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Collaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2022-063, 86 Pages, 2023/02
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 FY2019, this report summarizes the research results of the "The study of oxidative stress status in the organs exposed to low dose/low dose-rate radiation" conducted from FY2019 to FY2021. Since the final year of this proposal was FY2021, the results for three fiscal years were summarized. The present study aims to investigate the biological effects of low dose/low dose-rate radiation exposure, which is of great social interest, on the oxidative stress status of individual organs and will contribute to the collection of scientific data in a dose range to be required. The samples to be analyzed in this study were collected from wild Japanese macaques exposed in the ex-evacuation zone after the accident of 1F.
Collaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2021-050, 82 Pages, 2022/01
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 "The study of oxidative stress status in the organs exposed to low dose/low dose-rate radiation" conducted in FY2020. The present study aims to investigate the biological effects of low dose/low dose-rate radiation exposure, which is of great social interest, on the oxidative stress status of individual organs and will contribute to the collection of scientific data in a dose range to be required. An interdisciplinary collaborative study discussed the correlation between radiation dose and the biological effect by analyzing the samples of wild Japanese macaques exposed to radiation due to the accident of Fukushima Daiichi Nuclear Power Station and of animal experiments.
Collaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2020-048, 49 Pages, 2021/01
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 "The study of oxidative stress status in the organs exposed to low dose/low dose-rate radiation". This study investigates the biological effects of low dose/low dose-rate radiation exposure, which is of great social interest, on the oxidative stress status of individual organs and will contribute to the collection of scientific data in a dose range to be required. An interdisciplinary collaborative study discussed the correlation between radiation dose and the biological effect by analyzing the samples of wild Japanese macaques exposed to radiation due to the accident of Fukushima nuclear power station and of animal experiments.
Hashimoto, Shintaro; Sato, Tatsuhiko
EPJ Web of Conferences, 239, p.03015_1 - 03015_4, 2020/09
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)Particle transport simulation codes based on the Monte Carlo technique have been successfully applied to shielding calculations in accelerator facilities. Estimation of not only statistical uncertainties, which depend on the number of trials, but also systemic uncertainties, which are caused by uncertainty of total cross section models, is required to confirm the reliability of the simulation results. We evaluated unclear quantities of internal parameters included in the total cross section model by the KALMAN code, which is based on the least squares technique, comparing with experimental data of the total cross section. The uncertainties in the total cross sections obtained by the new model are comparable to the experimental errors. In the present study, the systematic uncertainty included in the simulation results can be estimated by performing the transport calculations with variation of the internal parameters within their unclear quantities.
Riyana, E. S.; Okumura, Keisuke; Terashima, Kenichi
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 4 Pages, 2019/05
Hashimoto, Shintaro; Sato, Tatsuhiko
Journal of Nuclear Science and Technology, 56(4), p.345 - 354, 2019/04
Times Cited Count:7 Percentile:55.95(Nuclear Science & Technology)Particle transport simulations based on the Monte Carlo method have been applied to shielding calculations. Estimation of not only statistical uncertainty related to the number of trials but also systematic one induced by unclear physical quantities is required to confirm the reliability of calculated results. In this study, we applied a method based on analysis of variance to shielding calculations. We proposed random- and three-condition methods. The first one determines randomly the value of the unclear quantity, while the second one uses only three values: the default value, upper and lower limits. The systematic uncertainty can be estimated adequately by the random-condition method, though it needs the large computational cost. The three-condition method can provide almost the same estimate as the random-condition method when the effect of the variation is monotonic. We found criterion to confirm convergence of the systematic uncertainty as the number of trials increases.
Furuta, Takuya; Sato, Tatsuhiko
Igaku Butsuri, 35(3), p.264 - 268, 2015/00
Time-consuming Monte Carlo dose calculation becomes feasible owing to the development of computer technology. However, the recent development is due to emergence of the multi-core high performance computers. Therefore, parallel computing becomes a key to achieve good performance of software programs. A Monte Carlo simulation code PHITS contains two parallel computing functions, the distributed-memory parallelization using protocols of MPI and the shared-memory parallelization using OpenMP directives. Users can choose the two functions according to their needs. This paper gives the explanation of the two functions with their advantages and disadvantages. Some test applications are also provided to show their performance using a typical multi-core high performance workstation.
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:87 Percentile:92.35(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.
Idomura, Yasuhiro
Purazuma, Kaku Yugo Gakkai-Shi, 81(8), p.581 - 592, 2005/08
A gyrokinetic particle simulation is a powerful tool in studying tokamak microturbulence. A method, which is a standard method in recent gyrokinetic particle simulations, dramatically improved an efficiency of a particle simulation by reducing a particle noise, and full torus turbulence simulations are enabled. In this paper, the
method is reviewed, and issues in full torus gyrokinetic particle simulations are discussed.
Takeyama, Akinori; Yamamoto, Shunya; Yoshikawa, Masahito; Ito, Hiroshi
Japanese Journal of Applied Physics, Part 1, 44(1B), p.750 - 753, 2005/01
Times Cited Count:0 Percentile:0.00(Physics, Applied)Pyramid shaped Cu precipitates were formed on Si (100) surface as a result of 200 keV Cu ion implantation and subsequent annealing. Then, ZnO nanorods were successfully synthesized on the Cu implanted substrates by chemical vapor transport (CVT). Hexagonal shaped nanorods with a diameter of 200 nm were grown nearly perpendicular to the Cu implanted substrate and their average density was increased as increasing that of Cu precipitates. The facts strongly indicate the Cu precipitates served as the catalytic particles for the growth of ZnO rods.
Terada, Hiroaki; Furuno, Akiko; Chino, Masamichi
Proceedings from the International Conference on Radioactivity in the Environment (CD-ROM), 4 Pages, 2002/09
The present study aims to expanding the capability of WSPEEDI, so that it can be applied to atmospheric releases of radionuclides in the world for terrorist attack as well as nuclear accident. A terrorist attack would be possible in any time, any place and any scale. Altough WSPEEDI has already had a function to acquire global meteorological forecasts to generate a geographical map at arbitrary region in the world, it had no capability for simultaneous multi-scale predictions. Thus, the combination of models, non-hydrostatic meteorological model MM5 and atmospheric dispersion model GEARN, is introduced to WSPEEDI. MM5 can forecast local and regional meteorological condition simultaneously by domain nesting calculations. By the input of meteorological condition generated by MM5, GEARN can forecast multi-scale environmental contaminations considering detailed boundary layer and precipitation processes. Using this improved WSPEEDI, we made test calculations assuming a nuclear accident or terrorist attack in Asia.
Niita, Koji*; Takada, Hiroshi; Meigo, Shinichiro; Ikeda, Yujiro
Nuclear Instruments and Methods in Physics Research B, 184(3), p.406 - 420, 2001/11
Times Cited Count:79 Percentile:97.60(Instruments & Instrumentation)no abstracts in English
Tobita, Kenji
Denki Gakkai Kenkyukai Shiryo, Pulazuma Kenkyukai (PST-01-73), p.43 - 46, 2001/09
Behavior of energetic particles in spherical torus (ST) is summarized in comparison with that in tokamaks. The issues treated in this article are neoclassical transport, ripple loss, Alfven eigenmodes and Magetohydrodynamic- instability-induced anomalous transport. ST is expected to be favorable in terms of neoclassical transport and ripple loss. On the other hand, Alfven eigenmodes and the resulting energetic particle loss can be serious concerns in a ST reactor because of a high volume-averaged beta and a super-Alfvenic speed of alpha particles.
Matsunaga, Takeshi
JAERI-Review 2001-018, 121 Pages, 2001/06
The present report reviews a series of studies conducted in JAERI which have dealt with the behavior of atmospherically-derived radionuclides in a fluvial environment. The studies cited here firstly include investigations of the evaluation of the transport rate of the atmospherically-derived 137Cs, 210Pb and 7Be from the ground via a river to the downstream areas where the affected water is consumed. The studies validated i) the importance of suspended particulate materials in the fluvial discharge of those radionuclides, and ii) a methodology to estimate the discharge of those radionuclides. Secondly, studies in rivers and lakes in the vicinity of the Chernobyl Nuclear Power Plant revealed the role of natural dissolved organics in affecting the dissolution and transport of 239,240Pu, 241Am through complexation to form soluble species with the aid of a chemical equilibrium model The same sort of a model was also applied successfully for the behavior of iron and manganese (hydr)oxides in river recharged aquifers which could bear riverborne radionuclides.
Mori, Takamasa; Okumura, Keisuke; Nagaya, Yasunobu
Transactions of the American Nuclear Society, 84, p.45 - 46, 2001/06
no abstracts in English
Takada, Hiroshi; Meigo, Shinichiro; Niita, Koji*
Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications, p.949 - 954, 2001/00
no abstracts in English
Kumagai, Akira*; Kubo, Hirotaka; Takenaga, Hidenobu; Suzuki, Shingo; Shimizu, Katsuhiro; Asakura, Nobuyuki; Shimada, Michiya
Plasma Physics and Controlled Fusion, 42(5), p.529 - 543, 2000/05
Times Cited Count:13 Percentile:39.37(Physics, Fluids & Plasmas)no abstracts in English
Kubo, Hirotaka; Higashijima, Satoru; Takenaga, Hidenobu; Kumagai, Akira*; Shimizu, Katsuhiro; Sugie, Tatsuo; Suzuki, Shingo; Sakasai, Akira; Asakura, Nobuyuki
NIFS-PROC-44, p.65 - 68, 2000/01
no abstracts in English
Takemiya, Hiroshi*; Higuchi, Kenji;
Modeling and Simulation Based Engineering, p.497 - 502, 1998/00
no abstracts in English
Higuchi, Kenji; Takemiya, Hiroshi*;
Nihon Genshiryoku Gakkai-Shi, 40(10), p.798 - 808, 1998/00
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)no abstracts in English