Development of a fiber-coupled laser-induced breakdown spectroscopy instrument for analysis of underwater debris in a nuclear reactor core

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

https://doi.org/10.1080/00223131.2014.917996

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.

Elemental analysis of solid samples under water by fiber-coupled laser induced breakdown spectroscopy

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 (BC, 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.

Laser remote analysis for next generation nuclear fuel, 1; Summary of results and future scope

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.

Application of laser based spectroscopy for nuclear fuel materials and environmental trace analysis

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.

Development of remote laser-induced breakdown spectroscopy for samples submerged in water

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.

Development of quick and remote analysis for severe accident reactor, 1; Laser remote analysis under severe environment

Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Oba, Masaki; Ruas, A.; Saeki, Morihisa; Miyabe, Masabumi; Ikeda, Yuji*; Sakka, Tetsuo*

no journal, , 

no abstracts in English

Laser remote analysis for decommissioning of damaged reactor core

Wakaida, Ikuo; Akaoka, Katsuaki; Oba, Masaki; Oba, Hironori; Tamura, Koji; Saeki, Morihisa; Matsumoto, Ayumu*; Sakka, Tetsuo*; Ikeda, Yuji*; Taira, Takunori*

no journal, , 

no abstracts in English

Elemental analysis of simulated debris of nuclear fuel in water by fiber-coupled laser induced breakdown spectroscopy

Saeki, Morihisa; Ito, Chikara; Wakaida, Ikuo; Thornton, B.*; Sakka, Tetsuo*; Oba, Hironori

no journal, , 

Basic R&D on decommissioning of Fukushima Daiichi Nuclear Power Station and application of Laser Remote Analysis for in-core and in-situ monitoring of debris

Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Oba, Masaki; Matsumoto, Ayumu; Miyabe, Masabumi; Ikeda, Yuji*; Sakka, Tetsuo*; Taira, Takunori*

no journal, , 

For the decommissioning of "Fukushima Daiichi Nuclear Power Station (F1NPS)", widely basic R&D and matting for actual application for decommissioning technology will be strongly required. CLADS/JAEA is one of the key institute for strategic promotion of Decommissioning Science on F1NPS. As for the development of rapid, easy, onsite and in-situ remote diagnostic/analysis techniques under extremely high radioactive condition, the concept of probing by light and diagnostic by light with radiation resistant optical fiber will be one of the simple, powerful and applicable choices as the innovative development based on laser induced breakdown spectroscopy (LIBS) technology. Optical fiber based LIBS is developed for in-core and in-situ elemental analysis of debris and its activity is performed under severe environmental conditions such as high radiation field of about 10kGy/h and under water. Long pulse laser, microwave assisted LIBS and microchip laser are also introduced for more high sensitivity.

Basic R&D on laser remote analysis for in-situ monitoring of nuclear debris in decommissioning of "Fukushima Daiichi Nuclear Power Station"

Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Masaki; Matsumoto, Ayumu*; Sakka, Tetsuo*; Taira, Takunori*; Ikeda, Yuji*

no journal, ,