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Shimada, Mikio*; Tokumiya, Takumi*; Miyake, Tomoko*; Tsukada, Kaima*; Kanzaki, Norie; Yanagihara, Hiromi*; Kobayashi, Junya*; Matsumoto, Yoshihisa*
Journal of Radiation Research (Internet), 64(2), p.345 - 351, 2023/03
Times Cited Count:0 Percentile:0.01(Biology)Kato, Masato; Machida, Masahiko; Hirooka, Shun; Nakamichi, Shinya; Ikusawa, Yoshihisa; Nakamura, Hiroki; Kobayashi, Keita; Ozawa, Takayuki; Maeda, Koji; Sasaki, Shinji; et al.
Materials Science and Fuel Technologies of Uranium and Plutonium mixed Oxide, 171 Pages, 2022/10
Innovative and advanced nuclear reactors using plutonium fuel has been developed in each country. In order to develop a new nuclear fuel, irradiation tests are indispensable, and it is necessary to demonstrate the performance and safety of nuclear fuels. If we can develop a technology that accurately simulates irradiation behavior as a technology that complements the irradiation test, the cost, time, and labor involved in nuclear fuel research and development will be greatly reduced. And safety and reliability can be significantly improved through simulation of nuclear fuel irradiation behavior. In order to evaluate the performance of nuclear fuel, it is necessary to know the physical and chemical properties of the fuel at high temperatures. And it is indispensable to develop a behavior model that describes various phenomena that occur during irradiation. In previous research and development, empirical methods with fitting parameters have been used in many parts of model development. However, empirical techniques can give very different results in areas where there is no data. Therefore, the purpose of this study is to construct a scientific descriptive model that can extrapolate the basic characteristics of fuel to the composition and temperature, and to develop an irradiation behavior analysis code to which the model is applied.
Shimizu, Kazuyuki*; Hayashida, Hirotoshi*; Toda, Hiroyuki*; Kai, Tetsuya; Matsumoto, Yoshihiro*; Matsumoto, Yoshihisa*
Nihon Kinzoku Gakkai-Shi, 83(11), p.434 - 440, 2019/11
Times Cited Count:1 Percentile:6.35(Metallurgy & Metallurgical Engineering)Yamasoto, Kotaro; Imaoka, Tatsuhiko*; Le Ngoc Thiem*; Matsumoto, Yoshihisa*
Hoshasen Kagaku, 52(10), p.21 - 25, 2009/10
The Fifth Asian Regional Conference of the Evolution of the System of Radiation Protection was held by OECD Nuclear Energy Agency, Committee on Radiation Protection and Public Health (OECD/NEA CRPPH), on September 3rd and 4th. Young researchers and engineers edit the session "securing and fostering of the younger experts responsible for radiation protection", in the conference. Chairman and each speakers summarize their findings.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Matsumoto, Mitsutaka*; Kato, Atsushi*; Saito, Eiji*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
Shingaku Giho, 108(80), p.65 - 70, 2008/06
The growth process of thermal oxides on Si(110) surface and the development of their interfacial bonding structures have been investigated by using real-time synchrotron radiation photoemission spectroscopy. As a result, it was clarified that the Si component in the Si 2p core-level spectra is always much higher than that of Si for 0-1 mono-layer (ML) oxides on Si(110) surface. Observations on the time-evolution of the O 1s core-level spectrum indicates that the autocatalytic-reaction model proposed for the Si(001) oxidation can be also applicable to the Si(110) oxidation.
Sasano, Nakashi*; Enomoto, Atsushi*; Hosoi, Yoshio*; Katsumura, Yosuke; Matsumoto, Yoshihisa*; Shiraishi, Kenshiro*; Miyagawa, Kiyoshi*; Igaki, Hiroshi*; Nakagawa, Keiichi*
Journal of Radiation Research, 48(6), p.495 - 503, 2007/11
Times Cited Count:20 Percentile:52.48(Biology)Shirato, Seiichi*; Kaneko, Yoshihisa*; Nishikimi, Masakazu*; Morimoto, Makoto*; Matsumoto, Shigeharu*; Motonaga, Tsutsuji*; Imai, Hiroshi*; Fukuda, Toru
PNC TN941 85-23, 193 Pages, 1985/02
To develop the small leak sodium-water reaction detection system in the steam generator for Fast Breeder Reactor, the series studies on system evaluation tests have been carried out at the 50MW Steam Generator Test Facility. This report deals with hydrogen and injection tests into the sodium outlet pipe from the superheater, test plans and test equipments for hydrogen injection tests into the evaporator, the response performances for the hydrogen meter and oxygen meter, detection ratio for hydrogen and oxygen and the water leak alarm system etc. The test results are summarized as follows: (1)Hydrogen injection tests & water injection tests into the sodium outlet pipe from the superheater were done and the hydrogen & oxygen behaviors were understood. (2)Hydrogen injection tests at the annulus, down-comer and cover-gas region in the evaporator were done and hydrogen behaviors were understood. (3)Hydrogen detection rates depending on hydrogen injection tests & water injection tests were arranged and factors giving the effect on the rate were evaluated. Also, hydrogen transfer times were evaluated. (4)Hydrogen detection rates at the water leakage in the evaporator were evaluated by the comparison of hydrogen injection test results & water injection test results into the sodium out1et pipe from the superheater and hydrogen injection test results into the evaporator. (5)The water leak alarm system by the computor was completed and the validity was confirmed.
Wada, Seiichi; Kobayashi, Yasuhiko; Funayama, Tomoo; Sakashita, Tetsuya; Yokota, Yuichiro; Matsumoto, Yoshihisa*; Oto, Takayo*; Hosoi, Yoshio*; Suzuki, Norio*; Hamada, Nobuyuki*; et al.
no journal, ,
Clustered DNA damages induced by high LET heavy ions are thought non-repairable or difficult to repair. However, much less is known about the reparability of clustered DNA damages. The major DNA repair pathway in mammalian cells is non-homologous end joining (NHEJ). In this study we investigated NHEJ pathway by exposure to high LET heavy ions, by analyzing responses of Ku to DNA damage induced by high LET heavy ions. pGFP and pGFP-Ku80 were transfected into xrs-5 cells (mutated in Ku80). Cells were irradiated with rays and ion beams (LET=2.7-1610 keV/m) at TIARA JAERI-Takasaki. Survival rates were measured by colony formation assay. To examine DNA damage and NHEJ pathway induced by heavy ion beams, H2AX and GFP signal on the nuclei were observed. Xrs5-GFP-Ku80 cells were radioresistant to rays and all ion beams, in comparison with xrs5-GFP cells. When the inactivation cross section was calculated to evaluate lethal effects per one particle, the difference of inactivation cross section between xrs5-GFP cells and xrs5-GFP-Ku80 cells became smaller with increasing LET. GFP and H2AX foci on the nuclei co-localized from 10 to 30 min after C (108 keV/m) and Ne ion (321 keV/m) irradiation. While GFP foci were observed for 10 min after Ar ion (1610 keV/m) irradiation, were not observed for 20 min. The difference of LET of ion beams influenced NHEJ responses.
Wada, Seiichi; Funayama, Tomoo; Matsumoto, Yoshihisa*; Oto, Takayo*; Sakashita, Tetsuya; Hamada, Nobuyuki*; Yokota, Yuichiro; Kakizaki, Takehiko; Hosono, Yoshio*; Suzuki, Norio*; et al.
no journal, ,
no abstracts in English
Wada, Seiichi*; Funayama, Tomoo; Matsumoto, Yoshihisa*; Oto, Takayo*; Sakashita, Tetsuya; Hamada, Nobuyuki*; Kakizaki, Takehiko; Hosoi, Yoshio*; Suzuki, Norio*; Kobayashi, Yasuhiko
no journal, ,
no abstracts in English
Wada, Seiichi*; Matsumoto, Yoshihisa*; Oto, Takayo*; Hamada, Nobuyuki*; Hara, Takamitsu*; Funayama, Tomoo; Sakashita, Tetsuya; Fukamoto, Kana; Kakizaki, Takehiko; Suzuki, Michiyo; et al.
no journal, ,
no abstracts in English
Nakano, Takuya*; Togashi, Hideaki*; Matsumoto, Mitsutaka*; Yamamoto, Yoshihisa*; Suzuki, Yasushi*; Teraoka, Yuden; Yoshigoe, Akitaka; Suemitsu, Maki*
no journal, ,
Time evolution of oxide layers in the H-terminated Si(110) surface by the UV/O treatment at room temperature was observed by photoemission spectroscopy with synchrotron radiation. Special oxidation mechanisms for the H-terminated Si(110) surface were found. Si(110) surfaces were hydrogenated by HF treatments. The surface was irradiated and oxidized by UV light (253.7, 184.9 nm) of a low pressure Hg lamp in the air. The UV/O irradiation time dependence of oxide thickness showed a step-wise profile. The step width was about 0.2 nm. The value is close to one oxide layer thickness (0.19 nm) for the Si(110) surface. Si atoms at the Si(110) surface are categolized to A bonds which are chain-like dense bonds, and B bonds which connect up and down A bond chains. The step-wise oxidation behaviour is reasonable if oxidation at the B bonds, in which oxidation strain is smaller than that of A bonds, has larger reaction rate than at the A bonds.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Matsumoto, Mitsutaka*; Saito, Eiji*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Ultra-thin oxide layer formation processes at Si(110) surface has been studied by using real-time photoemission spectroscopy with synchrotron radiation. Distribution of Si suboxides in the one mono layer oxide has been analyzed quantitatively and Si-O bonding configurations have been considered. Analyses for Si2p photoemission spectra, which were observed in the one mono layer oxide formed at 873 K and O pressure of 1.010 Pa on the Si(110) surface, resulted in avandance of an Si suboxide component whereas an Si component was dominant in the oxidation of Si(001) surface. The Si(110) surface consists of dense A bonds, which combine Si atoms in the same layer, and dilute B bonds, which combine Si atoms in the neibouring layers. Remaning of a part of the A bonds, which is easy to be distorted, as non-oxidized parts causes the dominant Si component formation.
Han, C. Y.*; Nagai, Haruyasu; Takeshita, Kenji*; Matsumoto, Yoshihisa*; Sagara, Hiroshi*
no journal, ,
In Tokyo Institute of Technology, a new graduate school educational program "Academy for Global Nuclear Safety and Security Agent" has been developed and implemented to cultivate the global leaders supported by MEXT. One of the experimental and training courses of "Nuclear Safety and Security Courses", Environmental Dynamics of Radioactive Nuclides has been developed. Numerical simulation of the environmental dispersion of radioactive materials released from hypothetical nuclear accidents and evaluation of the public exposure are performed, by using the WSPEEDI-II system. Students will be able to predict the environmental dispersion of radionuclides by nuclear accidents and its radiological consequence. Student deepens their understandings of the effect of climate condition on the dispersion of radioactive nuclides by comparing multiple climate conditions, with discussions based on physical phenomena.
Han, C. Y.*; Ebata, Shuichiro*; Sagara, Hiroshi*; Takeshita, Kenji*; Matsumoto, Yoshihisa*; Chiba, Satoshi*; Furuno, Akiko; Nagai, Haruyasu
no journal, ,
In Tokyo Institute of Technology, the nuclear human resource development program, "the Advanced Nuclear 3S Education and Training (ANSET)", was established in 2017, supported by Nuclear Regulatory Authority. This paper introduces the exercise on "Environmental Dynamics of Radioactive Material" of this program.
Shimada, Mikio*; Tsukada, Kaima*; Miyake, Tomoko*; Kanzaki, Norie; Yanagihara, Hiromi*; Matsumoto, Yoshihisa*
no journal, ,
Induced pluripotent stem cells (iPSCs) are generated by transduction of reprogramming transcriptional factors. iPSCs have multipotency to differentiate all organs and expected for the application of regenerative medicine. However, it is reported that cancer risk of iPSCs, because of expression of reprogramming factors increased DNA damage. It is important to analysis DNA damage response of iPSCs to prevent chromosomal abnormality and tumor formation. In this study, we attempted to elucidate the molecular mechanism of maintenance of genome stability in iPSCs. RNA-seq analysis by the next generation sequencer showed increased expression of genome maintenance genes such as DNA repair, cell cycle checkpoint and apoptosis. Interestingly, expression level of these genes was decreased after differentiation to the neural stem cells. Furthermore, colony formation assay showed high sensitivity and apoptosis activity to the IR exposure in iPSCs. These results suggested that instead of DNA repair, increasing of apoptosis activity maintain cell population having accurate genome DNA. These molecular insight have important implication for safety medical application of iPSCs.
Shimada, Mikio*; Kanzaki, Norie; Yanagihara, Hiromi*; Miyake, Tomoko*; Matsumoto, Yoshihisa*
no journal, ,
Although mutation frequency depends on organ cell types and differentiation level, it is not fully understood that organ cell types dependent mutation frequency in human cells. In this study, we aimed to establish measurement system of radiation dependent mutation frequency for analyze radiation effect to the human body. For this purpose, we derived four different organ cells such as neural cells, skin keratinocytes, heart muscle cells and blood cells from hiPSCs. Further, using artificial intelligence technology and machine leaning method, we w analyzed differences of mutation frequency during samples.