Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 66

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

JAEA Reports

Challenge to investigation of fuel debris in RPV by an advanced super dragon articulated robot arm (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*

JAEA-Review 2021-045, 65 Pages, 2022/01

JAEA-Review-2021-045.pdf:3.41MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Challenge to investigation of fuel debris in RPV by an advanced super dragon articulated robot arm" conducted in FY2020. The present study aims to develop the implementation techniques of the remote sensing method on a robot arm for monitoring the structure status in the reactor and the distribution of nuclear materials by a long-articulated robot arm with controlling and grasping the position and posture of the robot arm hand. In FY 2020, we have conducted fundamental operation check of the robot arm in the simulated environment, prototype construction of telescopic articulated arm and cable storage mechanism, investigation of drive wire specifications, improvement of LIBS probe, prototype construction of microchip

JAEA Reports

Challenge to advancement of debris composition and direct isotope measurement by microwave-enhanced LIBS (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Ilabo*

JAEA-Review 2021-027, 62 Pages, 2021/11

JAEA-Review-2021-027.pdf:3.06MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Challenge to advancement of debris composition and direct isotope measurement by microwave-enhanced LIBS" conducted in FY2020. Although LIBS (laser-induced breakdown spectroscopy) is commercially available for application to remote composition measurement, it is not suitable for high radiation environment due to loss in optical fibers derived from the influence of radiation, reduction in laser transmission output, and nuclear fuel debris properties. There are general concerns of the signal strength decrease. In addition, since LIBS is generally considered to be unsuitable for isotope measurement, there are problems to be improved. In this research, we aimed to realize a lightweight and compact system by superimposing

JAEA Reports

Challenge to investigation of fuel debris in RPV by an advanced super dragon articulated robot arm (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*

JAEA-Review 2020-040, 55 Pages, 2021/01

JAEA-Review-2020-040.pdf:3.95MB

JAEA/CLADS had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project in FY2019. Among the adopted proposals in FY2019, this report summarizes the research results of the "Challenge to Investigation of Fuel Debris in RPV by an Advanced Super Dragon Articulated Robot Arm" conducted in FY2019.

JAEA Reports

Measurement of plutonium spectrum using laser induced breakdown spectroscopy; High resolution spectroscopy (350-670nm)

Akaoka, Katsuaki; Oba, Masaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo

JAEA-Research 2020-001, 142 Pages, 2020/03

JAEA-Research-2020-001.pdf:4.0MB

Laser Induced Breakdown Spectroscopy (LIBS) method is an attractive technique because real-time, in-situ and remote elemental analysis is possible without any sample preparation. The LIBS technique can be applied for analyzing elemental composition of samples under severe environments such as the estimation of impurities in the next generation nuclear fuel material containing minor actinide (MA) and the detection of fuel debris in the post-accident nuclear core reactor of TEPCO's Fukushima Daiichi Nuclear Power Station. For applying LIBS to the analysis of nuclear fuel materials, it is indispensable to identify the emission spectrum and its intensity on impurities intermingled within complex emission spectra of matrix elements such as uranium (U) and plutonium (Pu). In the present study, an echelle spectrometer with a resolving power of 50,000 was employed to identify spectra of plutonium of wavelength ranging from 350 to 670nm. The 465 atomic spectra and 341 ionic spectra can be identified. We have confirmed that the measured wavelength of spectra is consistent with published values.

Journal Articles

Development of laser ablation absorption spectroscopy for nuclear fuel materials; Plume expansion behavior for refractory metals observed by laser-induced fluorescence imaging spectroscopy

Miyabe, Masabumi; Oba, Masaki; Akaoka, Katsuaki; Kato, Masaaki*; Hasegawa, Shuichi*; Wakaida, Ikuo

Applied Physics A, 126(3), p.213_1 - 213_10, 2020/03

The dynamic behavior of an ablation plume in low pressure rare gas ambient was investigated with laser-induced fluorescence imaging spectroscopy for three refractory metals, i.e. titanium, zirconium and hafnium. A comparison of the plume expansion behaviors for the species of these elements revealed an atomic weight effect on the plume structure formation. A hemispherical thin layer and cavity structure reported previously for gadolinium were observed also for these elements. It was found that the plume size increases as well as the layer thickness decreases with increasing atomic weight. For ground state atoms of Ti, substantial amount of atoms were observed even at the center of the plume. Also, the persistence of the Ti atomic plume was as long as 300 $$mu$$s, which was significantly longer than the other species studied. Furthermore, the mass-dependent elemental separation was observed in the ablation plume produced from a multielement sample. These results suggest that the observed plume structure arises from the ion-electron recombination process and the recoil of the ablated species during the multiple collisions with gas atoms.

Journal Articles

Radiation measurement and analysis

Wakaida, Ikuo; Hasegawa, Shuichi*; Tadokoro, Takahiro*

Nihon Kikai Gakkai-Shi, 122(1211), p.18 - 20, 2019/10

no abstracts in English

Journal Articles

A New measuring method for elemental ratio and Vickers hardness of metal-oxide-boride materials based on Laser-Induced Breakdown Spectroscopy (LIBS)

Abe, Yuta; Otaka, Masahiko; Okazaki, Kodai*; Kawakami, Tomohiko*; Nakagiri, Toshio

Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 7 Pages, 2019/05

Since the hardness of fuel debris containing boride from B$$_{4}$$C pellet in control rod is estimated to be two times higher as that of oxide, such as UO$$_{2}$$ and ZrO$$_{2}$$, it is necessary to select the efficient and appropriate operation for removal of fuel debris formed in the severe accident of nuclear power plants. We focused on the characteristics of LIBS, an innovative rapid chemical in-situ analysis technology that enables simultaneous detection of B, O, and other metal elements in fuel debris. Simulated solidified melt specimens were obtained in the plasma heating tests (CMMR-0/-2, performed by JAEA) of simulated fuel assembly (ZrO$$_{2}$$ is used to simulated UO$$_{2}$$ pellet, other materials such as stainless steel, B$$_{4}$$C are same as fuel assembly). The LIBS signals of (B/O)/Zr ratio showed good linear relationship with Vickers hardness. This technique can be also applied as in-situ assessment tool for elemental composition and Vickers hardness of metal-oxide-boride materials.

Journal Articles

Laser-induced breakdown spectroscopy and related resonance spectroscopy for nuclear fuel cycle management and for decommissioning of "Fukushima Daiichi Nuclear Power Station"

Wakaida, Ikuo; Oba, Hironori; Miyabe, Masabumi; Akaoka, Katsuaki; Oba, Masaki; Tamura, Koji; Saeki, Morihisa

Kogaku, 48(1), p.13 - 20, 2019/01

By Laser Induced Breakdown Spectroscopy and by related resonance spectroscopy, elemental and isotope analysis of Uranium and Plutonium for nuclear fuel materials and in-situ remote analysis under strong radiation condition for melt downed nuclear fuel debris at damaged core in "Fukushima Daiichi Nuclear Power Station", are introduced and performed as one of the application in atomic energy research field.

Oral presentation

Emission characteristics of microwave-assisted laser plasma induced in air, Ar, and He gases

Khumaeni, A.; Miyabe, Masabumi; Akaoka, Katsuaki; Wakaida, Ikuo

no journal, , 

Oral presentation

Validation studies on quick and in-situ analysis of MOX fuel by combination of laser induced breakdown spectroscopy and ablation resonance absorption spectroscopy

Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi; Kato, Masaaki; Otobe, Haruyoshi; Oba, Hironori; Khumaeni, A.

no journal, , 

In Japan Atomic Energy Agency (JAEA), research and development of quick analysis for next-generation MOX fuel without chemical analysis and neutron measurement had been carried out as the entrusted project by MEXT, and basic performances by using un-irradiated MOX fuel were demonstrated. In elemental analysis by Laser Induced Breakdown Spectroscopy (LIBS) with high resolution spectrometer, relative error of 2.9% at 30% Pu and the detection lower limit of 2,500 ppm in U oxide were demonstrated with the operation time of 5 min.. In isotope ratio analysis by Ablation Resonance Absorption Spectroscopy, tunable semiconductor laser system was constructed, and the relative deviation less than 1% in the ratio of $$^{240}$$Pu/$$^{239}$$Pu and sensitivity of 30-100 ppm in U were also accomplished within 5min. operation. As for an analysis in liquid sample, ultra-thin laminate flow was experimented as LIBS target, and the sensitivity comparable to conventional ICP-AES was confirmed.

Oral presentation

Development of laser analysis for nuclear fuel management

Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi; Khumaeni, A.; Oba, Hironori; Ito, Chikara

no journal, , 

In the new concept of next generation nuclear fuel cycle for long lived radioactive waste disposal by use of Accelerator Driven Subcritical reactor (ADS Cycle) and by a fast breeder reactor (FBR Cycle), utilization of low-decontaminated fuel with TRU will be promoted. Simultaneous analysis of element and isotope by the combination of Laser Induced Breakdown Spectroscopy (LIBS) and Ablation Resonance Absorption Spectroscopy was demonstrated by MOX fuel. For elemental analysis, detection lower limit of 1000 ppm of Pu in U oxide and relative error under 5% have been obtained within 5 min. For isotope analysis, $$^{240}$$Pu and $$^{239}$$Pu have been observed separately, and detection lower limit of several 10 ppm and error under 1% have been accomplished. A simple antenna coupled microwave assisted LIBS was performed and the enhancement of emission intensity of several 10 times was demonstrated. For liquid sample, ultra-thin laminate flow as the laser focused target was accomplished high sensitivity of ppb. For in-situ monitoring, Optical Fiber LIBS Probe by radiation resistant optical fiber is under construction.

Oral presentation

Application of laser spectroscopy in nuclear engineering; Characteristic of the linewidth in laser induced breakdown spectroscopy

Akaoka, Katsuaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo

no journal, , 

no abstracts in English

Oral presentation

Application of laser spectroscopy in nuclear engineering; Expansion dynamics of ablation plume in gas ambient

Miyabe, Masabumi; Oba, Masaki; Akaoka, Katsuaki; Kato, Masaaki; Wakaida, Ikuo

no journal, , 

no abstracts in English

Oral presentation

Measurement of uranium isotope and linewidth using laser induced break down spectroscopy

Akaoka, Katsuaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo

no journal, , 

no abstracts in English

Oral presentation

Challenging in laser based spectroscopy for nuclear engineering

Wakaida, Ikuo; Oba, Hironori; Akaoka, Katsuaki; Miyabe, Masabumi; Oba, Masaki; Ito, Chikara; Saeki, Morihisa; Kato, Masaaki

no journal, , 

In nuclear engineering, especially for the decommissioning of severe accident atomic power plant, development of quick, easy, non-contact, no-preparation, direct, remote, onsite and in-situ analysis of nuclear fuel materials which has very complex and large amount of optical emission lines will be indispensable. In these R&D, it may be important how we realize high sensitivity and high resolution spectroscopy and perform the identification of the specific element among a large number of emission spectra. Various kind of technique, such as Double-pulse LIBS and Microwave assisted LIBS for multiply the emission intensity, high resolution LIBS by ultra-high resolution spectrometer or Laser Ablation Resonance Absorption Spectroscopy for isotope analysis, Ultra-thin Liquid flow LIBS for liquid phase application and LIBS based on radiation resistant optical fiber for onsite/in-situ monitoring of melt downed nuclear fuel debris, will have been under investigation. Japan Atomic Energy Agency has opened the new research center "Collaborative Laboratories for Advanced Decommissioning Science", and laser based spectroscopy will be restarted as one of the basic projects.

Oral presentation

Measurement of emission spectra for uranium and plutonium by laser-induced breakdown spectroscopy

Akaoka, Katsuaki; Oba, Hironori; Otobe, Haruyoshi; Oba, Masaki; Miyabe, Masabumi; Wakaida, Ikuo

no journal, , 

For analysis of fuel debris in Fukushima Daiichi Nuclear Power Station, the emission spectra for uranium and plutonium by laser-induced breakdown spectroscopy were measured. The spectra through the irradiated fiber of $$gamma$$ ray was simulated.

Oral presentation

Application of laser-induced breakdown spectroscopy to zirconium in aqueous solution

Ruas, A.; Oba, Hironori; Akaoka, Katsuaki; Wakaida, Ikuo

no journal, , 

Oral presentation

Development of quick and remote analysis for severe accident reactor, 5; Analysis of spectra using the least-square method

Akaoka, Katsuaki; Oba, Masaki; Miyabe, Masabumi; Wakaida, Ikuo

no journal, , 

For quantitative analysis of the fuel debris using Laser Induced Breakdown Spectroscopy (LIBS), great deal of analysis and identification of spectra are necessary. Therefore, we tried "the analysis of the LIBS spectrum by the least-squares method" as quantitative analysis without identification and analysis of the spectra. As a result, the calibration curves for quantitative analysis could be got without them.

Oral presentation

Development of quick and remote analysis for severe accident reactor, 3; characteristics of microwave assisted LIBS

Oba, Masaki; Akaoka, Katsuaki; Miyabe, Masabumi; Wakaida, Ikuo; Oba, Hironori; Ruas, A.

no journal, , 

To enhance the emission intensity of laser plasma, the characteristics of microwave assisted LIBS (MW LIBS) were measured. Using gadorinium oxide as test sample, the emission strength in the case of MW LIBS was 4 times higher than that in the case of laser pulse only.

66 (Records 1-20 displayed on this page)