Quantitative measurement of boron and boride identification using neutron beam

Tsuchikawa, Yusuke ; Kai, Tetsuya   ; Abe, Yuta  ; Oishi, Yuji*; Sun, Y.*; Oikawa, Kenichi   ; Nakatani, Takeshi ; Sato, Ikken ; Joseph, P.*; Matsumoto, Yoshihiro*

In the decommissioning of the Fukushima Daiichi Nuclear Power Plant (NPP), the quantitative analysis of residual boron and borides in the reactor core and the identification of boron compound states are one of the important issues to be investigated. In this presentation, we report on the neutron energy-resolved analysis of boron samples irradiated with neutrons at J-PARC/MLF. We also investigated the possibility of identifying the compounds using peak broadening of the prompt gamma rays for each boride. The prompt gamma-ray peak-widths of metallic and non-metallic borides were significantly different from each other, while those of zirconium boride and iron boride were slightly different. The differences between these metal borides were measured and evaluated in detail by gamma-ray energy spectrum analysis. Finally, we will briefly introduce the current experiments and analysis results of our efforts toward two- and three-dimensional quantitative measurements using energy-analyzed two-dimensional detectors.