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Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*
JAEA-Review 2023-039, 71 Pages, 2024/03
JAEA-Review-2023-039.pdf:4.43MB
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 FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F), 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 FY2021, this report summarizes the research results of the "Improvement of aerosol time-of-flight mass spectrometer for on-line measurement of tiny particles containing alpha emitters" conducted in FY2021. The present study aims to improve Aerosol Time-Of-Flight Mass Spectrometer in order to monitor tiny particles containing alpha emitters such as U and Pu generated in removing debris from the reactors of 1F. In FY2021, for improving mass-resolution, we designed the optimized structure of mass spectrometer with much better mass resolution and ion transmittance than commercial ATOFMS by a PC simulation. Further, design of a detection part of ATOFMS fitted to the mass spectrometer was completed.
Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*
JAEA-Review 2021-074, 104 Pages, 2022/03
JAEA-Review-2021-074.pdf:4.91MB
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 "Basic study for on-line monitoring of tiny particles including alpha emitters by aerosol time-of-flight mass spectroscopy" conducted in FY2019 and FY2020. Since the final year of this proposal was FY2020, the results for two fiscal years were summarized. The present study aims to conduct a feasibility study of Aerosol time-of-flight mass spectroscopy (ATOFMS) to on-line measurement of tiny particles containing alpha emitters which might be dispersed in cutting the debris in reactors of the Fukushima Daiichi Nuclear Power Station for realizing their real-time monitoring.
Oda, Chie; Kawama, Daisuke*; Shimizu, Hiroyuki*; Benbow, S. J.*; Hirano, Fumio; Takayama, Yusuke; Takase, Hiroyasu*; Mihara, Morihiro; Honda, Akira
Journal of Advanced Concrete Technology, 19(10), p.1075 - 1087, 2021/10
Times Cited Count：0 Percentile：0(Construction & Building Technology)Concrete in a transuranic (TRU) waste repository is considered a suitable material to ensure safety, provide structural integrity and retard radionuclide migration after the waste containers fail. In the current study, coupling between chemical, mass-transport and mechanical, so-called non-linear processes that control concrete degradation and crack development were investigated by coupled numerical models. Application of such coupled numerical models allows identification of the dominant non-linear processes that will control long-term concrete degradation and crack development in a TRU waste repository.
Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*
JAEA-Review 2020-050, 69 Pages, 2021/01
JAEA-Review-2020-050.pdf:3.79MB
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 FY2019. 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 "Basic study for On-Line Monitoring of Tiny Particles including Alpha Emitters by Aerosol Time-Of-Flight Mass Spectroscopy" conducted in FY2019. The present study aims to conduct a feasibility study of Aerosol Time-Of-Flight Mass Spectroscopy (ATOFMS) technique to on-line measurement of tiny particles including alpha emitters which might be dispersed in cutting debris in reactors of the Fukushima Daiichi Nuclear Power Station for realizing real-time monitoring of the tiny particles. In FY2019, we prepared the solid (U, Zr)O
samples and the acidic and basic U solutions as model materials.
Iwamoto, Hiroki; Nishihara, Kenji; Yagi, Takahiro*; Pyeon, C.-H.*
Journal of Nuclear Science and Technology, 54(4), p.432 - 443, 2017/04
Times Cited Count：20 Percentile：88.37(Nuclear Science & Technology)Ido, Takeshi*; Miura, Yukitoshi; Hoshino, Katsumichi; Kamiya, Kensaku; Hamada, Yasuji*; Nishizawa, Akimitsu*; Kawasumi, Yoshiaki*; Ogawa, Hiroaki; Nagashima, Yoshihiko*; Shinohara, Koji; et al.
Nuclear Fusion, 46(5), p.512 - 520, 2006/05
Times Cited Count：86 Percentile：92.73(Physics, Fluids & Plasmas)The electrostatic fluctuation spectrum and the fluctuation-induced particle flux of the JFT-2M tokamak were estimated using the hevy ion beam probe (HIBP) measurement. A geodesic acoustic mode (GAM) of the frequency about15kHz was identified in the L-mode. The GAM has its peak at about 3cm inside of the separatrix with the electric field of about 1.4kV/m. The estimated turbulent particle flux is found to be intermittent. It is found that the density fluctuation is modulated by the GAM in the wide frequency range and the coherence analysis shows that the flucruation-induced particle flux is partially contributed by the GAM. In the H-mode the GAM disappears and the fluctuation and the flux is much decreased.The mechanism of the large burst-like flux in the L-mode is not understood yet and left as the future problem.
estimatorSuzuki, Katsuo; Suzudo, Tomoaki; Nabeshima, Kunihiko
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(1), p.24 - 33, 2004/03
This paper concerns an application of digital optimal H estimator to the detection of faulty reactivity in real-time. The detection system, fundamentally based on the reactivity balance method, is composed of three modules, i.e. the net reactivity estimator, the feedback reactivity estimator and the reactivity balance circuit. H optimal filters are used for these two reactivity estimators, and the nonlinear neutronics are taken into consideration especially for the design of the net reactivity estimator. A series of performance tests of the detection system are conducted by using numerical simulations of reactor dynamics with the insertion of a faulty reactivity for an experimental fast breeder reactor JOYO. The system detects the typical artificial reactivity insertions of 1￠ within a few seconds with the accuracy of 0.1￠, and is satisfactory for its practical use.
Nabeshima, Kunihiko; Ayaz, E.*; Seker, S.*; Barutcu, B.*; T
rkcan, E.*
Proceedings of International Conference on Artificial Neural Networks and the International Conference on Neural Information Processing (ICANN/ICONIP 2003), p.406 - 409, 2003/06
On-line plant monitoring system with neural networks and an expert system has been developed for Borssele Nuclear Power Plant (NPP) in the Netherlands. The feedforward and the recurrent neural networks are utilized for plant modeling and anomaly detection. The rule-based expert system is applied for plant diagnosis with the outputs of the neural networks. The off-line results showed that the neural network could model the plant dynamics precisely. The on-line results indicated that the monitoring system could sufficiently diagnose the plant status in real time.
Nabeshima, Kunihiko; Suzudo, Tomoaki; Ono, Tomio*; Kudo, Kazuhiko*
Mathematics and Computers in Simulation, 60(3-5), p.233 - 244, 2002/09
Times Cited Count：15 Percentile：69.77(Computer Science, Interdisciplinary Applications)This study presents a hybrid monitoring system for nuclear reactor utilizing neural networks and a rule-based real-time expert system. The whole monitoring system including a data acquisition system and the advisory displays has been tested by an on-line simulator of pressurized water reactor. From the testing results, it was shown that the neural network in the monitoring system successfully modeled the plant dynamics and detected the symptoms of anomalies earlier than the conventional alarm system. The real-time expert system also worked satisfactorily in diagnosing and displaying the system status by using the outputs of neural networks and a priori knowledge base.
-chain compound [Ni(chxn)
Br]Br; Spin-charge separation in hybridized 
-
chainsFujimori, Shinichi; Ino, Akihiro; Okane, Tetsuo; Fujimori, Atsushi; Okada, Kozo*; Manabe, Toshio*; Yamashita, Masahiro*; Kishida, Hideo*; Okamoto, Hiroshi*
Physical Review Letters, 88(24), p.247601_1 - 247601_4, 2002/06
Times Cited Count：13 Percentile：60.57(Physics, Multidisciplinary)We report on the results of angle-resolved photoemission experiments on a quasi-one-dimensional -chain compound [Ni(chxn)Br]Br (chxn = 1
,2-cyclohexanediamine), a one-dimensional Heisenberg system with 
and 
K, which shows a gigantic non-linear optical effect. A "band" having about 500meV energy dispersion is found in the first half of the Brillouin zone 
, but disappears at 
. Two dispersive features, expected from the spin-charge separation, as have been observed in other quasi-one-dimensional systems like SrCuO
, are not detected. These characteristic features are well reproduced by the - chain model calculations with a small charge-transfer energy 
compared with that of one-dimensional Cu-O based compounds. We propose that this smaller is the origin of the absence of clear spin- and charge-seperation in the photoemission spectra and strong non-linear optical effect in [Ni(chxn)Br]Br.
Otsubo, Takashi*; Oya, Susumu*; Goto, Jun*; *; Muto, Suguru*; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki
JAERI-Review 99-025, TIARA Annual Report 1998, p.206 - 207, 1999/10
no abstracts in English
*; *; *; *; *; *; *; Muto, Suguru*; Osa, Akihiko; Koizumi, Mitsuo; et al.
Hyperfine Interactions, 120-121(1-4), p.695 - 699, 1999/00
no abstracts in English
Sekine, Toshiaki; Ichikawa, Shinichi; Osa, Akihiko; Koizumi, Mitsuo; Iimura, Hideki; Tsukada, Kazuaki; Nishinaka, Ichiro; Hatsukawa, Yuichi; Nagame, Yuichiro; Asai, Masato*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 239(1), p.127 - 131, 1999/00
Times Cited Count：2 Percentile：21.16(Chemistry, Analytical)no abstracts in English
states in 
BaAsai, Masato*; *; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; *; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
"Fuanteikaku No Rikogaku Oyobi Kaku Keisokuho(II)" Ni Kansuru Semmon Kenkyukai Hokokusho, 0, p.97 - 100, 1997/00
no abstracts in English
- angular correlation measurements for mass-separated short-lived nucleiAsai, Masato*; Kawade, Kiyoshi*; *; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki
Nuclear Instruments and Methods in Physics Research A, 398, p.265 - 275, 1997/00
Times Cited Count：6 Percentile：50.07(Instruments & Instrumentation)no abstracts in English
Sekine, Toshiaki; Koizumi, Mitsuo; Osa, Akihiko
KURRI-KR-3, 0, p.13 - 17, 1996/00
no abstracts in English
Asai, Masato*; *; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; *; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
KURRI-KR-3, 0, p.36 - 40, 1996/00
no abstracts in English
Ba investigated by - angular correlation measurementAsai, Masato*; *; Osa, Akihiko; Koizumi, Mitsuo; Sekine, Toshiaki; *; Yamamoto, Hiroshi*; Kawade, Kiyoshi*
ENAM 95: Int. Conf. on Exotic Nuclei and Atomic Masses, 0, p.539 - 540, 1995/00
no abstracts in English
A.Saltelli*; Homma, Toshimitsu; T.Andres*
PC 94: Proc. of 6th Joint EPS-APS Int. Conf. on Physics Computing, 0, p.511 - 514, 1994/00
no abstracts in English
Robotica, 12, p.309 - 322, 1994/00
Times Cited Count：2 Percentile：32.49(Robotics)no abstracts in English
