Preliminary measurement of prompt gamma-ray from nuclear material for the classification of fuel debris and waste

Shiba, Tomooki  ; Kaburagi, Masaaki   ; Nomi, Takayoshi ; Suzuki, Risa; Kosuge, Yoshihiro*; Nauchi, Yasushi*; Takada, Akira*; Nagatani, Taketeru ; Okumura, Keisuke 

A technique that can easily determine the presence of nuclear material in removed object from Fukushima Daiichi Nuclear Power Plant site is important from the viewpoint of sorting fuel debris from radioactive waste. In the case of fresh uranium, the amount of nuclear material in the waste generated from nuclear facilities can be determined by measuring 1001 keV gamma-rays emitted by Pa, which is a daughter nuclide of U. However, it has been pointed out that such gamma-ray measurement cannot be used for fuel debris that contains a large portion of fission products (FPs) emitting various energies of gamma-rays. In this study, we focus on prompt fission gamma-rays that are directly emitted from nuclear materials and those energy exists in a higher energy region than those of FPs, and aim to measure them in simple manners.