Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 24

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

JAEA Reports

Transfer and operation of WSPEEDI-II automatic calculation system for responses to nuclear tests by North Korea

Nemoto, Miho*; Ebine, Noriya; Okamoto, Akiko; Hosaka, Yasuhisa*; Tsuzuki, Katsunori; Terada, Hiroaki; Hayakawa, Tsuyoshi; Togawa, Orihiko

JAEA-Technology 2021-013, 41 Pages, 2021/08

JAEA-Technology-2021-013.pdf:2.52MB

When North Korea has carried out nuclear tests, Nuclear Emergency Assistance and Training Center (NEAT) predicts atmospheric dispersion of radionuclides by using the WSPEEDI-II upon requests from Nuclear Regulation Authority (NRA) and submits the predicted results to NRA in cooperation with Nuclear Science and Engineering Center (NSEC). This is a part of the activity of NEAT supporting the Japanese Government in emergency responses. The WSPEEDI-II automatic calculation system specialized for responses to nuclear tests by North Korea was developed by NSEC and was used for responses to three nuclear tests from February 2013 to September 2017. This report describes the transfer and installation of the calculation system to NEAT, and the subsequent maintenance and operation. Future issues for responses to nuclear tests are also described in this report.

JAEA Reports

Investigation and consideration on evaluation of radiation doses to residents in the case of a nuclear emergency

Hashimoto, Makoto; Kinase, Sakae; Munakata, Masahiro; Murayama, Takashi; Takahashi, Masa; Takada, Chie; Okamoto, Akiko; Hayakawa, Tsuyoshi; Sukegawa, Masato; Kume, Nobuhide*; et al.

JAEA-Review 2020-071, 53 Pages, 2021/03

JAEA-Review-2020-071.pdf:2.72MB

In the case of a nuclear accident or a radiological emergency, the Japan Atomic Energy Agency (JAEA), as a designated public corporation assigned in the Disaster Countermeasures Basic Act and the Armed Attack Situation Response Law, undertakes technical supports to the national government and local governments. The JAEA is requested to support to evaluate radiation doses to residents in a nuclear emergency, which is specified in the Basic Disaster Management Plan and the Nuclear Emergency Response Manual. For the dose evaluation, however, its strategy, target, method, structure and so on have not been determined either specifically or in detail. This report describes the results of investigation and consideration discussed in the "Working Group for Radiation Dose Evaluation at a Nuclear Emergency" established within the Nuclear Emergency Assistance and Training Center to discuss technical supports for radiation dose evaluation to residents in the case of a nuclear emergency, and aims at contributing to specific and detailed discussion and activities in the future for the national government and local governments, also within the JAEA.

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

JAEA-Review-2020-017.pdf:2.24MB

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

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.

JAEA Reports

Activities on predictions of atmospheric dispersion of radionuclides for nuclear tests by North Korea

Ishizaki, Shuhei; Hayakawa, Tsuyoshi; Tsuzuki, Katsunori; Terada, Hiroaki; Togawa, Orihiko

JAEA-Technology 2018-007, 43 Pages, 2018/10

JAEA-Technology-2018-007.pdf:5.67MB

When North Korea has carried out a nuclear test, by a request from Nuclear Regulation Authority (NRA), Nuclear Emergency Assistance and Training Center (NEAT) predicts atmospheric dispersion of radionuclides by WSPEEDI-II system in cooperation with Nuclear Science and Engineering Center (NSEC), and submits the predicted results to NRA as the activity to assist responses by the Japanese Government. This report explains frameworks of the Japanese Government and Japan Atomic Energy Agency (JAEA) to cope with nuclear tests by North Korea, and describes a series of activities by NEAT regarding predictions of atmospheric dispersion of radionuclides in response to the 5th and 6th nuclear tests carried out by North Korea in September 2016 and September 2017. Future plans and issues to be solved for responses to nuclear tests are also described in this report, together with an outline of a computer program system used in the predictions.

Journal Articles

Proposal for selective isotope transmutation of long-lived fission products using quasi-monochromatic $$gamma$$-ray beams

Hayakawa, Takehito; Miyamoto, Shuji*; Hajima, Ryoichi; Shizuma, Toshiyuki; Amano, So*; Hashimoto, Satoshi*; Misawa, Tsuyoshi*

Journal of Nuclear Science and Technology, 53(12), p.2064 - 2071, 2016/12

 Times Cited Count:5 Percentile:43.6(Nuclear Science & Technology)

We have proposed a new selective isotope transmutation method using photonuclear reactions with quasi-monochromatic $$gamma$$-ray beams. This method is based on the fact that the particle threshold of a long-lived fission product (LLFP) such as $$^{93}$$Zr, $$^{107}$$Pd, or $$^{79}$$Se is lower than those of stable isotopes of the same chemical element. Therefore, this method has an excellent advantage that LLFPs cannot, in principle, be produced newly even if the target materials include stable isotopes in addition to a LLFP. Laser Compton scattering $$gamma$$-ray sources and neutron capture $$gamma$$-rays in nuclear reactors are candidates for this method.

JAEA Reports

Survey report of site selection process on the basis of local partnerships; Slovenia and Belgium

Yoshioka, Tatsuji; Kanzaki, Noriko; Osawa, Hideaki; Hayakawa, Tsuyoshi; Nakata, Hisakazu

JAEA-Review 2013-045, 158 Pages, 2014/01

JAEA-Review-2013-045.pdf:37.31MB

Local partnership approach to achieve stakeholder consensus on low-level waste disposal, with particular focus on the siting of repositories are adopted in Europe. Especially in Belgium and Slovenia, final repository site had been decided in each country. The authors investigate on these two cases on the basis of interviews with implementing organizations for final disposal, representatives of local partnerships and citizens concerned so that the problem of introducing a local partnership in Japan can be examined. Its results are used as a reference for studying measures to determine the radioactive final repository site in Japan.

Journal Articles

Proton acceleration to 40 MeV using a high intensity, high contrast optical parametric chirped-pulse amplification/Ti:sapphire hybrid laser system

Ogura, Koichi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Tanimoto, Tsuyoshi*; Sagisaka, Akito*; Esirkepov, T. Z.; Kando, Masaki; Shizuma, Toshiyuki; Hayakawa, Takehito; Kiriyama, Hiromitsu; et al.

Optics Letters, 37(14), p.2868 - 2870, 2012/07

 Times Cited Count:82 Percentile:95.91(Optics)

Using high contrast (10$$^{10}$$:1) and high intensity (10$$^{21}$$ W/cm$$^{2}$$) laser pulse with the duration of 40 fs from OPCPA/Ti:Sapphire laser, a 40 MeV proton bunch is obtained, which is a record for laser pulse with energy less than 10 J. The efficiency for generation of protons with kinetic energy above 15 MeV is 0.1%.

Journal Articles

Safeguards improvement for the Tokai Reprocessing Plant (TRP)

Onizawa, Toshikazu; Kimura, Takashi; Kurosu, Kazutoshi; Hayakawa, Tsuyoshi; Fukuhara, Junichi; Yatsu, Shoichi*

STI/PUB/1298 (CD-ROM), p.739 - 745, 2007/08

no abstracts in English

Journal Articles

Detailed structural analysis and dielectric properties of silicon nitride film fabricated using pure nitrogen plasma generated near atmospheric pressure

Hayakawa, Ryoma*; Nakae, Mari*; Yoshimura, Takeshi*; Ashida, Atsushi*; Fujimura, Norifumi*; Uehara, Tsuyoshi*; Tagawa, Masahito*; Teraoka, Yuden

Journal of Applied Physics, 100(7), p.073710_1 - 073710_8, 2006/10

 Times Cited Count:11 Percentile:42.6(Physics, Applied)

A structural analysis and dielectric property measurements of silicon nitride films fabricated using atmospheric pressure (AP) plasma were carried out, and the results were compared to a radio frequency (RF) plasma case. Using AP plasma, 1.8-nm-thick films composed of Si$$_{3}$$N$$_{3.5}$$O$$_{0.7}$$ were obtained in the temperature range from 298 to 773 K. X-ray photoelectron spectroscopy and Rutherford backscattering spectrometry revealed 10% more nitrogen atoms corresponding to the NSi$$_{3}$$ bond in the film using AP plasma than those using RF plasma. In the temperature range, the leakage current densities were not affected by the temperature. Films fabricated at 298 K showed leakage current density of as low as 7$$times$$10$$^{-2}$$A/cm$$^{2}$$ at 5MV/cm. This value was one order of magnitude lower than that using RF plasma.

Journal Articles

A World of sand viewing from an airplane; Missions of IAEA in Libya

Hayakawa, Tsuyoshi

Kaku Busshitsu Kanri Senta Nyusu, 35(8), p.12 - 13, 2006/08

no abstracts in English

Journal Articles

Design performance of front steering-type electron cyclotron launcher for ITER

Takahashi, Koji; Imai, Tsuyoshi; Kobayashi, Noriyuki*; Sakamoto, Keishi; Kasugai, Atsushi; Hayakawa, Atsuro*; Mori, Seiji*; Mori, Kensuke*

Fusion Science and Technology, 47(1), p.1 - 15, 2005/01

An applicability of a front steering type EC launcher to a fusion reactor is described with the design and thermal, electromagnetic and nuclear analysis using the ITER design conditions. Maximum stress of the support keys of the front shield module, the welds of the keys and the mirror shaft induced by electromagnetic force are 85.5MPa and 34.1MPa and 22MPa, respectively, which are less than 1.5Sm of stainless steel(205MPa). Maximum thermal stress in the front shield module and the mirror, which are 249MPa and 350MPa, respectively, are obtained at the inner surface of a stainless steel cooling tube. The stresses are less 3Sm of stainless steel at 200$$^{circ}$$C(410MPa). The annual neutron fluence and the dose rate at the vacuum window(closure plate) are estimated to be 10$$^{13}$$$$sim$$10$$^{12}$$ n/cm$$^{2}$$/yr and 45$$mu$$Sv/h, respectively that satisfy the shield criteria of the ITER. It appears that the design of the front steering type EC launcher is applicable to an ITER grade reactor.

Oral presentation

Comparison of chemical bonding structure at SiN/Si interface fabricated using atmospheric pressure plasma and RF plasma

Hayakawa, Ryoma*; Nakae, Mari*; Yoshida, Shinji*; Tagawa, Masahito*; Teraoka, Yuden; Yoshimura, Takeshi*; Ashida, Atsushi*; Kunugi, Shunsuke*; Uehara, Tsuyoshi*; Fujimura, Norifumi*

no journal, , 

Chemical bonding states of silicon nitride films formed by an atmospheric plasma method and a RF plasma method were analyzed by photoemission spectroscopy with synchrotron radiation and compared each other. The SiN/Si(111) interface formed by the RF plasma method consisted of 5 components. On the other hand, the SiN/Si(111) interface formed by the atmospheric plasma method consisted of 4 components. The Si$$_{3}$$N component is in the interface formed by the RF plasma method.

Oral presentation

Safeguards system and experience of Tokai reprocessing facility

Hayakawa, Tsuyoshi

no journal, , 

Histories of operation and safeguards, characterization and improvement of nuclear material account, characterization and development of installed safeguards equipment and future activity for Tokai reprocessing facility (reprocessing plant and Pu conversion facility) is presented.

Oral presentation

40 MeV proton beam Generation with ultra-high intensity high-contrast Ti:Sapphire laser system, 2

Ogura, Koichi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Tanimoto, Tsuyoshi; Sagisaka, Akito; Esirkepov, T. Z.; Shizuma, Toshiyuki; Hayakawa, Takehito; Hajima, Ryoichi; Kando, Masaki; et al.

no journal, , 

We demonstrated the energetic proton generation using 40 fsec intense Ti:Sapphire laser pulses. By drastically increasing the interaction intensity approximately 1E21 W/cm$$^{2}$$ with keeping a ultra high contrast of 1E10:1, even without using plasma mirror, over 40 MeV protons were detected with 800 nm thick Al foil.

Oral presentation

Plasma-mirror free 40 MeV proton beam generation with ultra-high intensity high-contrast Ti:sapphire laser system

Ogura, Koichi; Nishiuchi, Mamiko; Pirozhkov, A. S.; Tanimoto, Tsuyoshi; Esirkepov, T. Z.; Sagisaka, Akito; Kando, Masaki; Shizuma, Toshiyuki; Hayakawa, Takehito; Kiriyama, Hiromitsu; et al.

no journal, , 

Without plasma mirror, the maximum proton energy of 40 MeV is obtained using a compact, high spatiotemporal-quality, high-intensity Ti:sapphire laser system with an intensity of 1E21 W/cm/cm for the first time to our knowledge.

Oral presentation

Conceptual study of networking with radiation protection experts for nuclear emergency

Momose, Takumaro; Hayakawa, Tsuyoshi; Takada, Chie; Nakano, Masanao; Yoshida, Tadayoshi

no journal, , 

no abstracts in English

Oral presentation

Conceptual study of networking with radiation protection experts for nuclear emergency preparedness; Focuses on technical support for environmental monitoring and contamination survey for residents

Watanabe, Yuki; Nakano, Masanao; Yoshida, Tadayoshi; Takada, Chie; Hayakawa, Tsuyoshi; Momose, Takumaro

no journal, , 

no abstracts in English

Oral presentation

Thermoelectric properties of soil clay minerals treated by molten salt electrolysis

Honda, Mitsunori; Kaneta, Yui; Muraguchi, Masakazu*; Hayakawa, Kosetsu*; Oda, Masato*; Iino, Chiaki*; Ishii, Hiroyuki*; Goto, Takuya*; Yaita, Tsuyoshi

no journal, , 

Ten years have passed since the earthquake and nuclear power plant accident at 1F that occurred in 2011, and the contaminated soil generated in Fukushima Prefecture is now being managed as removed soil at intermediate storage facilities. In the course of developing technology to remove cesium from the removed soil, we have focused on the functionality of crystalline minerals after removal of cesium, and have been investigating their potential as thermoelectric materials. In this study, we report on the evaluation of thermoelectric properties (electrical conductivity, thermal diffusivity, and Seebeck coefficient) and structural analysis of crystalline minerals.

24 (Records 1-20 displayed on this page)