Japan Chemical Analysis Center

Ibaraki, Japan

Japan Chemical Analysis Center

Ibaraki, Japan
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PubMed | Institute For Hygiene Und Umwelt, National Water Research Institute, Servicio de Radioisotopos, Physikalische Chemie and 23 more.
Type: | Journal: Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine | Year: 2016

The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training.

PubMed | Chinese Ministry of Environmental Protection, Japan Chemical Analysis Center, Chinese National Institute for Radiological Protection and Hospital for Occupational Diseases Control of Shenzhen City
Type: | Journal: Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine | Year: 2015

An intercomparison of -spectrometry measurement and analysis was organized by the Japan Chemical Analysis Center (JCAC), the National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention (NIRP, China CDC), and the Radiation Monitoring Technical Center of Ministry of Environmental Protection, Chinese (RMTC). The main objective of this study was to assess the -spectrometry measurement and analysis technology. The JCAC completed the collection and preparation of soil and powdered rice samples. Three laboratories compared the measurement of seven radionuclides that included two samples of (214)Pb, (214)Bi, (208)Tl, (228)Ac, (40)K, (137)Cs, and (134)Cs with -spectrometry. During the studies conducted at the laboratory, the calculated value En was found to be the total uncertainty data of the reported activity. Except (134)Cs in powdered rice sample, the calculated En between each of the two laboratories was <1. The measurement results are acceptable except (134)Cs; therefore, measurement results in the three laboratories were consistent within a certain range except in the case of (134)Cs. Although there is a need to improve the accuracy of measurements and analysis of (134)Cs, an intercomparison was conducted of the tested levels on radionuclide analyzed in the three laboratories.

Bamba S.,Japan Chemical Analysis Center | Bamba S.,Toho University | Yamaguchi K.E.,Toho University | Amano H.,Japan Chemical Analysis Center | Amano H.,Toho University
Journal of Radioanalytical and Nuclear Chemistry | Year: 2014

A method that combines solid extraction with accelerator mass spectrometry was applied to determine 129I in terrestrial environmental water samples. To validate the method, water samples were spiked with diluted NIST SRM 3231 129I isotopic standard (high level). Then 129I/ 127I ratios in river and pond waters in Fukushima and Ibaraki prefectures were measured in samples obtained both before and after the Fukushima Daiichi nuclear power plant accident caused by the great earthquake and tsunami of 11 March 2011. Before the accident, 129I/ 127I was 1.1-3.5 × 10-9 in the river waters and 6.0-6.6 × 10-9 in the pond waters, and afterwards it was 3.3-8.4 × 10-9 in the river waters and 3.7-6.5 × 10 -8 in the pond waters, reflecting the large amounts of radionuclides that were released into the environment by the accident. In the samples collected in April 2011, 129I/127I ratios were about one order of magnitude larger in pond water, and several times higher in river water, compared with the samples collected before the accident. © 2014 Akadémiai Kiadó.

Nitta W.,Japan Chemical Analysis Center | Sanada T.,Japan Chemical Analysis Center | Isogai K.,Japan Chemical Analysis Center | Schlosser C.,Federal office for Radiation Protection
Journal of Nuclear Science and Technology | Year: 2014

Atmospheric 85Kr and 133Xe activity concentrations were determined from weekly air samples collected at Sapporo, Akita and Chiba, Japan, throughout 2011. The results demonstrated that the Fukushima Dai-ichi Nuclear Power Plant accident in early March 2011 resulted in high 133Xe activity concentrations as well as elevated levels of 85Kr activity; there was a striking increase in the concentrations of both isotopes over the week running from 14 to 22 March as the radioactive plume released from the plant was captured. At Chiba, following the accident, the 85Kr activity concentration increased from 1.38 to 17.7 Bq/m 3, while the 133Xe levels increased from below the minimum detectable concentration (MDC ≤ 1.9 × 10-3 Bq/m 3) to 1.3 × 103 Bq/m3. Conversely, at Sapporo and Akita, high 85Kr activity concentrations were not observed, due to differences in air transportation mechanisms based on wind directions. Duplicate samples were collected at Chiba to allow the simultaneous analyses of 85Kr and 133Xe at the Japan Chemical Analysis Center and the Bundesamt für Strahlenschutz in Germany and the results were in good agreement. The external effective radiation doses resulting from 85Kr and 133Xe releases following the accident were estimated to be approximately 7.0 × 10-3 and 1.3 Sv, respectively, based on the activity concentrations of these nuclides from March to June in 2011 at Chiba. © 2014 © 2014 Atomic Energy Society of Japan. All rights reserved.

Koarashi J.,Japan Atomic Energy Agency | Atarashi-Andoh M.,Japan Atomic Energy Agency | Amano H.,Japan Chemical Analysis Center | Matsunaga T.,Japan Atomic Energy Agency
Journal of Radioanalytical and Nuclear Chemistry | Year: 2016

Vertical distributions of global fallout 137Cs and 14C were investigated in a Japanese forest soil in 2001. Even 38 years after the fallout, 137Cs was still observed mostly in the uppermost 5 cm. A preferential accumulation of 137Cs was found in a 1-cm-thick transition layer between organic-rich A and underlying B horizons. This unique observation indicated that 137Cs migrated through the A horizon at a rate of 0.20 % year−1 and the transition layer acted as a barrier for 137Cs migration to deeper layers. The vertical distributions of 137Cs and 14C were significantly correlated, suggesting a coupled downward migration of 137Cs and organic matter on a time scale of decades, along the same physical pathways. © 2016 Akadémiai Kiadó, Budapest, Hungary

Ishimori K.-I.,Japan Atomic Energy Agency | Kameo Y.,Japan Atomic Energy Agency | Matsue H.,Japan Atomic Energy Agency | Ohki Y.,Japan Chemical Analysis Center | And 2 more authors.
Applied Radiation and Isotopes | Year: 2011

In order to establish a simple and rapid analytical method for 14C in solidified products made from non-metallic low-level radioactive solid wastes such as concrete, mortar and glass by melting treatment, a radiochemical analysis in combination with alkaline fusion as a sample decomposition method was examined. A simulated solidified product containing 14C, which was prepared by using nuclear reaction 14N(n, p)14C with thermal neutron irradiation, was analyzed by the present method to compare with a conventional radiochemical analysis using oxidizing combustion. The reproducible and quantitative recovery of 14C from the simulated solidified product indicates that the present method is more efficient for 14C analysis in solidified products than the conventional method using oxidizing combustion. © 2010 Elsevier Ltd.

Tanaka T.,Japan Atomic Energy Agency | Otosaka S.,Japan Atomic Energy Agency | Wakita M.,Japan Agency for Marine - Earth Science and Technology | Amano H.,Japan Chemical Analysis Center | Togawa O.,Japan Atomic Energy Agency
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2010

Radiocarbon in dissolved organic matter in seawater gives information on the dynamics and origin of the dissolved organic matter. Here, we present the vertical profile of Δ14C of dissolved organic carbon in the western North Pacific Ocean. The profile was almost parallel to that for Δ14C of dissolved inorganic carbon, indicating that the time scale of seawater circulation was the main influence on the Δ14C signature of dissolved organic carbon. On the basis of the Δ14C differences between dissolved organic carbon and dissolved inorganic carbon, and a comparison with Δ14C of dissolved organic carbon in the central North Pacific Ocean, we suggest that there may be a source of younger dissolved organic carbon in the western North Pacific Ocean. © 2009 Elsevier B.V. All rights reserved.

Uesugi M.,Kanazawa University | Noguchi M.,Japan Chemical Analysis Center | Yokoyama A.,Kanazawa University | Nakanishi T.,Kanazawa University
Journal of Radioanalytical and Nuclear Chemistry | Year: 2010

An improved method is proposed to determine the content of 210Pb in lead using 210Po measured by alpha-ray spectrometry. This improved method, which is based on radiochemical separation by DDTC-toluene extraction, employs EDTA and citrate as masking reagents for the lead ions. To selectively extract polonium from an alkaline solution, the pH dependency was examined using a liquid scintillation counting method. And pH 9 was chosen as an extraction condition. Then 210Po was electrodeposited on a stainless steel disk, and the chemical recovery was followed by 209Po tracer. The effectiveness of the new method was validated by the agreement with the analytical results from five samples as determined by gamma-ray spectrometry. © 2010 Akadémiai Kiadó, Budapest, Hungary.

Nagaoka K.,Japan Chemical Analysis Center | Sato S.,Japan Chemical Analysis Center | Araki S.,Japan Chemical Analysis Center | Ohta Y.,Japan Chemical Analysis Center | Ikeuchi Y.,Japan Chemical Analysis Center
Health Physics | Year: 2012

Damage to the Fukushima nuclear power plant caused by the 11 March 2011 earthquake and tsunami off the northeast coast of Japan resulted in the release into the environment of radioactive material. Airborne radioactive material was detected in metropolitan areas near Tokyo, and increases in radiation dose rate were observed at many locations. In this study, repeated measurements with the in situ Ge system were performed in Chiba City, which is about 220 km south of Fukushima. Increases in radiation dose rate were recorded on 15, 16, and 21 March, with a maximum of 0.5 μGy h. This level is clearly higher than natural background in Japan. Airborne 99Mo, 99mTc, 129mTe, 129Te, 132Te, 131I, 132I, 133I, 133Xe, 133mXe, 135Xe, 134Cs, 136Cs, 137Cs, and 140La were detected. Environmental radioactive contamination in the metropolitan area occurred mainly on 21 March by rainfall. The initial rates of decrease in radiation dose rate generally reflected radiological decay according to their physical (radiological) half-lives. However, the in situ half-lives of the long-lived radionuclides such as 134Cs and 137Cs reflected environmental dispersal rather than radiological decay. Copyright © 2012 Health Physics Society.

Amano H.,Japan Chemical Analysis Center | Akiyama M.,Japan Chemical Analysis Center | Chunlei B.,Japan Chemical Analysis Center | Kawamura T.,Japan Chemical Analysis Center | And 8 more authors.
Journal of Environmental Radioactivity | Year: 2012

Large amounts of radioactive substances were released into the environment from the Fukushima Dai-ichi Nuclear Power Plants in eastern Japan as a consequence of the great earthquake (M 9.0) and tsunami of 11 March 2011. Radioactive substances discharged into the atmosphere first reached the Chiba Metropolitan Area on 15 March. We collected daily samples of air, fallout deposition, and tap water starting directly after the incident and measured their radioactivity. During the first two months maximum daily concentrations of airborne radionuclides observed at the Japan Chemical Analysis Center in the Chiba Metropolitan Area were as follows: 4.7 × 10 1 Bq m -3 of 131I, 7.5 Bq m -3 of 137Cs, and 6.1 Bq m -3 of 134Cs. The ratio of gaseous iodine to total iodine ranged from 5.2 × 10 -1 to 7.1 × 10 -1. Observed deposition rate maxima were as follows: 1.7 × 10 4 Bq m -2 d -1 of 131I, 2.9 × 10 3 Bq m -2 d -1 of 137Cs, and 2.9 × 10 3 Bq m -2 d -1 of 134Cs. The deposition velocities (ratio of deposition rate to concentration) of cesium radionuclides and 131I were detectably different. Radioactivity in tap water caused by the accident was detected several days after detection of radioactivity in fallout in the area. Radiation doses were estimated from external radiation and internal radiation by inhalation and ingestion of tap water for people living outdoor in the Chiba Metropolitan Area following the Fukushima accident. © 2011 Elsevier Ltd.

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