi*; Hino, Ryutaro; Okumura, Tadahiko*

In our study, we focused on a nondestructive inspection method by which cosmic-ray muons could be used to observe the internal reactor from outside the RPV and the CV. We conducted an observation test on the HTTR to evaluate the applicability of the method to the internal visualization of a reactor. We also analytically evaluated the resolution of existing muon telescopes to assess their suitability for the HTTR observation, and were able to detect the major structures of the HTTR based on the distribution of the surface densities calculated from the coincidences measured by the telescopes. Our findings suggested that existing muon telescopes could be used for muon observation of the internal reactor from outside the RPV and CV.