Mechanisms and Models for Bentonite Erosion Used for Geologic Disposal of High Level Radioactive Waste: A Review
First author:Xu Yongfu (1967-), male, Taixing County, Jiangsu Province, Professor. Research areas include mechanics of fractal media, unsaturated soil mechanics and ground improvement.E-mail:yongfuxu@sjtu.edu.cn
Received date: 2017-04-20
Revised date: 2017-08-03
Online published: 2017-10-20
Supported by
Project supported by the National Natural Science Foundation of China “Geological disaster and its control method due to bentonite erosion under seepage at the bentonite/granite interface of a deep geological radioactive waste repository” (No.41630633).
Copyright
The performance of the bentonite buffer in nuclear waste repository concept relies to a great extent on the buffer surrounding the canister having sufficient dry density. Loss of buffer material caused by erosion remains as the most significant process reducing the density of the buffer. In the worst case, the process is assumed to last as long as the free volume between the pellets in the pellets filled regions is filled with groundwater. Erosion rate and mass erosion are calculated based on the erosion model, and the measures are presented to prevent the geological disaster due to bentonite erosion. The groundwaters may solubilise the smectite particles in the bentonite and carry them away as colloidal particles. A dynamic model is developed for sodium gel expansion in fractures where the gel soaks up groundwater as it expands. The model is based on a force balance between and on smectite particles, which move in the water. Attractive van der Waals forces, repulsive electric diffuse layer (DDL) forces, gravity and buoyancy forces and forces caused by the gradient of chemical potential of the particles act to move the particle in the water. The effect of the fracture width and the frictions between particles and water and surrouding rock is analysed based on erosion model. The DDL forces strongly depend on the type of clay minerals and the type of ion and concentration in the water surrounding the particles. In the designed safe use of nuclear waste disposal (tens of thousands of years to hundreds of thousands of years), the safety of nuclear waste disposal is affected by the hydrodynamic and chemical effects, and bentonite erosion. Due to the bentonite erosion, the buffer/backfill layers become loose, and their permeability increases, which causes the nuclear element diffusion and convection, and even the nuclear disaster. In this paper, the mechanisms, models, experiments and control measures of bentonite erosion were systematically summarized. The current deficiencies of bentonite erosion were pointed out, and new methods were put forward to carry out the research for bentonite erosion. The measures were presented to prevent the geological disaster due to bentonite erosion through changes. The project is not only academic innovation, but also has a large practical significance. The research results of this project can be widely applied to the design, construction and maintenance of the bentonite buffer in nuclear waste repository.
Key words: Nuclear waste; Geological disposal; Buffer/backfill layer; Bentonite; Erosion.
Yongfu Xu . Mechanisms and Models for Bentonite Erosion Used for Geologic Disposal of High Level Radioactive Waste: A Review[J]. Advances in Earth Science, 2017 , 32(10) : 1050 -1061 . DOI: 10.11867/j.issn.1001-8166.2017.10.1050
[1] | SKB. Interim Process Report for the Safety Assessment SR-Can[R]. Stockholm, Sweden:SKB R 04-33, Swedish Nuclear Fuel andWaste Management Co., 2004. |
[2] | Bennett D G.Bentonite Erosion[R]. Stockholm, Sweden:Swedish Nuclear Fuel and Waste Management Co., 2009. |
[3] | Pusch R.Stability of Bentonite Gels in Crystalline Rock-Physical Aspects[R]. Stockholm, Sweden:TR-83-04. Swedish Nuclear Fuel andWaste Management Co., 1983. |
[4] | Xu Y F, Matsuoka H, Sun D A.Swelling characteristics of fractal-textured bentonite and its mixtures[J]. Applied Clay Science, 2003, 22(4): 197-209. |
[5] | Qin Bing, Chen Zhenghan, Liu Yuemiao, et al. Swelling-shrinkage behaviour of Gaomiaozi bentonite[J]. Chinese Journal of Geotechnical Engineering, 2008, 30(7): 1 005-1 010. |
[5] | [秦冰,陈正汉,刘月妙,等. 高庙子膨润土的胀缩变形特性及其影响因素研究[J]. 岩土工程学报,2008,30(7):1 005-1 010.] |
[6] | Ye Weimin, Huang Wei, Chen Bao, et al. Diffuse double layer theory and volume change behavior of densely compacted Gaomiaozi bentonite[J]. Rock and Soil Mechanics, 2009, 30(7): 1 889-1 903. |
[6] | [叶为民,黄伟,陈宝,等. 双电层理论与高庙子膨润土的体变特征[J].岩土力学,2009,30(7):1 889-1 903.] |
[7] | Sun Wenjing, Liu Shiqing, Sun Dean, et al. Swelling characteristics of bentonite-sand mixtures with a high sand mixing ratio and its prediction[J]. Rock and Soil Mechanics, 2015, 37(9): 1 620-1 626. |
[7] | [孙文静,刘仕卿,孙德安,等. 高掺砂率膨润土混合土膨胀特性及其膨胀量预测[J]. 岩土力学,2015,37(9):1 620-1 626.] |
[8] | Missana T, Alonso U, Albarran N,et al. Analysis of colloids erosion from the bentonite barrier of a high level radioactive waste repository and implications in safety assessment[J]. Physics and Chemistry of the Earth, 2011, 36(17): 1 607-1 615. |
[9] | Pusch R.Clay Colloids Formation and Release from MX-80 Buffer[R]. SKB Technical Report No: TR-99-31, 1999. |
[10] | Xu Y F, Jiang H, Chu F F.Fractal model for surface erosion of cohesive sediments[J]. Fractals,2014, 3,doi: 10.1142/S0218348X14400064. |
[11] | Benna M, Kbir-Ariguib N, Mabnin A,et al. Effect of pH on rheological properties of purified sodium bentonite suspensions[J]. Journal of Colloid and Interface Science, 1999, 218(2): 442-455. |
[12] | Börgesson L, Nilsson U. Erosion in Fractures: Rheological properties of bentonite penetrating into fractures[C]∥Presented at the 7th Workshop on Bentonite Erosion, 2008, Stockholm, Sweden. |
[13] | Moreno L, Neretnieks I, Liu L.Bentonite expansion into seeping water[C]∥Presented at the 7th Workshop on Bentonite Erosion. Stockholm, Sweden,2008. |
[14] | Neretnieks I, Liu L, Moreno L.Mechanisms and Models for Bentonite Erosion[R]. Stockholm, Sweden: SKB TR-09-35,Swedish Nuclear Fuel andWaste Management Co., 2009. |
[15] | Kruyt H R.Colloid Science[M]. New York:Elsevier, 1952. |
[16] | Liu L, Moreno L, Neretnieks I.A novel approach to determine the critical coagulation concentration of a colloidal dispersion with plate-like particles[J]. Langmuir, 2009, 25(2): 688-697. |
[17] | Grindrod P, Peletier M, Takase H.Mechanical interaction between swelling compacted clay and fractured rock, and the leaching of clay colloids[J]. Engineering Geology, 1999, 54(1): 159-165. |
[18] | Jo H Y, Katsumi T, Benson C H.Hydraulic conductivity and swelling of nonprehydrated GCLs permeated with single-species salt solutions[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2001, 127(7): 557-567. |
[19] | Herbert H J, Kasbolini J, Sprenger H.Swelling pressures of MX-80 bentonite in solutions of different ionic strength[J].Physics and Chemistry of the Earth,2008,33: S327-S342. |
[20] | Zhang H Y, Cui S L, Zhang M.Swelling behaviors of GMZ bentonite-sand mixtures inundated in NaCl-Na2SO4 solutions[J]. Nuclear Engineering and Design, 2012, 242: 115-123. |
[21] | Sun Dean, Zhang Long.Swelling characteristics of Gaomiaozi bentonite saturated by salt solution and their prediction[J].Rock and Soil Mechanics, 2013, 34(10): 2 790-2 795. |
[21] | [孙德安,张龙. 盐溶液饱和高庙子膨润土膨胀特性及预测[J]. 岩土力学,2013,34(10): 2 790-2 795.] |
[22] | Xu Y F, Xiang G S, Jiang H.Role of osmotic suction in volume change of clays in salt solution[J]. Applied Clay Science, 2014, 101: 354-361. |
[23] | Ye W M, Zhang F, Chen B.Effects of salt solutions on the hydro-mechanical behavior of compacted GMZ bentonite[J]. Environmental Earth Sciences, 2014, 72(7): 2 621-2 630. |
[24] | Birgersson M, Börgesson L, Hedström K, et al. Bentinite Erosion[R]. Stockholm, Sweden: SKB TR-09-34, Swedish Nuclear Fuel and Waste Management Co., 2009. |
[25] | Chen Bao, Zhang Huixin, Chen Ping.Geochemical interactions between compacted Gaomiaozi bentonite and hyper-alkaline solution[J]. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(7): 1 478-1 485. |
[25] | [陈宝,张会新,陈萍. 高碱性溶液对高庙子膨润土溶蚀作用的研究[J]. 岩石力学与工程学报,2012,31(7):1 478-1 485.] |
[26] | Chen Bao, Zhang Huixin, Chen Ping.Erosion effect of hyper-alkaline solution on Gaomiaozi bentonite[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(1): 181-186. |
[26] | [陈宝,张会新,陈萍. 高碱溶液对高庙子膨润土侵蚀作用的研究[J]. 岩土工程学报,2013,35(1):181-186.] |
[27] | Winterwerp J C, van Kesteren W G M. Introduction to the Physics of Cohesive Sediment in the Marine Environment[M]. Amsterdam:Elsevier,2004. |
[28] | Sanford L P.Modeling a dynamically varying mixed sediments with erosion, deposition, bioturbation, consolidation, and armoring[J]. Computers & Geosciences, 2008, 34(10): 1 263-1 283. |
[29] | Kurosawa S, Kato H, Ueta S, et al. Erosion properties and dispersion- flocculation behavior of bentonite particles[J]. MRS Online Proceedings Library Archive, 1999, 556: 679-686. |
[30] | Knapen A, Poesen J, Govers G, et al. Resistance of soils to concentrated flow erosion: A review[J]. Earth-Science Reviews, 2007, 80: 75-109. |
[31] | Ariathurai R, Arulanandan K.Erosion rates of cohesive soils[J]. Journal of the Hydraulics Division, 1978, 104(2): 279-283. |
[32] | Parchure T M, Mehta A J.Erosion of soft cohesive sediment deposits[J]. Journal of Hydraulic Engineering, 1985, 111(10): 1 308-1 326. |
[33] | Liu L, Moreno L, Neretnieks I.Dynamic force balance model for colloidal expansion and its DLVO-based application[J]. Langmuir, 2009, 25(2): 679-687. |
[34] | Moreno L, Liu L C, Neretnieks I.Erosion of sodium bentonite by flow and colloid diffusion[J]. Physics and Chemistry of the Earth, 2011, 36(17): 1 600-1 606. |
[35] | Liu L C, Neretnieks I.Homo-interaction between parallel plates at constant charge[J].Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2008,317(1/2/3):636-642. |
[36] | Grabowski R C, Droppo I G, Wharton G.Erodibility of cohesive sediment: The importance of sediment properties[J]. Earth-Science Reviews, 2011, 105(3): 101-120. |
[37] | Cossette D, Mazurek K A, Rennie C D.Critical Shear Stress from Varied Method of Analysis of a Submerged Circular Turbulent Impinging Jet Test for Determining Erosion Resistance of Cohesive Soils[C]. Paris:6th International Conference on Scour and Erosion, 2012: 11-18. |
[38] | Hanson G J, Cook K R.Apparatus, test procedures, and analytical methods to measure soil erodibility in-situ[J]. Applied Engineering in Agriculture, 2004, 20(4): 455-462. |
[39] | Meakin P.Fractal aggregates[J]. Advances in Colloid and Lnterface Science, 1987, 28: 249-331. |
[40] | Kranenburg C.The fractal structure of cohesive sediment aggregates[J]. Estuarine, Coastal and Shelf Science, 1994, 39(6): 451-460. |
[41] | Black K S, Tolhurst T J, Paterson D M, et al. Working with natural cohesive sediments[J]. Journal of Hydraulic Engineering, 2002, 128(1): 2-8. |
[42] | Aberle J, Nikora V, Walters R.Effects of bed material properties on cohesive sediment erosion[J]. Marine Geology,2004, 207(1): 83-93. |
[43] | Hanson G J, Simon A.Erodibility of cohesive streambeds in the loess area of the midwestern USA[J]. Hydrological Processes,2001, 15(1): 23-38. |
[44] | Simon A, Pollen-Bankhead N, Thomas R E.Development and application of a deterministic bank stability and toe erosion model for stream restoration[J]. Geophysical Monograph Series,2001, 194: 453-474. |
[45] | Sane P, Laurila T, Olin M, ,et al. Current Status of Mechanical Erosion Studies of Bentonite Buffer[R]. Eurajoki. Current Status of Mechanical Erosion Studies of Bentonite Buffer[R]. Eurajoki, Finland:POSIVA Report2012-45, 2013. |
[46] | Chen Tao.Study on Bentonite Extrusion Process into Fracture and Erosion by Seepage in the Nuclear Water Repository[D]. Shanghai: Shanghai Jiao Tong University, 2016. |
[46] | [陈涛. 核废料处置库中膨润土在裂隙渗流作用下的侵蚀研究[D]. 上海:上海交通大学,2016.] |
[47] | Xu Y F, Gao Z R, Chu F F, et al. Fractal model for erosion mass of bentonite colloids[J]. Environmental Earth Sciences, 2016, 75(19): 1 330. |
[48] | Börgesson L, Sandén T.Piping and Erosion in Buffer and Backfill Materials: Current Knowledge[R]. Stockhdm, Sweden:Svensk Kärnbränslehantering AB, Swedish Nuclear Fuel and Waste Management Co., R-06-80, 2006. |
[49] | Baik M H, Cho W J, Hahn P S.Erosion of bentonite particles at the interface of a compacted bentonite and a fractured granite[J]. 2007, 91(2): 229-239. |
[50] | Jansson M.Laboratory Studies of Bentonite Erosion[R]. Stockholm, Sweden: Nuclear Chemistry, Royal Institute of Technology, KTH, 2009. |
[51] | Suzuki K, Asano H, Yagag R, et al. Experimental investigations of piping phenomena in bentonite-based buffer materials for an HLW repository[J]. Clay Minerals, 2013, 48(2): 363-382. |
[52] | Schatz T, Kanerva N, Martikainen J.Buffer Erosion in Dilute Groundwater[R].Finland, Eurgjoki: POSIVA 2012-44, 2013. |
[53] | Lahtinen M, Holtta P, Riekkola M L, et al. Analysis of colloids released from bentonite and crushed rock[J]. Physics and Chemistry of the Earth,2010, 35(6): 265-270. |
[54] | Kersting A B, Efurd D W, Finnegan D L, et al. Migration of plutonium in ground water at the Nevada test site[J]. Nature, 1999, 397(6 714): 56-59. |
[55] | Novikov A P, Kalmykov S N, Utsunomiya S, et al. Colloid transport of plutonium in the far-field of the Mayak Production Association, Russia[J]. Science, 2006, 314(5 799): 638-641. |
[56] | Torok J, Buckley L P, Woods B L.The separation of radionuclide migration by solution and particle transport in soil[J]. Journal of Contaminant Hydrology, 1990, 6(2): 185-203. |
[57] | Puls R W, Powell R M.Transport of inorganic colloids through natural aquifer material: Implications for contaminant transport[J]. Environmental Science & Technology, 1992, 26: 614-621. |
[58] | Artinger R, Kienzler B, Schubler W, et al. Effects of humic substances on the 241Am migration in a sandy aquifer: Column experiments with Gorleben groundwater/sediments systems[J]. Journal of Contaminant Hydrology,1998, 35(1): 261-275. |
[59] | Vilks P, Baik M.Laboratory migration experiments with radionuclide and natural colloid in a granite fracture[J]. Journal of Contaminant Hydrology,2001, 47(2): 197-210. |
[60] | SKB. Long-term Safety for KBS-3 Repositories at Forsmark and Laxemar-a First Evalu-ation: Main Report of the SR-Can Project[R]. Stockholm, Sweden: SKB TR-06-09, Swedish Nuclear Fuel and Waste Management Co., 2006. |
[61] | Börgesson L, Hernelind J.Consequences of Loss or Missing Bentonite in Deposition Holes: A theoretical study[R]. Stockholm, Sweden: SKB TR-06-13, Swedish Nuclear Fuel andWaste Management Co., 2006. |
[62] | Karnland O.Bentonite Swelling Pressure in Strength NaCl Solutions. Correlation Between Model Calculation and Experimentally Determined Data[R]. Stockholm, Sweden: SKB TR 97-31. Swedish Nuclear Fuel and Waste Management Co., 1997. |
[63] | Posiva. TKS-2009-Nuclear Waste Management at the Olkiluoto and Loviisa Power Plants[R]. Eurajoki, Finland: Posiva Report TKS-2009, Posiva Oy, 2010. |
[64] | Chen Yonggui, Huang Runqiu, Zhu Chunming, et al. Chemical environment effect on hydromechanical behavior of compacted bentonite[J]. Journal of Tongji University (Natural Science), 2014, 42(3): 398-405. |
[64] | [陈永贵,黄润秋,朱春明,等. 化学场对膨润土水—力特性影响研究进展[J]. 同济大学学报:自然科学版,2014,42(3):398-405.] |
[65] | Kaufhold S, Dohrmann R.Detachment of colloidal particles from bentonites in water[J]. Applied Clay Science,2008, 39(1): 50-59. |
[66] | Banin A, Lahav N.Particle size and optical properties of montmorillonite in suspension[J]. Israel Journal of Chemistry, 1968, 6(3): 235-250. |
[67] | Missana T, Alonso U, Turrero M J.Generation and stability of bentonite colloids at the bentonite/granite interface of a deep geological radioactive waste repository[J]. Journal of Contaminant Hydrology, 2003, 61(1): 17-31. |
[68] | García-García S, Wold S, Jonsson M.Effects of temperature on the stability of colloidal montmorillonite particles at different pH and ionic strength[J]. Applied Clay Science, 2009, 43(1): 21-26. |
[69] | Chegbeleh L P, Nishigaki M, Akudago J A, et al. Experimental study on ethanol/bentonite slurry injection into synthetic rock fractures: Application to seepage control[J]. Applied Clay Science, 2009, 45(4): 232-238. |
[70] | Mitchener H, Torfs H.Erosion of mud/sand mixtures[J]. Coastal Energy, 1996, 1996, 29(1/2): 1-25. |
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