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JAEA Reports

Registration and related activities of the Japan Atomic Energy Agency for the response and assistance network of the International Atomic Energy Agency

Togawa, Orihiko; Hayakawa, Tsuyoshi; Tanaka, Tadao; Yamamoto, Kazuya; Okuno, Hiroshi

JAEA-Review 2020-017, 36 Pages, 2020/09


In 2010, the government of Japan joined the Response and Assistance Network (RANET) of the International Atomic Energy Agency (IAEA), in order to contribute to offering international assistance in the case of a nuclear accident or radiological emergency. At that occasion, the Japan Atomic Energy Agency (JAEA) was registered as the National Assistance Capability (NAC) having resources capable of the External Based Support (EBS) in the following seven areas: (1) aerial survey, (2) radiation monitoring, (3) environmental measurements, (4) assessment and advice, (5) internal dose assessment, (6) bioassay and (7) dose reconstruction. After the registration, three inquiries were directed to the JAEA about a possibility of its support. However, the JAEA's assistance has not eventually been realized. On the other hand, the JAEA participated almost every year in the international Convention Exercise (ConvEx) carried out by the IAEA in connection with RANET. This report describes an outline of the RANET and related activities of the JAEA for RANET registration and participation in the ConvEx.

Journal Articles

Thermodynamic and thermophysical properties of the actinide nitrides

Uno, Masayoshi*; Nishi, Tsuyoshi*; Takano, Masahide

Comprehensive Nuclear Materials, 2nd Edition, Vol.7, p.202 - 231, 2020/08

On the thermodynamic and thermophysical properties of the actinide nitrides in Comprehensive Nuclear Materials published by Elsevier as the first edition in 2012, we have revised them by adding some brand-new data. The main topics added are the solid solubility of the actinide nitrides into the zirconium nitride matrix for transmutation fuel, the lattice expansion of actinide nitrides induced by self-irradiation damage, the influence of defects accumulation on thermal conductivity, and the thermal expansion in curium nitride lattice.

Journal Articles

Enhancement of permeability activated by supercritical fluid flow through granite

Nohara, Tsuyoshi; Uno, Masaoki*; Tsuchiya, Noriyoshi*

Geofluids, 2019, p.6053815_1 - 6053815_16, 2019/08

 Times Cited Count:3 Percentile:31.47(Geochemistry & Geophysics)

Amphibole-plagioclase thermometry was applied to estimate the temperature of a glassy vein as approximately 700. The results of observations of the rock core revealed that of supercritical fluid flow was microfracture filling with hornblende and plagioclase. The current high permeability was recognized to be microfracture network. A high-angle fracture of chlorite filling in combination with an open fracture was recognized as characteristics of a high-permeability type.

Journal Articles

Preparedness and response for nuclear or radiological emergency as a designated public corporation

Okuno, Hiroshi; Okamoto, Akiko; Ebine, Noriya; Hayakawa, Tsuyoshi; Tanaka, Tadao

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 15 Pages, 2019/05

In the event of a nuclear or radiological emergency, the Japan Atomic Energy Agency (JAEA) as a designated public corporation assigned in the Disaster Countermeasures Basic Act of Japan undertakes a role to support the national government and local governments. This paper (1) illuminates the roles of the JAEA as a designated public corporation for preparedness and response to a nuclear or radiological emergency of nuclear facilities; (2) summarizes emergency response activities of the JAEA in accordance with its Disaster Management Operation Plan against the off-site radiological emergencies attributed to a loss of control of the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station that occurred in 2011; and (3) reports its activities in normal times especially participation in the drills organized by the national government and local governments in the light of the Basic Disaster Management Plan of Japan and Local Disaster Management Plans of prefectural governments, respectively.

Journal Articles

Seismic evaluation for a large-sized reactor vessel targeting SFRs in Japan

Uchita, Masato*; Miyagawa, Takayuki*; Dozaki, Koji*; Chikazawa, Yoshitaka; Kubo, Shigenobu; Hayafune, Hiroki; Suzuno, Tetsuji*; Fukasawa, Tsuyoshi*; Kamishima, Yoshio*; Fujita, Satoshi*

Proceedings of 2018 International Congress on Advances in Nuclear Power Plants (ICAPP 2018) (CD-ROM), p.380 - 386, 2018/04

It is well-known that pool-type SFRs are the main streams recently in a field of Generation IV reactors. The pool-type encloses primary pumps and IHXs located around the core barrel in a main vessel. Consequently, the main vessel diameter trends to be larger than that of loop-types. From the viewpoint of commercialization in the future, a target of the vessel diameter and its weight including Sodium coolant will increase further. In this paper, the prospects are described in terms of seismic design and structural integrity for the thermal loadings to prevent buckling of the reactor vessel based on parameter studies with diameters of the vessel. In addition, the seismic isolation device which will be effective as a countermeasure is proposed in order to secure a margin against buckling of a large reactor vessel.

Journal Articles

Behavior of Nb$$_{3}$$Sn cable assembled with conduit for ITER central solenoid

Nabara, Yoshihiro; Suwa, Tomone; Takahashi, Yoshikazu; Hemmi, Tsutomu; Kajitani, Hideki; Ozeki, Hidemasa; Sakurai, Takeru; Iguchi, Masahide; Nunoya, Yoshihiko; Isono, Takaaki; et al.

IEEE Transactions on Applied Superconductivity, 25(3), p.4200305_1 - 4200305_5, 2015/06

 Times Cited Count:0 Percentile:0(Engineering, Electrical & Electronic)

Journal Articles

Measurement of neutron- and photon-production cross sections from heavy-ion reactions on tissue equivalent elements

Uozumi, Yusuke*; Shigyo, Nobuhiro*; Uehara, Haruhiko*; Nishizawa, Tomoya*; Mizuno, Takafumi*; Satoh, Daiki; Sanami, Toshiya*; Koba, Yusuke*; Takada, Masashi*; Matsufuji, Naruhiro*; et al.

HIMAC-140, p.234 - 235, 2013/08

In the heavy-ion radiotherapy, considerable discussion has been attracted regarding the potential for second cancer induction by secondary neutrons produced from the primary heavy-ion fragmentation. We have started new measurements at 100 MeV/u to investigate the neutron production by heavy ions decelerating in a patient body.

Journal Articles

Thermodynamic and thermophysical properties of the actinide nitrides

Uno, Masayoshi*; Nishi, Tsuyoshi; Takano, Masahide

Comprehensive Nuclear Materials, 2, p.61 - 85, 2012/03

In a review "Comprehensive Nuclear Materials", we wrote the thermophysical and mechanical properties of actinide nitrides. In Chapter 1, the introductive remark was shown. In Chapter 2, the phase diagram and crystal structure of actinide nitrides were summarized. In Chapter 3, the melting or decomposition temperature, equilibrium vapor pressure, heat capacity, Gibbs free energy of formation and thermal conductivity of actinide nitrides were described, including recent experimental data obtained in JAEA. In Chapter 4, the mechanical properties of actinide nitrides and thermal expansion data obtained in JAEA were shown. On the other hand, the characteristic of nitride fuel and its historical development were not described because there appeared in another chapter of this review.

Journal Articles

Actinide-handling experience for training and education of future expert under J-ACTINET

Osaka, Masahiko; Konashi, Kenji*; Hayashi, Hirokazu; Li, D.*; Homma, Yoshiya*; Yamamura, Tomoo*; Sato, Isamu; Miwa, Shuhei; Sekimoto, Shun*; Kubota, Takumi*; et al.

Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12

Summer schools for future experts have successfully been completed under Japan Actinide Network (J-ACTINET) for the purpose of development of human resources who are expected to be engaged in every areas of actinide-research/engineering. The first summer school was held in Ibaraki-area in August 2009, followed by the second one in Kansai-area in August 2010. Two summer schools have focused on actual experiences of actinides in actinide-research fields for university students and young researchers/engineers as an introductory course of actinide-researches. Several quasi actinide-handling experiences at the actinide-research fields have attracted attentions of participants at the first school in Ibaraki-area. The actual experiments using actinides-containing solutions have been carried out at the second school in Kansai-area. Future summer schools will be held every year for the sustainable human resource development in various actinide-research fields.

Journal Articles

Structural studies of lanthanide nitrate-${it N,N'}$-dimethyl-${it N,N'}$-diphenylpyridine-2,6-dicarboxyamide complexes

Fujiwara, Asako; Nakano, Yoshiharu*; Yaita, Tsuyoshi; Okuno, Kenji*

Journal of Alloys and Compounds, 456(1-2), p.429 - 435, 2008/05

 Times Cited Count:17 Percentile:64.87(Chemistry, Physical)

The tridentate ligand ${it N,N'}$-dimethyl-${it N,N'}$-diphenylpyridine-2,6-dicarboxyamide (DMDPhPDA) and the corresponding lanthanum complex [La(NO$$_{3}$$)$$_{3}$$(DMDPhPDA)$$_{2}$$] have been prepared and structurally characterised. In the lanthanum complex, two DMDPhPDA molecules coordinated to La(III) in a tridentate fashion and to three nitrate ions in a bidentate fashion make the lanthanum atom 12-coordinate. The stability constants determined by spectrophotometric titration suggest that [Ln(DMDPhPDA)$$_{2}$$]$$^{3+}$$ is the primary product in nitrate media and [Ln(DMDPhPDA)$$_{3}$$]$$^{3+}$$ is difficult to form. However, [Ln(DMDPhPDA)$$_{2}$$]$$^{3+}$$ could not be distinguished in $$^{13}$$C NMR spectra. The $$^{13}$$C NMR titration results imply that a fast ligand exchange process takes place.

Journal Articles

Laser-arc hybrid welding for the cover plate of ITER TF coil

Shiihara, Katsunori*; Makino, Yoshinobu*; Ogawa, Tsuyoshi*; Asai, Satoru*; Kanahara, Toshio*; Senda, Ikuo*; Okuno, Kiyoshi; Koizumi, Norikiyo; Matsui, Kunihiro

Proceedings of 26th International Congress on Applications of Lasers & Electro-Optics (ICALEO 2007) (CD-ROM), p.316 - 324, 2007/10

The toroidal field coil is manufactured as one of superconducting coil systems in the ITER. For welding the cover plate of TF coil, the prevention of the thermal effect on the coil and the deformation of the whole coil are required. Moreover, the application of high efficient welding is required in consideration for the productivity. Therefore, laser-arc hybrid welding process was investigated for the application to the cover plate welding, because its process is superior in the tolerance of the joint gap and the ease of the control for the heat input. In the experiment, it was confirmed that the application of laser-arc hybrid welding with the double gas shielding for high concentration arc and the filler wire for controlling the deposit amount is effective in the joint gap up to 0.8mm. Besides, twin spot laser head with the arc was developed in order to weld the both sides of cover plate simultaneously. By the optimization of welding condition for twin spot laser-arc hybrid welding process, it was confirmed to be effective in the prevention of the gap movement during welding and the acquisition of the proper penetration without the weld defect. Finally, the effectiveness of laser-arc hybrid welding for the welding deformation and the weldability on the quality was verified by the scale model test with the actual shape.

Journal Articles

Overview of national centralized tokamak program; Mission, design and strategy to contribute ITER and DEMO

Ninomiya, Hiromasa; Akiba, Masato; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Inoue, Nobuyuki; et al.

Journal of the Korean Physical Society, 49, p.S428 - S432, 2006/12

To contribute DEMO and ITER, the design to modify the present JT-60U into superconducting coil machine, named National Centralized Tokamak (NCT), is being progressed under nationwide collaborations in Japan. Mission, design and strategy of this NCT program is summarized.

Journal Articles

Dissolution behavior of slag in cement-equilibrated aqueous solutions

Maeda, Toshikatsu; Bamba, Tsunetaka*; Mizuno, Tsuyoshi*; Terakado, Shogo; Kitagawa, Isamu; Numata, Masami

Haikibutsu Gakkai Rombunshi, 17(4), p.271 - 281, 2006/07

no abstracts in English

Journal Articles

Irregular loops with long time constants in CIC conductor

Yagai, Tsuyoshi*; Sato, Hidenari*; Tsuda, Makoto*; Hamajima, Takataro*; Nunoya, Yoshihiko; Takahashi, Yoshikazu; Okuno, Kiyoshi

IEEE Transactions on Applied Superconductivity, 16(2), p.835 - 838, 2006/06

 Times Cited Count:7 Percentile:40.87(Engineering, Electrical & Electronic)

AC losses in the CIC conductor consist of both regular loss that are proportional to cable twisting pitch squared and irregular loss that could not be estimated from short conductor sample results. It was explained from our previous works that irregular loops produce the losses with long time constants up to several hundred seconds. The observed long time constant indicates that contact conditions between the two strands forming the loop should be line contact. We traced the sample conductor with 1 m in length. The measured results show that large displacements of strands from their original positions due to compressing the conductor provide many line contacts. It is found that the averaged line contact length reaches about 10 mm that is three orders of magnitude larger than the 0.01 mm of point contact length.

Journal Articles

Low-density tin targets for efficient extreme ultraviolet light emission from laser-produced plasmas

Okuno, Tomoharu*; Fujioka, Shinsuke*; Nishimura, Hiroaki*; Tao, Y.*; Nagai, Keiji*; Gu, Q.*; Ueda, Nobuyoshi*; Ando, Tsuyoshi*; Nishihara, Katsunobu*; Norimatsu, Takayoshi*; et al.

Applied Physics Letters, 88(16), p.161501_1 - 161501_3, 2006/04

 Times Cited Count:64 Percentile:87.76(Physics, Applied)

no abstracts in English

Journal Articles

Overview of the national centralized tokamak programme

Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.

Nuclear Fusion, 46(3), p.S29 - S38, 2006/03

 Times Cited Count:13 Percentile:42.04(Physics, Fluids & Plasmas)

The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.

JAEA Reports

Melting treatment of incineration ashes of radioactive waste

Ozawa, Tatsuya; Maeda, Toshikatsu; Mizuno, Tsuyoshi; Bamba, Tsunetaka; Nakayama, Shinichi; Hotta, Katsutoshi*

JAEA-Technology 2006-001, 11 Pages, 2006/02


Melting treatment is a candidate solidification technique for nonflammable low-level radioactive wastes including metals, incineration ashes, and glasses. Simulated incineration ashes of a wide range of chemical compositions were molten at 1,600$$^{circ}$$C to produce lab-scale slag form. No visible pores and separated phases were observed in the slag specimens. It was found by optical observation that some precipitates and small voids were uniformly distributed in many of the specimens. The precipitates were identified to be iron oxides by XRD analysis. The present tests indicate that melting treatment is technically capable to produce stable slag from incineration ashes, which is one of representative TRU-cotaminated radioactive wastes.

Journal Articles

A Migration analysis of ${it Sogatella furcifera}$ (Horv$'a$th) (Homoptera: Delphacidae) using hourly catches and a three-dimensional simulation model

Otsuka, Akira*; Watanabe, Tomonari*; Suzuki, Yoshito*; Matsumura, Masaya*; Furuno, Akiko; Chino, Masamichi; Kondo, Tomoya*; Kamimuro, Tsuyoshi*

Agricultural and Forest Entomology, 8(1), p.35 - 47, 2006/02

 Times Cited Count:16 Percentile:56.28(Entomology)

1 Migration of Sogatella furcifera captured in Japan in the 2003 season were analyzed using hourly catches and a simulation model.2. The catch data showed several clear migration peaks, with average durations of 4 h. The peaks were separated from each other by approximately 12 h, corresponding to the observed fact that planthoppers take off at dusk and dawn.3. The simulation model, together with the hourly catches, enabled an estimation of migration source regions.4. Possible migration sources during our hourly observation period were located in the coastal area of Fujian province in China, as well as Taiwan.

Journal Articles

Engineering design and control scenario for steady-state high-beta operation in national centralized tokamak

Tsuchiya, Katsuhiko; Akiba, Masato; Azechi, Hiroshi*; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; et al.

Fusion Engineering and Design, 81(8-14), p.1599 - 1605, 2006/02

 Times Cited Count:1 Percentile:10.02(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Thermochemical and thermophysical properties of advanced fission fuel materials

Minato, Kazuo; Takano, Masahide; Nishi, Tsuyoshi; Akabori, Mitsuo; Arai, Yasuo; Uno, Masayoshi*

Advances in Science and Technology, 45, p.1931 - 1940, 2006/00

no abstracts in English

51 (Records 1-20 displayed on this page)