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Journal Articles

Preface of SI; RNs in the environments

Tanaka, Kazuya; Kaplan, D. I.*; Onuki, Toshihiko

Applied Geochemistry, 85(Part B), p.119 - 120, 2017/10

We have prepared a special issue for Applied Geochemistry entitled "Transformation and Fate of Natural and Anthropogenic Radionuclides in the Environments". Here, we present 13 peer-reviewed articles on the general theme of natural and anthropogenic radionuclides in different environments. At the same time, these articles cover various topics of field research on the distribution of radionuclides, as well as laboratory experiments on adsorption and redox chemistry of these. The articles have been written by the attendees of the session at the Goldschmidt 2016 held in Yokohama, Japan, and by other authors who submitted their manuscripts to Applied Geochemistry focusing on the theme of the special issue.

Journal Articles

Preparation of solid phase extraction cartridges for trace analysis of radionuclides

Asai, Shiho; Saito, Kyoichi*

Biomedical Research on Trace Elements, 28(1), p.1 - 10, 2017/04

Radionuclides are commonly determined with radiometry and mass spectrometry. For $$gamma$$-emitting nuclides, the activities can be measured without chemical separation due to the strong penetration ability. In contrast, the measurements of alpha and beta-emitting nuclides are generally associated with tedious and time-consuming chemical separation procedures to remove concomitants. Thus, an adsorbent that achieves rapid separation is desirable to reduce separation time and workload. Our research team has developed compact cartridge-type solid phase extraction materials which enable to facilitate separation procedures. In this review, basic separation performances of the developed cartridges were overviewed along with two application examples to radionuclide-containing samples.

Journal Articles

Noble gas monitoring at the Takasaki radionuclide station of JAEA; Certification by the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Organization

Yamamoto, Yoichi

Isotope News, (736), p.31 - 33, 2015/08

The Takasaki radionuclide (RN) station for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) has been in operation for monitoring of radioactive noble gases (radioxenon) by the Japan Atomic Energy Agency (JAEA) since 2007, first as a test run prior to receiving the certification. The noble gas system in the station was certified by the CTBT Organization (CTBTO) on December 19, 2014. Monitoring of radioxenon is expected to have a particularly valuable role in detection of an underground nuclear test. The Takasaki RN station detected radioxenon isotopes simultaneously with radioactive concentration exceeding normal background range in April, 2013. This abnormal event was identified as being associated with the nuclear test declared by North Korea in February, 2013. Since the Takasaki RN station is located at the east end of Asia, it is receiving widespread international attention as the station for radionuclides dispersed by the westerlies.

Journal Articles

Outline of the national mapping projects implemented after the Fukushima accident

Saito, Kimiaki; Onda, Yuichi*

Journal of Environmental Radioactivity, 139, p.240 - 249, 2015/01

 Times Cited Count:20 Percentile:7.39(Environmental Sciences)

no abstracts in English

Journal Articles

Outline of UNSCEAR 2013 report, 1; Radionuclide releases, dispersion and deposition

Nagai, Haruyasu; Kurihara, Osamu*

Nippon Genshiryoku Gakkai-Shi, 56(12), p.791 - 795, 2014/12

no abstracts in English

Journal Articles

Revaluation of hydrogen generation by water radiolysis in SDS vessels at TMI-2 accident

Nagaishi, Ryuji; Morita, Keisuke; Yamagishi, Isao; Hino, Ryutaro; Ogawa, Toru

Proceedings of 2014 Nuclear Plant Chemistry Conference (NPC 2014) (USB Flash Drive), 9 Pages, 2014/10

BB2014-1745.pdf:0.92MB

Two years after Three Mile Island Unit 2 (TMI-2) loss-of-coolant accident, radioactive contaminated water has been processed by Submerged Demineralizer System (SDS) with two types of zeolite adsorbents to remove radioactive nuclides. During and after the process, adsorption amount and distribution of nuclides on the zeolites, residual water content and thermal conductivity in the SDS vessels have been measured or estimated for verification of safety in the process, subsequent transportation and disposal. Hydrogen generation has been also evaluated mainly by direct monitoring in the large-scale of vessel after the process. In this work, the revaluation of hydrogen generation was demonstrated on the basis of the open information of vessel, and the latest experimental data obtained in adsorption and radiolysis occurring in small-scale of zeolite-water mixtures. As a result, the evaluated data was found to be comparable with the reported data obtained in the large-scale of real vessel.

Journal Articles

Anthropogenic radionuclides in sediment in the Japan Sea; Distribution and transport processes of particulate radionuclides

Otosaka, Shigeyoshi; Amano, Hikaru; Ito, Toshimichi; Kawamura, Hideyuki; Kobayashi, Takuya; Suzuki, Takashi; Togawa, Orihiko; Chaykovskaya, E. L.*; Lishavskaya, T. S.*; Novichkov, V. P.*; et al.

Journal of Environmental Radioactivity, 91(3), p.128 - 145, 2006/00

 Times Cited Count:12 Percentile:65.26(Environmental Sciences)

Distributions of radionuclides ($$^{90}$$Sr, $$^{137}$$Cs and $$^{239+240}$$Pu) in seabed sediment in the Japan Sea were observed during 1998-2002. Observed inventories of anthropogenic radionuclides in sediment ranged 0.1-86 Bq m$$^{-2}$$ for $$^{90}$$Sr, 23-379 Bq m$$^{-2}$$ for $$^{137}$$Cs and 0.1-86 Bq m$$^{-2}$$ for $$^{239+240}$$Pu. In the deep part ($$>$$ 2 km depth) of the western Japan Basin, $$^{239+240}$$Pu/$$^{137}$$Cs inventory ratios were larger than those in the central Yamato Basin although inventories of radionuclides were not different between basins. The higher $$^{239+240}$$Pu/$$^{137}$$Cs ratios in the western Japan Basin were derived by the production of Pu-enriched particle in the surface layer and effective sinking of particulate materials in this region. In the marginal Yamato Basin and the Ulleung Basin, both inventories and $$^{239+240}$$Pu/$$^{137}$$Cs ratios in sediment were larger than those in the central Yamato Basin. In the eastern/southern Japan Sea, it was suggested that the supply of particulate radionuclides by the TWC enhanced accumulation of radionuclides in this region.

Journal Articles

Development of the ocean forecasting system for Shimokita region

In, Teiji*; Shima, Shigeki*; Nakayama, Tomoharu*; Ishikawa, Yoichi*; Togawa, Orihiko; Kobayashi, Takuya; Kawamura, Hideyuki

Gekkan Kaiyo, 37(9), p.674 - 680, 2005/09

no abstracts in English

Journal Articles

Status of research activities for development of CTBT-related technologies in JAERI

Shinohara, Nobuo; Inoue, Yoji; Uchikoshi, Takako*; Oda, Tetsuzo*; Kumata, Masahiro; Kurosawa, Yoshiaki; Hirota, Naoki*; Hokida, Takanori; Nakahara, Yoshinori*; Yamamoto, Yoichi

Dai-25-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.51 - 58, 2005/00

The Japan Atomic Energy Research Institute (JAERI) conducts researches and developments related to Comprehensive Nuclear-Test-Ban Treaty (CTBT) on the basis of Japan's pragmatic and progressive efforts toward peaceful use of atomic energy and non-proliferation with the goal of realizing a peaceful and safe world free from nuclear weapons. The Treaty aims for the establishment of a global verification regime comprising an International Monitoring System (IMS) and the JAERI has engaged in the following activities: construction and operation of the radionuclide monitoring stations at Okinawa (RN37) and Takasaki (RN38) and the certified radionuclide laboratory at Tokai (RL11) as specified in Annex 1 of CTBT Protocol, and preparation of the National Data Center at Tokai (JAERI NDC). Research activities of JAERI related to the CTBT verification regime are presented in the paper. The subjects of this presentation are (1) an overview of the CTBT verification regime, (2) construction and operation of RN37, RN38 and RL11, and (3) preparation of the JAERI NDC for radionuclide data.

Journal Articles

Journal Articles

Nuclear decay data used in radiation protection

Endo, Akira

Hoken Butsuri, 38(4), p.308 - 317, 2003/12

no abstracts in English

Journal Articles

Field tests on migration of TRU-nuclide, 2; Migration test for engineered barrier materials in aerated soil

Maeda, Toshikatsu; Tanaka, Tadao; Mukai, Masayuki; Ogawa, Hiromichi; Yamaguchi, Tetsuji; Munakata, Masahiro; Matsumoto, Junko; Kozai, Naofumi; Bamba, Tsunetaka; Fan, Z.*; et al.

Nippon Genshiryoku Gakkai Wabun Rombunshi, 2(3), p.336 - 341, 2003/09

no abstracts in English

JAEA Reports

Deposition of radionuclides and stable elements in Tokai-mura

Ueno, Takashi; Amano, Hikaru

JAERI-Data/Code 2003-004, 49 Pages, 2003/03

JAERI-Data-Code-2003-004.pdf:4.55MB

This report presents the data of deposition of radionuclides (Sep. 1993-March 2001) and stable elements (Sep.1993-Oct.1995) in Tokai-mura. To evaluate the migration of radionuclides and stable elements migration from the atmosphere to the ground surface, atmospheric deposition samples were collected from 1993 to 2001 with three basins (distance to grand surface were 1.5m, 4m, 10m) set up in the enclosure of JAERI in Tokai-mura, Ibaraki-ken, Japan. Monthly samples were evaporated to dryness to obtain residual samples and measured with a well type Ge detector for 7Be, 40K, 137Cs and 210Pb. According to the analysis of radioactivity, clear seasonal variations with spring peaks of deposition weight (dry) and deposition amounts of all objective radionuclides were found. Correlation analysis of deposition data also showed that these radionuclides can be divided into two groups. A part of dried sample was irradiated to reactor neutrons at JRR-4 for determination of stable element's deposition.

Journal Articles

Depth profiles of long lived radionuclides in Chernobyl soils sampled around 10 years after the accident

Amano, Hikaru; Onuma, Yoshikazu*

Journal of Radioanalytical and Nuclear Chemistry, 255(1), p.217 - 222, 2003/01

 Times Cited Count:6 Percentile:53.93(Chemistry, Analytical)

no abstracts in English

Journal Articles

Radionuclide monitoring stations in CTBT verification regime

Kumata, Masahiro; Oda, Tetsuzo; Miyamoto, Yutaka; Uchikoshi, Takako*; Nakahara, Yoshinori; Yamamoto, Yoichi; Hokida, Takanori; Hirota, Naoki*; Inoue, Yoji; Shinohara, Nobuo

Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.39 - 44, 2002/12

The International Monitoring System (IMS) will be established across the world to verify compliance with the Comprehensive Test Ban Treaty (CTBT). The IMS will be capable of detecting and identifying nuclear explosions of detonated within the atmosphere, underwater and underground. 321 monitoring stations will be set around the world as a monitoring network of the IMS. The four technologies of seismology, hydroacoustic, infrasound, and radionuclide will be used for monitoring purposes. In order to build the radionuclide monitoring network, 80 radionuclide stations were chosen. Particles in the atmosphere are collected on a filter at each station to measure radioactivity by a HP-Ge detector. Further, 40 out of these 80 stations will be equipped with an automatic radioactive noble gas sampler/analyzer. The JAERI is establishing infrastructure to host radionuclide air monitoring equipment for two raionuclide stations in Japan. This paper presents the current status of the establishment and promising performance of the stations in Japan.

Journal Articles

JAERI-Tokai radionuclide laboratory in CTBT verfication regime

Shinohara, Nobuo; Yamamoto, Yoichi; Inoue, Yoji; Kumata, Masahiro; Oda, Tetsuzo; Uchikoshi, Takako*; Hokida, Takanori; Hirota, Naoki*; Nakahara, Yoshinori; Usuda, Shigekazu

Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu, p.45 - 52, 2002/12

no abstracts in English

Journal Articles

Workshop on Internal Dosimetry of Radionuclides Occupational, Public and Medical Exposure

Kinase, Sakae

Hoken Butsuri, 37(4), p.270 - 273, 2002/12

no abstracts in English

Journal Articles

Radiological characterisation of LLW arising from JAERI Tokai Research Establishment

Okoshi, Minoru; Sakai, Akihiro; Abe, Masayoshi; Tanaka, Mitsugu

IAEA-CN-87/50 (CD-ROM), p.113 - 118, 2002/12

As the result of research activities for nuclear energy utilization over 45 years, large amounts of low-level radioactive waste (LLW) are stored at Tokai Research Establishment of JAERI. In order to plan the disposal program, JAERI carried out the radiological characterization of the waste. The results show that about 34,400 tons of LLW will arise from the operation and dismantling of the facilities by the end of 2045. The total activities of beta- and gamma-radionuclides and alpha-radionuclides are about 44 PBq and 56 TBq, respectively. By using the estimated total weight and radioactivities of the waste, important radionuclides were selected from the viewpoint of safety according to the performance assessment of near surface disposal facilities. As the results, twenty-seven radionuclides including twelve alpha-ray emitting actinides were selected as the candidate important radionuclides. Those are slightly different from important radionuclides selected for commercial nuclear power plants because of materials used for facilities and so on.

JAEA Reports

Considerations on aims and approaches of the study on the transport of trace elements in a river watershed

Matsunaga, Takeshi

JAERI-Review 2002-021, 101 Pages, 2002/10

JAERI-Review-2002-021.pdf:6.16MB

Concerning the study subject on the transport of radioactive and trace elements in a river watershed, its aims and methodological approaches have been discussed. It is stressed that a numerical model is prerequisite and to be keenly developed to assess the physiological impact and to provide appropriate countermeasures in case of a nuclear accident. The outcome of the modeling will be also important for the other environmental issues,for example, associated with metals and metalloids. From a methodological aspect, techniques, which are ought to the nuclear sciences, will have further contribution to the questions of toxic chemicals hereafter.

Journal Articles

Marine environmental assessment system of radionuclides around Japan

Kobayashi, Takuya; Togawa, Orihiko

Proceedings from the International Conference on Radioactivity in the Environment (CD-ROM), 4 Pages, 2002/09

A marine environmental assessment system STEAMER is developing for predicting the short-term (30days) dispersion and assessing the collective dose to the Japanese population due to radionuclides released to the ocean. The computer code system for short-term predictions of radionuclide dispersion is a combination of the Princeton Ocean Model (POM) for predicting ocean currents and a particle random walk model SEA-GEARN for oceanic dispersion of dissolved radionuclides. The system has been applied to a hypothetical accident of a nuclear submarine if it sinks in an offshore region around Japan, by using measured currents, temperature, salinity and meteorological regional objective analysis data (RANAL). Another computer code system DSOCEAN is also applied to the same hypothetical accident in order to compare the results of radionuclide dispersion in the ocean and the collective dose to the Japanese population. An equidistant-grid compartment model combined with a model of the geostrophic current analysis is used in DSOCEAN.

306 (Records 1-20 displayed on this page)