1
|
Periáñez R, Brovchenko I, Jung KT, Kim KO, Liptak L, Little A, Kobayashi T, Maderich V, Min BI, Suh KS. Some considerations on the dependence to numerical schemes of Lagrangian radionuclide transport models for the aquatic environment. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 261:107138. [PMID: 36841197 DOI: 10.1016/j.jenvrad.2023.107138] [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: 05/04/2020] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 06/18/2023]
Abstract
Lagrangian models present several advantages over Eulerian models to simulate the transport of radionuclides in the aquatic environment in emergency situations. A radionuclide release is simulated as a number of particles whose trajectories are calculated along time and thus these models do not require a spatial discretization (although it is always required in time). In this paper we investigate the dependence of a Lagrangian model output with the grid spacing which is used to calculate concentrations from the final distribution of particles, with the number of particles in the simulation and with the interpolation schemes which are required because of the discrete nature of the water circulation data used to feed the model. Also, a Lagrangian model may describe the exchanges of radionuclides between phases (liquid and solid), which is done in terms of transition probabilities. The dependence of these probabilities with time step is analyzed as well. It was found that the optimum grid size used to calculate concentrations should be carefully checked, and that temporal interpolation is more significant than spatial interpolation to obtain a more accurate solution. A method to estimate the number of particles required to have a certain accuracy level is proposed. Finally, it was found that for low sediment concentrations and small radionuclide kd, exact equations for the transition probabilities should be used; and that phase transitions introduce a stability condition as in Eulerian models.
Collapse
Affiliation(s)
- R Periáñez
- Dpt Física Aplicada I, ETSIA Universidad de Sevilla, Ctra Utrera km 1, 41013-Sevilla, Spain.
| | - I Brovchenko
- Institute of Mathematical Machine and System Problems, Glushkov av., 42, Kiev 03187, Ukraine
| | - K T Jung
- Environmental Research Institute of Oceanic Co. Ltd., 403 Munlnva-Building, 90 Yangpyung-ro, Yeongdeungpo-gu, Seoul, Republic of Korea
| | - K O Kim
- Korea Institute of Ocean Science and Technology, 385, Haeyang-ro, Yeongdo-gu, Busan Metropolitan City, Republic of Korea
| | - L Liptak
- AB Merit s.r.o., Hornopotocna 1, 917 01 Trnava, Slovakia
| | - A Little
- Defence Academy of the United Kingdom, HMS Sultan, Military Road Gosport, Hampshire P012 3BY, UK
| | - T Kobayashi
- Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Ibaraki 319-1195, Japan
| | - V Maderich
- Institute of Mathematical Machine and System Problems, Glushkov av., 42, Kiev 03187, Ukraine
| | - B I Min
- Korea Atomic Energy Research Institute, Daedeok-Daero 989-111, Yuseong-Gu, Daejeon, Republic of Korea
| | - K S Suh
- Korea Atomic Energy Research Institute, Daedeok-Daero 989-111, Yuseong-Gu, Daejeon, Republic of Korea
| |
Collapse
|
2
|
Hirose K. Fukushima Daiichi Nuclear Plant accident: Atmospheric and oceanic impacts over the five years. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 157:113-130. [PMID: 27032342 DOI: 10.1016/j.jenvrad.2016.01.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 01/21/2016] [Indexed: 06/05/2023]
Abstract
The Fukushima Daiichi Nuclear Plant (FDNPP) accident resulted in huge environmental and socioeconomic impacts to Japan. To document the actual environmental and socioeconomic effects of the FDNPP accident, we describe here atmospheric and marine contamination due to radionuclides released from the FDNPP accident using papers published during past five years, in which temporal and spatial variations of FDNPP-derived radionuclides in air, deposition and seawater and their mapping are recorded by local, regional and global monitoring activities. High radioactivity-contaminated area in land were formed by the dispersion of the radioactive cloud and precipitation, depending on land topography and local meteorological conditions, whereas extremely high concentrations of (131)I and radiocesium in seawater occurred due to direct release of radioactivity-contaminated stagnant water in addition to atmospheric deposition. For both of atmosphere and ocean, numerical model simulations, including local, regional and global-scale modeling, were extensively employed to evaluate source terms of the FDNPP-derived radionuclides from the monitoring data. These models also provided predictions of the dispersion and high deposition areas of the FDNPP-derived radionuclides. However, there are significant differences between the observed and simulated values. Then, the monitoring data would give a good opportunity to improve numerical modeling.
Collapse
Affiliation(s)
- Katsumi Hirose
- Department of Materials and Life Sciences, Sophia University, Tokyo, Japan.
| |
Collapse
|
3
|
Inomata Y, Aoyama M, Tsubono T, Tsumune D, Hirose K. Spatial and temporal distributions of (134)Cs and (137)Cs derived from the TEPCO Fukushima Daiichi Nuclear Power Plant accident in the North Pacific Ocean by using optimal interpolation analysis. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2016; 18:126-136. [PMID: 26662211 DOI: 10.1039/c5em00324e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Optimal interpolation (OI) analysis was used to investigate the oceanic distributions of (134)Cs and (137)Cs released from the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant (FNPP1) accident. From the end of March to early April 2011, extremely high activities were observed in the coastal surface seawater near the FNPP1. The high activities spread to a region near 165°E in the western North Pacific Ocean, with a latitudinal center of 40°N. Atmospheric deposition also caused high activities in the region between 180° and 130°W in the North Pacific Ocean. The inventory of FNPP1-released (134)Cs in the North Pacific Ocean was estimated to be 15.3 ± 2.6 PBq. About half of this activity (8.4 ± 2.6 PBq) was found in the coastal region near the FNPP1. After 6 April 2011, when major direct releases ceased, the FNPP1-released (134)Cs in the coastal region decreased exponentially with an apparent half-time of about 4.2 ± 0.5 days and declined to about 2 ± 0.4 PBq by the middle of May 2011. Taking into account that the (134)Cs/(137)Cs activity ratio was about 1 just after release and was extremely uniform during the first month after the accident, the amount of (137)Cs released by the FNPP1 accident increased the North Pacific inventory of (137)Cs due to bomb testing during the 1950s and early 1960s by 20%.
Collapse
Affiliation(s)
- Y Inomata
- Atmospheric Research Department, Asia Center for Air Pollution Research, 1182, Sowa, Nishiku, Niigata-shi, Niigata-ken 950-2144, Japan.
| | - M Aoyama
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima-shi, Fukushima-ken 960-1296, Japan
| | - T Tsubono
- Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba-ken 270-1194, Japan
| | - D Tsumune
- Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba-ken 270-1194, Japan
| | - K Hirose
- Department of Material and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyodaku, Tokyo 102-8554, Japan
| |
Collapse
|
4
|
Maderich V, Jung KT, Bezhenar R, de With G, Qiao F, Casacuberta N, Masque P, Kim YH. Dispersion and fate of ⁹⁰Sr in the Northwestern Pacific and adjacent seas: global fallout and the Fukushima Dai-ichi accident. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 494-495:261-271. [PMID: 25058893 DOI: 10.1016/j.scitotenv.2014.06.136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 06/28/2014] [Accepted: 06/28/2014] [Indexed: 06/03/2023]
Abstract
The 3D compartment model POSEIDON-R was applied to the Northwestern Pacific and adjacent seas to simulate the transport and fate of (90)Sr in the period 1945-2010 and to perform a radiological assessment on the releases of (90)Sr due to the Fukushima Dai-ichi nuclear accident for the period 2011-2040. The contamination due to runoff of (90)Sr from terrestrial surfaces was taken into account using a generic predictive model. A dynamical food-chain model describes the transfer of (90)Sr to phytoplankton, zooplankton, molluscs, crustaceans, piscivorous and non-piscivorous fishes. Results of the simulations were compared with observation data on (90)Sr for the period 1955-2010 and the budget of (90)Sr activity was estimated. It was found that in the East China Sea and Yellow Sea the riverine influx was 1.5% of the ocean influx and it was important only locally. Calculated concentrations of (90)Sr in water, bottom sediment and marine organisms before and after the Fukushima Dai-ichi accident are in good agreement with available experimental measurements. The concentration of (90)Sr in seawater would return to the background levels within one year after leakages were stopped. The model predicts that the concentration of (90)Sr in fish after the Fukushima Dai-ichi accident shall return to the background concentrations only 2 years later due to the delay of the transfer throughout the food web and specific accumulation of (90)Sr. The contribution of (90)Sr to the maximal dose rate due to the FDNPP accident was three orders of magnitude less than that due to (137)Cs, and thus well below the maximum effective dose limits for the public.
Collapse
Affiliation(s)
- V Maderich
- Institute of Mathematical Machine and System Problems, Glushkov av., 42, Kiev 03187, Ukraine.
| | - K T Jung
- Korea Institute of Ocean Science and Technology, 787, Haean-ro, Ansan 426-744, Republic of Korea.
| | - R Bezhenar
- Ukrainian Center of Water and Environmental Projects, Glushkov av., 42, Kiev 03187, Ukraine.
| | - G de With
- NRG, Utrechtseweg 310, 6800 ES Arnhem, The Netherlands.
| | - F Qiao
- First Institute of Oceanography, 6 Xianxialing Road, Qingdao 266061, China.
| | - N Casacuberta
- Laboratory of Ion Beam Physics, ETH-Zurich, Schafmattstrasse 20, 8093 Zurich, Switzerland.
| | - P Masque
- Institut de Ciència i Tecnologia Ambientals & Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
| | - Y H Kim
- Korea Institute of Ocean Science and Technology, 787, Haean-ro, Ansan 426-744, Republic of Korea.
| |
Collapse
|
5
|
Inomata Y, Aoyama M, Tsumune D, Motoi T, Nakano H. Optimum interpolation analysis of basin-scale ¹³⁷Cs transport in surface seawater in the North Pacific Ocean. JOURNAL OF ENVIRONMENTAL MONITORING : JEM 2012; 14:3146-55. [PMID: 23117411 DOI: 10.1039/c2em30707c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
¹³⁷Cs is one of the conservative tracers applied to the study of oceanic circulation processes on decadal time scales. To investigate the spatial distribution and the temporal variation of ¹³⁷Cs concentrations in surface seawater in the North Pacific Ocean after 1957, a technique for optimum interpolation (OI) was applied to understand the behaviour of ¹³⁷Cs that revealed the basin-scale circulation of Cs ¹³⁷Cs in surface seawater in the North Pacific Ocean: ¹³⁷Cs deposited in the western North Pacific Ocean from global fallout (late 1950s and early 1960s) and from local fallout (transported from the Bikini and Enewetak Atolls during the late 1950s) was further transported eastward with the Kuroshio and North Pacific Currents within several years of deposition and was accumulated in the eastern North Pacific Ocean until 1967. Subsequently, ¹³⁷Cs concentrations in the eastern North Pacific Ocean decreased due to southward transport. Less radioactively contaminated seawater was also transported northward, upstream of the North Equatorial Current in the western North Pacific Ocean in the 1970s, indicating seawater re-circulation in the North Pacific Gyre.
Collapse
Affiliation(s)
- Y Inomata
- Atmospheric Research Department, Asia Center For Air Pollution Research, Niigata, Japan.
| | | | | | | | | |
Collapse
|