Misono, Toshiharu; Tsuruta, Tadahiko; Nakanishi, Takahiro; Sanada, Yukihisa; Shiribiki, Takehiko; Miyamoto, Kenji*; Urabe, Yoshimi*
JAEA-Research 2020-008, 166 Pages, 2020/10
After the accident at TEPCO Fukushima Daiichi Nuclear Power Station (1F), marine monitoring survey on radioactive substances have been conducted with financially supported by the Nuclear Regulatory Agency from FY2019. Results obtain in the project in FY2019 are presented in this report. Based on scientific grounds, the concept necessary for "progress of sea area monitoring" was arranged for the future medium- to long-term investigation of radiocesium concentrations. As basic information of survey frequency revise, a seabed topography and sediment distribution survey was conducted, and an attempt was made to understand the relationship between the seabed topography and the grain size distribution of bottom sediment. A columnar core sample was collected in the coastal area and analyzed for radioactive cesium concentration. In order to understand the dynamics of radioactive cesium contained in suspended matter flowing in from a river, suspended solids was collected using a sediment trap and the concentration of radioactive cesium was measured. We re-analyzed the towed monitoring data that had been implemented since 2013, and tried to improve the accuracy of the radioactive cesium distribution estimation map in the coastal area.
Hagiwara, Hiroki; Nakanishi, Takahiro; Konishi, Hiromi*; Tsuruta, Tadahiko; Misono, Toshiharu; Fujiwara, Kenso; Kitamura, Akihiro
Journal of Environmental Radioactivity, 220-221, p.106294_1 - 106294_9, 2020/09
Tachi, Yukio; Sato, Tomofumi*; Akagi, Yosuke*; Kawamura, Makoto*; Nakane, Hideji*; Terashima, Motoki; Fujiwara, Kenso; Iijima, Kazuki
Science of the Total Environment, 724, p.138098_1 - 138098_11, 2020/07
To understand and predict radiocesium transport behaviors in the environment, highly contaminated sediments from Ukedo and Odaka rivers around the Fukushima Daiichi Nuclear Power Plant were investigated systematically focusing on key factors controlling radiocesium sorption and fixation, including particle size, clay mineralogy and organic matter.
Tachi, Yukio; Sato, Tomofumi*; Takeda, Chizuko*; Ishidera, Takamitsu; Fujiwara, Kenso; Iijima, Kazuki
Science of the Total Environment, 724, p.138097_1 - 138097_10, 2020/07
To understand and predict radiocesium transport behaviors in the environment, sorption and fixation behaviors of radiocesium on river sediments from Ukedo and Odaka rivers around the Fukushima Daiichi Nuclear Power Plant were investigated systematically focusing on Cs sorption and fixation mechanisms and their relationship with Cs concentrations and sediment properties including clay mineralogy and organic matter.
Gorlachev, I.*; Kharkin, P.*; Dyussembayeva, M.*; Lukashenko, S.*; Gluchshenko, G.*; Matiyenko, L.*; Zheltov, D.*; Kitamura, Akihiro; Khlebnikov, N.*
Journal of Environmental Radioactivity, 213, p.106110_1 - 106110_10, 2020/03
The main goal of the presented research activities is to determine the degree of water contamination of the largest waterway of the STS, the Shagan river, with heavy elements and artificial radionuclides. Such approach made it possible to identify the most significant elements-contaminants typical for the selected object, to determine the most dirty points of the Shagan riverbed, to compare the degree of water contamination with heavy metals and artificial radionuclides, and to calculate the complex indices of water contamination with heavy metals. According to the obtained data, the recommendations can be made for application of Shagan's water for household purpose.
Taniguchi, Keisuke*; Onda, Yuichi*; Smith, H. G.*; Blake, W.*; Yoshimura, Kazuya; Yamashiki, Yosuke*; Kuramoto, Takayuki*; Saito, Kimiaki
Environmental Science & Technology, 53(21), p.12339 - 12347, 2019/11
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
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.
Ho, H. Q.; Ishitsuka, Etsuo
Physical Sciences and Technology, 5(2), p.53 - 56, 2019/00
Increasing of tritium concentration in the primary coolant of the research and test reactors during operation had been reported. To check the source for tritium release into the primary coolant during operation of the JMTR and the JRR-3M, the tritium release from the driver fuels was calculated by MCNP6 and PHITS. It is clear that the calculated values of tritium release from fuels are as about 10 and 10 Bq for the JMTR and JRR-3M, respectively, and that calculated values are about 4 order of magnitude smaller than that of the measured values. These results show that the tritium release from fuels is negligible for both the reactors.
Azami, Kazuhiro*; Otagaki, Takahiro*; Ishida, Mutsushi; Sanada, Yukihisa
Landscape and Ecological Engineering, 14(1), p.3 - 15, 2018/01
Nomura, Katsuhiro; Tanikawa, Shinichi*; Amamiya, Hiroki; Yasue, Kenichi
JAEA-Data/Code 2016-015, 49 Pages, 2017/03
The uplift of the last hundred thousand years in the Japanese Islands has been acquired mainly using marine and river terraces. We arranged information regarding the uplift in a table. This data is one of the useful information for the development of the investigation technology of uplift and for the research of the landform evolution in Japanese islands.
Konoplev, A.*; Golosov, V.*; Laptev, G.*; Namba, Kenji*; Onda, Yuichi*; Takase, Tsugiko*; Wakiyama, Yoshifumi*; Yoshimura, Kazuya
Journal of Environmental Radioactivity, 151(Part 3), p.568 - 578, 2016/01
Matsunaga, Takeshi; Monte, L.; Tsuzuki, Katsunori; Yanase, Nobuyuki; Hanzawa, Yukiko; Ueno, Takashi
JAERI-Review 2003-039, 150 Pages, 2004/01
Concerning radionuclides that might be released in an event of an accident from a nuclear facility, much attention has been paid to the migration pathways including the inflow to surface water bodies since the Chernobyl accident. In order to have discussions related to the current development of a mathematical model of the behavior of radionuclides in a river watershed, JAERI invited a guest scientist specializing in mathematical modeling of radioecology, Luigi Monte of Italian National Agency for New Technologies Energy and the Environment (ENEA: Ente per le Nuove tecnologie,L'Energia e l'Ambiente) of Italy, from May 22 to June 20 of 2003. This report is a summary of presentations and discussion made at the occasion of the visit of Dr. Monte at JAERI and also at relevant institutions of Japan involved in this study field. As a result of these discussions, distinct advantages and key problems of a mathematical model for prediction of the migration of radionuclides in a river watershed have been identified and analyzed.
Hayashi, Hiroko*; Matsuoka, Shungo*; Takahashi, Tomoyuki*; Amano, Hikaru
JAERI-Conf 2003-010, p.122 - 130, 2003/09
Two dynamic compartment models were constructed as basic river models for MOGRA (Migration Of GRound Additions), an environmental-load effect predicting code. One is 1 component river model, in which radionuclides in particulate form and dissolved form are considered to be in equilibrium in the river water. Another one is 2 component river model, in which particulate form and dissolved form are considered to be different component and are separately compartmentalized. In each model the river sediment is set in a compartment, and the sedimentation of particulate form and resuspension of radionuclides in the river sediment are taken into account.To verify the analysis function of the constructed models, calculation conditions were set using data of Cs-137 concentration in the river water derived from Kuji river, Japan, and analysis was carried out. Comparing two models, almost no difference is seen when sedimentation velocity is low, while there is apparent difference when sedimentation velocity is high.
Nagao, Seiya*; Fujitake, Nobuhide*; Kodama, Hideki*; Matsunaga, Takeshi; Yamazawa, Hiromi
Journal of Radioanalytical and Nuclear Chemistry, 255(3), p.459 - 464, 2003/03
no abstracts in English
Sanada, Yukihisa*; Matsunaga, Takeshi; Yanase, Nobuyuki; Nagao, Seiya; Amano, Hikaru; Takada, Hideshige*; Tkachenko, Y.*
Applied Radiation and Isotopes, 56(5), p.751 - 760, 2002/04
Areas contaminated with radionuclides from the Chernobyl nuclear accident have been identified in Pripyat River near the Chernobyl Nuclear Power Plant. The bottom sediments contained Cs (10 - 10 Bq/m) within 0-30 cm depth, which is comparable to the ground soil of in the vicinity of the nuclear power plant (the Exclusion Zone). The sediments also accumulated Sr (10 Bq/m ), Pu (10 Bq/m ), Am (10 Bq/m ) derived from the accident.The comparison of these inventories with those of the released radionuclides at the accident and the experimental analysis using the selective sequential extraction of the radionuclides in the sediments suggest that the potential mobility of Cs and Pu is low compared with Sr in the bottom sediment, while the potential dissolution of Sr from the river bottom sediment should be taken into account with respect to the long-term radiological influence on the aquatic environment.
Nagao, Seiya; Matsunaga, Takeshi; Suzuki, Yasuhiro*; Hiraki, Keizo*
Chikyu Kagaku, 35(3), p.107 - 120, 2001/08
no abstracts in English
JAERI-Review 2001-018, 121 Pages, 2001/06
The present report reviews a series of studies conducted in JAERI which have dealt with the behavior of atmospherically-derived radionuclides in a fluvial environment. The studies cited here firstly include investigations of the evaluation of the transport rate of the atmospherically-derived 137Cs, 210Pb and 7Be from the ground via a river to the downstream areas where the affected water is consumed. The studies validated i) the importance of suspended particulate materials in the fluvial discharge of those radionuclides, and ii) a methodology to estimate the discharge of those radionuclides. Secondly, studies in rivers and lakes in the vicinity of the Chernobyl Nuclear Power Plant revealed the role of natural dissolved organics in affecting the dissolution and transport of 239,240Pu, 241Am through complexation to form soluble species with the aid of a chemical equilibrium model The same sort of a model was also applied successfully for the behavior of iron and manganese (hydr)oxides in river recharged aquifers which could bear riverborne radionuclides.
Suyama, Kenya; Kiyosumi, Takehide*; Mochizuki, Hiroki*
JAERI-Data/Code 2000-027, 88 Pages, 2000/07
no abstracts in English
P.A.Davis*; W.J.G.Workman*; B.D.Amiro*; F.S.Spencer*; Noguchi, Hiroshi; Amano, Hikaru; Ichimasa, Yusuke*; Ichimasa, Michiko*
Fusion Technology, 28, p.840 - 845, 1995/10
no abstracts in English