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JAEA Reports

Status of study of long-term assessment of transport of radioactive contaminants in the environment of Fukushima (FY2018) (Translated document)

Nagao, Fumiya; Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Dohi, Terumi; Nakanishi, Takahiro; Sakuma, Kazuyuki; Hagiwara, Hiroki; Funaki, Hironori; et al.

JAEA-Research 2020-007, 249 Pages, 2020/10

JAEA-Research-2020-007.pdf:15.83MB

The accident of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. occurred due to the Great East Japan Earthquake, Sanriku offshore earthquake, of 9.0 magnitude and the accompanying tsunami. As a result, large amount of radioactive materials was released into the environment. Under these circumstances, Japan Atomic Energy Agency (JAEA) has been conducting "Long-term Assessment of Transport of Radioactive Contaminants in the Environment of Fukushima" concerning radioactive materials released in environment, especially migration behavior of radioactive cesium since November 2012. This report is a summary of the research results that have been obtained in environmental dynamics research conducted by JAEA in Fukushima Prefecture.

JAEA Reports

Status of study of long-term assessment of transport of radioactive contaminants in the environment of Fukushima (FY2018)

Nagao, Fumiya; Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Dohi, Terumi; Nakanishi, Takahiro; Sakuma, Kazuyuki; Hagiwara, Hiroki; Funaki, Hironori; et al.

JAEA-Research 2019-002, 235 Pages, 2019/08

JAEA-Research-2019-002.pdf:21.04MB

The accident of the Fukushima Daiichi Nuclear Power Station (hereinafter referred to 1F), Tokyo Electric Power Company Holdings, Inc. occurred due to the Great East Japan Earthquake, Sanriku offshore earthquake, of 9.0 magnitude and the accompanying tsunami. As a result, large amount of radioactive materials was released into the environment. Under these circumstances, JAEA has been conducting Long-term Environmental Dynamics Research concerning radioactive materials released in environment, especially migration behavior of radioactive cesium since November 2012. This report is a summary of the research results that have been obtained in environmental dynamics research conducted by JAEA in Fukushima Prefecture.

Journal Articles

Structure of active sites of Fe-N-C nano-catalysts for alkaline exchange membrane fuel cells

Kishi, Hirofumi*; Sakamoto, Tomokazu*; Asazawa, Koichiro*; Yamaguchi, Susumu*; Kato, Takeshi*; Zulevi, B.*; Serov, A.*; Artyushkova, K.*; Atanassov, P.*; Matsumura, Daiju; et al.

Nanomaterials (Internet), 8(12), p.965_1 - 965_13, 2018/12

 Times Cited Count:6 Percentile:39.54(Chemistry, Multidisciplinary)

Journal Articles

Polarized neutrons

Hiraka, Haruhiro*; Yamaguchi, Yasuo*; Maruyama, Ryuji; Oku, Takayuki; Ino, Takashi*

Hamon, 28(3), p.144 - 149, 2018/08

no abstracts in English

Journal Articles

Determination of fusion barrier distributions from quasielastic scattering cross sections towards superheavy nuclei synthesis

Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.

Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01

 Times Cited Count:10 Percentile:72.43(Physics, Multidisciplinary)

Excitation functions of quasielastic scattering cross sections for the $$^{48}$$Ca + $$^{208}$$Pb, $$^{50}$$Ti + $$^{208}$$Pb, and $$^{48}$$Ca + $$^{248}$$Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the $$^{48}$$Ca + $$^{208}$$Pb and $$^{50}$$Ti + $$^{208}$$Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the $$^{48}$$Ca + $$^{248}$$Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.

Journal Articles

Study of the reaction $$^{48}$$Ca + $$^{248}$$Cm $$rightarrow$$ $$^{296}$$Lv$$^{ast}$$ at RIKEN-GARIS

Kaji, Daiya*; Morita, Kosuke*; Morimoto, Koji*; Haba, Hiromitsu*; Asai, Masato; Fujita, Kunihiro*; Gan, Z.*; Geissel, H.*; Hasebe, Hiroo*; Hofmann, S.*; et al.

Journal of the Physical Society of Japan, 86(3), p.034201_1 - 034201_7, 2017/03

 Times Cited Count:16 Percentile:79.57(Physics, Multidisciplinary)

The fusion reaction of $$^{48}$$Ca + $$^{248}$$Cm $$rightarrow$$ $$^{296}$$Lv$$^{ast}$$ was studied using the gas-filled recoil-ion separator GARIS at RIKEN. A total of seven $$alpha$$ and spontaneous-fission decay chains were observed, which would originate from the reaction products of the element 116, $$^{292}$$Lv and $$^{293}$$Lv. Decay properties observed in the chains are in good agreement with the previously published ones. However, one of the chains showed a discrepancy, indicating the new spontaneous-fission branch in $$^{285}$$Cn or the production of the new isotope $$^{294}$$Lv.

Journal Articles

Development of non-PGM catalysts for anion exchange membrane fuel cells

Sakamoto, Tomokazu*; Kishi, Hirofumi*; Yamaguchi, Susumu*; Tanaka, Hirohisa*; Matsumura, Daiju; Tamura, Kazuhisa; Nishihata, Yasuo

Hyomen Kagaku, 37(2), p.78 - 83, 2016/02

We have developed direct liquid fuel anion exchange membrane fuel cell vehicles to deal with the global warming. Non-platinum group metals (PGM) catalyst has been researched to apply for both anode and cathode electrodes. A test driving was carried out for the fuel cell vehicle equipped with no precious metals as catalysts at SPring-8 in 2013. Here we introduce our results of advanced analysis for reaction mechanism and active site of non-PGM catalyst using synchrotron radiation X-rays at SPring-8.

Journal Articles

Science from the initial operation of HRC

Ito, Shinichi*; Yokoo, Tetsuya*; Masuda, Takatsugu*; Yoshizawa, Hideki*; Soda, Minoru*; Ikeda, Yoichi*; Ibuka, Soshi*; Kawana, Daichi*; Sato, Taku*; Nambu, Yusuke*; et al.

JPS Conference Proceedings (Internet), 8, p.034001_1 - 034001_6, 2015/09

Journal Articles

Mathematical Modeling of Radioactive Contaminants in the Fukushima Environment

Kitamura, Akihiro; Kurikami, Hiroshi; Yamaguchi, Masaaki; Oda, Yoshihiro; Saito, Tatsuo; Kato, Tomoko; Niizato, Tadafumi; Iijima, Kazuki; Sato, Haruo; Yui, Mikazu; et al.

Nuclear Science and Engineering, 179(1), p.104 - 118, 2015/01

 Times Cited Count:8 Percentile:65.81(Nuclear Science & Technology)

The prediction of the distribution and fate of radioactive materials eventually deposited at surface in the Fukushima area is one of the main objectives and expected to be achieved in an efficient manner. In order to make such prediction, a number of mathematical models of radioactive contaminants, with particular attention on cesium, on the land and in rivers, lakes, and estuaries in the Fukushima area are developed. Simulation results are examined with the field investigations simultaneously implemented. The basic studies of the adsorption/absorption mechanism of cesium and soils have been performed to shed light on estimating distribution coefficient between dissolved contaminant and particulate contaminant.

Journal Articles

Predicting the long-term $$^{137}$$Cs distribution in Fukushima after the Fukushima Dai-ichi Nuclear Power Plant accident; A Parameter sensitivity analysis

Yamaguchi, Masaaki; Kitamura, Akihiro; Oda, Yoshihiro; Onishi, Yasuo*

Journal of Environmental Radioactivity, 135, p.135 - 146, 2014/09

 Times Cited Count:36 Percentile:78.6(Environmental Sciences)

We applied a model, to predict long term cesium distribution on Fukushima area, based on the USLE and simple sediment discharge formulas. Sensitivity analysis was conducted here to narrow the range of the output results due to the uncertainties of parameters. The preliminary calculation indicated significant deposition of sand portion within river basins. On the other hand the most of the eroded silt and clay portions were transported downstream to the river mouths. Annual sediment outflow into the ocean from Abukuma River and its total from the other 13 river basins vary between calculation cases based on the variation of land use, landform or precipitation. On the other hand, contributions of those parameters are relatively small for $$^{137}$$Cs concentration within transported soil. This indicates the total amount of $$^{137}$$Cs outflow into the ocean could be controlled by amount of soil erosion and transport, and total amount of $$^{137}$$Cs remaining within the basin.

Journal Articles

Predicting sediment and cesium-137 discharge from catchments in eastern Fukushima

Kitamura, Akihiro; Yamaguchi, Masaaki; Kurikami, Hiroshi; Yui, Mikazu; Onishi, Yasuo*

Anthropocene, 5, p.22 - 31, 2014/03

Amount of soil and cesium losses in Eastern Fukushima Prefecture is evaluated by a simple and fast simulation model which we developed utilizing the universal soil loss equation and the geographical information system. We focused on the land use factor of the universal soil loss equation in this study. It was estimated that the forest occupies 64% of the total land surface of the study area, but only accounts for 24% of total soil runoff and 33% of total cesium dispersion. The most contributing component comes from the crop field, while the forest becomes the second. Also, calculation was performed for each river basins and results were compared with field monitoring data.

Journal Articles

Development of the training tools for nuclear security; Physical Protection Exercise Field (PPEF) and Virtual Reality (VR) training system

Kawata, Norio; Wakabayashi, Shuji; Hanai, Tasuku; Yamaguchi, Yasuo; Nonaka, Nobuyuki; Scharmer, C.*

Proceedings of International Conference on Nuclear Security; Enhancing Global Efforts (CD-ROM), 10 Pages, 2014/03

The ISCN of the JAEA provides effective trainings in order to strengthen nuclear security for emerging nuclear power countries in Asia to realize Japan's National Statement at the Washington Nuclear Security Summit in April 2010. As a part of these activities, the ISCN has developed the PPEF and the VR training system, which are training tools to implement experience-oriented and interactive lessons. These two facilities are mutually complemented and contribute to deeper understandings through actual practices in addition to the classroom lesson. The ISCN initiated its full-scale training from 2012 JFY, and these two facilities received more than 450 trainees or vistors from Japan and over-sea countries. This paper provides the basic concepts and outlines of these two facilities and the training programs that use them for teaching the nuclear security.

Journal Articles

Development of a model to predict a radionuclide distribution based on soil migration after Fukushima Dai-ichi Nuclear Power Plant accident

Yamaguchi, Masaaki; Maekawa, Keisuke; Takeuchi, Shinji*; Kitamura, Akihiro; Onishi, Yasuo*

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 20(2), p.53 - 69, 2013/12

We developed a simple novel and fast simulation model to predict a long-term distribution of $$^{137}$$Cs deposited on the land surface of Fukushima due to the Fukushima Dai-ichi Nuclear Power Plant accident triggered by a magnitude 9.0 earthquake and resulting tsunami on 11 March 2011. The model utilizes the Geographical Information System (GIS) to integrate online open data provided by individual institutes, and simulate mechanisms of soil erosion, transport and sedimentation. A preliminary calculation shows the significant deposition of sediments in lakes and reservoirs and eroded silt and clay tend to be transported downstream to river mouths than eroded sand. These results were found to be qualitatively consistent with existing data.

Journal Articles

Simulating long-term $$^{137}$$Cs distribution on territory of Fukushima

Kitamura, Akihiro; Yamaguchi, Masaaki; Oda, Yoshihiro; Kurikami, Hiroshi; Onishi, Yasuo*

Transactions of the American Nuclear Society, 109(1), p.153 - 155, 2013/11

Long term $$^{137}$$Cs transport and its future distribution on the territory of Fukushima were predicted based on the USLE and the GIS. By modeling the soil erosion, transport, and deposition, we simulated the future distributions of air dose rates of $$^{137}$$Cs in mSv/h for 2, 6 and 21 years after the accident. The predictions made by METI were compared with the present results. The predictions of relatively high air dose rate areas were consistently matched between the two models over time. However, our model seemed to predict the decreasing rate of the $$^{137}$$Cs concentration with time to be slightly less than that of METI prediction. Some portions of the results obtained in the present study were used to provide influxes of sediments and $$^{137}$$Cs as boundary conditions and lateral inflows for the hydraulic river model.

Journal Articles

Preliminary calculation of sediment and $$^{137}$$Cs transport in the Ukedo River of Fukushima

Kurikami, Hiroshi; Kitamura, Akihiro; Yamaguchi, Masaaki; Onishi, Yasuo*

Transactions of the American Nuclear Society, 109(1), p.149 - 152, 2013/11

We applied the TOMAM model to the Ukedo River as a preliminary analysis to roughly understand what was important for cesium migration. The main lessons were as follows: Cesium migrates mainly in high river discharge conditions. Migration in a dissolved form is important in low river discharge conditions, while suspended sediments, especially silt and clay, are main carriers of cesium in high discharge conditions. Bed contamination is mainly reflected by sediment erosion and deposition instead of direct sorption in the riverbed.

Journal Articles

Development of a virtual reality system for training in nuclear security

Hanai, Tasuku; Yamaguchi, Yasuo

Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07

The Integrated Support Center for Nuclear Nonproliferation and Nuclear Security (ISCN), under the Japan Atomic Energy Agency (JAEA), has been doing activities, since its establishment, that contribute to the strengthening of nuclear nonproliferation and nuclear security. ISCN is providing training courses for the purpose of capacity-building assistance through human-resource development. ISCN has a Virtual Reality (VR) System specifically for training in nuclear security. The course is specifically for trainees who have had few experiences in nuclear security. Trainees can see the nuclear physical-protection (PP) system of a nuclear power station in virtual space and learn how it works. ISCN has also been preparing another training course that will be for operators in Central Alarm Stations (CAS). Trainees will be able to brush up their skills through simulation exercises against enforced entry.

Journal Articles

Development of multi-purpose MW gyrotrons for fusion devices

Minami, Ryutaro*; Kariya, Tsuyoshi*; Imai, Tsuyoshi*; Numakura, Tomoharu*; Endo, Yoichi*; Nakabayashi, Hidetaka*; Eguchi, Taku*; Shimozuma, Takashi*; Kubo, Shin*; Yoshimura, Yasuo*; et al.

Nuclear Fusion, 53(6), p.063003_1 - 063003_7, 2013/06

Journal Articles

Development of multi-purpose MW gyrotrons for fusion devices

Minami, Ryutaro*; Kariya, Tsuyoshi*; Imai, Tsuyoshi*; Numakura, Tomoharu*; Endo, Yoichi*; Nakabayashi, Hidetaka*; Eguchi, Taku*; Shimozuma, Takashi*; Kubo, Shin*; Yoshimura, Yasuo*; et al.

Nuclear Fusion, 53(6), p.063003_1 - 063003_7, 2013/06

 Times Cited Count:12 Percentile:54.31(Physics, Fluids & Plasmas)

Journal Articles

New result in the production and decay of an isotope, $$^{278}$$113 of the 113th element

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.

Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10

 Times Cited Count:142 Percentile:97.35(Physics, Multidisciplinary)

An isotope of the 113th element, $$^{278}$$113, was produced in a nuclear reaction with a $$^{70}$$Zn beam on a $$^{209}$$Bi target. We observed six consecutive $$alpha$$ decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of $$^{262}$$Db and $$^{258}$$Lr both in decay energies and decay times. This indicates that the present decay chain consisted of $$^{278}$$113, $$^{274}$$Rg (Z = 111), $$^{270}$$Mt (Z = 109), $$^{266}$$Bh (Z = 107), $$^{262}$$Db (Z = 105), and $$^{258}$$Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope $$^{278}$$113, of the 113th element.

Journal Articles

Identified charged hadron production in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

 Times Cited Count:156 Percentile:99.42(Physics, Nuclear)

Transverse momentum distributions and yields for $$pi^{pm}, K^{pm}, p$$, and $$bar{p}$$ in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different $$sqrt{s}$$ collisions. We also present the scaling properties such as $$m_T$$ and $$x_T$$ scaling and discuss the mechanism of the particle production in $$p + p$$ collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

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