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Saeki, Morihisa; Iwanade, Akio; Ito, Chikara; Wakaida, Ikuo; Thornton, B.*; Sakka, Tetsuo*; Oba, Hironori
Journal of Nuclear Science and Technology, 51(7-8), p.930 - 938, 2014/07
Times Cited Count：70 Percentile：98.67(Nuclear Science & Technology)To inspect post-accident nuclear core reactor of the TEPCO Fukushima Daiichi Nuclear Power Plant, a transportable fiber-coupled LIBS instrument was developed. The developed LIBS instrument was designed to analyze the underwater sample in high-radiation field by single-pulse breakdown with gas flow or double-pulse breakdown. To check the feasibility of the assembled fiber-coupled LIBS instrument to the inspection inside Fukushima Daiichi Nuclear Power Plant, we investigated (1) influence of radiation dose on optical transmittance of the laser delivery fiber, (2) survey of the LIBS techniques to analyze the underwater sample and (3) candidates of emission lines for analysis of the debris. By employing the selected emission lines, we demonstrated that the developed LIBS instrument can analyze the simulated debris underwater by the single-pulse breakdown with the gas flow with high signal to noise ratio.
Saeki, Morihisa; Hirata, Koichi*; Sakka, Tetsuo*; Oba, Hironori; Yokoyama, Atsushi
Journal of Applied Physics, 98(4), p.044912_1 - 044912_6, 2005/08
Times Cited Count：3 Percentile：13.67(Physics, Applied)no abstracts in English
and D
O in two-liquid-phase system*; *; *; *; ; Suzuki, Kazuya
Journal of Physical Chemistry, 93(13), p.5139 - 5143, 1989/00
Times Cited Count：6 Percentile：32.12(Chemistry, Physical)no abstracts in English
Wakaida, Ikuo; Akaoka, Katsuaki; Oba, Masaki; Maruyama, Yoichiro; Miyabe, Masabumi; Otobe, Haruyoshi; Kato, Masaaki; Oba, Hironori; Niki, Hideaki*; Ikeda, Yuji*; et al.
no journal, ,
"Development of laser remote analysis for low-decontaminated TRU fuel" entrusted to Japan Atomic Energy Agency by the MEXT has been studied by combination of laser induced breakdown spectroscopy for elemental analysis and resonance absorption spectroscopy for isotope analysis. In this presentation, results on elemental analysis of the detection limit of order 100 ppm and the performance on isotopic measurement of the detection limit of 350 ppm success to detect 
U in natural uranium are summarized. And the new program of "Development of laser remote analysis for next generation nuclear fuel and demonstration study by MOX sample" will be introduced and temporal results will be described.
Wakaida, Ikuo; Akaoka, Katsuaki; Oba, Masaki; Maruyama, Yoichiro; Miyabe, Masabumi; Otobe, Haruyoshi; Kato, Masaaki; Oba, Hironori; Niki, Hideaki*; Ikeda, Yuji*; et al.
no journal, ,
Laser remote analysis for next generation nuclear fuel has been studied by combination of laser induced breakdown spectroscopy (LIBS) for elemental analysis and resonance absorption spectroscopy for isotope analysis. For elemental analysis in Uranium oxide, detection limit of 100 ppm (Ca, etc.) or 300 ppm (Lanthanide) and detection linearity up to several 10% are performed. For higher sensitivity, emission intensity by double pulse LIBS will be realized several ten times higher than that of conventional LIBS. The performance on isotopic measurement of the detection limit of 300 ppm success to detect U in natural uranium is summarized. And the new program of "Development of laser remote analysis for next generation nuclear fuel and applied study by MOX sample" will be introduced and temporal results will be described.
Wakaida, Ikuo; Maruyama, Yoichiro; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Tampo, Motonobu; Oba, Hironori; Otobe, Haruyoshi; Kato, Masaaki; Niki, Hideaki*; et al.
no journal, ,
"Development of laser remote analysis for next generation nuclear fuel and applied study by MOX sample" entrusted to Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) has been studied by combination of laser induced breakdown spectroscopy (LIBS) for elemental analysis and resonance absorption spectroscopy for isotope analysis. In this presentation, recent results on LIBS for elemental analysis by the high resolution spectrometer, co-linear double pulse LIBS for higher sensitivity and simultaneous measurement of isotope ratio by ablation initiated resonance absorption spectroscopy are generally discussed. And will be also discussed on recent trials of microwave assist LIBS and liquid phase LIBS.
Wakaida, Ikuo; Akaoka, Katsuaki; Oba, Masaki; Maruyama, Yoichiro; Miyabe, Masabumi; Tampo, Motonobu; Oba, Hironori; Otobe, Haruyoshi; Kato, Masaaki; Ikeda, Yuji*; et al.
no journal, ,
The research program of "Development of laser remote analysis for next generation nuclear fuel and demonstration study by MOX sample" will be introduced and recent topical results will be described. For elemental analysis in uranium oxide sample, laser induced breakdown spectroscopy (LIBS) using by the high resolution spectrometer was performed and good linearity and low detection limit were accomplished without deconbolution analysis. For a powder phase sample, good performance was obtained by compressed molding powder. Basic characteristics of microwave assisted LIBS were studied, and atomic emission of higher intensity and longer emission time were realized. In isotope analysis moving characteristics of ablate plume were observed and high resolution and high sensitivity was simultaneously achieved. For the application of liquid phase sample, high sensitivity like ICP-AES was successfully realized by LIBS using ultra thin liquid flow.
Wakaida, Ikuo; Maruyama, Yoichiro; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Tampo, Motonobu; Oba, Hironori; Otobe, Haruyoshi; Takano, Masahide; Kato, Masaaki; et al.
no journal, ,
The background and recent results of "Development of laser remote analysis for next generation nuclear fuel and applied study by MOX sample" entrusted to Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) will be summarized. Measurement accuracy in elemental analysis by laser induced breakdown spectroscopy and the analysis of the expansion phenomena of ablation plume by resonance fluorescence spectroscopy will be globally discussed. Application for the inner monitoring in the accident of Fukushima power plant and an environmental monitoring of 
Sr by semiconductor laser resonance ionization spectroscopy will be also introduced.
Toshimitsu, Masaaki; Saeki, Morihisa; Sugiyama, Akira; Oba, Hironori; Thornton, B.*; Sakka, Tetsuo*
no journal, ,
no abstracts in English
Toshimitsu, Masaaki; Saeki, Morihisa; Oba, Hironori; Thornton, B.*; Sakka, Tetsuo*
no journal, ,
A laser-induced breakdown spectroscopy (LIBS) technique for element analysis of samples submerged in water using a fiber optic light delivery set-up has been developed. The set-up delivers air to the sample surface via a tube and uses the same fiber optic for laser light delivery, and for observation of the light emitted by the micro-plasma generated for analysis. The emission spectra from metals, alloys and oxide samples such as Fe, SUS304, zircaloy-2, ZrO can be clearly observed at wavelengths ranging from 730 nm to 870 nm.
Wakaida, Ikuo; Akaoka, Katsuaki; Oba, Masaki; Maruyama, Yoichiro; Miyabe, Masabumi; Tampo, Motonobu; Oba, Hironori; Otobe, Haruyoshi; Kato, Masaaki; Ikeda, Yuji*; et al.
no journal, ,
The background and recent results of the R&D titled of "Development of laser remote analysis for next generation nuclear fuel and applied study by MOX sample" entrusted to Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) will be summarized as the first speaker of the series lecture consist with five titles. Measurement accuracy in elemental analysis by laser induced breakdown spectroscopy (LIBS), characteristics of microwave assisted LIBS, LIBS for liquid solution by ultra-thin liquid flow, and the analysis of the expansion phenomena of ablation plume by resonance fluorescence spectroscopy will be globally introduced. Application for the inner monitoring in the accident of Fukushima power plant will be also discussed.
Saeki, Morihisa; Iwanade, Akio; Ito, Chikara; Wakaida, Ikuo; Thornton, B.*; Sakka, Tetsuo*; Oba, Hironori
no journal, ,
To perform elemental analysis of solid samples under water and radiation field, we designed and constructed the instrument for fiber-coupled laser induced breakdown spectroscopy (LIBS). The LIBS analysis of the underwater sample is difficult, because the water quickly quenches the plasma plume that is generated by the ablation. To solve this problem, we prepared quasi-atmospheric condition around the plasma plume by using gas flow or double pulse irradiation system, and succeeded to observe similar spectrum between atmospheric and underwater condition. Moreover, the optical property of the fiber was investigated by exposing 
Co 
-ray with total dose over 1 MGy to the optic fiber. As a result, we found that radiation exposure to the fiber leads to slight damage in near infrared one. Thus, we designed the fiber-coupled LIBS system to perform laser ablation by near-infrared laser beam (1064 nm) and to efficiently detect plasma emission in near infrared region.
Saeki, Morihisa; Iwanade, Akio; Ito, Chikara; Wakaida, Ikuo; Thornton, B.*; Sakka, Tetsuo*; Oba, Hironori
no journal, ,
no abstracts in English
Oba, Hironori; Saeki, Morihisa; Miyabe, Masabumi; Akaoka, Katsuaki; Wakaida, Ikuo; Iwanade, Akio; Ito, Chikara; Tanabe, Rie*; Ito, Yoshiro*; Sakka, Tetsuo*; et al.
no journal, ,
no abstracts in English
Oba, Hironori; Saeki, Morihisa; Iwanade, Akio; Wakaida, Ikuo; Ito, Chikara; Sugiyama, Akira; Sakka, Tetsuo*; Thornton, B.*
no journal, ,
no abstracts in English
using laser-induced breakdown spectroscopy (LIBS)Oba, Hironori; Saeki, Morihisa; Ito, Chikara; Takano, Masahide; Akaoka, Katsuaki; Thornton, B.*; Sakka, Tetsuo*; Wakaida, Ikuo
no journal, ,
In the post-accident nuclear core reactor of the TEPCO Fukushima Daiichi Nuclear Power Plants, melted fuel core, fuel cladding and construction material (corium debris) might drop in the lower part of the reactor, which filled with seawater that was injected for urgent cooling. The major components of the debris material are assumed to be uranium oxide (UO, fuel core), zirconium alloy (Zry, fuel cladding) and iron (Fe, construction material). In this presentation, we report underwater analysis of simulated corium debris, (U,Zr)O, by the transportable fiber-coupled LIBS instrument. The experiments were carried out using a wavelength region of 730-1100 nm for pulsed-lasers and plasma emission measurements, which shows no attenuation in the optical transmittance of the fiber optic cable by intense radiation dose. Based on the observed emission spectrum in the region of 750-870 nm, we determined candidates of the emission lines of Zr, U and Fe that are applicable to analyses of the debris without mutual interference. The LIBS spectra of five different concentration ratio samples for Zr/U were measured to obtain calibration data. We succeeded to obtain linear calibration data for emission intensity ratio versus concentration ratio of Zr/U.
Saeki, Morihisa; Ito, Chikara; Wakaida, Ikuo; Thornton, B.*; Sakka, Tetsuo*; Oba, Hironori
no journal, ,
Oba, Hironori; Saeki, Morihisa; Ito, Chikara; Takano, Masahide; Akaoka, Katsuaki; Wakaida, Ikuo; Sakka, Tetsuo*; Thornton, B.*
no journal, ,
In order to inspect the post-accident nuclear core reactor of the TEPCO Fukushima Daiichi Nuclear Power Plants, a transportable fiber-coupled laser-induced breakdown spectroscopy (LIBS) instrument has been developed. In this presentation, we report underwater analysis of simulated corium debris, (U,Zr)O, by the transportable fiber-coupled LIBS instrument. The experiments were carried out using a wavelength region of 730
1100 nm for pulsed-lasers and plasma emission measurements, which shows no attenuation in the optical transmittance of the fiber optic cable by intense radiation dose. Based on the observed emission spectrum in the region of 750870 nm, we determined candidates of the emission lines of Zr, U and Fe that are applicable to analyses of the debris without mutual interference.
Oba, Hironori; Saeki, Morihisa; Ito, Chikara; Takano, Masahide; Akaoka, Katsuaki; Thornton, B.*; Sakka, Tetsuo*; Wakaida, Ikuo
no journal, ,
To inspect the post-accident nuclear core reactor of the TEPCO Fukushima Daiichi Nuclear Power Plants, a transportable fiber-coupled laser-induced breakdown spectroscopy (LIBS) instrument has been employed. In the post-accident nuclear core reactor, melted fuel core, fuel cladding and construction material might drop in the lower part of the reactor, which filled with seawater that was injected for urgent cooling. The major components of the debris material are assumed to be uranium oxide (UO, fuel core), zirconium alloy (Zry, fuel cladding), stainless steel (Fe, construction material) and boron carbide (B
C, critical control material). In this presentation, we report underwater analysis of simulated corium debris, (U,Zr)O, and BC by fiber-coupled LIBS instrument. The experiments were carried out using near-infrared wavelength region for pulsed-lasers and plasma emission measurements, which shows no attenuation in the optical transmittance of the fiber optic cable by intense radiation dose. We determined candidates of the emission lines of Zr, U, Fe and B (BO) that are applicable to analyses of the debris without mutual interference.
Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Oba, Masaki; Ruas, A.; Saeki, Morihisa; Miyabe, Masabumi; Ikeda, Yuji*; Sakka, Tetsuo*
no journal, ,
no abstracts in English
