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Machida, Masahiko; Yamada, Susumu; Kim, M.; Okumura, Masahiko; Miyamura, Hiroko; Shikaze, Yoshiaki; Sato, Tomoki*; Numata, Yoshiaki*; Tobita, Yasuhiro*; Yamaguchi, Takashi; et al.
RIST News, (69), p.2 - 18, 2023/09
The contamination of radioactive materials leaked from the reactor has resulted in numerous hot spots in the Fukushima Daiichi Nuclear Power Station (1F) building, posing obstacles to its decommissioning. In order to solve this problem, JAEA has conducted research and development of the digital technique for inverse estimation of radiation source distribution and countermeasures against the estimated source in virtual space for two years from 2021 based on the subsidy program "Project of Decommissioning and Contaminated Water Management" performed by the funds from the Ministry of Economy, Trade and Industry. In this article, we introduce the results of the project and the plan of the renewal project started in April 2023. For the former project, we report the derivative method for LASSO method considering the complex structure inside the building and the character of the source and show the result of the inverse estimation using the method in the real reactor building. Moreover, we explain the platform software "3D-ADRES-Indoor" which integrates these achievements. Finally, we introduce the plan of the latter project.
Okumura, Masahiko; Kerisit, S.*; Bourg, I. C.*; Lammers, L. N.*; Ikeda, Takashi*; Sassi, M.*; Rosso, K. M.*; Machida, Masahiko
Journal of Environmental Radioactivity, 189, p.135 - 145, 2018/09
Times Cited Count：52 Percentile：87.23(Environmental Sciences)no abstracts in English
Maebara, Sunao; Sukegawa, Keiichi*; Tadano, Shuya*; Kasugai, Atsushi; Suzuki, Hiromitsu; Abe, Kazuhiko*; Oku, Ryuji*; Sugimoto, Masayoshi
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1140 - 1142, 2015/09
For the IFMIF/EVEDA accelerator prototype RFQ linac, the operation frequency of 175MHz was selected to accelerate a large current of 125mA. The driving RF power of 1.28MW by 8 RF input couplers has to be injected to the RFQ cavity for CW operation mode. For each RF input coupler, nominal RF power of 160kW and maximum transmitted RF power of 200kW are required. For this purpose, an RF input coupler with cooling functions was designed, based on a 6 1/8 inch co-axial waveguide, and the RF coupler was manufactured by way of trial. For the trial RF coupler, high-power tests using a high voltage standing wave on a high-Q load circuit wave were carried out, and a 200kW-14 sec CW operation were performed after four days of RF aging. No RF contact defects, unnecessary low-Q value and extraordinary outgassing were observed. This report describes the high-power tests of the RF input coupler.
Yaita, Tsuyoshi; Kobayashi, Toru; Ikeda, Takashi; Matsumura, Daiju; Machida, Masahiko; Okumura, Masahiko; Nakamura, Hiroki
Hoshako, 27(6), p.315 - 322, 2014/11
no abstracts in English
Shinto, Katsuhiro; Ichikawa, Masahiro; Takahashi, Yasuyuki*; Kubo, Takashi*; Tsutsumi, Kazuyoshi; Kikuchi, Takayuki; Kasugai, Atsushi; Sugimoto, Masayoshi; Gobin, R.*; Girardot, P.*; et al.
Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1009 - 1012, 2014/10
The prototype accelerator is being developed as an engineering validation for the International Fusion Materials Irradiation Facility (IFMIF) equipped with an accelerator-driven-type neutron source for developing fusion reactor materials. This prototype accelerator is a deuteron linear accelerator consisting of an injector, an RFQ, a superconducting linac and their auxiliaries. It aims to produce a CW D
beam with the energy and current of 9 MeV/125 mA. The injector test was completed at CEA/Saclay in 2012 for producing a CW H beam and a CW D beam with the energy and current of 100 keV/140 mA. After the beam test at CEA/Saclay, the injector was transported to the International Fusion Energy Research Centre (IFERC) located in Rokkasho, Aomori, Japan. In the end of 2013, installation of the injector was started at IFERC for the injector beam test beginning from summer 2014 in order to obtain better beam qualities to be satisfied with the injection and acceleration of the following accelerators. In this paper, some results of the injector beam test performed at CEA/Saclay and the status quo of the installation of the injector at IFERC are presented.
Ohira, Shigeru; Utsumi, Shigeo*; Kubo, Takashi; Yonemoto, Kazuhiro; Kasuya, Kenichi; Ejiri, Shintaro; Kimura, Haruyuki; Okumura, Yoshikazu
Journal of Plasma and Fusion Research SERIES, Vol.9, p.665 - 669, 2010/08
Under the Agreement Between the Government of Japan and the EURATOM for the Joint Implementation of the Broader Approach Activities (BA Activities) in the Field of Fusion Energy Research, JAEA develop a new site at Rokkasho-mura in Aomori prefecture of Japan as the Japanese Implementing Agency. In this new site, two of the three projects of the BA Activities are to be implemented, namely, International Fusion Energy Research Center (IFERC) Project and International Fusion Material Irradiation Facility/Engineering Validation and Engineering Design Activity (IFMIF/EVEDA) Project. In March 2009, the Administration and Research Building was completed, and the other research facilities; CSC&REC Building, DEMO R&D Building and IFMIF/EVEDA Accelerator Building will be completed in March 2010. In this presentation, the specifications and construction schedule of the individual research buildings will be presented, especially special features of the IFMIF/EVEDA Accelerator Building.
Yamamoto, Masahiro*; Uchiyama, Takashi*; Miyajima, Tsukasa*; Honda, Yosuke*; Sato, Kotaro*; Matsuba, Shunya*; Saito, Yoshio*; Kobayashi, Masanori*; Kurisu, Hiriki*; Hajima, Ryoichi; et al.
Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.717 - 720, 2010/08
A 500-kV photocathode DC electron gun which can supply the beam of a low emittance and a high average current has been developed in collaboration with KEK, JAEA, Hiroshima Univ., Nagoya Univ. and Yamaguchi Univ. The vacuum of the gun chamber has to be lower Extreme High Vacuum for maintain cathode-life time. A titanium chamber and new material of ceramic were employed to reduce outgassing rate. The result of outgassing rate of the gun chamber is described in this report.
Mosnier, A.*; Beauvais, P. Y.*; Branas, B.*; Comunian, M.*; Facco, A.*; Garin, P.*; Gobin, R.*; Gournay, J. F.*; Heidinger, R.*; Ibarra, A.*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.588 - 590, 2010/05
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Shinto, Katsuhiro; Vermare, C.*; Asahara, Hiroo; Sugimoto, Masayoshi; Garin, P.*; Maebara, Sunao; Takahashi, Hiroki; Sakaki, Hironao; Kojima, Toshiyuki; Ohira, Shigeru; et al.
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.668 - 670, 2010/03
Progress of the IFMIF/EVEDA prototype accelerator in fiscal year of 2008 is described. All the sub-systems of the prototype accelerator have started to design, settled the plan of the manufacturing and component tests and fixed the design parameters. As a result of the analysis of planning for the engineering validation of the IFMIF accelerator system, the project duration to be prolonged to the end of 2014 including some months for contingency was approved by the BA Steering Committee. In this article, the design status of each accelerator component, the interface between the accelerator components and the IFMIF/EVEDA Accelerator Building settled in International Fusion Energy Research Centre (IFERC) in Rokkasho and the proposed accelerator commissioning plan for the engineering validation will be presented.
Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Uchiyama, Takashi*; Kobayashi, Masanori*; Muto, Toshiya*; Matsuba, Shunya*; Sakanaka, Shogo*; Sato, Kotaro*; Saito, Yoshio*; et al.
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.860 - 862, 2009/08
A newly 500 kV electron gun (2nd - 500 kV gun) for an ERL light source is designed at KEK. A new concept and state of-the-art technologies of vacuum system, ceramic insulators, high voltage power supply, photocathode and preparation system will be employed. The details are described in this report.
Sugimoto, Makoto; Takano, Katsutoshi*; Tsuji, Hiroshi; Abe, Kazuhiko*; *; *
Teion Kogaku, 33(11), p.716 - 723, 1998/00
no abstracts in English
Kubo, Takashi; Okumura, Yoshikazu; Ohira, Shigeru; Maebara, Sunao; Sakaki, Hironao; Onishi, Seiki; Yonemoto, Kazuhiro; Kojima, Toshiyuki; Garin, P.*; Sugimoto, Masayoshi; et al.
no journal, ,
The Accelerator Prototype Building for the IFMIF/EVEDA Project, in which enforce the engineering validation of the Accelerator, will be constructed in the BA site at Rokkasho-mura, Aomori-ken. Before detail design started, Japan and EU implementing agencies concluded the Procurement Arrangement based on agreed basic design. The building length is about 58 m east-west and about 37 m north-south. The area is about 2,020 m
. The Accelerator Vault is center of north and south. RF and electric system are in north of the Vault, and HVAC and cooling water system are in south of the Vault. The control room is put in northwest of the building. Shielding design is based on the evaluation estimated by experts of Japan and EU. The Accelerator will accelerate deuteron to approximately 125 mA and 10 MeV, so the Accelerator Vault is covered with 1.5 m thickness normal concrete shield to protect radiation. To protect neutron streaming, the RF wave guides are through the underground pit into the Vault.
Hemmi, Tsutomu; Matsui, Kunihiro; Hase, Takashi*; Koizumi, Norikiyo; Takahashi, Yoshikazu; Okuno, Kiyoshi; Suzuki, Hiroshi; Harjo, S.; Aizawa, Kazuya; Tsuchiya, Yoshinori*; et al.
no journal, ,
JAEA is responsible for the procurement of the CS conductor of the ITER magnet system. In order to start the procurement of the CS conductor, the performance of the CS conductor have to be demonstrated. The qualification sample has been fabricated for the test using SULTAN apparatus at the Plasma Physics Research Centre (CRPP) of the Swiss Federal Institute of Technology of Lausanne (EPFL). In this presentation, the design and the fabrication of the qualification sample is reported. The residual strain should be controlled for the measurement of the correct performance. The neutron diffraction will be applied to the direct measurement of the strain of the superconducting cable. This plan is also presented.
Hase, Takashi*; Shimizu, Tatsuya; Hemmi, Tsutomu; Matsui, Kunihiro; Koizumi, Norikiyo; Takahashi, Yoshikazu; Okuno, Kiyoshi
no journal, ,
Nb
Sn conductors (40 kA, 13 T) are employed in ITER CS. The characteristics of the sample in which two kinds of conductors are connected with OFC blocks will be evaluated. The joint part will be exposed to fields widely ranging from 0.29-8.4 T when an external field of 11 T is generated. Therefore, current distribution due to the magnetic resistance may bring incorrect evaluation of performance of the sample. The current distribution in the joint part of the conductor has been analyzed with the FEM to confirm the speculation and to get an idea for make the current distribution more uniformly. It has been found as a result that the current distribution in the conventional joint structure employing the OFC with a RRR of 100 leads to a current density ratio of 1.65, though a total resistance is very low. On the contrary, by employing copper plate of RRR = 4, the current density ratio can be reduced to 1.23, while keeping the total resistance below 2 n
.
Kubo, Takashi; Maebara, Sunao; Ohira, Shigeru; Takahashi, Hiroki; Yonemoto, Kazuhiro; Kojima, Toshiyuki; Kikuchi, Takayuki; Sakaki, Hironao; Kimura, Haruyuki; Okumura, Yoshikazu; et al.
no journal, ,
IFMIF/EVEDA Prototype Accelerator Building is a facility for validation of prototype accelerator which will be made for the Engineering Validation and Engineering Design Activity (EVEDA) of the International Fusion Material Irradiation Facility (IFMIF). This building is constructed the International Fusion Energy Research Center in Rokkasho village, Aomori prefecture, as a part of the Broader Approach activity which is an international cooperation between Japan and EU. The detail design was completed in 2007, and its construction work was started in March, 2008. The building is an one story, steel construction. The width of east-west is 58 m, north-south is 37 m, maximum height is 10.95 m, and floor area is 2019.5 m. The Accelerator Vault which made of concrete is in center of the building. The southern side is HVAC and cooling machines room, and the other side is Radio Frequebcy power supply area. Its underground was constructed in 2008, and the Accelerator Vault was constructed in May, 2009. Now, roofing work is doing. The building will be completed in May, 2010.
Shinto, Katsuhiro; Ohira, Shigeru; Kikuchi, Takayuki; Kubo, Takashi; Yonemoto, Kazuhiro; Kasuya, Kenichi; Maebara, Sunao; Takahashi, Hiroki; Kojima, Toshiyuki; Tsutsumi, Kazuyoshi; et al.
no journal, ,
no abstracts in English
Ohira, Shigeru; Kubo, Takashi; Yonemoto, Kazuhiro; Kasuya, Kenichi; Kimura, Haruyuki; Okumura, Yoshikazu
no journal, ,
Under the Agreement Between the Government of Japan and the EURATOM for the Joint Implementation of the Broader Approach Activities (BA Activities) in the Field of Fusion Energy Research, JAEA develop a new site at Rokkasho-mura in Aomori prefecture of Japan as the Japanese Implementing Agency. In this new site, two of the three projects of the BA Activities are to be implemented, namely, International Fusion Energy Research Center (IFERC) project and International Fusion Material Irradiation Facility/Engineering Validation and Engineering Design Activity (IFMIF/EVEDA) Project. In March 2009, the Administration and Research Building was completed, and the other research facilities; CSC&REC Building, DEMO R&D Building and IFMIF/EVEDA Accelerator Building will be completed in March 2010. In this presentation, the specifications and construction schedule of the individual research buildings will be presented.
Yaita, Tsuyoshi; Suzuki, Shinichi; Momma, Toshiyuki; Nakayama, Shinichi; Machida, Masahiko; Okumura, Masahiko; Ikeda, Takashi
no journal, ,
no abstracts in English
Kumasaka, Hiroo*; Kobayashi, Shinji*; Kosuga, Keiichi*; Okuyama, Yasuji*; Kusano, Takashi*; Kurita, Kazuaki*; Yamawaki, Hiroyuki; Sato, Toshinori
no journal, ,
Shotcreting is currently underway in the south research access tunnel 500 m underground at Mizunami Underground Research Laboratory. The use of the low alkaline super shotcrete spraying method, which makes it possible to obtain high strength and high stiffness quickly after spraying while minimizing an environmental impact, is being considered as a means of stabilizing an excavated rock surface whose condition is rapidly deteriorating. For the purpose of evaluating the applicability of the method to the shotcreting work currently in progress, a verification field test was conducted. This paper briefly reports on the test.
