Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Yamamoto, Keisuke; Nakagawa, Takuya; Shimojo, Hiroto; Kijima, Jun; Miura, Daiya; Onose, Yoshihiko*; Namba, Koji*; Uchida, Hiroaki*; Sakamoto, Kazuhiko*; Ono, Chika*; et al.
JAEA-Technology 2024-019, 211 Pages, 2025/02
JAEA-Technology-2024-019.pdf:35.35MB
The uranium enrichment facilities at the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency (JAEA) were constructed sequentially to develop uranium enrichment technology with centrifugal separation method. The developed technologies were transferred to Japan Nuclear Fuel Limited until 2001. And the original purpose has been achieved. Wastewater Treatment Facility, one of the uranium enrichment facilities, was constructed in 1976 to treat radioactive liquid waste generated at the facilities, and it finished the role in 2008. In accordance with the Medium/Long-Term Management Plan of JAEA Facilities, interior equipment installed in this facility had been dismantled and removed since November 2021 to August 2023. This report summarizes the findings obtained through the work related to the contamination inspection methods cancellation the controlled area of Wastewater Treatment Facility from September 2023 to March 2024.
Hayashi, Teppei*; Yamashita, Takuma*; Mitsuyasu, Yusuke*; Ono, Kenta*; Iwami, Satone*; Kino, Yasushi*; Sekine, Tsutomu*; Oka, Toshitaka; Takahashi, Atsushi*; Shimizu, Yoshinaka*; et al.
International Journal of Radiation Biology, 8 Pages, 2025/00
Times Cited Count：0 Percentile：0.00no abstracts in English
Yamashita, Takuma*; Hayashi, Teppei*; Mitsuyasu, Yusuke*; Ono, Kenta*; Iwami, Satone*; Kino, Yasushi*; Sekine, Tsutomu*; Oka, Toshitaka; Takahashi, Atsushi*; Shimizu, Yoshinaka*; et al.
International Journal of Radiation Biology, 8 Pages, 2025/00
Times Cited Count：1 Percentile：76.46(Biology)no abstracts in English
and 
study of biological effects on cancer cells in the presence of metallic materials during radiotherapyNagano, Takuya*; Matsuya, Yusuke; Kaida, Atsushi*; Nojima, Hitomi*; Furuta, Takuya; Sato, Kaoru; Yoshimura, Ryoichi*; Miura, Masahiko*
Journal of Radiation Research (Internet), 65(5), p.628 - 639, 2024/09
Times Cited Count：1 Percentile：29.17(Biology)In X-ray therapy, radiation regimen is planned to eliminate tumors while minimizing side effects on normal tissue. When irradiating the oral cavity, which includes dental metallic crowns, intense mucositis can occasionally be induced. However, the mechanism underlying the radiosensitization remains unclear. In this study, we investigated the radiosensitization mechanism using cell experiments and computational simulations. As a result, the enhancement ratio observed in the cell experiments was 1.2-1.4, which was found to be predominately attributed to local dose increase near metal. On the other hand, as a result of dose evaluation based on CT images as a preclinical test, it was found that the dose increase was underestimated due to the complex anatomical structure of the human body, and microscopic dose evaluation was necessary. This outcome contributes to the precise understanding of side effects on normal cells around metals.
Nojima, Hitomi*; Kaida, Atsushi*; Matsuya, Yusuke; Uo, Motohiro*; Yoshimura, Ryoichi*; Arazi, L.*; Miura, Masahiko*
Scientific Reports (Internet), 14, p.11468_1 - 11468_13, 2024/05
Times Cited Count：0 Percentile：21.08(Multidisciplinary Sciences)Diffusing alpha-emitters radiation therapy (Alpha-DaRT) is a unique radiotherapy that uses seeds emitting alpha particles placed in solid tumors to kill cancer cells surrounding the seeds. Although the DNA damage response is an important cellular response that determines cell death after radiation; however, how DNA damage response occurs during Alpha-DaRT treatment has not yet been explored. In this study, we measured the spatiotemporal characteristics of the DNA damage response, including the number of DNA double-strand breaks and G2 arrest, during Alpha-DaRT treatment by cell experiments using HeLa cells expressing the Fucci cell cycle visualization system. As a result, we found a strong correlation between the number of alpha particles detected by solid-state track detector CR-39 and 
-H2AX staining, a marker for detecting DNA damage, and that the area of G2-arrested cells spread over a wider area up to 24 hours. In addition, time-lapse observations revealed that cell cycle dynamics change depending on the distance from the seed. The experimental model in this study revealed for the first time the spatiotemporal information of the DNA damage response around the seed during Alpha-DaRT treatment.
Sakamoto, Kan*; Sakaguchi, Chisato*; Miura, Yusuke*; Yokoyama, Hironori*; Matsunaga, Junji*; Kasahara, Hideyuki*; Miyata, Hajime*; Ioka, Ikuo; Yamashita, Shinichiro; Osaka, Masahiko
Proceedings of 2023 Water Reactor Fuel Performance Meeting (WRFPM 2023), p.20 - 28, 2024/00
An oxide-dispersion-strengthened FeCrAl (FeCrAl-ODS) has been continuously developed in Japan as a promising candidate alloy for the accident tolerant fuel cladding of BWRs (boiling water reactors). This paper will introduce the progress in practical development of accident tolerant FeCrAl-ODS fuel claddings for BWRs in the program fully or partially supported and organized by the Ministry of Economy, Trade and Industry (METI) of Japan. The experimental studies have been conducted to obtain and accumulate key material properties of FeCrAl-ODS fuel claddings to support the evaluations in the analytical studies. For the evaluation at normal operation condition, fatigue test of unirradiated fuel cladding and tensile test of irradiated sheet specimen were conducted. In the fatigue test, a tensile-compressive bending strain was loaded on the C-shaped specimens by cyclic movement of a push-pull rod. Test temperature was 623 K, frequency was 1 Hz, and strain amplitude were 0.27, 0.34 and 0.55 %. The results of fatigue tests demonstrated that cycles to failure of the FeCrAl-ODS cladding were higher than that of the O'Donnell and Langer fatigue curve of Zr-based alloy. The tensile test was conducted in a hot cell using the SS-J2 type specimens at ambient temperature, 573 K and 623 K at a strain rate of 10-3 s-1. The specimens were irradiated up to 7.8 and 13 dpa at 573 K in the High Flux Isotope Reactor at ORNL. The irradiation hardening and ductility loss obtained at 7.8 and 13 dpa were comparable to those at 3.9 dpa.
-edge for Ce in bauxites using transition-edge sensors; Implications for Ti-rich geological samplesLi, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count：16 Percentile：76.25(Chemistry, Analytical)no abstracts in English
Sakamoto, Kan*; Miura, Yusuke*; Ukai, Shigeharu; Ono, Naoko*; Kimura, Akihiko*; Yamaji, Akifumi*; Kusagaya, Kazuyuki*; Takano, Sho*; Kondo, Takao*; Ikegawa, Tomohiko*; et al.
Journal of Nuclear Materials, 557, p.153276_1 - 153276_11, 2021/12
A FeCrAl-oxide dispersion strengthened (ODS) alloy is a promising candidate alloy for the accident tolerant fuel (ATF) cladding of light water reactors (LWRs) and being developed in Japan recently. This paper will introduce the progress of development of accident tolerant FeCrAl-ODS fuel claddings for boiling water reactors (BWRs) in Japan. Both the experimental and the analytical studies have been performed to evaluate the influence of implementation of the FeCrAl-ODS fuel claddings to the current BWRs. The experimental studies have been conducted to obtain and accumulate key material properties of FeCrAl-ODS fuel claddings by using bar, sheet and tube-shaped materials to support the evaluations in the analytical studies. At the end of paper, the challenges and prospects found in the program are highlighted to enhance international collaborations to accelerate the development of FeCrAl-ODS fuel cladding.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：60 Percentile：95.33(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Moriya, Katsuhiro; Kawane, Yusuke*; Miura, Akihiko; Futatsukawa, Kenta*; Miyao, Tomoaki*
Journal of Physics; Conference Series, 1067, p.072009_1 - 072009_3, 2018/09
Times Cited Count：0 Percentile：0.00(Physics, Particles & Fields)no abstracts in English
Kamiya, Junichiro; Ogiwara, Norio*; Miura, Akihiko; Kinsho, Michikazu; Hikichi, Yusuke*
Journal of Physics; Conference Series, 1067, p.072006_1 - 072006_6, 2018/09
Times Cited Count：7 Percentile：91.22(Physics, Particles & Fields)A beam profile monitor using interaction between the beam and the gas molecules distributed in sheet shape has been developed. Ions or luminescence generated by passing the beam through the gas sheet has the information of cross-section shape of the beam. The gas sheet beam monitor will become a useful tool to measure the profile of high power beams because it has no breakable element such as wires. Furthermore, 2-D beam profile can be obtaine at a certain position of beam line. We applied the gas-sheet based beam profile monitor to J-PARC LINAC, where the negative hydrogen atoms are accelerated to the energy of 400 MeV. The vacuum system was carefully designed not to make an unacceptable pressure rise in nearby cavities when the gas was injected. The clear image of the beam profile was successfully obtained by detecting the ionized N gas.
Miura, Akihiko; Kawane, Yusuke*; Moriya, Katsuhiro; Futatsukawa, Kenta*; Miyao, Tomoaki*; Fukuoka, Shota*
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.2183 - 2186, 2018/06
In order to mitigate the beam loss during a beam transportation in the high-brilliant accelerator facilities, wire-based profile monitors are used to measure by both transverse and longitudinal beam profiles using wire-scanner monitors and bunch-shape monitors for the tuning of quadrupole magnets and buncher cavities. Signals are generated due to the direct interaction between a metallic wire and beam. We have used the tungsten wire as a high melting-point material by estimation of heat loading during the impact of beam particles. In addition, a spring is applied for the relaxing a flexure under wire's own weight. A tensile fracture test is conducted by supplying an electrical current as a simulated beam loading. As the results, we obtained the relation between the thermal limit to fracture and tension loading of tungsten wire.
Miura, Akihiko; Fukuoka, Shota*; Miyao, Tomoaki*; Kawane, Yusuke*; Futatsukawa, Kenta*
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.560 - 562, 2017/12
no abstracts in English
Kondo, Yasuhiro; Asano, Hiroyuki*; Chishiro, Etsuji; Hirano, Koichiro; Ishiyama, Tatsuya; Ito, Takashi; Kawane, Yusuke; Kikuzawa, Nobuhiro; Meigo, Shinichiro; Miura, Akihiko; et al.
Proceedings of 28th International Linear Accelerator Conference (LINAC 2016) (Internet), p.298 - 300, 2017/05
We have constructed a linac for development of various accelerator components at J-PARC. The ion source is same as the J-PARC linac's, and the RFQ is a used one in the J-PARC linac. The beam energy is 3 MeV and nominal beam current is 30 mA. The accelerator has been already commissioned, and the first development program, laser-charge-exchange experiment for the transmutation experimental facility, has been started. In this paper, present status of this 3-MeV linac is presented.
Hirano, Koichiro; Asano, Hiroyuki; Ishiyama, Tatsuya; Ito, Takashi; Okoshi, Kiyonori; Oguri, Hidetomo; Kondo, Yasuhiro; Kawane, Yusuke; Kikuzawa, Nobuhiro; Sato, Yoshikatsu; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.310 - 313, 2016/11
We have used a beam scraper with the incident angle of 65deg to reduce the beam power deposition density in the MEBT between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC linac. The 65 scraper was irradiated by the H
beam up to particle number of 1.47E22. We observed a lot of surface projections with several hundred micrometers high in the beam irradiation damage on the scraper by using the laser microscope. In order to study the limits of scrapers, we constructed a new 3 MeV linac at J-PARC. We will conduct the scraper irradiation test at the end of this year.
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Miura, Akihiko; Maruta, Tomofumi*; Liu, Y.*; Miyao, Tomoaki*; Kawane, Yusuke; Ouchi, Nobuo; Oguri, Hidetomo; Ikegami, Masanori*; Hasegawa, Kazuo
JPS Conference Proceedings (Internet), 8, p.011002_1 - 011002_6, 2015/09
In the J-PARC Linac, an energy upgrade project has started since 2009 using Annular-ring Coupled Structure cavities to achieve design beam power of 1 MW at the exit of the downstream rapid cycling synchrotron. Linac beam parameters of the upgraded Linac is drastically improved especially for the beam energy from 181 to 400 MeV in the project. To meet with the significant upgrades of the Linac, beam monitors to be used for the upgraded beam line are newly designed and fabricated as well as the beam monitor layout is designed with the consideration to the beam commissioning strategies. This paper introduces the beam monitor layout in the new beam line and the commissioning results to confirm the beam monitor functioning.
Futatsukawa, Kenta*; Kawane, Yusuke; Tamura, Jun; Nemoto, Yasuo; Hayashi, Naoki; Fukuoka, Shota*; Mayama, Minoru*; Miura, Akihiko; Miyao, Tomoaki*
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1246 - 1250, 2015/09
no abstracts in English
Hirano, Koichiro; Kondo, Yasuhiro; Kawane, Yusuke; Shinozaki, Shinichi; Miura, Akihiko; Morishita, Takatoshi; Sawabe, Yuki; Sugimura, Takashi*; Naito, Fujio*; Fang, Z.*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.944 - 947, 2015/09
Two RF-deflecting cavities as a chopper and a beam scraper have been used in the MEBT1 between a 324 MHz RFQ and a 50-MeV DTL of the J-PARC Linac. We replaced with a newly fabricated RF chopper to decrease beam loss for the operation with 50 mA. We installed two new scrapers to absorb the higher power of the deflected beam by the RF chopper. This paper describes the RF chopper system and beam irradiation test results of the scraper.
Miyao, Tomoaki*; Miura, Akihiko; Kawane, Yusuke; Tamura, Jun; Nemoto, Yasuo; Ao, Hiroyuki*; Hayashi, Naoki; Oguri, Hidetomo; Ouchi, Nobuo; Mayama, Minoru*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1338 - 1341, 2015/09
no abstracts in English
