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

Journal Articles

Interaction between caesium iodide particles and gaseous boric acid in a flowing system through a thermal gradient tube (1030 K-450 K) and analysis with ASTEC/SOPHAEROS

Gou$"e$llo, M.*; Hokkinen, M.*; Suzuki, Eriko; Horiguchi, Naoki; Barrachin, M.*; Cousin, F.*

Progress in Nuclear Energy, 138, p.103818_1 - 103818_10, 2021/08

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

The present work aimed to study the transport of caesium iodide particles through a Thermal Gradient Tube (TGT) from 1023 K to 453 K. Retention inside the tube was evaluated for laminar flowrates composed of argon and steam. Higher retention of particles was highlighted for the experiments using higher steam content and lower flowrate. The second phase of the experiment aimed at identifying the possible revaporization or/and resuspension processes after the deposition. Three atmosphere compositions (Ar/H$$_{2}$$O, Ar/H$$_{2}$$ and Ar/Air) were investigated. The particles removed from what was deposited on the surface walls during the sampling phase exhibited a similar GMD in Ar/H$$_{2}$$O and Ar/H$$_{2}$$ and a bigger diameter in Ar/Air. The experimental results were then analysed with the SOPHAEROS module of the ASTEC code. Overall, the results obtained during the first phase were in agreement with the measured experimental results and during second phase led to no resuspension process.

Journal Articles

Radiocaesium accumulation capacity of epiphytic lichens and adjacent barks collected at the perimeter boundary site of the Fukushima Dai-ichi Nuclear Power Station

Dohi, Terumi; Omura, Yoshihito*; Yoshimura, Kazuya; Sasaki, Takayuki*; Fujiwara, Kenso; Kanaizuka, Seiichi*; Nakama, Shigeo; Iijima, Kazuki

PLOS ONE (Internet), 16(5), p.e0251828_1 - e0251828_16, 2021/05

 Times Cited Count:1 Percentile:0(Multidisciplinary Sciences)

Journal Articles

Reservoir sediments as a long-term source of dissolved radiocaesium in water system; a mass balance case study of an artificial reservoir in Fukushima, Japan

Funaki, Hironori; Sakuma, Kazuyuki; Nakanishi, Takahiro; Yoshimura, Kazuya; Katengeza, E. W.*

Science of the Total Environment, 743, p.140668_1 - 140668_9, 2020/11

 Times Cited Count:5 Percentile:39.03(Environmental Sciences)

JAEA Reports

Contribution to risk reduction in decommissioning works by the elucidation of basic property of radioactive microparticles (Contract research); FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; Ibaraki University*

JAEA-Review 2019-041, 71 Pages, 2020/03

JAEA-Review-2019-041.pdf:3.38MB

JAEA/CLADS, has been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") since FY2018. The Project aims at solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. For this purpose, intelligence has been collected from all over the world, and basic research and human resource development have been promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. Among the adopted proposals in FY2018, this report summarizes the research results of the "Contribution to Risk Reduction in Decommissioning Works by the Elucidation of Basic Property of Radioactive Microparticles". In order to establish the decommissioning procedures (recovery of the melted fuels, decontamination inside the reactors, ensuring the safety of the workers, etc.) of the Fukushima Daiichi Nuclear Power Station, radioactive microparticles released by the accident are an important information source for clarifying what had happened inside the reactors in the course of the accident. The purpose of the present study is to obtain detailed knowledge on the basic properties (particle size, composition, electrical/optical properties, etc.) of the radioactive microparticles, as well as to further elucidate the various properties of the radioactive microparticles including the quantitative evaluation of alpha-ray-emitters, through the Japan-UK synergetic research. Thus, we are conducting research and development that will contribute to the comprehensive works towards the risk reduction in the "decommissioning" plan.

JAEA Reports

Separation of radiocaesium-bearing micro particle from environmental samples; Application to litter samples

Tagomori, Hisaya; Dohi, Terumi; Ishii, Yasuo; Kanaizuka, Seiichi*; Fujiwara, Kenso; Iijima, Kazuki

JAEA-Technology 2019-001, 37 Pages, 2019/03

JAEA-Technology-2019-001.pdf:26.85MB

An efficient methodology for separating the radiocaesium-bearing micro particles (CsMPs) released by the TEPCO's Fukushima Dai-ichi Nuclear Power Station accident is required to investigate their spatial distribution and physicochemical properties. In this report we developed an efficiency separation method for CsMP from litters since the radiocaesium in litter may affect the radiocaesium cycling in forest ecosystem. One CsMP separation from litter containing lots of soil particles was attained within three days using electron microscopic analysis with digestion treatment of organic matter. This methodology is expected as CsMPs efficient separation method for not only forest floor litter but also barks and leaves of living tree, and other organic materials in the forested environment.

Journal Articles

Decreasing trend of ambient dose equivalent rates over a wide area in eastern Japan until 2016 evaluated by car-borne surveys using KURAMA systems

Ando, Masaki; Mikami, Satoshi; Tsuda, Shuichi; Yoshida, Tadayoshi; Matsuda, Norihiro; Saito, Kimiaki

Journal of Environmental Radioactivity, 192, p.385 - 398, 2018/12

 Times Cited Count:10 Percentile:55.61(Environmental Sciences)

Car-borne surveys using KURAMA systems have been conducted over a wide area in eastern Japan since 2011. The measurement data collected until 2016 was analyzed, and decreasing trend of the dose rates in regions within 80 km of Fukushima Dai-ichi Nuclear Power Plant were examined. The averaged dose rates tended to decrease considerably with respect to the physical decay of radiocaesium, and the ecological half-lives of the fast and slow decay components were estimated. The decrease of the dose rate in the forest was slower than its decrease in other regions, and the decrease of the dose rate in urban area was the fastest. The decrease in the dose rates obtained via the car-borne survey was larger than that obtained on flat ground with few disturbances using survey meters approximately 1.5 y after the accident; hereafter, the decrease in the dose rates obtained via the car-borne survey was same as the latter measurement.

Journal Articles

Synthesis and characterization of CeO$$_{2}$$-based simulated fuel containing CsI

Takamatsu, Yuki*; Ishii, Hiroto*; Oishi, Yuji*; Muta, Hiroaki*; Yamanaka, Shinsuke*; Suzuki, Eriko; Nakajima, Kunihisa; Miwa, Shuhei; Osaka, Masahiko; Kurosaki, Ken*

Nihon Genshiryoku Gakkai Wabun Rombunshi, 17(3/4), p.106 - 110, 2018/12

In order to establish the synthesis method of simulated fuel contacting Cesium (Cs) which is required for the evaluation of physical/chemical characteristics in fuel and release behavior of Cs, sintering tests of the cerium dioxide (CeO$$_{2}$$) based simulated fuels containing Cesium iodide (CsI) are performed by using spark plasma sintering (SPS) method. The sintered CeO$$_{2}$$ pellets with homogeneous distribution of several micro meter of CsI spherical precipitates were successfully obtained by optimizing SPS conditions.

Journal Articles

Towards enhancing Fukushima environmental resilience

Miyahara, Kaname

Transactions of the American Nuclear Society, 117(1), p.51 - 52, 2017/10

This presentation highlights JAEA's challenges for contributing to recovering the previous life of residents and the development of resilient communities in Fukushima Prefecture based on considering needs of local people on the environmental restoration categorized by the state of evacuation orders and the lifting of such orders.

Journal Articles

Implementation of decontamination technologies appropriate to Japanese boundary conditions

Kawase, Keiichi

Global Environmental Research (Internet), 20(1&2), p.83 - 90, 2017/03

Major challenges to implementing full-scale environmental decontamination were the absence of real-world examples and also lack of experience in planning and implementing decontamination technology appropriate to the physical and social boundary conditions in both Japan and Fukushima. The Japan Atomic Energy Agency was thus charged with conducting a range of Decontamination Pilot Project to examine the applicability of decontamination technologies, with a special focus on reducing dose rates and thus allowing evacuees to return to re-establish their normal lifestyles as quickly as possible, whilst simultaneously maintaining worker safety. In this report, re-edit the report of the Decontamination Pilot Project (Nakayama et al.,2014), do the commentary for the decontamination technology.

Journal Articles

Temporal changes of radiocesium in irrigated paddy fields and its accumulation in rice plants in Fukushima

Yang, B.*; Onda, Yuichi*; Wakiyama, Yoshifumi*; Yoshimura, Kazuya; Sekimoto, Hitoshi*; Ha, Y.*

Environmental Pollution, 208(Part B), p.562 - 570, 2016/01

 Times Cited Count:12 Percentile:49.59(Environmental Sciences)

Journal Articles

Behavior of accidentally released radiocesium in soil-water environment; Looking at Fukushima from a Chernobyl perspective

Konoplev, A.*; Golosov, V.*; Laptev, G.*; Namba, Kenji*; Onda, Yuichi*; Takase, Tsugiko*; Wakiyama, Yoshifumi*; Yoshimura, Kazuya

Journal of Environmental Radioactivity, 151(Part 3), p.568 - 578, 2016/01

 Times Cited Count:56 Percentile:93.46(Environmental Sciences)

Journal Articles

Fukushima cleanup; Status and lessons

Miyahara, Kaname; McKinley, I. G.*; Saito, Kimiaki; Iijima, Kazuki; Hardie, S. M. L.*

Nuclear Engineering International, 60(736), p.12 - 14, 2015/11

Remediation work in Fukushima is based on a comprehensive technical knowledge base, which is translated into actions that enable the rapid return of evacuees but also provides a globally valuable resource for disaster planning and contaminated site remediation.

Journal Articles

Radiocaesium activity concentrations in parmelioid lichens within a 60 km radius of the Fukushima Dai-ichi Nuclear Power Plant

Dohi, Terumi; Omura, Yoshihito*; Kashiwadani, Hiroyuki*; Fujiwara, Kenso; Sakamoto, Yoshiaki; Iijima, Kazuki

Journal of Environmental Radioactivity, 146, p.125 - 133, 2015/08

 Times Cited Count:13 Percentile:48.04(Environmental Sciences)

Radiocaesium activity concentrations ($$^{134}$$Cs, $$^{137}$$Cs) were measured in parmelioid lichens collected within the Fukushima Prefecture approximately 2 y after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. A total of 44 samples consisting of nine species were collected at 16 points within a 60 km radius of the FDNPP. The activity concentration of $$^{134}$$Cs ranged from 4.6 to 1000 kBq kg$$^{-1}$$ and for $$^{137}$$Cs ranged from 7.6 to 1740 kBq kg$$^{-1}$$. A significant positive correlation was found between the $$^{137}$$Cs activity concentration in lichens and the $$^{137}$$Cs deposition density on soil, based on the calculated Spearman's rank correlation coefficients as $$r$$ = 0.90 ($$P$$ $$<$$ 0.01). The two dominant species, Flavoparmelia caperata and Parmotrema clavuliferum, showed strong positive correlations, for which the r values were calculated as 0.92 ($$P$$ $$<$$ 0.01) and 0.90 ($$P$$ $$<$$ 0.01) respectively. Therefore, they are suggested as biomonitoring species for levels of radiocaesium fallout within the Fukushima Prefecture.

JAEA Reports

Remediation of contaminated areas in the aftermath of the accident at the Fukushima Daiichi Nuclear Power Station; Overview, analysis and lessons learned, 2; Recent developments, supporting R&D and international discussions

Fukushima Environmental Safety Center, Sector of Fukushima Research and Development

JAEA-Review 2014-052, 49 Pages, 2015/03

JAEA-Review-2014-052.pdf:25.4MB

The Japan Atomic Energy Agency (JAEA) was charged with conducting a range of "Decontamination Pilot Project" to examine the applicability of decontamination technologies. The project was implemented at 16 sites in 11 municipalities within the evacuated zone. Despite tight boundary conditions in terms of timescale and resources, the project provides a good basis for developing recommendations on how to assure decontamination efficiency and worker safety whilst additionally constraining costs, subsequent waste management and environmental impacts. This report, based on the Japanese detailed reports that have been published elsewhere, consists of two volumes. The volume 1 summarises the Decontamination Pilot Project, providing the background required to put this work in context for an international audience. In this volume 2, the subsequent application of output from these projects to regional remediation now being conducted by the Japanese government and municipalities, is discussed, along with a status update on such work, an overview of associated JAEA's R&D and international input to/review of regional environmental decontamination in Fukushima.

JAEA Reports

Remediation of contaminated areas in the aftermath of the accident at the Fukushima Daiichi Nuclear Power Station: Overview, analysis and lessons learned, 1; A report on the "decontamination pilot project"

Fukushima Environmental Safety Center, Sector of Fukushima Research and Development

JAEA-Review 2014-051, 121 Pages, 2015/03

JAEA-Review-2014-051.pdf:64.45MB

The Japan Atomic Energy Agency (JAEA) was charged with conducting a range of "Decontamination Pilot Project" to examine the applicability of decontamination technologies. The project was implemented at 16 sites in 11 municipalities within the evacuated zone. Despite tight boundary conditions in terms of timescale and resources, the project provides a good basis for developing recommendations on how to assure decontamination efficiency and worker safety whilst additionally constraining costs, subsequent waste management and environmental impacts. This report, based on the Japanese detailed reports that have been published elsewhere, consists of two volumes. This volume 1 summarises the Decontamination Pilot Project, providing the background required to put this work in context for an international audience. In volume 2, the subsequent application of output from these projects to regional remediation now being conducted by the Japanese government and municipalities, is discussed, along with a status update on such work, an overview of associated JAEA's R&D and international input to/review of regional environmental decontamination in Fukushima.

Journal Articles

The Resonance raman effect of dicaesium uranyl tetrachloride in dimethyl sulfoxide

Soga, Takeshi

Spectrochimica Acta, Part A, 57(9), p.1767 - 1780, 2001/08

no abstracts in English

JAEA Reports

Conversion and modification of the MLSOIL and DFSOIL codes

Togawa, Orihiko

JAERI-Data/Code 95-009, 35 Pages, 1995/07

JAERI-Data-Code-95-009.pdf:1.43MB

no abstracts in English

Oral presentation

Transport behavior of radioactive caesium from forests contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident through river water system

Iijima, Kazuki; Funaki, Hironori; Oyama, Takuya; Niizato, Tadafumi; Sato, Haruo*; Yui, Mikazu

no journal, , 

Goal of the project is to develop mechanistic models to predict transport behavior of radioelements strongly adsorbed on soil particles from forests to sea through river systems, evaluate evolution of dose, and propose methods to constrain the transport. This study overviewed the behavior of radioactive caesium through one of the river systems in the coastal area of Fukushima. Concequently, caesium is considered to be strongly adsorbed on the soil particles in the transport through the river water system since more than 90% of caesium has still remained within 5 cm from the surface of topsoil in the forest, and the concentration of caesium in the lake water was extremely low. The difference of concentrations of caesium in the sediments in the river water system can be explained by the effect of particle size on the adsorption site density of caesium.

Oral presentation

Cs$$_{2}$$O and ZrO$$_{2}$$ containing Cr$$_{2}$$O$$_{3}$$-CoO-Al$$_{2}$$O$$_{3}$$-Fe$$_{2}$$O$$_{3}$$-P$$_{2}$$O$$_{5}$$ glasses

Yano, Tetsuji*; Kishi, Tetsuo*; Nakata, Yoshiyuki*; Kofuji, Hirohide; Takeuchi, Masayuki

no journal, , 

Oral presentation

Challenges for Fukushima environmental recovery

Miyahara, Kaname

no journal, , 

Remediation work at Fukushima enables the return of evacuees and provides a valuable resource for disaster planning and contaminated site remediation.

24 (Records 1-20 displayed on this page)