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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.

Journal Articles

Repeatability and reproducibility of measurements of low dissolved radiocesium concentrations in freshwater using different pre-concentration methods

Kurihara, Momo*; Yasutaka, Tetsuo*; Aono, Tatsuo*; Ashikawa, Nobuo*; Ebina, Hiroyuki*; Iijima, Takeshi*; Ishimaru, Kei*; Kanai, Ramon*; Karube, Jinichi*; Konnai, Yae*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 322(2), p.477 - 485, 2019/11

 Times Cited Count:2 Percentile:21.95(Chemistry, Analytical)

We assessed the repeatability and reproducibility of methods for determining low dissolved radiocesium concentrations in freshwater in Fukushima. Twenty-one laboratories pre-concentrated three of 10 L samples by five different pre-concentration methods (prussian-blue-impregnated filter cartridges, coprecipitation with ammonium phosphomolybdate, evaporation, solid-phase extraction disks, and ion-exchange resin columns), and activity of radiocesium was measured. The z-scores for all of the $$^{137}$$Cs results were within $$pm$$2, indicating that the methods were accurate. The relative standard deviations (RSDs) indicating the variability in the results from different laboratories were larger than the RSDs indicating the variability in the results from each separate laboratory.

Journal Articles

Electron microscopic analysis of radiocaesium-bearing microparticles in lichens collected within 3 km of the Fukushima Dai-ichi Nuclear Power Plant

Dohi, Terumi; Tagomori, Hisaya; Omura, Yoshihito*; Fujiwara, Kenso; Kanaizuka, Seiichi*; Iijima, Kazuki

Environmental Radiochemical Analysis VI, p.58 - 70, 2019/09

In this study we established a separation method for radiocaesium-bearing microparticles (CsMPs) from lichens using electron microscopic analysis. Lichens were first digested within hydrogen peroxide and then an automatic particle analyser system based on FE-EPMA was used for detecting CsMPs within lots of mineral-like and metallic particles quickly. The elemental composition and radiocaesium activities of the separated CsMPs were measured, and the results show that the digestion treatment did not influence the CsMPs characteristics. An inhomogeneous elemental distribution was found in some CsMPs by two-dimensional elemental analysis using FE-EMPA. Our methods for separation of CsMPs and analysing their elemental composition are expected to be useful for grasping the chemical composition trends of CsMPs statistically.

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.

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

None

; Jinno, Kenji*; Saeki, Kazutoshi*; *; *; Tagomori, Hisaya*

Sui Kogaku Rombunshu, 46, p.205 - 210, 2002/00

None

Oral presentation

Examination of the isolation method of the radioactive microparticles in the environmental sample

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

no journal, , 

In order to evaluate the chemical form and distribution of radionuclide in soil and litter near the Fukushima Daiichi Nuclear Power Plant, method for isolating radioactive particles were carried out. Main procedures for isolating radioactive particles are as follows; After drying and size classification, samples are decomposed with hydrogen peroxide. And then, IP method is carried out to monitor the distribution of radionuclide. A portion showing high radiation is selected as microscopic analysis which composed of Field Emission-Electron Prove Micro-Analyzer (FE-EPMA) and Energy-Dispersive X-ray Spectroscopy (EDS). As results of above method, several particles with unique elemental compositions such as Ba was identified. Moreover, methods for isolating particles of 100 - 200 um using the Micro Manipulator were established. The isolation of fine particles (less than 50 um), were also applied by the meaning of digging a trench on the carbon tape using Focused Ion Beam (FIB).

Oral presentation

Origin of atmospheric particle matter captured near at the location where Namie-city forest fire has occurred

Ishii, Yasuo; Muto, Kotomi; Hagiwara, Hiroki; Ito, Shoichi*; Takahashi, Makoto*; Tagomori, Hisaya; Dohi, Terumi; Kitamura, Akihiro

no journal, , 

A forest fire broke out on 29 April, 2017 in the Mount-Juman that straddles the Namie-city and Futaba-city in Fukushima Prefecture. The fire was extinguished on 10 May, 2017. In this period, atmospheric particle matters have been collected by Radiation Monitoring Unit Fukushima Prefectural Government in neighboring region. In this study we performed chemical analysis of the atmospheric particle matters and investigated the origination.

Oral presentation

Estimation of on-site radionuclides inventories of Fukushima Daiichi NPS based on their off-site distribution, 5; Elemental compositions of the particles in lichens collected around the Fukushima Daiichi NPS

Dohi, Terumi; Tagomori, Hisaya; Omura, Yoshihito*; Kanaizuka, Seiichi*; Fujiwara, Kenso; Iijima, Kazuki

no journal, , 

no abstracts in English

Oral presentation

Retention of radiocaesium particle in Parmelioid lichens

Dohi, Terumi; Fujiwara, Kenso; Omura, Yoshihito*; Tagomori, Hisaya*; Iijima, Kazuki; Kitamura, Akihiro

no journal, , 

Oral presentation

Development of pretreatment and analysis for environmental samples containing radiocaesium; Preliminary ToF-SIMS analysis of Cs isotope ratio in the microparticle

Tagomori, Hisaya*; Kawamura, Hidehisa*; Kusano, keiichi*; Dohi, Terumi

no journal, , 

To investigate their spatial distribution and physicochemical properties of the radiocaesium-bearing micro particles (CsMPs), an efficient methodology for determine and analysis them is required. Here we focused on CsMPs from litters as they may affect the radiocaesium cycling in forest ecosystem. In this study we developed a method to determine CsMPs (mostly 1-10 $$mu$$m sizes) from litters by combine digestion treatment and automatic particle analysis with FE-EPMA. In total it took up to 3 days for detecting one CsMP from huge amounts of mineral-like and metallic particles. In the ToF-SIMS analysis for Cs isotope ratios of CsMPs to understand their emission source as the next step, pretreatment for easily detecting micron-sized samples is needed. To solve this problem, FIB technique was used for Gallium marking formation around target sample. Preliminary Cs isotope ratios(133Cs, 134(Cs + Ba), 135Cs, 137(Cs + Ba)) and their distributions of CsMPs were determined by applying these approaches. We developed pretreatment for microscopy and ToF-SIMS analysis of CsMPs.

Oral presentation

High-speed chemical analysis of nano-particle using inductively coupled plasma time-of-flight mass spectrometer

Horikoshi, Ko*; Numa, Rinka*; Tagomori, Hisaya*; Ito, Satomi; Takahashi, Hiroaki*; Hirata, Takafumi*

no journal, , 

no abstracts in English

Oral presentation

Preliminary study of isotopic ratio of $$^{135}$$Cs/$$^{133}$$Cs for micron sized particle by ToF-SIMS

Tagomori, Hisaya*; Kawamura, Hidehisa*; Kusano, keiichi*; Dohi, Terumi; Fujiwara, Kenso

no journal, , 

no abstracts in English

Oral presentation

Influence of humification on radiocesium elution from contaminated litter to water phase

Terashima, Motoki; Tagomori, Hisaya*; Sasaki, Yoshito

no journal, , 

no abstracts in English

Oral presentation

Chemical equilibrium modelling of radiocesium elution from contaminated litter and its humus into water phase

Terashima, Motoki; Tagomori, Hisaya*; Watanabe, Yusuke; Sasaki, Yoshito

no journal, , 

Oral presentation

Application of NICA-Donnan model for radiocesium elution from forest A0 layer into water phase

Terashima, Motoki; Sasaki, Yoshito; Tagomori, Hisaya*; Watanabe, Yusuke

no journal, , 

no abstracts in English

16 (Records 1-16 displayed on this page)
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