1
|
Zhu J, Hao Y, Chen C, Wang T, Chen K, Zhang L, Zhang A, Xie T, Zhang Q. Transformation and environmental risk of 90Sr and 137Cs under extreme rainstorm at a proposed nuclear facility site in China. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 278:107498. [PMID: 39013308 DOI: 10.1016/j.jenvrad.2024.107498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 07/07/2024] [Accepted: 07/09/2024] [Indexed: 07/18/2024]
Abstract
This paper explores the environmental hazards associated with nuclear facilities in arid regions, focusing on the rapid migration of radionuclides facilitated by flood runoff resulting from extreme rainstorms. Through a case study of a proposed nuclear facility site in China, the study developed a comprehensive model to calculate the transformation of 90Sr and 137Cs in flood and subsurface water during accidents. The methodology employs a combination of field tests, radionuclide adsorption tests, the SWAT model, and the HGS model to create a fully integrated model. This approach allows for the several complex couplings (radionuclide-flood runoff-subsurface water) that have not been previously examined in the reactive solute transport. The findings reveal that despite groundwater movement being relatively sluggish, 90Sr and 137Cs migrate downstream rapidly due to their transportation by floods, which permeate the Upper Pleistocene gravel aquifer along the route. The study underscores the importance of considering the migration of radionuclides carried by floods generated by extreme rainstorms, as it poses a significant risk that cannot be ignored.
Collapse
Affiliation(s)
- Jun Zhu
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China; Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, 030006, China
| | - Ying Hao
- Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, 030006, China
| | - Chao Chen
- Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, 030006, China
| | - Ting Wang
- Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, 030006, China
| | - Ke Chen
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Linlin Zhang
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China
| | - Aiming Zhang
- Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, 030006, China
| | - Tian Xie
- Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, 030006, China; College of Environmental Science and Engineering, Taiyuan University of Technology, Jinzhong, 030600, China.
| | - Qiulan Zhang
- School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, China.
| |
Collapse
|
2
|
Banerjee A. Conceptualization of the comprehensive phyto-radiotoxicity incurred by radiocesium and strategies to expunge the metal using biotechnological and phytoremediative approaches. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 207:108330. [PMID: 38181642 DOI: 10.1016/j.plaphy.2023.108330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/27/2023] [Accepted: 12/31/2023] [Indexed: 01/07/2024]
Abstract
Agricultural pollution with 137Cs is an ecological threat due to its sustained half-life and radioactivity. Release of radiocesium isotopes after major nuclear power plant accidents like the Fukushima Dai-ichi and the Chernobyl nuclear power plant disasters have severely affected the surrounding growth of agricultural crops and vegetables cultivated across extensive areas. Even years after the nuclear accidents, biosafety in these agricultural fields is still questionable. Due to similarity in charge and ionic radius between radiocesium and K+, the radionuclides are promiscuously uptaken via K+ channels expressed in plants. Bioaccumulation of radiocesium reportedly promotes physiological and anatomical anomalies in crops due to radiation and also affects the rhizospheric architecture. Due to radiation hazard, the ecological balance and quality are compromised and ingestion of such contaminated food results in irreversible health hazards. Recently, strategies like exogenous supplementation of K+ or genetic engineering of K+ channels were able to reduce radiocesium bioaccumulation in plants taking the advantage of competition between radiocesium and K+ translocation. Furthermore, bioremediation strategies like phycoremediation, mycoremediation, phytoremediation and rhizofiltration have also showed promising results for removing radiocesium from polluted sites. It has been proposed that these eco-friendly ways can be adopted to de-pollute the contaminated sites prior to subsequent cultivation of crops and vegetables. Hence it is essential to: 1) understand the basic radiotoxic effects of radiocesium on agricultural crops and surrounding vegetation and, 2) design sustainable ameliorative strategies to promote radiocesium tolerance for ensuring food and social security of the affected population.
Collapse
Affiliation(s)
- Aditya Banerjee
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
3
|
Zhu J, Xu C, Chen C, Zhang A, Shao J, Zhang Q. Solution to the particle concentration effect on determining K d value of radionuclides. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 255:107028. [PMID: 36206605 DOI: 10.1016/j.jenvrad.2022.107028] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/10/2022] [Accepted: 09/18/2022] [Indexed: 06/16/2023]
Abstract
The particle concentration effect on Kd values of radionuclides has been observed but the underlying mechanism remains controversial. The hope is to use the relationship between particle concentration, adsorption-desorption isotherms and reversibility, in combination with surface component activity of model (SCA model), to solve this issue. 137Cs, 60Co, 90Sr were used as tracers, batch experiments were conducted in freshwater-sediment and seawater-sediment. The experiment of each radionuclide was designed with five different particle concentrations Cp, and for each Cp there were seven different initial concentrations C0. After adsorption experiments, four consecutive desorption experiments were carried out. At the fourth desorption experiment, radionuclide concentrations in the supernatant and sediment were measured. The results showed that adsorption and single desorption data of 137Cs, 60Co, 90Sr might be described by linear isotherms. 137Cs was reversible in the seawater-sediment, so hysteresis angles of the five-particle concentration were approximately 0°, all adsorption and desorption data could be classified into one line. In the remaining systems, besides the adsorption and single desorption isotherms moved upward with the decrease of particle concentration, hysteresis angles and irreversibility also increased, thus, the particle concentration effect was obvious. The reversible and resistant component concentrations calculated by adsorption, single desorption and consecutive desorption isotherm were linear functions of equilibrium concentration Ce1, respectively. Data from adsorption and desorption experiments with particle concentration effect could be classified into the same line using the Freundlich-SCA model. The results of this study indicate that the particle concentration effect is related to reversibility. When adsorption isotherm and single desorption isotherm are both linear, consecutive desorption isotherm, reversible and resistant component concentrations approach linearity too. After the Freundlich-SCA model eliminated the particle concentration effect on adsorption and desorption data, the data can be used to predict the adsorption, single desorption isotherm and Kd value at any particle concentration.
Collapse
Affiliation(s)
- Jun Zhu
- School of Water Resources & Environment, China University of Geosciences, Beijing, PR China; Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, PR China
| | - Chenglong Xu
- China Appraisal Center for Environment and Engineering, Ministry of Ecology and Environment, Beijing, PR China; State Environmental Protection Key Laboratory of Numerical Modeling for Environmental Impact Assessment, Beijing, PR China
| | - Chao Chen
- Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, PR China
| | - Aiming Zhang
- Key Laboratory of Nuclear Environmental Simulation and Evaluation Technology, China Institute for Radiation Protection, Taiyuan, PR China
| | - Jingli Shao
- School of Water Resources & Environment, China University of Geosciences, Beijing, PR China
| | - Qiulan Zhang
- School of Water Resources & Environment, China University of Geosciences, Beijing, PR China.
| |
Collapse
|
4
|
Investigation on the radiocesium transfer to rice plants near the water inlet of paddy fields via an in situ experiment using non-contaminated soil. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08448-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
5
|
Elevated rice 137Cs concentrations near the water inlet in paddy fields after the Fukushima nuclear accident. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08350-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
6
|
Tajima S, Yoshida S, Fukui T, Nihei N, Kobayashi NI. Cesium-137 stored on and discharged from banks of an agricultural canal in Iitate, Fukushima. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 241:106775. [PMID: 34781091 DOI: 10.1016/j.jenvrad.2021.106775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 11/02/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
This study aimed to investigate the dynamics of 137Cs around banks along an agricultural canal for paddy fields in Iitate, Fukushima, Japan. Five plots (2.4-12.6 m2) on the banks were monitored intermittently during six time periods from May 2018 to November 2019. We directly collected runoff water samples discharged from the banks followed by partitioning it into particulate and dissolved fractions and determining 137Cs in them. To investigate the source of 137Cs in the runoff water, we sequentially extracted 137Cs in various chemical forms from litter samples collected on the banks. The results showed that the discharge rates of the dissolved 137Cs per unit area from the plots were lower than those observed at the downstream of the agricultural canal, whereas more than 50% of the 137Cs discharged from the plots was in the dissolved fraction. Moreover, the results indicate that 137Cs stored in the standing plants and the litter was the primary source of the dissolved 137Cs discharged into the agricultural canal. The concentrations of the water-soluble 137Cs in the litter per plot area may have been retained by the sufficiently higher concentrations of 137Cs in litter in other chemical forms and those in the standing plants, which are the source of the litter.
Collapse
Affiliation(s)
- Satoshi Tajima
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan.
| | - Shuichiro Yoshida
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Taku Fukui
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Naoto Nihei
- Faculty of Food and Agricultural Sciences, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan
| | - Natsuko I Kobayashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| |
Collapse
|
7
|
Ueda S, Hasegawa H, Ohtsuka Y, Ochiai S, Tani T. Ten-year radiocesium fluvial discharge patterns from watersheds contaminated by the Fukushima nuclear power plant accident. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 240:106759. [PMID: 34700123 DOI: 10.1016/j.jenvrad.2021.106759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
After the Fukushima Dai-ichi nuclear power plant accident in March 2011, the fluvial discharge of 137Cs from watersheds to rivers was analyzed between 2011 and 2021. The concentrations of dissolved and particulate 137Cs were measured in river water samples collected from two rivers (the Hiso and Wariki rivers, mainly draining farmlands and forests, respectively) draining approximately 4-7 km2 watersheds in a montane area (the areal deposition of 134+137Cs; 1-3 MBq·m-2 in March 2011) of Iitate Village, Fukushima. Over the 10 yr analysis, the particulate 137Cs concentrations in the Hiso and Wariki rivers decreased by 70 and 50 times, respectively, and that of the dissolved form decreased by 150 and 130 times, respectively. Moreover, the apparent Kd (distribution coefficient) of 137Cs for water samples from both rivers have increased gradually over these periods. In 2011, the 137Cs discharge rates through the Hiso and Wariki rivers were 0.63% and 0.46% per year of the total amount of 137Cs deposited in their catchments, respectively; however, by 2021, these rates had decreased to 0.09% and 0.03% per year. The cumulative 137Cs discharge rates over 10 yr in the farmland- and forest-dominated rivers were 1.95% and 1.33%, respectively. These rates of the farmland-dominated river were ∼1.4-fold greater than those of the forest-dominated river. Moreover, ∼90% of the of the discharge occurred in particulate form while the remaining ∼10% was in the dissolved form. Thus, 137Cs deposited within these watersheds due to the accident was gradually discharged by the rivers over the 10-yr period; however, the majority remains stored in soils and litters etc. of the catchment area. These results indicate that 137Cs outflow from land-to-ocean will be limited in the future, as the river export of 137Cs is expected to continue decreasing.
Collapse
Affiliation(s)
- Shinji Ueda
- Department of Radioecology, Institute for Environmental Sciences 1-7 Rokkasho, Aomori 039-3212, Japan.
| | - Hidenao Hasegawa
- Department of Radioecology, Institute for Environmental Sciences 1-7 Rokkasho, Aomori 039-3212, Japan
| | - Yoshihito Ohtsuka
- Department of Radioecology, Institute for Environmental Sciences 1-7 Rokkasho, Aomori 039-3212, Japan
| | - Shinya Ochiai
- Institute of Nature and Environmental Technology, Kanazawa University Kakuma, Kanazawa, Ishikawa 920-1192, Japan
| | - Takashi Tani
- Department of Radioecology, Institute for Environmental Sciences 1-7 Rokkasho, Aomori 039-3212, Japan
| |
Collapse
|
8
|
Sakai M, Tsuji H, Ishii Y, Ozaki H, Takechi S, Jo J, Tamaoki M, Hayashi S, Gomi T. Untangling radiocesium dynamics of forest-stream ecosystems: A review of Fukushima studies in the decade after the accident. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117744. [PMID: 34243085 DOI: 10.1016/j.envpol.2021.117744] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Forest-stream ecosystems are widespread and biodiverse terrestrial landscapes with physical and social connections to downstream human activities. After radiocesium is introduced into these ecosystems, various material flows cause its accumulation or dispersal. We review studies conducted in the decade after the Fukushima nuclear accident to clarify the mechanisms of radiocesium transfer within ecosystems and to downstream areas through biological, hydrological, and geomorphological processes. After its introduction, radiocesium is heavily deposited in the organic soil layer, leading to persistent circulation due to biological activities in soils. Some radiocesium in soils, litter, and organisms is transported to stream ecosystems, forming contamination spots in depositional habitats. While reservoir dams function as effective traps, radiocesium leaching from sediments is a continual phenomenon causing re-contamination downstream. Integration of data regarding radiocesium dynamics and contamination sites, as proposed here, is essential for contamination management in societies depending on nuclear power to address the climate crisis.
Collapse
Affiliation(s)
- Masaru Sakai
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan.
| | - Hideki Tsuji
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan
| | - Yumiko Ishii
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan
| | - Hirokazu Ozaki
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan
| | - Seiichi Takechi
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan
| | - Jaeick Jo
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan
| | - Masanori Tamaoki
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan
| | - Seiji Hayashi
- Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan
| | - Takashi Gomi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| |
Collapse
|
9
|
Sakuma K, Yoshimura K, Nakanishi T. Leaching characteristics of 137Cs for forest floor affected by the Fukushima nuclear accident: A litterbag experiment. CHEMOSPHERE 2021; 264:128480. [PMID: 33032218 DOI: 10.1016/j.chemosphere.2020.128480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 09/09/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
In forest ecosystems, forest litter is considered an active medium for radiocesium (137Cs). To understand discharge mechanisms of highly bioavailable dissolved 137Cs from forests to river systems, we investigated the characteristics of 137Cs leaching from forest litter as observed from litterbag experiments. Leaching experiments with conifer needle and deciduous broadleaf litters were then conducted. After soaking conifer needles and broadleaf litters for 20 min, 140 min, and 1 day, the mean values of the 137Cs leaching ratios were 0.13-2.0% and 0.81-6.6%, respectively, indicating that 137Cs leaching ratios are different between forest litter types. To elucidate the factors affecting 137Cs leaching from forest litter, a multi-regression analysis of 137Cs leaching ratios was conducted against antecedent mean precipitation and temperature before sampling the litterbag and accumulated temperature during the litterbag experiments. The 137Cs leaching ratios showed a negative correlation to the antecedent mean precipitation for both litters and the accumulated temperature for broadleaf litters, whereas it exhibited a positive correlation with the antecedent mean temperature for both litters and the accumulated temperature for conifer needle litters. It was proposed that the fraction of 137Cs in labile sites in forest litter increased/decreased due to litter decomposition by antecedent/accumulated temperature, and that this fraction can be washed off by the antecedent precipitation. The different effects of accumulated temperature on 137Cs leaching from conifer needles and broadleaf litters could be due to their different decomposition rates. Our results contribute further the understanding of the mechanisms associated with dissolved 137Cs discharge from forested catchments.
Collapse
Affiliation(s)
- Kazuyuki Sakuma
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, Fukushima, 963-7700, Japan.
| | - Kazuya Yoshimura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, Fukushima, 963-7700, Japan
| | - Takahiro Nakanishi
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, Fukushima, 963-7700, Japan
| |
Collapse
|
10
|
Konoplev A, Wakiyama Y, Wada T, Udy C, Kanivets V, Ivanov MM, Komissarov M, Takase T, Goto A, Nanba K. Radiocesium distribution and mid-term dynamics in the ponds of the Fukushima Dai-ichi nuclear power plant exclusion zone in 2015-2019. CHEMOSPHERE 2021; 265:129058. [PMID: 33250230 DOI: 10.1016/j.chemosphere.2020.129058] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
This study analyzes the 137Cs behavior in the ponds of Okuma Town from 2015 to 2019 in the Fukushima Dai-ichi nuclear power plant (FDNPP) exclusion zone. A decline in both particulate and dissolved 137Cs activity concentrations was revealed. The decline rate constants for the particulate 137Cs activity concentration were found to be higher than for the dissolved 137Cs activity concentration. In terms of seasonality the dissolved 137Cs concentrations were higher from June to October, depending on the specific pond and year, most likely due to temperature dependence of 137Cs desorption from frayed edge sites of micaceous clay minerals. The apparent Kd(137Cs) in the studied ponds, in absolute value, appeared to be much higher than that for closed and semi-closed lakes of the Chernobyl contaminated area; however, these were comparable to the values characteristic of the rivers and reservoirs of the FDNPP contaminated area. The apparent Kd(137Cs) in the suspended sediment-water system was observed to decrease over time. It was hypothesized that this trend was associated with the decomposition of glassy hot particles. Relying on the theory of selective sorption and fixation, the exchangeable radiocesium interception potential, RIPex(K) was estimated using data on 137Cs speciation in the surface bottom-sediment layer and its distribution in the sediment-water system. For the studied ponds, RIPex(K) was on the average 2050 mEq/kg, which is within the range of values measured in laboratory studies reported in the literature.
Collapse
Affiliation(s)
- Alexei Konoplev
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan.
| | - Yoshifumi Wakiyama
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Toshihiro Wada
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Cameron Udy
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, 80521, USA
| | - Volodymyr Kanivets
- Ukrainian Hydrometeorological Institute, Nauki Av., 37, Kiev, 03028, Ukraine
| | - Maxim M Ivanov
- Faculty of Geography, Moscow State University, Moscow, 119991, Russia
| | | | - Tsugiko Takase
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Azusa Goto
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Kenji Nanba
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| |
Collapse
|
11
|
Mouri G. Reproduction of sediment deposition and prediction of 137Cs concentration in the major urban rivers of Tokyo. Sci Rep 2020; 10:9523. [PMID: 32533055 PMCID: PMC7293220 DOI: 10.1038/s41598-020-65700-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 04/16/2020] [Indexed: 11/09/2022] Open
Abstract
Radioactive caesium- 137 (137Cs) can be used as a tracer to infer sediment dynamics due not only to its long radioactive half-life but also its affinity for fine sediment. A novel advanced interpolation assessment was conducted to examine radionuclide activity in terraced land covered with volcanic ash soil in Tokyo, Japan, which had a time-dependent input function and incorporated the effects of mixed-sediment particle dynamic behaviour on radioactive decay. In addition, transport parameters derived from Chernobyl measurements were applied as predictors of the long-term contamination of the cardinal urban rivers by the fallout from the Tokyo Electric Power Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011. The behaviour of suspended sediment substances, incorporating the effects of deposition and pickup, was assessed using a mixed-sediment particle dynamics model. The concentrations of 137Cs adsorbed on fine sediment particles of each size fraction were determined. Removal of 137Cs from the cardinal urban river channel had significant effects on both long-term decline, including extreme flash flood events, and the dynamic and time-dependent behaviours of interspersed 137Cs and sediment activity. A novel advanced interpolation assessment method was used to examine radionuclide activity in terraced land covered with volcanic ash soil in Tokyo, Japan. The assessment procedure has a time-dependent input function and incorporates the effects of mixed-sediment particle dynamics on this time dependence. The results indicated that sediment and 137Cs concentrations could decline more rapidly than observed in the Fukushima and Chernobyl regions. This rate of decrease depended on terraces covered with volcanic ash soil, which incorporated the effects of fine sediment behaviour for particle adsorption. In addition, comparatively large impacts were observed during extreme flash flooding events, which were associated with the land cover of the major urban river catchments in Tokyo. This work provides a new perspective for understanding 137Cs behaviour associated with reproduction of sediment deposition and prediction of 137Cs concentration in the major urban rivers of Tokyo, incorporating the effects of baseline 137Cs behaviour with the impact of sediment particle adsorption in a volcanic ash soil-covered terrace.
Collapse
Affiliation(s)
- Goro Mouri
- Earth Observation Data Integration & Fusion Research Initiative (EDITORIA), The University of Tokyo, Be505, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan.
| |
Collapse
|
12
|
Tsuji H, Ishii Y, Shin M, Taniguchi K, Arai H, Kurihara M, Yasutaka T, Kuramoto T, Nakanishi T, Lee S, Shinano T, Onda Y, Hayashi S. Factors controlling dissolved 137Cs concentrations in east Japanese Rivers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134093. [PMID: 31487585 DOI: 10.1016/j.scitotenv.2019.134093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 07/23/2019] [Accepted: 08/23/2019] [Indexed: 06/10/2023]
Abstract
To investigate the main factors that control the dissolved radiocesium concentration in river water in the area affected by the Fukushima Daiichi nuclear power plant accident, the correlations between the dissolved 137Cs concentrations at 66 sites normalized to the average 137Cs inventories for the watersheds with the land use, soil components, topography, and water quality factors were assessed. We found that the topographic wetness index is significantly and positively correlated with the normalized dissolved 137Cs concentration. Similar positive correlations have been found for European rivers because wetland areas with boggy organic soils that weakly retain 137Cs are mainly found on plains. However, for small Japanese river watersheds, the building area ratio in the watershed strongly affected the dissolved 137Cs concentration. One reason for this would be because the high concentrations of solutes, such as K+ and dissolved organic carbon, discharged in urban areas would inhibit 137Cs absorption to soil particles. A multiple regression equation was constructed to predict the normalized dissolved 137Cs concentration with the topography, land use, soil component, and water quality data as explanatory variables. The best model had the building land use as the primary predictor. When comparing two multiple regression models in which the explanatory variables were limited to (1) the land use and soil composition and (2) the water quality, the water quality model underestimated the high normalized dissolve 137Cs concentration in urban areas. This poor reproducibility indicates that the dissolved 137Cs concentration value in urban areas cannot be solely explained by the solid-liquid distribution of 137Cs owing to the influence of the water quality, but some specific 137Cs sources in urban areas would control the dissolved 137Cs concentration.
Collapse
Affiliation(s)
- Hideki Tsuji
- National Institute for Environmental Studies, Fukushima Branch, 10-2 Fukasaku, Miharu, Tamura, Fukushima 963-7700, Japan.
| | - Yumiko Ishii
- National Institute for Environmental Studies, Fukushima Branch, 10-2 Fukasaku, Miharu, Tamura, Fukushima 963-7700, Japan.
| | - Moono Shin
- Faculty of Food and Agricultural Sciences, Fukushima University, 1 Kanayagawa, Fukushima City, Fukushima Prefecture 960-1296, Japan.
| | - Keisuke Taniguchi
- Fukushima Prefectural Centre for Environmental Creation, 10-2 Fukasaku, Miharu, Tamura, Fukushima 963-7700, Japan.
| | - Hirotsugu Arai
- Fukushima Prefectural Centre for Environmental Creation, 10-2 Fukasaku, Miharu, Tamura, Fukushima 963-7700, Japan.
| | - Momo Kurihara
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan.
| | - Tetsuo Yasutaka
- National Institute of Advanced Science and Technology, Research Institute for Geo-resources and Environment, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8560, Japan.
| | - Takayuki Kuramoto
- Tokai University, School of Humanities and Culture, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1207, Japan.
| | - Takahiro Nakanishi
- Japan Atomic Energy Agency, Sector of Fukushima Research and Development, 45-169 Sukakeba, Kaihana, Haramachi-ku, Minamisoma City, Fukushima 975-0036, Japan.
| | - Sangyoon Lee
- National Agriculture and Food Research Organization, Western Region Agricultural Research Center, Shikoku Research Station, 2575 Ikano-cho, Zentsuji-shi, Kagawa 765-0053, Japan.
| | - Takuro Shinano
- Hokkaido University, Research Faculty of Agriculture, Kita 9 Jo, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan.
| | - Yuichi Onda
- University of Tsukuba, Center for Research in Isotopes and Environmental Dynamics, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
| | - Seiji Hayashi
- National Institute for Environmental Studies, Fukushima Branch, 10-2 Fukasaku, Miharu, Tamura, Fukushima 963-7700, Japan.
| |
Collapse
|
13
|
Funaki H, Yoshimura K, Sakuma K, Iri S, Oda Y. Evaluation of particulate 137Cs discharge from a mountainous forested catchment using reservoir sediments and sinking particles. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 210:105814. [PMID: 30529107 DOI: 10.1016/j.jenvrad.2018.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 02/24/2018] [Accepted: 03/13/2018] [Indexed: 06/09/2023]
Abstract
The time and size dependencies of particulate 137Cs concentrations in a reservoir were investigated to evaluate the dynamics of 137Cs pollution from a mountainous forested catchment. Sediment and sinking particle samples were collected using a vibracorer and a sediment trap at the Ogaki Dam Reservoir in Fukushima, which is located in the heavily contaminated area that formed as a result of the Fukushima Dai-ichi Nuclear Power Plant accident of 2011. The inventory of 137Cs discharged into the reservoir during the post-accident period (965 days) was estimated to be approximately 3.0 × 1012-3.9 × 1012 Bq, which is equivalent to 1.1%-1.4% of the initial estimated catchment inventory. The particulate 137Cs concentration showed a decline with time, but the exponent value between the specific surface area and the 137Cs concentration for the fine-sized (<63 μm) particle fraction remained almost constant from the immediate aftermath of the accident. These quantitative findings obtained by reconstructing the contamination history of particulate 137Cs in reservoir sediments and sinking particles have important implications for the evaluation of 137Cs dynamics in mountainous forested catchments.
Collapse
Affiliation(s)
- Hironori Funaki
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan.
| | - Kazuya Yoshimura
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan
| | - Kazuyuki Sakuma
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan
| | - Shatei Iri
- West Japan Engineering Consultants, Inc., 1-1, 1-chome, Watanabe-dori, Chuo-ku, Fukuoka-shi, Fukuoka, 810-0004, Japan
| | - Yoshihiro Oda
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan
| |
Collapse
|
14
|
Sakuma K, Tsuji H, Hayashi S, Funaki H, Malins A, Yoshimura K, Kurikami H, Kitamura A, Iijima K, Hosomi M. Applicability of K d for modelling dissolved 137Cs concentrations in Fukushima river water: Case study of the upstream Ota River. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 210:105815. [PMID: 30340874 DOI: 10.1016/j.jenvrad.2018.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/25/2017] [Accepted: 01/04/2018] [Indexed: 06/08/2023]
Abstract
A study is presented on the applicability of the distribution coefficient (Kd) absorption/desorption model to simulate dissolved 137Cs concentrations in Fukushima river water. The upstream Ota River basin was simulated using GEneral-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) for the period 1 January 2014 to 31 December 2015. Good agreement was obtained between the simulations and observations on water and suspended sediment fluxes, and on particulate bound 137Cs concentrations under both base and high flow conditions. By contrast the measured concentrations of dissolved 137Cs in the river water were much harder to reproduce with the simulations. By tuning the Kd values for large particles, it was possible to reproduce the mean dissolved 137Cs concentrations during base flow periods (observation: 0.32 Bq/L, simulation: 0.36 Bq/L). However neither the seasonal variability in the base flow dissolved 137Cs concentrations (0.14-0.53 Bq/L), nor the peaks in concentration that occurred during storms (0.18-0.88 Bq/L, mean: 0.55 Bq/L), could be reproduced with realistic simulation parameters. These discrepancies may be explained by microbial action and leaching from organic matter in forest litter providing an additional input of dissolved 137Cs to rivers, particularly over summer, and limitations of the Kd absorption/desorption model. It is recommended that future studies investigate these issues in order to improve simulations of dissolved 137Cs concentrations in Fukushima rivers.
Collapse
Affiliation(s)
- Kazuyuki Sakuma
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan; Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
| | - Hideki Tsuji
- Fukushima Branch, National Institute of Environmental Studies, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Seiji Hayashi
- Fukushima Branch, National Institute of Environmental Studies, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Hironori Funaki
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Alex Malins
- Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Kazuya Yoshimura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Hiroshi Kurikami
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan; Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Akihiro Kitamura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan; Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Kazuki Iijima
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Masaaki Hosomi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| |
Collapse
|
15
|
Sakuma K, Nakanishi T, Yoshimura K, Kurikami H, Nanba K, Zheleznyak M. A modeling approach to estimate the 137Cs discharge in rivers from immediately after the Fukushima accident until 2017. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 208-209:106041. [PMID: 31494389 DOI: 10.1016/j.jenvrad.2019.106041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 08/15/2019] [Accepted: 08/27/2019] [Indexed: 06/10/2023]
Abstract
We developed a simple model to evaluate and predict the 137Cs discharge from catchments using a tank model and the L-Q equation. Using this model, the 137Cs discharge and discharge ratio from the Abukuma River and 13 other rivers in the Fukushima coastal region were estimated from immediately after the Fukushima accident up to 2017. The 137Cs discharge (and discharge ratio to the deposition inventory in the catchment) of the Abukuma River and 13 other rivers in the Fukushima coastal region during the initial six months after the accident were estimated to be 18 TBq (3.1%) and 11 TBq (0.79%), respectively. These values of 137Cs discharge ratio were 1-2 orders of magnitude higher than those observed after June 2011 in previous studies (Ueda et al., 2013; Tsuji et al., 2016; Iwagami et al., 2017a), indicating that the initial 137Cs discharge from the catchments through the rivers was significant. The simulated initial 137Cs discharge rates for the initial six months after the Fukushima accident were about 9-30 times larger in each catchment than those after that point until 2017, though initial 137Cs concentration in river water was derived from an extrapolation of data based on a two exponentially decreasing fitting. However, it was found that the impact on the ocean from the initial 137Cs discharge through the rivers can be limited because the 137Cs discharge from the Abukuma River and the 13 other rivers in the Fukushima coastal region (29 TBq) was two orders of magnitude smaller than the direct release from Fukushima Dai-ichi Nuclear Power Plant (FDNPP) into the ocean (3.5 PBq) and from atmospheric deposition into the ocean (7.6 PBq) (Kobayashi et al., 2013). This model is expected to be useful to evaluate and predict 137Cs discharge from catchments in future water management and in the estimation of 137Cs discharge into reservoirs and the ocean.
Collapse
Affiliation(s)
- Kazuyuki Sakuma
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, Fukushima, 963-7700, Japan.
| | - Takahiro Nakanishi
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, Fukushima, 963-7700, Japan
| | - Kazuya Yoshimura
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, Fukushima, 963-7700, Japan
| | - Hiroshi Kurikami
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, Fukushima, 963-7700, Japan
| | - Kenji Nanba
- Institute of Environmental Radioactivity, Fukushima University, Fukushima, 960-1296, Japan
| | - Mark Zheleznyak
- Institute of Environmental Radioactivity, Fukushima University, Fukushima, 960-1296, Japan
| |
Collapse
|
16
|
Repeatability and reproducibility of measurements of low dissolved radiocesium concentrations in freshwater using different pre-concentration methods. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06696-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
17
|
Funaki H, Yoshimura K, Sakuma K, Iri S, Oda Y. Evaluation of particulate 137Cs discharge from a mountainous forested catchment using reservoir sediments and sinking particles. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 189:48-56. [PMID: 29602059 DOI: 10.1016/j.jenvrad.2018.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 02/24/2018] [Accepted: 03/13/2018] [Indexed: 06/08/2023]
Abstract
The time and size dependencies of particulate 137Cs concentrations in a reservoir were investigated to evaluate the dynamics of 137Cs pollution from a mountainous forested catchment. Sediment and sinking particle samples were collected using a vibracorer and a sediment trap at the Ogaki Dam Reservoir in Fukushima, which is located in the heavily contaminated area that formed as a result of the Fukushima Dai-ichi Nuclear Power Plant accident of 2011. The inventory of 137Cs discharged into the reservoir during the post-accident period (965 days) was estimated to be approximately 3.0 × 1012-3.9 × 1012 Bq, which is equivalent to 1.1%-1.4% of the initial estimated catchment inventory. The particulate 137Cs concentration showed a decline with time, but the exponent value between the specific surface area and the 137Cs concentration for the fine-sized (<63 μm) particle fraction remained almost constant from the immediate aftermath of the accident. These quantitative findings obtained by reconstructing the contamination history of particulate 137Cs in reservoir sediments and sinking particles have important implications for the evaluation of 137Cs dynamics in mountainous forested catchments.
Collapse
Affiliation(s)
- Hironori Funaki
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan.
| | - Kazuya Yoshimura
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan
| | - Kazuyuki Sakuma
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan
| | - Shatei Iri
- West Japan Engineering Consultants, Inc., 1-1, 1-chome, Watanabe-dori, Chuo-ku, Fukuoka-shi, Fukuoka, 810-0004, Japan
| | - Yoshihiro Oda
- Fukushima Environmental Safety Center, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Fukushima, 963-7700, Japan
| |
Collapse
|
18
|
Sakuma K, Tsuji H, Hayashi S, Funaki H, Malins A, Yoshimura K, Kurikami H, Kitamura A, Iijima K, Hosomi M. Applicability of K d for modelling dissolved 137Cs concentrations in Fukushima river water: Case study of the upstream Ota River. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 184-185:53-62. [PMID: 29353199 DOI: 10.1016/j.jenvrad.2018.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/25/2017] [Accepted: 01/04/2018] [Indexed: 06/07/2023]
Abstract
A study is presented on the applicability of the distribution coefficient (Kd) absorption/desorption model to simulate dissolved 137Cs concentrations in Fukushima river water. The upstream Ota River basin was simulated using GEneral-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) for the period 1 January 2014 to 31 December 2015. Good agreement was obtained between the simulations and observations on water and suspended sediment fluxes, and on particulate bound 137Cs concentrations under both base and high flow conditions. By contrast the measured concentrations of dissolved 137Cs in the river water were much harder to reproduce with the simulations. By tuning the Kd values for large particles, it was possible to reproduce the mean dissolved 137Cs concentrations during base flow periods (observation: 0.32 Bq/L, simulation: 0.36 Bq/L). However neither the seasonal variability in the base flow dissolved 137Cs concentrations (0.14-0.53 Bq/L), nor the peaks in concentration that occurred during storms (0.18-0.88 Bq/L, mean: 0.55 Bq/L), could be reproduced with realistic simulation parameters. These discrepancies may be explained by microbial action and leaching from organic matter in forest litter providing an additional input of dissolved 137Cs to rivers, particularly over summer, and limitations of the Kd absorption/desorption model. It is recommended that future studies investigate these issues in order to improve simulations of dissolved 137Cs concentrations in Fukushima rivers.
Collapse
Affiliation(s)
- Kazuyuki Sakuma
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan; Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
| | - Hideki Tsuji
- Fukushima Branch, National Institute of Environmental Studies, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Seiji Hayashi
- Fukushima Branch, National Institute of Environmental Studies, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Hironori Funaki
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Alex Malins
- Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Kazuya Yoshimura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Hiroshi Kurikami
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan; Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Akihiro Kitamura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan; Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Kazuki Iijima
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2, Fukasaku, Miharu-machi, Tamura-gun, Fukushima 963-7700, Japan
| | - Masaaki Hosomi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| |
Collapse
|
19
|
Sakuma K, Malins A, Funaki H, Kurikami H, Niizato T, Nakanishi T, Mori K, Tada K, Kobayashi T, Kitamura A, Hosomi M. Evaluation of sediment and 137Cs redistribution in the Oginosawa River catchment near the Fukushima Dai-ichi Nuclear Power Plant using integrated watershed modeling. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 182:44-51. [PMID: 29190508 DOI: 10.1016/j.jenvrad.2017.11.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 10/23/2017] [Accepted: 11/21/2017] [Indexed: 06/07/2023]
Abstract
The Oginosawa River catchment lies 15 km south-west of the Fukushima Dai-ichi nuclear plant and covers 7.7 km2. Parts of the catchment were decontaminated between fall 2012 and March 2014 in preparation for the return of the evacuated population. The General-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) code was used to study sediment and 137Cs redistribution within the catchment, including the effect of decontamination on redistribution. Fine resolution grid cells were used to model local features of the catchment, such as paddy fields adjacent to the Oginosawa River. The simulation was verified using monitoring data for river water discharge rates (r = 0.92), suspended sediment concentrations, and particulate 137Cs concentrations (r = 0.40). Cesium-137 input to watercourses came predominantly from land adjacent to river channels and forest gullies, e.g. the paddy fields in the Ogi and Kainosaka districts, as the ground in these areas saturates during heavy rain and is easily eroded. A discrepancy between the simulation and monitoring results on the sediment discharge rate following decontamination may be explained by fast erosion occurring after decontamination. Forested areas far from the channels only made a minor contribution to 137Cs input to watercourses, total erosion of between 0.001 and 0.1 mm from May 2011 to December 2015, as ground saturation is infrequent in these areas. The 2.3-6.9% y-1 decrease in the amount of 137Cs in forest topsoil over the study period can be explained by radioactive decay (approximately 2.3% y-1), along with a migration downwards into subsoil and a small amount of export. The amount of 137Cs available for release from land adjacent to rivers is expected to be lower in future than compared to this study period, as the simulations indicate a high depletion of inventory from these areas by the end of 2015. However continued monitoring of 137Cs concentrations in river water over future years is advised, as recultivation of paddy fields by returnees may again lead to fast erosion rates and release of the remaining inventory.
Collapse
Affiliation(s)
- Kazuyuki Sakuma
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2 Fukasaku, Miharu-machi, Fukushima 963-7700, Japan; Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan.
| | - Alex Malins
- Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Hironori Funaki
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2 Fukasaku, Miharu-machi, Fukushima 963-7700, Japan
| | - Hiroshi Kurikami
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2 Fukasaku, Miharu-machi, Fukushima 963-7700, Japan; Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Tadafumi Niizato
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2 Fukasaku, Miharu-machi, Fukushima 963-7700, Japan
| | - Takahiro Nakanishi
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2 Fukasaku, Miharu-machi, Fukushima 963-7700, Japan
| | - Koji Mori
- Geosphere Environmental Technology Corporation, 2-1 Kanda-Awajicho, Chiyoda-ku, Tokyo 101-0063, Japan
| | - Kazuhiro Tada
- Geosphere Environmental Technology Corporation, 2-1 Kanda-Awajicho, Chiyoda-ku, Tokyo 101-0063, Japan
| | - Takamaru Kobayashi
- Geosphere Environmental Technology Corporation, 2-1 Kanda-Awajicho, Chiyoda-ku, Tokyo 101-0063, Japan
| | - Akihiro Kitamura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 10-2 Fukasaku, Miharu-machi, Fukushima 963-7700, Japan; Center for Computational Science & e-Systems, Japan Atomic Energy Agency, University of Tokyo Kashiwanoha Campus Satellite, 178-4-4 Wakashiba, Kashiwa-shi, Chiba 277-0871, Japan
| | - Masaaki Hosomi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo 184-8588, Japan
| |
Collapse
|
20
|
“Caddisfly watch,” a biomonitoring program using Stenopsyche larvae to determine radioactive cesium contamination in rivers following the Fukushima nuclear disaster. LANDSCAPE AND ECOLOGICAL ENGINEERING 2018. [DOI: 10.1007/s11355-017-0333-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
21
|
Uematsu S, Vandenhove H, Sweeck L, Hees MV, Wannijn J, Smolders E. Foliar uptake of radiocaesium from irrigation water by paddy rice (Oryza sativa): an overlooked pathway in contaminated environments. THE NEW PHYTOLOGIST 2017; 214:820-829. [PMID: 28102551 DOI: 10.1111/nph.14416] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 11/28/2016] [Indexed: 06/06/2023]
Abstract
Flooded (paddy) rice (Oryza sativa) can take up ions from the irrigation water by foliar uptake via the exposed stem base. We hypothesised that the stem base uptake of radiocaesium (RCs) is a pathway for rice grown in RCs-contaminated environments. We developed a bi-compartmental device which discriminates the stem base from root RCs uptake from solutions, thereby using RCs isotopes (137 Cs and 134 Cs) with < 2% solution leak between the compartments. Radiocaesium uptake was linear over time (0-24 h). Radiocaesium uptake to the entire plant, expressed per dry weight of the exposed parts, was sixfold higher for the roots than for the exposed stem base. At equal RCs concentrations in both compartments, the exposed stem base and root uptake contributed almost equally to the total shoot RCs concentrations. Reducing potassium supply to the roots not only increased the root RCs uptake but also increased RCs uptake by the stem base. This study was the first to experimentally demonstrate active and internally regulated RCs uptake by the stem base of rice. Scenario calculations for the Fukushima-affected area predict that RCs in irrigation water could be an important source of RCs in rice as indirectly suggested from field data.
Collapse
Affiliation(s)
- Shinichiro Uematsu
- Biosphere Impact Studies, SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400, Mol, Belgium
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| | - Hildegarde Vandenhove
- Biosphere Impact Studies, SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400, Mol, Belgium
| | - Lieve Sweeck
- Biosphere Impact Studies, SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400, Mol, Belgium
| | - May Van Hees
- Biosphere Impact Studies, SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400, Mol, Belgium
| | - Jean Wannijn
- Biosphere Impact Studies, SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400, Mol, Belgium
| | - Erik Smolders
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| |
Collapse
|
22
|
Naulier M, Eyrolle-Boyer F, Boyer P, Métivier JM, Onda Y. Particulate organic matter in rivers of Fukushima: An unexpected carrier phase for radiocesiums. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 579:1560-1571. [PMID: 27923577 DOI: 10.1016/j.scitotenv.2016.11.165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/23/2016] [Accepted: 11/23/2016] [Indexed: 06/06/2023]
Abstract
The role of particulate organic matter in radiocesium transfers from soils to rivers was investigated in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Suspended and deposited sediments, filtered water, macro organic debris and dead leaves were sampled along the six most contaminated coastal river catchments of the Fukushima prefecture in the early autumns 2013 and 2014. Radiocesium concentrations of river samples and total organic carbon concentrations in suspended and deposited sediments were measured. Radiocesium concentrations of suspended and deposited sediments were significantly correlated to 137Cs inventories in soils and total organic carbon. The distributions of radiocesium between the organic and mineral phases of both types of sediment were assessed by using a modelling approach. The results suggest that, during the early autumn season, the organic fraction was the main phase that carried the radiocesiums in deposited sediments and in suspended sediments for suspended loads <25mg·L-1. For higher suspended loads like those occurring during typhoon periods, the mineral fraction was the main carrier phase. Thus, high apparent distribution coefficient values noted by various authors in Fukushima could be attributed to the high radiocesium contents of particulate organic matter. Since it is well known that organic compounds generally do not significantly adsorb radiocesium onto specific sites, several hypotheses are suggested: 1) Radiocesiums may have been absorbed into organic components at the early stage of atmospheric radioactive deposits and/or later due to biomass recycling and 2) Those elements would be partly carried by glassy hot particles together with organic matter transported by rivers in Fukushima. Both hypotheses would lead to conserve the amount of radiocesiums associated with particles during their transfers from the contaminated areas to the marine environment. Finally, such organically bound radiocesium would lead to significant deliveries of bioavailable radiocesium for living organisms at Fukushima.
Collapse
Affiliation(s)
- Maud Naulier
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV, SERIS/LRTE, SESURE/LEREN, BP 3, 13115 Saint-Paul-lez-Durance, France.
| | - Frédérique Eyrolle-Boyer
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV, SERIS/LRTE, SESURE/LEREN, BP 3, 13115 Saint-Paul-lez-Durance, France
| | - Patrick Boyer
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV, SERIS/LRTE, SESURE/LEREN, BP 3, 13115 Saint-Paul-lez-Durance, France
| | - Jean-Michel Métivier
- Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV, SERIS/LRTE, SESURE/LEREN, BP 3, 13115 Saint-Paul-lez-Durance, France
| | - Yuichi Onda
- Center of Research in Isotopes and Environmental Dynamics (CRIED), Tsukuba, Japan
| |
Collapse
|
23
|
Inoue K, Tsuruoka H, Van Le T, Arai M, Saito K, Fukushi M. Impact on ambient dose rate in metropolitan Tokyo from the Fukushima Daiichi Nuclear Power Plant accident. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 158-159:1-8. [PMID: 27055250 DOI: 10.1016/j.jenvrad.2016.03.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/22/2016] [Accepted: 03/27/2016] [Indexed: 06/05/2023]
Abstract
A car-borne survey was made in metropolitan Tokyo, Japan, in December 2014 to estimate external dose. This survey was conducted for all municipalities of Tokyo and the results were compared with measurements done in 2003. The ambient dose rate measured in the whole area of Tokyo in December 2014 was 60 nGy h(-1) (23-142 nGy h(-1)), which was 24% higher than the rate in 2003. Higher dose rates (>70 nGy h(-1)) were observed on the eastern and western ends of Tokyo; furthermore, the contribution ratio from artificial radionuclides ((134)Cs and (137)Cs) to ambient dose rate in eastern Tokyo was twice as high as that of western Tokyo. Based on the measured ambient dose rate, the effective dose rate after the accident was estimated to be 0.45 μSv h(-1) in Tokyo. This value was 22% higher than the value before the accident as of December 2014.
Collapse
Affiliation(s)
- Kazumasa Inoue
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-ku, Tokyo 116-8551, Japan.
| | - Hiroshi Tsuruoka
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-ku, Tokyo 116-8551, Japan
| | - Tan Van Le
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-ku, Tokyo 116-8551, Japan
| | - Moeko Arai
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-ku, Tokyo 116-8551, Japan
| | - Kyoko Saito
- Department of Radiological Technology, Faculty of Health Sciences, Nihon Institute of Medical Science, 1276 Shimogawara, Moroyamamachi, Irumagun, Saitama 350-0435, Japan
| | - Masahiro Fukushi
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashiogu, Arakawa-ku, Tokyo 116-8551, Japan
| |
Collapse
|
24
|
Yamasaki S, Imoto J, Furuki G, Ochiai A, Ohnuki T, Sueki K, Nanba K, Ewing RC, Utsunomiya S. Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 551-552:155-162. [PMID: 26874771 DOI: 10.1016/j.scitotenv.2016.01.155] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 01/22/2016] [Accepted: 01/23/2016] [Indexed: 06/05/2023]
Abstract
The migration and dispersion of radioactive Cs (mainly (134)Cs and (137)Cs) are of critical concern in the area surrounding the Fukushima Daiichi Nuclear Power Plant (FDNPP). Considerable uncertainty remains in understanding the properties and dynamics of radioactive Cs transport by surface water, particularly during rainfall-induced flood events to the ocean. Physical and chemical properties of unique estuary sediments, collected from the Kuma River, 4.0km south of the FDNPP, were quantified in this study. These were deposited after storm events and now occur as dried platy sediments on beach sand. The platy sediments exhibit median particle sizes ranging from 28 to 32μm. There is increasing radioactivity towards the bottom of the layers deposited; approximately 28 and 38Bqg(-1) in the upper and lower layers, respectively. The difference in the radioactivity is attributed to a larger number of particles associated with radioactive Cs in the lower part of the section, suggesting that radioactive Cs in the suspended soils transported by surface water has decreased over time. Sequential chemical extractions showed that ~90% of (137)Cs was strongly bound to the residual fraction in the estuary samples, whereas 60~80% of (137)Cs was bound to clays in the six paddy soils. This high concentration in the residual fraction facilitates ease of transport of clay and silt size particles through the river system. Estuary sediments consist of particles <100μm. Radioactive Cs desorption experiments using the estuary samples in artificial seawater revealed that 3.4±0.6% of (137)Cs was desorbed within 8h. More than 96% of (137)Cs remained strongly bound to clays. Hence, particle size is a key factor that determines the travel time and distance during the dispersion of (137)Cs in the ocean.
Collapse
Affiliation(s)
- Shinya Yamasaki
- Faculty of Pure and Applied Sciences and Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.
| | - Junpei Imoto
- Department of Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Genki Furuki
- Department of Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Asumi Ochiai
- Department of Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Toshihiko Ohnuki
- Advanced Science Research Center, Japan Atomic Energy Agency, Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195, Japan
| | - Keisuke Sueki
- Faculty of Pure and Applied Sciences and Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Kenji Nanba
- Department of Environmental Management, Faculty of Symbiotic System Science, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Rodney C Ewing
- Department of Geological Sciences and Center for International Security and Cooperation, Stanford University, Stanford, CA 94305-2115, USA
| | - Satoshi Utsunomiya
- Department of Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| |
Collapse
|
25
|
Miyazu S, Yasutaka T, Yoshikawa N, Tamaki S, Nakajima K, Sato I, Nonaka M, Harada N. Measurement and estimation of radiocesium discharge rate from paddy field during land preparation and mid-summer drainage. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 155-156:23-30. [PMID: 26895347 DOI: 10.1016/j.jenvrad.2016.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 01/08/2016] [Accepted: 01/24/2016] [Indexed: 06/05/2023]
Abstract
In this research, we evaluated the range of (137)Cs discharge rates from paddy fields during land preparation and mid-summer drainage. First, we investigated (137)Cs discharge loads during land preparation and mid-summer drainage and their ratio to the (137)Cs inventory of paddy field soil. We found that total discharge rates were 0.003-0.028% during land preparation and 0.001-0.011% during mid-summer drainage. Next, we validated the range of obtained total discharge of (137)Cs from the paddy fields using a simplified equation and literature review. As a result, we conclude that the range of total outflow loads of suspended solids for the investigated paddy field was generally representative of paddy fields in Japan. Moreover, the (137)Cs discharge ratio had a wide range, but was extremely small relative to (137)Cs present in paddy field soil before irrigation.
Collapse
Affiliation(s)
- Susumu Miyazu
- National Institute for Rural Engineering, National Agriculture and Food Research Organization, 2-1-6 Kannondai, Tsukuba, Ibaraki 305-8609, Japan
| | - Tetsuo Yasutaka
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8567, Japan.
| | - Natsuki Yoshikawa
- Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
| | - Shouhei Tamaki
- Narusawa Consultant Co., Ltd., 1-21-11 Amigawara, Chuo-ku, Niigata-city, Niigata prefecture 950-0964, Japan
| | - Kousei Nakajima
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
| | - Iku Sato
- School of Engineering, Tohoku University, 6-6 Aza-Aoba, Aramaki, Aoba-ku, Sendai-city, Miyagi prefecture 980-8579, Japan
| | - Masanori Nonaka
- Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
| | - Naoki Harada
- Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
| |
Collapse
|
26
|
Murakami M, Shibayama N, Sueki K, Mouri G, O H, Nomura M, Koibuchi Y, Oki T. Occurrence and partition ratios of radiocesium in an urban river during dry and wet weather after the 2011 nuclear accident in Fukushima. WATER RESEARCH 2016; 92:87-93. [PMID: 26841232 DOI: 10.1016/j.watres.2016.01.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 01/18/2016] [Accepted: 01/20/2016] [Indexed: 06/05/2023]
Abstract
After the 2011 nuclear accident in Fukushima, radiocesium was released from the Fukushima Dai-ichi Nuclear Power Plant and contaminated waters in urban areas near Tokyo. By intensive field monitoring during 3 years, this study investigated the temporal trends and the occurrence of radiocesium during dry and wet weather, and analyzed the variations in radiocesium during rainfall events and factors controlling them. Concentrations of particulate radiocesium decreased rapidly from May 2012 to March 2013 and reached an equilibrium in 2014. Concentrations of particulate (137)Cs during wet weather were almost double those during dry weather in the same period. In contrast to the small variations in (137)Cs concentrations in the particulate phase on a suspended solids (SS) weight basis during events, those in the dissolved phase on a liquid-volume basis fluctuated greatly, resulting in variations in the partition coefficient (apparent Kd). The apparent Kd of (137)Cs during wet weather ranged from 30,000 to 150,000 L kg(-1) and showed a significant negative correlation with SS concentrations during wet weather. Specific surface area in solids contributed to the variations in apparent Kd.
Collapse
Affiliation(s)
- Michio Murakami
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8505, Japan; Department of Health Risk Communication, School of Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima City, 960-1295, Japan.
| | - Nao Shibayama
- Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Keisuke Sueki
- Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Goro Mouri
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8505, Japan
| | - Haechong O
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8563, Japan
| | - Mihiro Nomura
- Faculty of Arts and Sciences Programs in English at Komaba (PEAK), The International Program on Environmental Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo, 153-8902, Japan
| | - Yukio Koibuchi
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8563, Japan
| | - Taikan Oki
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8505, Japan
| |
Collapse
|
27
|
Yang B, Onda Y, Wakiyama Y, Yoshimura K, Sekimoto H, Ha Y. Temporal changes of radiocesium in irrigated paddy fields and its accumulation in rice plants in Fukushima. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 208:562-570. [PMID: 26561453 DOI: 10.1016/j.envpol.2015.10.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Revised: 10/17/2015] [Accepted: 10/19/2015] [Indexed: 06/05/2023]
Abstract
About half of the total paddy field area, which is the dominant agricultural land in Fukushima Prefecture, was contaminated by radiocesium released by the Fukushima Daiichi Nuclear Power Plant accident. In this study, we investigated the temporal changes of radiocesium in soil, irrigation water, and rice plant in two adjacent rice paddies, with and without surface-soil-removal, in Fukushima Prefecture for over three years (2012-2014) after the nuclear accident. Our results showed that radiocesium migrated into 24-28 cm soil layers and that the activity concentration of radiocesium in paddy soils showed a significant reduction in 2014. The newly added radiocesium to paddies through irrigation water contributed only a maximum value of 0.15% and 0.75% of the total amount present in control and decontaminated paddies, respectively, throughout the study period. The radiocesium activity concentration in suspended sediment in irrigation water exponentially decreased, and the effective half-lives (Teff) for (137)Cs and (134)Cs were 1.3 and 0.9 years, respectively. Additionally, the average suspended sediment concentration in irrigation water increased between 2012 and 2014, suggesting that enhanced soil erosion had occurred in the surrounding environment. Radiocesium accumulation in rice plant also decreased with time in both paddies. However, the concentration ratio of radiocesium for rice plant in the decontaminated paddy increased compared with control paddy, despite approximately 96% of fallout radiocesium removed in paddy soil. Further analysis is required to clarify the reasons of high concentration ratio of radiocesium for rice plant in the decontaminated paddy.
Collapse
Affiliation(s)
- Baolu Yang
- Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China; Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, 305-8572, Japan.
| | - Yuichi Onda
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, 305-8572, Japan
| | - Yoshifumi Wakiyama
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Kazuya Yoshimura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, Tokyo, 100-8577, Japan
| | - Hitoshi Sekimoto
- Faculty of Agriculture, Utsunomiya University, Utsunomiya, 321-8505, Japan
| | - Yiming Ha
- Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| |
Collapse
|
28
|
Eyrolle-Boyer F, Boyer P, Garcia-Sanchez L, Métivier JM, Onda Y, De Vismes A, Cagnat X, Boulet B, Cossonnet C. Behaviour of radiocaesium in coastal rivers of the Fukushima Prefecture (Japan) during conditions of low flow and low turbidity--Insight on the possible role of small particles and detrital organic compounds. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 151 Pt 1:328-340. [PMID: 26588202 DOI: 10.1016/j.jenvrad.2015.10.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/25/2015] [Accepted: 10/26/2015] [Indexed: 06/05/2023]
Abstract
To investigate riverine transfers from contaminated soils of the Fukushima Prefecture in Japan to the marine environment, suspended sediments, filtered water, sediments and detrital organic macro debris deposited onto river beds were collected in November 2013 within small coastal rivers during conditions of low flow rates and low turbidity. River waters were directly filtered on the field and high efficiency well-type Ge detectors were used to analyse radiocaesium concentrations in very small quantities of suspended particles and filtered water (a few mg to a few g). For such base-flow conditions, our results show that the watersheds studied present similar hydro-sedimentary behaviours at their outlets and that the exports of dissolved and particulate radiocaesium are comparable. Moreover, the contribution of these rivers to the instantaneous export of radiocaesium to the ocean is similar to that of the Abukuma River. Our preliminary results indicate that, in the estuaries, radiocaesium concentrations in suspended sediments would be reduced by more than 80%, while radiocaesium concentration in filtered waters would be maintained. Significant correlations between radiocaesium concentrations and radiocaesium inventories in the soils of the catchments indicate that there was at that time little intra and inter-watershed variability in the transfer processes of radiocaesium from lands to rivers at this regional scale. The apparent liquid-solid partition coefficient (KD) values acquired for the lowest loads/finest particles complement the values acquired by using sediment traps and highlight the strong capacity of the smallest particles to transfer radiocaesium. Finally, but not least, our observations suggest that there could be a significant transfer of highly contaminated detrital biomass from forest litter to the downstream rivers in a rather conservative way.
Collapse
Affiliation(s)
- Frédérique Eyrolle-Boyer
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France.
| | - Patrick Boyer
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France
| | - Laurent Garcia-Sanchez
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France
| | - Jean-Michel Métivier
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France
| | - Yuichi Onda
- Center for Research in Isotopes and Environmental Dynamics (CRIED), Tsukuba University, Tsukuba, Japan
| | - Anne De Vismes
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France
| | - Xavier Cagnat
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France
| | - Béatrice Boulet
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France
| | - Catherine Cossonnet
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV, SESURE/LERCM, SERIS/LM2E, L2BT, STEME/LMRE, BP 3, 13115, Saint Paul Lez Durance, France
| |
Collapse
|
29
|
Evrard O, Laceby JP, Lepage H, Onda Y, Cerdan O, Ayrault S. Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 148:92-110. [PMID: 26142817 DOI: 10.1016/j.jenvrad.2015.06.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/11/2015] [Accepted: 06/22/2015] [Indexed: 06/04/2023]
Abstract
The devastating tsunami triggered by the Great East Japan Earthquake on March 11, 2011 inundated the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) resulting in a loss of cooling and a series of explosions releasing the largest quantity of radioactive material into the atmosphere since the Chernobyl nuclear accident. Although 80% of the radionuclides from this accidental release were transported over the Pacific Ocean, 20% were deposited over Japanese coastal catchments that are subject to frequent typhoons. Among the radioisotopes released during the FDNPP accident, radiocesium ((134)Cs and (137)Cs) is considered the most serious current and future health risk for the local population. The goal of this review is to synthesize research relevant to the transfer of FDNPP derived radiocesium from hillslopes to the Pacific Ocean. After radiocesium fallout deposition on vegetation and soils, the contamination may remain stored in forest canopies, in vegetative litter on the ground, or in the soil. Once radiocesium contacts soil, it is quickly and almost irreversibly bound to fine soil particles. The kinetic energy of raindrops instigates the displacement of soil particles, and their bound radiocesium, which may be mobilized and transported with overland flow. Soil erosion is one of the main processes transferring particle-bound radiocesium from hillslopes through rivers and streams, and ultimately to the Pacific Ocean. Accordingly this review will summarize results regarding the fundamental processes and dynamics that govern radiocesium transfer from hillslopes to the Pacific Ocean published in the literature within the first four years after the FDNPP accident. The majority of radiocesium is reported to be transported in the particulate fraction, attached to fine particles. The contribution of the dissolved fraction to radiocesium migration is only relevant in base flows and is hypothesized to decline over time. Owing to the hydro-meteorological context of the Fukushima region, the most significant transfer of particulate-bound radiocesium occurs during major rainfall and runoff events (e.g. typhoons and spring snowmelt). There may be radiocesium storage within catchments in forests, floodplains and even within hillslopes that may be remobilized and contaminate downstream areas, even areas that did not receive fallout or may have been decontaminated. Overall this review demonstrates that characterizing the different mechanisms and factors driving radiocesium transfer is important. In particular, the review determined that quantifying the remaining catchment radiocesium inventory allows for a relative comparison of radiocesium transfer research from hillslope to catchment scales. Further, owing to the variety of mechanisms and factors, a transdisciplinary approach is required involving geomorphologists, hydrologists, soil and forestry scientists, and mathematical modellers to comprehensively quantify radiocesium transfers and dynamics. Characterizing radiocesium transfers from hillslopes to the Pacific Ocean is necessary for ongoing decontamination and management interventions with the objective of reducing the gamma radiation exposure to the local population.
Collapse
Affiliation(s)
- Olivier Evrard
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France.
| | - J Patrick Laceby
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France
| | - Hugo Lepage
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France
| | - Yuichi Onda
- Graduate School of Life and Environmental Sciences, Center for Research in Isotopes and Environmental Dynamics (CRIED), University of Tsukuba, Tsukuba, Japan
| | - Olivier Cerdan
- Bureau de Recherches Géologiques et Minières, Orléans, France
| | - Sophie Ayrault
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France
| |
Collapse
|