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Journal Articles

Atmospheric modeling of $$^{137}$$Cs plumes from the Fukushima Daiichi Nuclear Power Plant; Evaluation of the model intercomparison data of the Science Council of Japan

Kitayama, Kyo*; Morino, Yu*; Takigawa, Masayuki*; Nakajima, Teruyuki*; Hayami, Hiroshi*; Nagai, Haruyasu; Terada, Hiroaki; Saito, Kazuo*; Shimbori, Toshiki*; Kajino, Mizuo*; et al.

Journal of Geophysical Research; Atmospheres, 123(14), p.7754 - 7770, 2018/07

 Times Cited Count:24 Percentile:69.81(Meteorology & Atmospheric Sciences)

We compared seven atmospheric transport model results for $$^{137}$$Cs released during the Fukushima Daiichi Nuclear Power Plant accident. All the results had been submitted for a model intercomparison project of the Science Council of Japan in 2014. We assessed model performance by comparing model results with observed hourly atmospheric concentrations of $$^{137}$$Cs, focusing on nine plumes over the Tohoku and Kanto regions. The results showed that model performance for $$^{137}$$Cs concentrations was highly variable among models and plumes. We also assessed model performance for accumulated $$^{137}$$Cs deposition. Simulated areas of high deposition were consistent with the plume pathways, though the models that best simulated $$^{137}$$Cs concentrations were different from those that best simulated deposition. The ensemble mean of all models consistently reproduced $$^{137}$$Cs concentrations and deposition well, suggesting that use of a multimodel ensemble results in more effective and consistent model performance.

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:56.13(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.

JAEA Reports

Research on engineering technology in the full-scale demonstration of EBS and operation technology for HLW disposal; Research report in 2012 (Joint research)

Nakatsuka, Noboru; Sato, Haruo; Tanai, Kenji; Nakayama, Masashi; Sawada, Sumiyuki*; Asano, Hidekazu*; Saito, Masahiko*; Yoshino, Osamu*; Tsukahara, Shigeki*; Hishioka, Sosuke*; et al.

JAEA-Research 2013-034, 70 Pages, 2014/01

JAEA-Research-2013-034.pdf:9.11MB

Japan Atomic Energy Agency (JAEA) and Radioactive Waste Management Funding and Research Center (RWMC) concluded the letter of cooperation agreement on the research and development of radioactive waste disposal in April, 2005, and have been carrying out the collaboration work based on the agreement. JAEA have been carrying out the Horonobe Underground Research Laboratory (URL) Project which is intended for a sedimentary rock in the Horonobe town, Hokkaido, since 2001. In the project, geoscientific research and research and development on geological disposal technology are being promoted. Meanwhile, the government (the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry) has been promoting construction of equipments for the full-scale demonstration of engineered barrier system and operation technology for high-level radioactive waste (HLW) disposal since 2008, to enhance public's understanding to the geological disposal of HLW, e.g. using underground facility. RWMC received an order of the project in fiscal year 2012 (2011/2012) continuing since fiscal year 2008 (2008/2009). Since topics in this project are included in the Horonobe URL Project, JAEA carried out this project as collaboration work continuing in fiscal year 2008. This report summarizes the results of engineering technology carried out in this collaboration work in fiscal year 2012. In fiscal year 2012, part of the equipments for emplacement of buffer material was produced and visualization test for water penetration in buffer material were carried out.

JAEA Reports

Research on engineering technology in the full-scale demonstration of EBS and operation technology for HLW disposal; Research report in 2011 (Joint research)

Nakatsuka, Noboru; Sato, Haruo; Tanai, Kenji; Sugita, Yutaka; Nakayama, Masashi; Sawada, Sumiyuki*; Niinuma, Hiroaki*; Asano, Hidekazu*; Saito, Masahiko*; Yoshino, Osamu*; et al.

JAEA-Research 2013-027, 34 Pages, 2013/11

JAEA-Research-2013-027.pdf:5.84MB

Japan Atomic Energy Agency (JAEA) and Radioactive Waste Management Funding and Research Center (RWMC) concluded the letter of cooperation agreement on the research and development of radioactive waste disposal in April, 2005, and have been carrying out the collaboration work based on the agreement. JAEA have been carrying out the Horonobe Underground Research Laboratory (URL) Project which is intended for a sedimentary rock in the Horonobe town, Hokkaido, since 2001. In the project, geoscientific research and research and development on geological disposal technology are being promoted. Meanwhile, the government (the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry) has been promoting construction of equipments for the full-scale demonstration of engineered barrier system and operation technology for high-level radioactive waste (HLW) disposal since 2008, to enhance public's understanding to the geological disposal of HLW, e.g. using underground facility. RWMC received an order of the project in fiscal year 2010 (2010/2011) continuing since fiscal year 2008 (2008/2009). Since topics in this project are included in the Horonobe URL Project, JAEA carried out this project as collaboration work continuing in fiscal year 2008. This report summarizes the results of engineering technology carried out in this collaboration work in fiscal year 2011. In fiscal year 2011, part of the equipments for emplacement of buffer material was produced and visualization test for water penetration in buffer material were carried out.

JAEA Reports

Research on engineering technology in the full-scale demonstration of EBS and operation technology for HLW disposal; Research report in 2010 (Joint research)

Nakatsuka, Noboru; Hatanaka, Koichiro; Sato, Haruo; Sugita, Yutaka; Nakayama, Masashi; Asano, Hidekazu*; Saito, Masahiko*; Suyama, Yasuhiro*; Hayashi, Hidero*; Honda, Yuko*; et al.

JAEA-Research 2013-026, 57 Pages, 2013/11

JAEA-Research-2013-026.pdf:7.48MB

JAEA and RWMC concluded the letter of cooperation agreement on the research and development of radioactive waste disposal in April, 2005, and have been carrying out the collaboration work described above based on the agreement. JAEA have been carrying out the Horonobe URL Project which is intended for a sedimentary rock in the Horonobe town, Hokkaido, since 2001. In the project, geoscientific research and research and development on geological disposal technology are being promoted. Meanwhile, the government (the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry) has been promoting construction of equipments for the full-scale demonstration of engineered barrier system and operation technology for high-level radioactive waste (HLW) disposal since 2008, to enhance public's understanding to the geological disposal of HLW, using underground facility, etc. RWMC received an order of the project in fiscal year 2010 continuing since fiscal year 2008. Since topics in this project are included in the Horonobe URL Project, JAEA carried out this project as collaboration work continuing in FY 2008. This report summarizes the results of engineering technology carried out in this collaboration work in fiscal year 2010. In fiscal year 2010, part of the equipments for emplacement of buffer material was produced and a house for the equipments and apparatus was opened in the adjoining land of Public Information House of JAEA Horonobe.

Journal Articles

Report of the Special Symposium on the Transport and Diffusion of Contaminants from the Fukushima Dai-ichi Nuclear Power Plant; Present status and future directions

Kondo, Hiroaki*; Yamada, Tetsuji*; Chino, Masamichi; Iwasaki, Toshiki*; Katata, Genki; Maki, Takashi*; Saito, Kazuo*; Terada, Hiroaki; Tsuruta, Haruo*

Tenki, 60(9), p.723 - 729, 2013/09

AA2013-0745.pdf:0.51MB

no abstracts in English

JAEA Reports

Research on engineering technology in the full-scale demonstration of EBS and operation technology for HLW disposal; Research report in 2009 (Joint research)

Nakatsuka, Noboru; Hatanaka, Koichiro; Sato, Haruo; Sugita, Yutaka; Nakayama, Masashi; Miyahara, Shigenori; Asano, Hidekazu*; Saito, Masahiko*; Suyama, Yasuhiro*; Hayashi, Hidero*; et al.

JAEA-Research 2010-060, 50 Pages, 2011/02

JAEA-Research-2010-060.pdf:6.7MB

Japan Atomic Energy Agency (JAEA) and Radioactive Waste Management Funding and Research Center (RWMC) concluded the letter of cooperation agreement on the research and development of radioactive waste disposal in April, 2005, and have been carrying out the collaboration work described above based on the agreement. JAEA have been carrying out the Horonobe Underground Research Laboratory (URL) Project which is intended for sedimentary rock in the Horonobe town, Hokkaido, since 2001. In the project, geoscientific research and research and development on geological disposal technology are being promoted. Meanwhile, the government (the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry) has been promoting construction of equipments for the full-scale demonstration of engineered barrier system and operation technology for high-level radioactive waste (HLW) disposal since 2008, to enhance publics understanding to the geological disposal of HLW, using underground facility, etc. RWMC received an order of the project in fiscal year 2009 (2009/2010) continuing in fiscal year 2008 (2008/2009). Since topics in this project are included in the Horonobe URL Project, JAEA carried out this project as collaboration work continuing in fiscal year 2008. This report summarizes the results of engineering technology carried out in this collaboration work in fiscal year 2009. In fiscal year 2009, a part of the equipments for equipment of buffer material and visualization test apparatus for water penetration in buffer material were produced and house for the equipments and apparatus was constructed.

JAEA Reports

Research on engineering technology in the full-scale demonstration of EBS and operation technology for HLW disposal; Research report in 2008 (Joint research)

Nakatsuka, Noboru; Hatanaka, Koichiro; Sato, Haruo; Sugita, Yutaka; Nakayama, Masashi; Miyahara, Shigenori; Asano, Hidekazu*; Saito, Masahiko*; Suyama, Yasuhiro*; Hayashi, Hidero*; et al.

JAEA-Research 2009-044, 53 Pages, 2010/01

JAEA-Research-2009-044.pdf:9.03MB

Japan Atomic Energy Agency (JAEA) and Radioactive Waste Management Funding and Research Center (RWMC) effect an agreement about research and development of high level radioactive waste (HLW) disposal and carried out research and technological development about geological disposal technology. JAEA has been carried out the Horonobe Underground Research Laboratory (URL) Project which is intended for sedimentary rock and the Project includes geoscientific research and geological disposal technology. RWMC carried out an investigation about full-scale demonstration of engineered barrier system (EBS) and operation technology for HLW disposal, under the contract with the Natural Resources and Energy Agency, Ministry of Economy, the Trade and Industry. The investigation aims to obtain the citizens' understanding of the geological disposal. This work includes the full-scale demonstration of operation technology in the Horonobe URL. This joint research is about engineering technology concerned with the work. In 2008 fiscal year (2008/2009), the master plan of the work was made, and a part of the device for transportation of engineered barrier was made, and it has begun the exhibition of full-scale bentonite block and overpack.

JAEA Reports

Horonobe Underground Research Laboratory project research and development plan in Phase 2; H20-21

Iwatsuki, Teruki; Sato, Haruo; Tanai, Kenji; Inagaki, Manabu; Sawada, Atsushi; Niinuma, Hiroaki; Ishii, Eiichi; Maekawa, Keisuke; Tomura, Goji; Sanada, Hiroyuki; et al.

JAEA-Research 2009-002, 156 Pages, 2009/05

JAEA-Research-2009-002.pdf:12.86MB

The research and development plan for geological investigation, engineering technology and safety assessment during the drilling of a shaft down to intermediate depth are summarized according to the Midterm Plan till 2009 Fiscal year of JAEA. This report describes subject, current status and programme in the "Phase 2: Construction phase" (investigations during construction of the underground facilities). Furthermore regarding R&D plan in next Midterm Plan of JAEA, preliminary ideas are summarized.

Journal Articles

Interlaboratory comparison of positron annihilation lifetime measurements

Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.

Materials Science Forum, 607, p.248 - 250, 2009/00

So far no standard procedure for the positron annihilation lifetime (PAL) technique has been established. A lack of the standards has led to difficulty in ensuring the equivalency and reliability of data from different laboratories. As a first, we conducted an interlaboratory comparison of PAL measurements for metal, polymer and silica glass with agreed procedures for data recording and analysis. The PAL data recorded at different laboratories were analyzed with a single lifetime component for the metal sample and with three components for the others, respectively. Based on the results of the reported positron and ortho-positronium lifetimes, the possible sources of the uncertainties in the PAL measurements are discussed. To reduce the effect of scattered $$gamma$$ rays, a lead shield was placed between the detectors. The uncertainty was significantly decreased, signifying that placing lead shields between the detectors effectively reduced the false signals due to the scattered $$gamma$$ rays.

Journal Articles

Interlaboratory comparison of positron annihilation lifetime measurements for synthetic fused silica and polycarbonate

Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.

Journal of Applied Physics, 104(2), p.026102_1 - 026102_3, 2008/07

 Times Cited Count:48 Percentile:83.5(Physics, Applied)

Interlaboratory comparison of positron annihilation lifetime measurements using synthetic fused silica and polycarbonate was conducted with the participation of 12 laboratories. By regulating procedures for the measurement and data analysis the uncertainties of the positron lifetimes obtained at different laboratories were significantly reduced in comparison with those reported in the past.

Journal Articles

Isolated hydrogen center in wide gap semiconductors studied by $$mu$$SR

Shimomura, Koichiro*; Kadono, Ryosuke*; Nishiyama, Kusuo*; Watanabe, Isao*; Suzuki, Takao*; Pratt, F.*; Oishi, Kazuki; Mizuta, Masashi*; Saito, Mineo*; Chow, K. H.*; et al.

Physica B; Condensed Matter, 376-377, p.444 - 446, 2006/04

 Times Cited Count:1 Percentile:6.64(Physics, Condensed Matter)

Journal Articles

Operation of circular dichroism measurements with periodic photon-helicity switching by an APPLE-2 type undulator at BL23SU at SPring-8

Agui, Akane; Yoshigoe, Akitaka; Nakatani, Takeshi; Matsushita, Tomohiro*; Saito, Yuji; Mizumaki, Masaichiro*; Yokoya, Akinari; Tanaka, Hitoshi*; Miyahara, Yoshikazu*; Shimada, Taihei; et al.

Hoshako, 14(5), p.339 - 348, 2001/11

no abstracts in English

Journal Articles

First operation of circular dichroism measurements with periodic photon-helicity switching by a variably polarizing undulator at BL23SU at SPring-8

Agui, Akane; Yoshigoe, Akitaka; Nakatani, Takeshi*; Matsushita, Tomohiro*; Saito, Yuji; Yokoya, Akinari; Tanaka, Hitoshi*; Miyahara, Yoshikazu*; Shimada, Taihei; Takeuchi, Masao*; et al.

Review of Scientific Instruments, 72(8), p.3191 - 3197, 2001/08

 Times Cited Count:21 Percentile:71.63(Instruments & Instrumentation)

no abstracts in English

Oral presentation

Comparison of positron annihilation measurements of quartz glass and polycarbonate

Kobayashi, Yoshinori*; Ito, Kenji*; Oka, Toshitaka*; Sakaki, Koji*; Shirai, Yasuharu*; Honda, Yoshihide*; Shimazu, Akira*; Fujinami, Masanori*; Hirade, Tetsuya; Saito, Haruo*; et al.

no journal, , 

For making a standard sample of positron annihilation measurement, quartz glass and polycarbonate were measured with 12 apparatus at AIST, Chiba Univ., Tokyo Univ., Tsukuba Univ., Touhoku Univ., Tokyo Gakugei Univ. JAEA, Nitto Denko, and Toray Research Center. By regulating procedure for the measurement and data analysis the uncertainties of the positron annihilation lifetime obtained at different laboratories were significantly reduced.

Oral presentation

Interlaboratry comparison of psotitron annihilation lifetime measurement

Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.

no journal, , 

So far no standard procedure for the positron annihilation lifetime (PAL) technique has been established. A lack of the standards has led to difficulty in ensuring equivalency and reliability of data from different laboratories. Recently, as a first step toward the standardization of the PAL technique, we conducted an interlaboratory comparison of PAL measurements for fused silica, polycarbonate and metal with agreed procedures for data recording and analysis. Based on the results of the reported lifetimes, possible sources of the uncertainties in the PAL measurements is probably caused by the backscattered $$gamma$$-rays by other detectors. We succeeded to show that inserting shields between detectors can reduce the uncertainty.

Oral presentation

Estimation of measurement uncertainty for positron annihilation lifetimes at an interlaboratory comparison

Ito, Kenji*; Oka, Toshitaka*; Kobayashi, Yoshinori*; Shirai, Yasuharu*; Wada, Kenichiro*; Matsumoto, Masataka*; Fujinami, Masanori*; Hirade, Tetsuya; Honda, Yoshihide*; Hosomi, Hiroyuki*; et al.

no journal, , 

An interlaboratory comparison for positron annihilation lifetime measurements for pure nickel, polycarbonate (PC) and fused silica was performed. Based on the reported data of positron (for nickel) and positronium (for PC and fused silica) components, the uncertainties in the PAL measurements were estimated and their possible source was discussed.

Oral presentation

Ion detection efficiency of a tapered microchannnel plate

Matoba, Shiro; Narumi, Kazumasa; Saito, Yuichi; Chiba, Atsuya; Yamada, Keisuke; Kamiya, Tomihiro; Koizumi, Tetsuo*; Takahashi, Karin*; Ishikawa, Manabu*; Moriya, Sosuke*; et al.

no journal, , 

no abstracts in English

Oral presentation

Measurements of ion detection efficiencies of a tapered microchannel-plate with a high open-area-ratio

Matoba, Shiro; Narumi, Kazumasa; Saito, Yuichi; Yamada, Keisuke; Chiba, Atsuya; Koizumi, Tetsuo*; Takahashi, Karin*; Ishikawa, Manabu*; Shiromaru, Haruo*; Kato, Ryoya*; et al.

no journal, , 

no abstracts in English

Oral presentation

Environmental dynamics analysis of $$^{137}$$Cs due to the Fukushima Daiichi Nuclear Power Station accident based on the intercomparison of atmospheric dispersion models

Morino, Yu*; Kitayama, Kyo*; Takigawa, Masayuki*; Nakajima, Teruyuki*; Hayami, Hiroshi*; Nagai, Haruyasu; Terada, Hiroaki; Saito, Kazuo*; Shimbori, Toshiki*; Kajino, Mizuo*; et al.

no journal, , 

For the evaluation of the validity and variability of atmospheric transport model results, we compared results of seven models submitted for the model inter-comparison project of Science Council of Japan to simulate $$^{137}$$Cs released from the Fukushima Daiichi Nuclear Power Plant. Model reproducibility was assessed with the observed hourly atmospheric concentrations of $$^{137}$$Cs in Tohoku and Kanto regions. Among nine plumes from 12 to 21 in March 2011, performance of the models was the best for the plume which dispersed over the Kanto region in 15 March. The models generally reproduced the observed $$^{137}$$Cs concentrations in plumes which widely spread inland of Tohoku or Kanto regions. By contrast, the models largely underestimated the observed $$^{137}$$Cs concentrations for the case which passed coastal areas of Japan. Ensemble average of seven models showed reasonable performance for most of plumes, and no individual models reproduced better than the ensemble average.

22 (Records 1-20 displayed on this page)