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Kazakevičiūtė-Jakučiūnienė L, Druteikienė R, Maceika E, Lukšienė B, Juškėnas R, Pakštas V, Žukauskaitė Z, Gvozdaitė R, Tarasiuk N. Impact of soil organic matter on Pu migration in five Lithuanian surface soils. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 237:106702. [PMID: 34284309 DOI: 10.1016/j.jenvrad.2021.106702] [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: 07/18/2020] [Revised: 06/28/2021] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
Pu distribution coefficient Kd variation was experimentally determined and examined in natural soil samples considering the type of soil, particle size, pH, the concentration of macroelements and organic matter content. This research was carried out with sand, silty sand, peat, clayey sand and clayey loam samples by applying 236Pu tracer in flow-through column tests. Due to relatively short contact time of 0.5-40 h the tests are considered as have not reached equilibrium state and represent the fast-moving contaminants retardation processes closer to field conditions. Every soil sample was fractionated into two particle size fractions: ≤0.25 mm and 0.25 ÷ 0.5 mm. Analysis revealed that Kd of Pu is higher for the smaller soil particle fraction (≤0.25 mm). The experimental study with 1.6, 4, 6 and 9 pH tracer solution revealed a tendency of elevated Kd when 4 pH and 6 pH solutions were applied, but obtained Kd values were not correlated with initial soil pH due to high buffering capacity of soils. This study shows a very significant influence (r = 0.98) of organic matter content on the Pu distribution coefficient. The Kd of Pu for the fine fraction of peat soil with high organic matter content (67%) reached maximum values of 6597 L/kg and 6200 L/kg when tracer solution was applied of pH = 4 and pH = 6, respectively. In comparison, the minimum Kd value of 3.9 L/kg was obtained for the coarse silty sand fraction with the lowest organic matter content of 1.3% at tracer pH = 1.6. A statistically reliable high correlations of r = 0.95 and 0.94 were also observed between Kd and specific soil elements Mg and Pb content in soils, respectively. The content of Fe in soils was significantly correlated (r = 0.67) with the Kd values of plutonium as well. However, the organic matter content in soils appeared to be the governing factor determining good correlations and causing the highest Kd of Pu values.
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Affiliation(s)
| | - Rūta Druteikienė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Evaldas Maceika
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania.
| | - Benedikta Lukšienė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Remigijus Juškėnas
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Vidas Pakštas
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Zita Žukauskaitė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Rasa Gvozdaitė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Nikolaj Tarasiuk
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
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Bouisset P, Nohl M, Cossonnet C, Boulet B, Thomas S, Cariou N, Salaun G. Contribution of close-in fallout from the French atmospheric tests in inventories of 137Cs, 241Am and plutonium (238, 239, 240) in Gambier Islands (French Polynesia) - Signatures of stratospheric fallout in the Southern Hemisphere. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 235-236:106624. [PMID: 34059369 DOI: 10.1016/j.jenvrad.2021.106624] [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: 12/23/2020] [Revised: 04/10/2021] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
The inventories of 137Cs (503 ± 34 Bq.m-2), 241Am (11.3 ± 1.2 Bq.m-2), 241Pu (33.7 ± 3.4 Bq.m-2), 238Pu (6.82 ± 0.87 Bq.m-2) and 239+240Pu (113.0 ± 5.9 Bq.m-2), sum of 239Pu (100 ± 11 Bq.m-2) and 240Pu (14.5 ± 1.7 Bq.m-2), in the Gambier archipelago (23°S) of the French Polynesia, are well higher the global fallout at this latitude, in unequal proportions for the different radionuclides. (240Pu/239Pu)AR (AR: atomic ratio) of 0.0394 ± 0.0062, and (241Pu/239Pu)AR of (2.03 ± 0.39)10-4, confirm that the overwhelmingly dominant source of these radionuclides comes from local fallout during the 1970s of the French atmospheric tests of Moruroa and Fangataufa located nearly 400 km from Gambier. The signatures of the local fallout were deduced from the excess of its inventory in 137Cs and from the mixing lines established from the signatures of the global fallout, some of the test sites and the isotopic ratios measured in Gambier. Signatures obtained are 2.0 ± 0.4 for 137Cs/239+240Pu, 0.045 ± 0.008 for 238Pu/239+240Pu, 0.031 ± 0.009 for 241Am/239+240Pu, 0.092 ± 0.027 for 241Pu/239+240Pu, 0.0163 ± 0.0049 for (240Pu/239Pu)AR, (0.78 ± 0.23)10-4 for (241Pu/239Pu)AR. The concordance of the mixing lines of the [(240Pu/239Pu)AR, (241Pu/239Pu)AR] and the linear regression of these ratios measured in the stratosphere (40°S) during the 1970s, indicates that the signatures of the close-in deposition are also those of the stratospheric injections of the French tests. The signatures of stratospheric fallout in the Southern Hemisphere were evaluated by considering that the fission energy of these injections represents 11% and that of the Northern Hemisphere represents 89% and that the isotopic ratios of stratospheric injections remained the same over the period 1970-1974. The activity ratios deducted are 21.9 ± 0.1 in 137Cs/239+240Pu, 0.11 ± 0.05 in 238Pu/239+240Pu, 1.03 ± 0.12 in 241Pu/239+240Pu and 0.35 ± 0.04 in 241Am/239+240Pu. The associated atom ratios are 0.157 ± 0.011 for (240Pu/239Pu)AR and (8.33 ± 0.48)10-4 for (241Pu/239Pu)AR. These signatures appear to be consistent with the results of the inventories at Hiva Oa, located more than 1,000 km north of both French test sites, and with those found in the Australian continent, in regions not impacted by UK-test debris. The proportions of close-in tropospheric fallout from the French tests are about 90% in Gambier. They represent a proportion in the inventories of 40% for the 137Cs, 60% for 241Am and in the range between 80 and 90% for Pu isotopes.
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Affiliation(s)
- P Bouisset
- Institut de Radioprotection et de Sûreté nucléaire, BP 182, 98725, Vairao, Tahiti, French Polynesia.
| | - M Nohl
- Institut de Radioprotection et de Sûreté nucléaire, BP 182, 98725, Vairao, Tahiti, French Polynesia
| | - C Cossonnet
- Institut de Radioprotection et de Sûreté nucléaire, Bât 501, bois des Rames, 91400, Orsay, France
| | - B Boulet
- Institut de Radioprotection et de Sûreté nucléaire, Bât 501, bois des Rames, 91400, Orsay, France
| | - S Thomas
- Institut de Radioprotection et de Sûreté nucléaire, Bât 501, bois des Rames, 91400, Orsay, France
| | - N Cariou
- Institut de Radioprotection et de Sûreté nucléaire, Bât 501, bois des Rames, 91400, Orsay, France
| | - G Salaun
- Institut de Radioprotection et de Sûreté nucléaire, Cadarache Bât 153, 13108, St Paul-lès-Durance, France
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Alpha emitters in the beach sands of the Mexican Pacific littoral. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06616-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Determination of plutonium-241 in low-level radwastes using radiochemical separation combined with LSC, alpha spectrometer and ICP-MS. J Radioanal Nucl Chem 2018. [DOI: 10.1007/s10967-018-6362-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ni Y, Wang Z, Guo Q, Zheng J, Li S, Lin J, Tan Z, Huang W. Distinctive distributions and migrations of 239+240Pu and 241Am in Chinese forest, grassland and desert soils. CHEMOSPHERE 2018; 212:1002-1009. [PMID: 30286529 DOI: 10.1016/j.chemosphere.2018.09.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/10/2018] [Accepted: 09/03/2018] [Indexed: 06/08/2023]
Abstract
The vertical distributions and downward migrations of the global fallout derived 239+240Pu and 241Am in diverse types of Chinese soils (forest, grassland and desert) were studied. The mean 239+240Pu and 241Am activity concentrations in the investigated soil cores were 0.28-0.69 mBq/g and 0.13-0.37 mBq/g, respectively, while the accumulative inventories were 61.53-138.99 Bq/m2 for 239+240Pu and 28.29-61.05 Bq/m2 for 241Am. The convection-dispersion equation (CDE) was used to calculate the migration parameters of 239+240Pu and higher apparent dispersion coefficients (D) were observed for the acidic forest soils compared with the alkaline grassland and desert soils; meanwhile a compartment model was employed to compare the migration of 239+240Pu and 241Am in successive soil layers which showed that the migration behaviors of 239+240Pu and 241Am were rather similar; both velocities were less than 0.3 cm/y in diverse types of soils and these findings were compatible with those of short-term laboratory simulation experiments in China.
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Affiliation(s)
- Youyi Ni
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China; National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan
| | - Zhongtang Wang
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
| | - Qiuju Guo
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Jian Zheng
- National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan.
| | - Sixuan Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Jinxian Lin
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China
| | - Zhaoyi Tan
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China
| | - Wenna Huang
- Radiation Monitoring Technical Center of Ministry of Environmental Protection, Hangzhou 310012, China
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Bouisset P, Nohl M, Bouville A, Leclerc G. Inventory and vertical distribution of 137Cs, 239+240Pu and 238Pu in soil from Raivavae and Hiva Oa, two French Polynesian islands in the southern hemisphere. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 183:82-93. [PMID: 29306711 DOI: 10.1016/j.jenvrad.2017.12.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/20/2017] [Accepted: 12/24/2017] [Indexed: 06/07/2023]
Abstract
Atmospheric nuclear weapons tests carried out by the United States, the former Soviet Union, the United Kingdom, France and China between 1945 and 1980 resulted in radioactive fallout over the earth's surface of long-lived radionuclides, such as 137Cs, 239+240Pu and 238Pu that could be detected more than 50 years after their production. In addition, the burnup in the upper atmosphere of a thermoelectric generator fueled by 238Pu, SNAP-9A, contributed to the inventory of 238Pu deposited on the ground. In order to estimate the deposition densities of 137Cs, 239+240Pu and 238Pu in French Polynesia, we collected undisturbed soil samples up to 30 cm deep at eight sites in two islands (Hiva Oa, 139°W - 10°S and Raivavae, 148°W - 24°S) in 2015-2016. The top 0-10 cm of the soil cores were sliced into five 2-cm layers and the bottom 10-30 cm into four 5-cm layers for gamma spectrometry and alpha spectrometry measurements. We found that more than 50% of the radioactive inventories are still contained within the first 10 cm and that the average vertical migration velocities of 137Cs and Pu are less than 0.2 cm y-1. The average accumulated depositions, deduced from the profile measurements, are 236 ± 11 Bq.m-2 and 313 ± 39 Bq.m-2 for 137Cs, 12.1 ± 1.5 Bq.m-2 and 22.1 ± 1.7 Bq.m-2 for 239+240Pu, and 1.23 ± 0.46 Bq.m-2 and 1.58 ± 0.60 Bq.m-2 for 238Pu, in Hiva Oa and Raivavae, respectively. The 238Pu/239+240Pu ratios are 0.102 ± 0.050 at Hiva Oa and 0.072 ± 0.033 at Raivavae. Both values are higher than the ratio in nuclear weapons tests fallout estimated to be 0.016 in 2016 (Hardy et al., 1973), because of the contribution of 238Pu fallout from SNAP-9A, which is latitude dependent. The 137Cs/239+240Pu ratios, 19.5 ± 3.2 at Hiva Oa and 14.2 ± 2.8 at Raivavae are in the lower part of the range of values observed in other regions of the world.
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Affiliation(s)
- P Bouisset
- Institut de Radioprotection et de Sûreté Nucléaire, BP 182 - 98725 Vairao, Tahiti, French Polynesia.
| | - M Nohl
- Institut de Radioprotection et de Sûreté Nucléaire, BP 182 - 98725 Vairao, Tahiti, French Polynesia
| | - A Bouville
- National Cancer Institute, 9609 Medical Center Drive, Rockville, MD, United States
| | - G Leclerc
- Institut de Radioprotection et de Sûreté Nucléaire, BP 182 - 98725 Vairao, Tahiti, French Polynesia
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Lin P, Xu C, Zhang S, Fujitake N, Kaplan DI, Yeager CM, Sugiyama Y, Schwehr KA, Santschi PH. Plutonium Partitioning Behavior to Humic Acids from Widely Varying Soils Is Related to Carboxyl-Containing Organic Compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11742-11751. [PMID: 28933160 DOI: 10.1021/acs.est.7b03409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In order to examine the influence of the HA molecular composition on the partitioning of Pu, ten different kinds of humic acids (HAs) of contrasting chemical composition, collected and extracted from different soil types around the world were equilibrated with groundwater at low Pu concentrations (10-14 M). Under mildly acidic conditions (pH ∼ 5.5), 29 ± 24% of the HAs were released as colloidal organic matter (>3 kDa to <0.45 μm), yet this HA fraction accounted for a vast majority of the bound Pu, 76 ± 13% on average. In comparison, the particulate HA fraction bound only 8 ± 4% on average of the added Pu. The truly dissolved Pu fraction was typically <1%. Pu binding was strongly and positively correlated with the concentrations of organic nitrogen in both particulate (>0.45 μm) and colloidal phases in terms of activity percentage and partitioning coefficient values (logKd). Based on molecular characterization of the HAs by solid state 13C nuclear magnetic resonance (NMR) and elemental analysis, Pu binding was correlated to the concentration of carboxylate functionalities and nitrogen groups in the particulate and colloidal phases. The much greater tendency of Pu to bind to colloidal HAs than to particulate HA has implications on whether NOM acts as a Pu source or sink during natural or man-induced episodic flooding.
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Affiliation(s)
- Peng Lin
- Department of Marine Science, Texas A & M University at Galveston , Galveston, Texas 77553, United States
| | - Chen Xu
- Department of Marine Science, Texas A & M University at Galveston , Galveston, Texas 77553, United States
| | - Saijin Zhang
- Department of Marine Science, Texas A & M University at Galveston , Galveston, Texas 77553, United States
| | - Nobuhide Fujitake
- Division of Agroenvironmental Biology, Graduate School of Agriculture Science, Kobe University , Kyoto, 606-8501, Japan
| | - Daniel I Kaplan
- Savannah River National Laboratory , Aiken, South Carolina 29808, United States
| | - Chris M Yeager
- Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Yuko Sugiyama
- School of Human Science and Environment, University of Hyogo , 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Kathleen A Schwehr
- Department of Marine Science, Texas A & M University at Galveston , Galveston, Texas 77553, United States
| | - Peter H Santschi
- Department of Marine Science, Texas A & M University at Galveston , Galveston, Texas 77553, United States
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Bu W, Zheng J, Guo Q, Uchida S. Vertical distribution and migration of global fallout Pu in forest soils in southwestern China. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2014; 136:174-180. [PMID: 24963802 DOI: 10.1016/j.jenvrad.2014.06.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/30/2014] [Accepted: 06/08/2014] [Indexed: 06/03/2023]
Abstract
Soil samples collected in southwestern China were analyzed for Pu isotopes. The (240)Pu/(239)Pu atom ratios were around 0.18, which indicated the dominant source of global fallout. Consistent sub-surface maximums followed by exponential decline of (239+240)Pu activities in the soil cores were observed. Most of the Pu has still remained in the 0-10 cm layers since its deposition. Convection velocities and dispersion coefficients for Pu migration in the soils were estimated by the convection-dispersion equation (CDE) model. The effective convection velocities and effective dispersion coefficients ranged from 0.05 to 0.11 cm/y and from 0.06 to 0.29 cm(2)/y, respectively. Other factors that control the vertical migration of Pu in soil besides precipitation, soil particle size distribution and organic matter were suggested. Long-term migration behaviors of Pu in the soils were simulated. The results provide the Pu background baseline for further environmental monitoring and source identification of non-global fallout Pu inputs in the future.
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Affiliation(s)
- Wenting Bu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China; Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan
| | - Jian Zheng
- Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan.
| | - Qiuju Guo
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China.
| | - Shigeo Uchida
- Research Center of Radiation Protection, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage, Chiba 263-8555, Japan
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Abstract
A simple and rapid procedure for the determination of plutonium isotopes in the environment is presented. The procedure combines alpha spectrometry, solvent extraction and liquid scintillation measurements to ensure that both alpha- and beta-emitting isotopes are determined. Of five tested extractants, bis-(2-ethylhexyl) phosphoric acid was found to be the best choice. The procedure was applied to soil samples contaminated with Chernobyl fallout.
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Affiliation(s)
- M Piekarz
- Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warsaw, Poland
| | - A Komosa
- Maria Curie-Sklodowska University, Pl. M. C. Sklodowskiej 3, 20-031 Lublin, Poland
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