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柴田 卓弥; 大場 弘則; 瀬古 典明*; 赤岡 克昭; 若井田 育夫
no journal, ,
In decommission of the Fukushima Daiichi Nuclear Power Station, it is indispensable to assess contaminations by radioactive materials on workplaces. However, aqueous solution analysis methods are currently not established. Therefore, we have developed an aqueous solution analysis method which is simple and rapid on site. This method is collaborated with the laser-induced breakdown spectroscopy (LIBS) technique and the radiation-induced graft polymerization (RIGP) technique.
若井田 育夫; 大場 弘則; 宮部 昌文; 赤岡 克昭; 大場 正規; 田村 浩司; 佐伯 盛久; 中西 隆造; 池田 裕二*; 作花 哲夫*; et al.
no journal, ,
For the decommissioning of "Fukushima Daiichi Nuclear Power Station (F1NPS)", development of quick, easy, onsite and especially in-situ remote analysis/surveillance/screening techniques will be strongly required under the extremely high radioactive condition. Innovative Laser remote analysis combined with radiation resistant optical fiber based laser induced breakdown spectroscopy (Fiber LIBS) and laser ablation resonance absorption spectroscopy (LARAS) are one of the available technique for elemental and isotope analysis of nuclear fuel debris. The Retrieving of nuclear fuel debris of reactor No.2, will be planned and the screening of nuclear fuel debris will be strongly required. In order to establish an actual and applicable technique, basic study for higher sensitivity and more flexible use will be indispensable. For higher sensitivity, LIBS by long pulse laser and Microwave assisted LIBS are under developing. For more flexible and easy laser light delivery, Microchip laser use LIBS (MC-LIBS) is also under developing for higher performance in screening analysis.
赤岡 克昭; 大場 正規; 宮部 昌文; 若井田 育夫
no journal, ,
For LIBS, which can measure two-dimensional composition distribution with a spatial resolution of several hundred micrometers, it is important to select the sets of interference-free spectrum. However, it is difficult to select such a set of spectra for nuclear fuel debris containing many heavy elements, such as uranium, which occurred at the accident at the TEPCO's Fukushima Daiichi Nuclear Power Plant. Therefore, in this presentation, we report the results of two-dimensional elemental composition measurements and analysis using the least-square method of Gd
O
containing a small amount of HoO as simulated nuclear fuel debris using LIBS.
田村 浩司; 中西 隆造; 大場 弘則; 佐伯 盛久; 田口 富嗣*; Lim, H. H.*; 平等 拓範*; 若井田 育夫
no journal, ,
For the remote inspection in harsh radiation environment, laser induce breakdown spectroscopy (LIBS) system has been developed, where micro-chip laser (MCL) using a Nd:YAG/Cr:YAG composite was utilized. A ceramics composite is considered effective as a laser medium for the system because ceramics has many advantageous features (machinable, scalable, etc). In this study, for the development of the remote LIBS system, radiation effects to the optical properties of Nd:YAG ceramics and single crystal (SC) were measured and compared. Transmission spectra were measured and effects by gamma ray irradiation and temperature change were examined.
大場 弘則; 田村 浩司; 中西 隆造; 佐伯 盛久; Lim, H. H.*; 平等 拓範*; 若井田 育夫
no journal, ,
For a nuclear power plant decommissioning process, there are some probes related inspection systems to be considered to make the process faster and more accessible, more secure. In the inspection of the damaged reactor core, combining the imaging observation and the Laser-induced breakdown spectroscopy (LIBS) analysis provides more rich information. In this study, we present a newly developed fiber-optic LIBS probe using a passively Q-switched ceramic micro-laser for remote sensing. And then, we will present application to Gd detection in mixed oxides of simulated nuclear fuel debris (Ce (: surrogate of U)-Zr-Fe oxides) using this probe.