Tritium concentration in monthly precipitation in Okinawa and Kagoshima, southern Japan

Naofumi Akata, Kaho Ohno, Haruka Kuwata, Khemruthai Kheamsiri, Yukiko Yoshinaka, Ryohei Yamada, Yuisa Kitayama, Sana Aizawa, Shunya Nakasone, Akinobu Ishimine, Masahiro Tanaka, Yoshitaka Shiroma, Shinji Tokonami, Masahide Furukawa

Radiation Protection Dosimetry   200 ( 16-18 )   1792 - 1796   2024.11

Evaluation of combustion system for organically bound tritium analysis using dried fish samples

Haruka Kuwata, Ryohei Yamada, Khemruthai Kheamsiri, Hideki Kakiuchi, Toshiya Tamari, Nagayoshi Shima, Naofumi Akata

Radiation Protection Dosimetry   200 ( 16-18 )   1807 - 1812   2024.11

Effect of sampling face velocity on the ultrafine particle surface collection efficiency of a cellulose membrane filter and a cellulose-glass fiber filter for environmental airborne radioactivity monitoring

Mizuki Kiso, Manaya Taoka, Aoi Sampei, Hiroki Hashimoto, Yuki Abe, Yuki Oda, Yasutaka Omori, Ryohei Yamada, Masahiro Hosoda, Chutima Kranrod, Tetsuo Ishikawa, Shinji Tokonami

Radiation Protection Dosimetry   200 ( 16-18 )   1671 - 1675   2024.11

Characteristics of tritium, stable isotopes and chemical components in monthly precipitation at Hiroshima, Japan

Ryohei Yamada, Haruka Kuwata, Khemruthai Kheamsiri, Kaho Ohno, Yuisa Kitayama, Yukiko Yoshinaka, Shinji Yoshinaga, Naoyuki Kurita, Naofumi Akata

Radiation Protection Dosimetry   200 ( 16-18 )   1797 - 1801   2024.11

Behavior of radioactive cesium concentration for 13 years after FDNPP accident at Koriyama campus of Nihon University, Fukushima, Japan

Ryoko Suzuki, Katsuhiko Okuyama, Kohei Chiba, Taiki Hashimoto, Natsumi Katsumata, Azusa Ukitsu, Khemruthai Kheamsiri, Ryohei Yamada, Naofumi Akata

Radiation Protection Dosimetry   200 ( 16-18 )   1835 - 1839   2024.11

Performance Test of Improved Commercially Available Tritium Enrichment System: Toward Rapid and High Efficiency Enrichment

Akata Naofumi, Okada Kazusa, Otashiro Nao, Kuwata Haruka, Kheamsiri Khemruthai, Ohno Kaho, Yoshinaka Yukiko, Yamada Ryohei, Tanaka Masahiro

Radiation Environment and Medicine   13 ( 2 )   60 - 64   2024.8

Tissue-free water tritium and non-exchangeable organically bound tritium concentrations in fish near coastline during and after operation of Japan's first nuclear fuel reprocessing facility

Naofumi Akata, Donovan Anderson, Hideki Kakiuchi, Ryohei Yamada, Hidenao Hasegawa, Shinji Ueda

Science of The Total Environment   947   174404 - 174404   2024.7

Tritium concentration in bottled drinking water and internal dose assessment

Khemruthai Kheamsiri, Naofumi Akata, Haruka Kuwata, Masahiro Tanaka, Masahiro Hosoda, Michiya Sasaki, Yoshitaka Shiroma, Shinji Tokonami, Ryohei Yamada, Chutima Kranrod, Kazuki Iwaoka, Tibor Kovάcs

Journal of Radioanalytical and Nuclear Chemistry   333 ( 5 )   2597 - 2603   2024.5

Changes in Particulate Matter (PM2.5 and PM10) Concentrations and Ambient Dose Equivalent Rates at Different Altitudes in Chiang Mai, Thailand

Kranrod Chutima, Thumvijit Tarika, Yamada Ryohei, Poltabtim Worawat, Kiso Mizuki, Sriburee Sompong, Somboon Siriprapa, Ruktinnakorn Kewalin, Tokonami Shinji

Radiation Environment and Medicine   13 ( 1 )   28 - 34   2024.2

Temporal variation of tritium concentration in monthly precipitation collected at a Difficult-to-Return Zone in Namie Town, Fukushima Prefecture, Japan

Ryohei Yamada, Hidenao Hasegawa, Naofumi Akata, Hideki Kakiuchi, Shinya Ochiai, Haruka Kuwata, Khemruthai Kheamsiri, Shinji Tokonami, Shinji Ueda

Environmental Science and Pollution Research   31 ( 5 )   7818 - 7827   2024.1

Calibration experiments for radon in drinking water measurements using portable-type electrostatic-collection radon monitors

Masahiro Hosoda, Yasutaka Omori, Hiroki Hashimoto, Maho Matsumoto, Yumi Yasuoka, Tetsuya Sanada, Yuki Oda, Mizuki Kiso, Aoi Sampei, Chutima Kranrod, Hirofumi Tazoe, Naofumi Akata, Yasuyuki Taira, Yuki Tamakuma, Ryohei Yamada, Hiromi Kudo, Mayumi Shimizu, Shinji Tokonami

Radiation Protection Dosimetry   199 ( 18 )   2203 - 2206   2023.11

Tritium Concentration in Natural Spring Water Collected at Hirosaki, Japan

AKATA Naofumi, OKADA Kazusa, KUWATA Haruka, KHEAMSIRI Khmruthai, HOSODA Masahiro, TAZOE Hirofumi, YASUHARA Ryo, SUGIHARA Shinji, YAMADA Ryohei, TANAKA Masahiro

Plasma and Fusion Research   18 ( 0 )   2405030 - 2405030   2023.4

INFLUENCE OF SAMPLING FLOW RATE ON THORON EXHALATION RATE MEASUREMENTS BY THE CIRCULATION METHOD

Masahiro Hosoda, Ryohei Yamada, Hiromu Kobyashi, Yuki Tamakuma, Eka Djatnika Nugraha, Hiroki Hashimoto, Ryoju Negami, Chutima Kranrod, Yasutaka Omori, Hirofumi Tazoe, Naofumi Akata, Shinji Tokonami

Radiation Protection Dosimetry   198 ( 13-15 )   904 - 908   2022.9

222Rn and 226Ra Concentrations in Spring Water and Their Dose Assessment Due to Ingestion Intake

Ryohei Yamada, Masahiro Hosoda, Tomomi Tabe, Yuki Tamakuma, Takahito Suzuki, Kevin Kelleher, Takakiyo Tsujiguchi, Yoshiki Tateyama, Eka Djatnika Nugraha, Anna Okano, Yuki Narumi, Chutima Kranrod, Hirofumi Tazoe, Kazuki Iwaoka, Yumi Yasuoka, Naofumi Akata, Tetsuya Sanada, Shinji Tokonami

International Journal of Environmental Research and Public Health   19 ( 3 )   1758 - 1758   2022.2

A Preliminary Study of Radon Equilibrium Factor at a Tourist Cave in Okinawa, Japan

Ryohei Yamada, Yuki Tamakuma, Takahito Suzuki, Shunya Nakasone, Yoshitaka Shiroma, Masahide Furukawa, Hiroki Hashimoto, Masahiro Hosoda, Naofumi Akata, Shinji Tokonami

Atmosphere   12 ( 12 )   1648 - 1648   2021.12

Comprehensive exposure assessments from the viewpoint of health in a unique high natural background radiation area, Mamuju, Indonesia

Eka Djatnika Nugraha, Masahiro Hosoda, Kusdiana, Untara, June Mellawati, Nurokhim, Yuki Tamakuma, Abarrul Ikram, Mukh Syaifudin, Ryohei Yamada, Naofumi Akata, Michiya Sasaki, Masahide Furukawa, Shinji Yoshinaga, Masaru Yamaguchi, Tomisato Miura, Ikuo Kashiwakura, Shinji Tokonami

Scientific Reports   11 ( 1 )   14578   2021.7

Discriminative Measurement of Absorbed Dose Rates in Air from Natural and Artificial Radionuclides in Namie Town, Fukushima Prefecture

Koya Ogura, Masahiro Hosoda, Yuki Tamakuma, Takahito Suzuki, Ryohei Yamada, Ryoju Negami, Takakiyo Tsujiguchi, Masaru Yamaguchi, Yoshitaka Shiroma, Kazuki Iwaoka, Naofumi Akata, Mayumi Shimizu, Ikuo Kashiwakura, Shinji Tokonami

International Journal of Environmental Research and Public Health   18 ( 3 )   978 - 978   2021.2

Long-Term Measurements of Radon and Thoron Exhalation Rates from the Ground Using the Vertical Distributions of Their Activity Concentrations

Oumar Bobbo Modibo, Yuki Tamakuma, Takahito Suzuki, Ryohei Yamada, Weihai Zhuo, Chutima Kranrod, Kazuki Iwaoka, Naofumi Akata, Masahiro Hosoda, Shinji Tokonami

International Journal of Environmental Research and Public Health   18 ( 4 )   1489 - 1489   2021.2

A unique high natural background radiation area – Dose assessment and perspectives

Masahiro Hosoda, Eka Djatnika Nugraha, Naofumi Akata, Ryohei Yamada, Yuki Tamakuma, Michiya Sasaki, Kevin Kelleher, Shinji Yoshinaga, Takahito Suzuki, Chanis Pornnumpa Rattanapongs, Masahide Furukawa, Masaru Yamaguchi, Kazuki Iwaoka, Tetsuya Sanada, Tomisato Miura, Kusdiana, Dadong Iskandar, Eko Pudjadi, Ikuo Kashiwakura, Shinji Tokonami

Science of The Total Environment   750   142346 - 142346   2021.1

Environmental Monitoring of ¹³⁴Cs and ¹³⁷Cs Levels in Namie Town in 2018 and 2019

Hegedűs Miklós, Ploykrathok Thamaborn, Shiroma Yoshitaka, Iwaoka Kazuki, Yamada Ryohei, Tsujiguchi Takakiyo, Yamaguchi Masaru, Suzuki Takahito, Ogura Koya, Tamakuma Yuki, Tazoe Hirofumi, Akata Naofumi, Hosoda Masahiro, Kashiwakura Ikuo, Tokonami Shinji

Radiation Environment and Medicine   9 ( 2 )   70 - 78   2020.8

Lessons From a Japan-Korea Collaboration on Medical Response Training for a Nuclear or Radiological Emergency, Assuming Mass Casualty

Takakiyo Tsujiguchi, Maiko Kitajima, Toshiko Tomisawa, Yuki Shiroto, Ryohei Yamada, Kyoji Saito, Hiroyuki Hanada, Young Woo Jin, Minsu Cho, Seongjae Jang, Hyunjung Kim, Minjung Pak, Toshiya Nakamura

Disaster Medicine and Public Health Preparedness   14 ( 4 )   431 - 432   2020.8

Cesium concentrations in various environmental media at Namie, Fukushima

M. Hegedűs, Y. Shiroma, K. Iwaoka, M. Hosoda, T. Suzuki, Y. Tamakuma, R. Yamada, T. Tsujiguchi, M. Yamaguchi, K. Ogura, H. Tazoe, N. Akata, I. Kashiwakura, S. Tokonami

Journal of Radioanalytical and Nuclear Chemistry   323 ( 1 )   197 - 204   2020.1

COMPARATIVE STUDY ON PERFORMANCE OF VARIOUS ENVIRONMENTAL RADIATION MONITORS

Y. Tamakuma, R. Yamada, T. Suzuki, T. Kuroki, R. Saga, H. Mizuno, H. Sasaki, K. Iwaoka, M. Hosoda, S. Tokonami

Radiation Protection Dosimetry   184 ( 3-4 )   307 - 310   2019.10

A portable radioactive plume monitor using a silicon photodiode

Yuki Tamakuma , Ryohei Yamada , Kazuki Iwaoka , Masahiro Hosoda , Tomohiro Kuroki , Hiroyuki Mizuno , Koji Yamada , Masahide Furukawa , Shinji Tokonami

Perspectives in Science   12   100414 - 100414   2019.7

Evaluation of a Surface Collection Efficiency and a Stability of Flow Rate for the Commercially Available Filters Used for Ambient Radioactive Aerosols

TAMAKUMA Yuki, YAMADA Ryohei, IWAOKA Kazuki, HOSODA Masahiro, TOKONAMI Shinji

Japanese Journal of Health Physics   54 ( 1 )   5 - 12   2019.4

Study of Chemical Etching Conditions for Alpha-particle Detection and Visualization Using Solid State Nuclear Track Detectors

Yamada Ryohei, Odagiri Taiki, Iwaoka Kazuki, Hosoda Masahiro, Tokonami Shinji

Radiation Environment and Medicine   8 ( 1 )   21 - 25   2019.2

Measurement system for alpha and beta emitters with continuous air sampling under different exposure situations

Yamada Ryohei, Tamakuma Yuki, Iwaoka Kazuki, Hosoda Masahiro, Shiroma Yoshitaka, Akata Naofumi, Mizuno Hiroyuki, Yamada Kouji, Kuroki Tomohiro, Tokonamia Shinji

APPLIED RADIATION AND ISOTOPES   126   79 - 82   2017.8

Characteristic of thoron (Rn-220) in environment

Hosoda Masahiro, Kudo Hiromi, Iwaoka Kazuki, Yamada Ryohei, Suzuki Takahito, Tamakuma Yuki, Tokonami Shinji

APPLIED RADIATION AND ISOTOPES   120   7 - 10   2017.2

Response to Naturally Occurring Radioactive Material (NORM) in Japan; A Comprehensive Survey of Exposure from NORM in FY2021

Ryohei Yamada, Yuto Tomisaka, Kazuki Iwaoka, Naofumi Akata

Hokenbutsuri   57 ( 4 )   181 - 185   2022.12

Annual report on the environmental radiation monitoring around the Tokai Reprocessing Plant FY2020

Nakada Akira, Nakano Masanao, Kanai Katsuta, Seya Natsumi, Nishimura Shusaku, Nemoto Masashi, Tobita Keiji, Futagawa Kazuo, Yamada Ryohei, Uchiyama Rei, Nagaoka Mika, Matsubara Natsumi, Matsuo Kazuki, Maehara Yushi, Hirao Moe, Nihei Hidekazu, Ito Chihiro, Onuma Toshimitsu, Fujii Jun, Kaminaga Masayuki, Sugai Masamitsu, Watanabe Hajime, Tadokoro Satoshi, Sato Yoshimi, Maejima Kyoko, Sasaya Shinji, Terakado Ryo, Tayama Tomohiro, Enokido Yuka, Yubune Kazuhiro, Takahasi Hirokazu

JAEA-Review 2021-062   1 - 163   2022.2

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2020

Nakano, Masanao, Nakada, Akira, Kanai, Katsuta, Nagaoka, Mika, Koike, Yuko, Yamada, Ryohei, Kubota, Tomohiro, Yoshii, Hideki, Otani, Kazunori, Hiyama, Yoshinori, Kikuchi, Masaaki, Onuki, Yasuhiro, Yamada, Shiori, Ishizaki, Kota, Motohashi, Masahiro, Nishida, Tetsuro, Kawasaki, Ichio, Komatsu, Seiji, Terada, Hideyuki, Okada, Noriyuki, Kaneta, Yoshiharu

JAEA-Review 2021-040   1 - 118   2021.12

Development of the Desalting Method for Gross Alpha Activity Determination (Contract Research)

Koike, Yuko, Yamada, Ryohei, Nagaoka, Mika, Nakano, Masanao, Ono, Yosuke, Suitsu, Yuichi

JAEA-Technology 2021-011   ( 2021-011 )   1 - 39   2021.8

若手研・学友会における社会コミュニケーション活動報告－千葉市科学フェスタ－

山田 椋平 , 河野 恭彦, 中嶌 純也, 廣内 淳, 辻 智也, 梅田 昌幸, 五十嵐 悠, 小池 弘美

保健物理   56 ( 1 )   32 - 38   2021.3

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2019

Nakano, Masanao, Fujii, Tomoko, Nagaoka, Mika, Koike, Yuko, Yamada, Ryohei, Kubota, Tomohiro, Yoshii, Hideki, Otani, Kazunori, Hiyama, Yoshinori, Kikuchi, Masaaki, Onuki, Yasuhiro, Yamada, Shiori, Motohashi, Masahiro, Nishida, Tetsuro, Terada, Hideyuki, Kawasaki, Ichio, Shimizu, Harunori, Komatsu, Seiji, Okada, Noriyuki, Kaneta, Yoshiharu

JAEA-Review 2020-070   1 - 120   2021.2

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2018

Nakano, Masanao, Fujii, Tomoko, Nagaoka, Mika, Inoue, Kazumi, Koike, Yuko, Yamada, Ryohei, Yoshii, Hideki, Otani, Kazunori, Hiyama, Yoshinori, Kikuchi, Masaaki, Onuki, Yasuhiro, Yamada, Shiori, Sakai, Mitsuo, Asano, Naoki, Terada, Hideyuki, Ishiyama, Toru, Shimizu, Harunori, Komatsu, Seiji, Okada, Noriyuki, Kaneta, Yoshiharu

JAEA-Review 2019-045   1 - 120   2020.3

Joint meeting of young researchers in the field of radiation protection and radiation biology

Noriaki Kataoka, Junya Nakajima, Kazuji Miwa, Seiko Hirota, Yoichi Tsubota, Ryohei Yamada, Yuki Fujimichi, Junya Ishikawa, Masaaki Sunaoshi

Hoken Butsuri   54 ( 2 )   140 - 145   2019.6

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2017

Nakano Masanao, Fujita Hiroki, Mizutani Tomoko, Nagaoka Mika, Inoue Kazumi, Koike Yuko, Yamada Ryohei, Yoshii Hideki, Hiyama Yoshinori, Otani Kazunori, Kikuchi Masaaki, Sakauchi Nobuyuki, Onuki Yasuhiro, Sakai Mitsuo, Asano Naoki, Terada Hideyuki, Ishiyama Toru, Yamaguchi Yuji, Shimizu Harunori, Okada Noriyuki, Kaneta Yoshiharu

JAEA-Review 2018-028   1 - 120   2019.2

第11回日本保健物理学会学生研究発表会の報告

松山 嗣史, 石井 康太, 伊豆本 幸恵, 五十嵐 悠, 大鷹 豊, 小芝 嵩広, 山田 椋平

保健物理   52 ( 4 )   324 - 328   2017.12

第7回低レベル放射能測定技術に関する国際会議 (ICRM-LLRMT2016) への参加報告

山田　椋平

保健物理   52 ( 3 )   218 - 221   2017.9

「日本保健物理学会第49回研究発表会」印象記

山田　椋平

保健物理   51 ( 3 )   177 - 180   2016.9