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Sanada, Yukihisa; Urabe, Yoshimi*; Misono, Toshiharu; Shiribiki, Takehiko; Nakanishi, Takahiro; Watanabe, Yusuke; Tsuruta, Tadahiko
Scientific Reports (Internet), 11(1), p.23175_1 - 23175_13, 2021/11
Times Cited Count:2 Percentile:13.39(Multidisciplinary Sciences)After the accident at the Fukushima Daiichi Nuclear Power Station (FDNPP) on March 15, 2011, a large amount of volatile radionuclides were released into the atmosphere and hydrosphere. Monitoring of radioactive cesium in sediments is important for assessing the behavior and effects of radioactive cesium in the environment. In this study, the distribution of radioactive cesium in the superficial deposits around FDNPP was visualized as a radioactive cesium map using regular survey data from a towed gamma-ray detection system.
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:21.58(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 Cs results were within 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.
Nakanishi, Chika; Hirayama, Yusuke; Akiyama, Kiyomitsu
Hoken Butsuri, 49(3), p.139 - 144, 2014/09
After the Fukushima Daiichi Nuclear Power Station accident, the Nuclear Emergency Response Guidelines developed by the Nuclear Regulatory Authority of Japan has introduced Operational Intervention Levels (OILs). Particularly, the screening level defined as OIL4 of decontamination against surface contaminations on the skin, clothes and others has adopted, and the default OIL4 value is 13,000 cpm. The count rate value indicated by GM survey meters varies according to the model. Thus, count rates measurements using the same radiation source were performed with four typical GM survey meters in this work, and the instrument efficiencies were compared. In addition, the dependences of the distance between the detector and the source are also evaluated between 1 cm and 5 cm. The screening levels corresponding to OIL4 for each GM survey meter were derived, and the value has 7,000-9,000 cpm from the instrument efficiencies. Count rates were decreased with the increasing distance from the source at the different ratios depending on the model. Then the screening levels at 5 cm between the source and the detector windows showed 3,000-6,000 cpm. This study suggested the importance to evaluate the intrinsic characteristics of the model and to derivate the appropriate screening level at a few centimeters from the screening object to detect contamination reliably.
Sato, Takeshi; Muto, Shigeo; Okuno, Hiroshi; Katagiri, Hiromi; Akiyama, Kiyomitsu; Okamoto, Akiko; Koie, Masahiro; Ikeda, Takeshi; Nemotochi, Toshimasa; Saito, Toru; et al.
JAEA-Review 2013-046, 65 Pages, 2014/02
When a nuclear emergency occurs in Japan, the Japan Atomic Energy Agency (JAEA) has the responsibility of providing technical support to the National government, local governments, police, fire stations and nuclear operators etc., because the JAEA has been designated as the Designated Public Institution under the Basic Act on Disaster Control Measures and the Act on Response to Armed Attack Situations, etc.. The Nuclear Emergency Assistance and Training Center (NEAT) of JAEA provides a comprehensive range of technical support activities to an Off-Site Center in case of a nuclear emergency. Specifically, NEAT gives technical advice and information, dispatches specialists as required, and supplies the National Government and local governments with emergency equipments and materials. NEAT provides various exercise and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response organizations at normal times. The tasks of NEAT, with its past experiences as a designated public institution including the responses to TEPCO's Fukushima Accident, have been shifted to technical supports to the national government for strengthening its abilities to emergency responses; the NEAT therefore focused on maintenance and operation of its functions, and strengthening its response abilities in cooperation with the national government. This annual report summarized these activities of JAEA/NEAT in the fiscal year 2012.
Kinase, Sakae; Washiyama, Koshin*; Shiga, Hideaki*; Taki, Junichi*; Nakanishi, Yusuke*; Koshida, Kichiro*; Miwa, Takaki*; Kinuya, Seigo*; Amano, Ryohei*
KEK Proceedings 2012-7, p.35 - 40, 2012/10
no abstracts in English
Li, T.*; Garg, U.*; Liu, Y.*; Marks, R.*; Nayak, B. K.*; Madhusudhana Rao, P. V.*; Fujiwara, Mamoru*; Hashimoto, Hisanobu*; Nakanishi, Kosuke*; Okumura, Shun*; et al.
Physical Review C, 81(3), p.034309_1 - 034309_11, 2010/03
Times Cited Count:107 Percentile:97.48(Physics, Nuclear)Kinase, Sakae; Washiyama, Koshin*; Shiga, Hideaki*; Taki, Junichi*; Nakanishi, Yusuke*; Koshida, Kichiro*; Miwa, Takaki*; Kinuya, Seigo*; Amano, Ryohei*
no journal, ,
no abstracts in English
Nishihata, Yasuo; Nakanishi, Yusuke*; Sakaue, Kiyoshi*
no journal, ,
no abstracts in English
Lan, Z.*; Yogo, Akifumi*; Mirfayzi, S. R.*; Hayakawa, Takehito*; Koizumi, Mitsuo; Wei, T.*; Shi, B.*; Ishimoto, Takashi*; Golovin, D.*; Mori, Takato*; et al.
no journal, ,
Yogo, Akifumi*; Mirfayzi, S. R.*; Arikawa, Yasunobu*; Abe, Yuki*; Iwamoto, Akihumi*; Hayakawa, Takehito*; Koizumi, Mitsuo; Golovin, D.*; Mori, Takato*; Lan, Z.*; et al.
no journal, ,
no abstracts in English
Noguchi, Marie*; Miyamoto, Tatsuki*; Sugai, Toshihiko*; Nakanishi, Toshimichi*; Komatsu, Tetsuya; Suginaka, Yusuke*; Endo, Kunihiko*
no journal, ,
Discussions on the history of crustal development based on sedimentary facies analysis using the boring cores GC-NG-1, GC-OY-1, and GC-OY-2 in the central Kanto Plain, from the Sarushima Plateau to the Takaragi Plateau, are underway. In the study, paleoenvironmental restoration based on diatom analysis was performed. These core samples are likely to preserve sea-level changes and landing processes since MIS9. From the results of the diatom community analysis, the paleoenvironment in each core was found to change according to the boring site, such as inner bay, brackish water to freshwater, freshwater, lakes, river environment, and land environment. We also attempted to objectively present changes in community composition by cluster analysis of diatom analysis results.
Lan, Z.*; Yogo, Akifumi*; Mirfayzi, S. R.*; Koizumi, Mitsuo; Hayakawa, Takehito*; Arikawa, Yasunobu*; Abe, Yuki*; Golovin, D.*; Mori, Takato*; Wei, T.*; et al.
no journal, ,
Takata, Hyoe*; Otsuki, Azusa*; Sato, Shun*; Otosaka, Shigeyoshi*; Toda, Ryoji*; Nishikawa, Jun*; Kenmochi, Hideyuki*; Ishikura, Mei*; Yamada, Momoka*; Shinkai, Yusuke*; et al.
no journal, ,
Research cruises were conducted by the Shinsei Maru from October 7 to October 17, 2021, and from October 2 to 13, 2022, in the coastal waters off Fukushima Prefecture. Those cruises aimed to monitor radionuclide distribution and to clarify the dynamics of radionuclides in the coastal water and the environmental response of ecosystems after the Fukushima Daiichi Nuclear Power Plant accident in March 2011.