Radiation dose rate effects on the properties of a laser-induced breakdown spectroscopy system developed using a ceramics micro-laser for fiber-optic remote analysis

Tamura, Koji; Oba, Hironori; Saeki, Morihisa; Taguchi, Tomitsugu*; Lim, H. H.*; Taira, Takunori*; Wakaida, Ikuo

Journal of Nuclear Science and Technology, 58(4), p.405 - 415, 2021/04

https://doi.org/10.1080/00223131.2020.1854880

Radiation dose rate effects on the properties of a compact fiber-optic laser-induced breakdown spectroscopy (LIBS) system with a monolithic Nd:YAG/Cr:YAG composite ceramics were investigated for remote analysis in hazardous environment. To investigate radiation effects on the LIBS signal, properties related to the Nd:YAG laser operation such as oscillation threshold, output energy, oscillation timing, temporal pulse shape, and beam profile were measured as a function of the radiation dose rate from 0 to 10 kGy/hr in view of their influences to the signal. LIBS spectra of zirconium metal were measured under irradiation. Although signal intensity decreased considerably by irradiation, informative spectra were well obtained even at the maximum radiation dose rate. From the comparison of the LIBS-related parameters among the laser properties, signal reduction was mainly ascribed to the pulse energy reduction. Scintillation emission spectra were also measured from the ceramics during the irradiation, where the signal intensity increased linearly with the dose rate. The results show that the developed system.

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.

Application of remote laser analysis for decommissioning of Fukushima Daiichi Nuclear Power Station

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

no journal, , 

no abstracts in English

Approach for fuel debris analysis in decommissioning of Fukushima Daiichi Nuclear Power Station and basic R&D

Wakaida, Ikuo; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Hironori; Taira, Takunori*

no journal, , 

no abstracts in English

Laser remote analysis for decommissioning of Fukushima Daiichi Nuclear Power Station

Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Masaki; Taira, Takunori*

no journal, , 

Advanced study on remote and in-situ elemental analysis for molten fuel debris in damaged core by innovative optical spectroscopy

Wakaida, Ikuo; Sakka, Tetsuo*; Ikeda, Yuji*; Oba, Hironori*; Taira, Takunori*

no journal, , 

no abstracts in English

Practical application of LIBS and rerated spectroscopy for decommissioning work of Fukushima Daiichi Nuclear Power Station

Wakaida, Ikuo; Oba, Hironori; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Tamura, Koji; Saeki, Morihisa; Nakanishi, Ryuzo; Ikeda, Yuji*; Sakka, Tetsuo*; et al.

no journal, , 

no abstracts in English

Rare earth elements detection in mixed oxide using a fiber optic LIBS with a ceramic micro-laser

Oba, Hironori; Tamura, Koji; Nakanishi, Ryuzo; Saeki, Morihisa; Lim, H. H.*; Taira, Takunori*; Wakaida, Ikuo

no journal, , 

Laser remote analysis for in-situ screening of nuclear debris in damaged reactor

Wakaida, Ikuo; Oba, Hironori; Taira, Takunori*; Ikeda, Yuji*

no journal, , 

no abstracts in English

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

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

no journal, , 

Fiber-coupled LIBS analysis using a microchip laser in a harsh environment

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

no journal, , 

Development of remote inspection and elemental analysis methods in a harsh radiation environment is required, such as inspection of the nuclear fuel debris at the bottom of the post-accident nuclear reactor (Tokyo Electric Power Company, Fukushima Daiichi Nuclear Power Plant). Laser-induced breakdown spectroscopy (LIBS) has been utilized as an effective qualitative and quantitative analytical method for elemental analysis. Inspecting the damaged reactor vessels requires a longer fiber-optic (FO) cable, which significantly attenuates the delivered laser energy by absorption and scattering in the fiber. We report on the first trial of our FO-LIBS system using the microchip laser (MCL) to identify and quantify elements in surrogate nuclear fuel debris under gamma irradiation, the results of trials on surrogate debris analysis, containing uranium oxide, using the MCL, and the results of 100 m-long fiber-delivered LIBS.