LIBS for "Fukushima"; Current results and challenge as a remote in-situ screening analysis

LIBSを福島に; 遠隔その場スクリーニング分析の現状とチャレンジ

若井田 育夫  ; 大場 弘則  ; 大場 弘則*  ; 赤岡 克昭 ; 狩野 貴宏 ; 中西 隆造*; 坂本 寛*; 池田 裕二*; 平等 拓範*

Wakaida, Ikuo; Oba, Hironori; Oba, Hironori*; Akaoka, Katsuaki; Karino, Takahiro; Nakanishi, Ryuzo*; Sakamoto, Kan*; Ikeda, Yuji*; Taira, Takunori*

The decommissioning of the Fukushima Daiichi Nuclear Power Station with melt downed core, it will be required a rapid, remote and in-situ screening analysis of fuel debris and a large amount of waste materials in a narrow and extremely high radiation environment. Radiation-resistant optical fiber based LIBS is one of the practical techniques as the remote in-situ analysis. In the ultra-long-distance remote analysis, a microchip laser delivered by 100 m optical fiber was used to simulate a long-distance analysis. Although a little bit attenuation was observed in emission light intensity, there was no effect on the calibration curve, and the same performance by using a 5 m optical fiber was demonstrated. In the analysis of spent fuel, a portable optical fiber LIBS system was prepared, and only the probe head was introduced into the Hot Cell facility. Spent fuel samples containing Zr and Fe oxides were analyzed, and spectra with no change were obtained even in high-dose environments. These demonstrated the applicability of LIBS for in-situ remote analysis of nuclear fuel debris.