Nondestructive assay of Pu in spent fuel using nuclear resonance fluorescence with monochromatic -rays

Hayakawa, Takehito; Shizuma, Toshiyuki; Hajima, Ryoichi; Kikuzawa, Nobuhiro ; Fujiwara, Mamoru; Seya, Michio

We have proposed a nondestructive assay for Pu-239 in spent fuel assembly using nuclear resonance fluorescence with energy tunable monochromatic -rays generated by Compton scattering of laser photons and high energy electrons. This method has advantages that one can detect Pu-239 in a fuel assembly kept in a water pool from outside the pool wall and that one can identify isotopes. We use the -ray beam with the energy of about 2 MeV and thereby we can detect isotopes though water shields with a thickness of several ten centimeters. We present the concept design of this system, the basic study, and detection accuracy of Pu-239 derived from simulation calculation results using a code GEANT4.