Advances in researches on buffer/backfilling materials—bentonite pellets and pellet mixtures

LIU Zhang-rong; CUI Yu-jun; YE Wei-min; WANG Qiong; ZHANG Zhao; CHEN Yong-gui

doi:10.11779/CJGE202008004

Volume 42 Issue 8

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Chinese Journal of Geotechnical Engineering > 2020 > 42(8): 1401-1410. > DOI: 10.11779/CJGE202008004

LIU Zhang-rong, CUI Yu-jun, YE Wei-min, WANG Qiong, ZHANG Zhao, CHEN Yong-gui. Advances in researches on buffer/backfilling materials—bentonite pellets and pellet mixtures[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(8): 1401-1410. DOI: 10.11779/CJGE202008004

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Advances in researches on buffer/backfilling materials—bentonite pellets and pellet mixtures

LIU Zhang-rong^1,,
CUI Yu-jun^{1, 3},
YE Wei-min^{1, 2, ,},
WANG Qiong^{1, 4},
ZHANG Zhao¹,
CHEN Yong-gui^{1, 2}

1.
Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China
2.
Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China
3.
Laboratoire Navier, Ecole des Ponts ParisTech, Paris 77455, France
4.
Institute for Advanced Study, Tongji University, Shanghai 200092, China

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Received Date: September 15, 2019
Available Online: December 05, 2022

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Abstract

Abstract

The bentonite pellet is considered as an alternative buffer/backfilling material to fill technological voids and empty space in high-level radioactive waste (HLW) repository. The previous studies on the bentonite pellets are carefully reviewed and summarized, including their manufacturing methods, emplacement techniques, thermal conductivity, hydraulic behavior, structural change and mechanical behavior. Correspondingly, the research subjects worth further investigation are put forward. The results in the literatures indicate that the pellets can be manufactured and emplaced using several techniques, which together with size gradation and packing protocol can influence the packing dry density and homogeneity. For the pellet mixtures, the thermal conductivity is mainly governed by dry density, water content and temperature, and the hydro-mechanical behavior is related to size gradation, dry density and temperature. Upon liquid or suction controlled hydration, the initial loose-structured pellet mixtures will gradually transfer to the cemented state and finally present a homogeneous appearance at saturation. However, much longer duration is required before getting a completely homogeneous state. Considering the complexity of the operation conditions in a HLW repository, the improvements on emplacement techniques of the pellets and the investigations on the hydro-mechanical behavior and structural change under the coupled thermo-hydro-chemo-mechanical conditions should be further conducted.
- geological disposal,
- buffer/backfilling material,
- bentonite pellet,
- pellet mixture

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References (47)

References

[1]	崔玉军, 陈宝. 高放核废物地质处置中工程屏障研究新进展[J]. 岩石力学与工程学报, 2006, 25(4): 842-847. doi: 10.3321/j.issn:1000-6915.2006.04.019 CUI Yu-jun, CHEN Bao. Recent advances in research on engineered barrier for geological disposal of high-level radioactive nuclear waste[J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(4): 842-847. (in Chinese) doi: 10.3321/j.issn:1000-6915.2006.04.019
[2]	陈永贵, 贾灵艳, 叶为民, 等. 施工接缝对缓冲材料水–力特性影响研究进展[J]. 岩土工程学报, 2017, 39(1): 138-147. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201701014.htm CHEN Yong-gui, JIA Ling-yan, YE Wei-min, et al. Advances in hydro-mechanical behaviors of buffer materials under effect of technological gaps[J]. Chinese Journal of Geotechnical Engineering, 2017, 39(1): 138-147. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201701014.htm
[3]	WANG Q, TANG A M, CUI Y J, et al. The effects of technological voids on the hydro-mechanical behaviour of compacted bentonite–sand mixture[J]. Soils and Foundations, 2013, 53(2): 232-245. doi: 10.1016/j.sandf.2013.02.004
[4]	SALO J-P, KUKKOLA T. Bentonite Pellets, an Alternative Buffer Material for Spent Fuel Canister Deposition Holes[R]. Paris: NEA/CEC Workshop “Sealing of Radioactive Waste Repositories” (Braunschweig, Germany), OECD, 1989.
[5]	DIXON D, SANDÉN T, JONSSON E, et al. Backfilling of Deposition Tunnels: Use of Bentonite Pellets[R]. Stockholm: Svensk Kärnbränslehantering AB, SKB P-11-44, 2011.
[6]	刘樟荣. 高庙子膨润土颗粒混合物的堆积性质与考虑温度影响的水力特性研究[D]. 上海: 同济大学, 2019. LIU Zhang-rong. Investigation on the Packing Behaviour and Thermal-Hydraulic Properties of GMZ Bentonite Pellet Mixtures[D]. Shanghai: Tongji University, 2019. (in Chinese)
[7]	ANDERSSON L, SANDÉN T. Optimization of Backfill Pellet Properties, ÅSKAR DP2, Laboratory Tests[R]. Stockholm: Svensk Kärnbränslehantering AB, SKB R-12-18, 2012.
[8]	MARJAVAARA P, HOLT E, SJÖBLOM V. Customized Bentonite Pellets: Manufacturing, Performance and Gap Filling Properties[R]. Eurajoki: Posiva OY, 2013.
[9]	IMBERT C, VILLAR M V. Hydro-mechanical response of a bentonite pellets/powder mixture upon inﬁltration[J]. Applied Clay Science, 2006, 32(3/4): 197-209.
[10]	HOFFMANN C, ALONSO E E, ROMERO E. Hydro- mechanical behaviour of bentonite pellet mixtures[J]. Physics and Chemistry of the Earth, 2007, 32(8/9/10/11/12/13/14): 832-849.
[11]	KIM C S, MAN A, DIXON D, et al. Clay-Based Pellets for Use in Tunnel Backfill and as Gap Fill in a Deep Geological Repository: Characterisation of Thermal-mechanical Properties[R]. Toronto: Nuclear Waste Management Organisation, 2012.
[12]	MOLINERO-GUERRA A, MOKNI N, DELAGE P, et al. In-depth characterisation of a mixture composed of powder/pellets MX80 bentonite[J]. Applied Clay Science, 2017, 135: 538-546. doi: 10.1016/j.clay.2016.10.030
[13]	CHEN L, LIU Y M, WANG J, et al. Investigation of the thermal-hydro-mechanical (THM) behavior of GMZ bentonite in the China-Mock-up test[J]. Engineering Geology, 2014, 172: 57-68. doi: 10.1016/j.enggeo.2014.01.008
[14]	张虎元, 王学文, 刘平, 等. 缓冲回填材料砌块接缝密封及愈合研究[J]. 岩石力学与工程学报, 2016, 35(增刊2): 3605-3614. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2016S2019.htm ZHANG Hu-yuan, WANG Xue-wen, LIU Ping, et al. Sealing and healing of compacted bentonite block joints in HLW disposal[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(S2): 3605-3614. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2016S2019.htm
[15]	陈香波. 颗粒膨润土堆积性质及压实性质研究[D]. 兰州: 兰州大学, 2018. CHEN Xiang-bo. Packing and Static Compaction of Pellet Bentonite for HLW Disposal[D]. Lanzhou: Lanzhou University, 2018. (in Chinese)
[16]	ZHANG Z, YE W M, LIU Z R, et al. Inﬂuences of PSD curve and vibration on the packing dry density of crushed bentonite pellet mixtures[J]. Construction and Building Materials, 2018, 185: 246-255. doi: 10.1016/j.conbuildmat.2018.07.096
[17]	LIU Z R, YE W M, ZHANG Z, et al. Particle size ratio and distribution effects on packing behaviour of crushed GMZ bentonite pellets[J]. Powder Technology, 2019, 351: 92-101. doi: 10.1016/j.powtec.2019.03.038
[18]	LIU Z R, YE W M, ZHANG Z, et al. A nonlinear particle packing model for multi-sized granular soils[J]. Construction and Building Materials, 2019, 221: 274-282. doi: 10.1016/j.conbuildmat.2019.06.075
[19]	LIU Z R, YE W M, CUI Y J, et al. Investigation on vibration-induced segregation behaviour of crushed GMZ bentonite pellet mixtures[J]. Construction and Building Materials, 2020, 241: 117949. doi: 10.1016/j.conbuildmat.2019.117949
[20]	谈云志, 李辉, 彭帆, 等. 膨润土团粒的压实性能研究[J]. 防灾减灾工程学报, 2018, 38(5): 773-780. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXK201805001.htm TANG Yun-zhi, LI Hui, PENG Fan, et al. Compaction properties of bentonite agglomerate[J]. Journal of Disaster Prevention and Mitigation Engineering, 2018, 38(5): 773-780. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-DZXK201805001.htm
[21]	FERRARI A, SEIPHOORI A, RÜEDI J, et al. Shot-clay MX-80 bentonite: An assessment of the hydro-mechanical behaviour[J]. Engineering Geology, 2014, 173: 10-18. doi: 10.1016/j.enggeo.2014.01.009
[22]	KÖHLER S, MAYOR J C, NUSSBAUM C, et al. Report of the Construction of the HE-E Experiment[R]. PEBS Report, 2012.
[23]	KÖHLER S, MAYOR J C, NUSSBAUM C, et al. Report of the construction of the HE-E experiment[R]. PEBS Report, 2012.
[24]	GARCÍA-SIÑERIZ J L, VILLAR M V, REY M, et al. Engineered barrier of bentonite pellets and compacted blocks: State after reaching saturation[J]. Engineering Geology, 2015, 192: 33-45. doi: 10.1016/j.enggeo.2015.04.002
[25]	MASUDA R, ASANO H, TOGURI S, et al. Buffer construction technique using granular bentonite[J]. Journal of nuclear science and technology, 2007, 44(3): 448-455. doi: 10.1080/18811248.2007.9711307
[26]	MARJAVAARA P, KIVIKOSKI H. Filling the gap between buffer and rock in the deposition hole[R]. Eurajoki: Posiva OY, 2011.
[27]	ÅBERG A. Effects of Water Inflow on the Buffer: An Experimental Study[R]. Stockholm: Svensk Kärnbränslehantering AB, SKB Rapport R-09-29, 2009.
[28]	KIVIKOSKI H, HEIMONEN I, HYTTINEN H. Bentonite Pellet Thermal Conductivity Techniques and Measurements[R]. Eurajoki: Posiva OY, 2015.
[29]	马国梁. 膨润土颗粒材料的工程性能研究[D]. 兰州: 兰州大学, 2018. MA Guo-liang. Engineering Properties of Granular Bentonite Materials for HLW Disposal[D]. Lanzhou: Lanzhou University, 2018. (in Chinese)
[30]	WIECZOREK K, MIEHE R, GARITTE B. Thermal Characterisation of HE-E Buffer[R]. PEBS Report, DELIVERABLE (D-N°: 2.2-9), 2013.
[31]	MOLINERO-GUERRA A. Experimental and Numerical Characterizations of the Hydro-Mechanical Behavior of a Heterogeneous Material: Pellet/Powder Bentonite Mixture[D]. Paris: University of Paris-Est, 2018.
[32]	MOLINERO-GUERRA A, CUI Y J, HE Y, et al. Characterization of water retention, compressibility and swelling properties of a pellet/powder bentonite mixture[J]. Engineering Geology, 2019, 248: 14-21. doi: 10.1016/j.enggeo.2018.11.005
[33]	MOLINERO-GUERRA A, DELAGE P, CUI Y J, et al. Water-retention properties and microstructure changes of a bentonite pellet upon wetting/drying; application to radioactive waste disposal[J]. Géotechnique, 2020, 70(3): 199-209. doi: 10.1680/jgeot.17.P.291
[34]	VILLAR M V, MARTÍN P L, ROMERO F J. Long-term THM Tests Reports: THM Cells for the HE-E Test: Update of Results Until February 2014[R]. Madrid: CIEMAT, 2014.
[35]	KARNLAND O, NILSSON U, WEBER H, et al. Sealing ability of wyoming bentonite pellets foreseen as buffer material-Laboratory results[J]. Physics and Chemistry of the Earth, 2008, 33: S472-S475. doi: 10.1016/j.pce.2008.10.024
[36]	MOLINERO GUERRA A, CUI Y J, MOKNI N, et al. Investigation of the hydro-mechanical behaviour of a pellet/powder MX80 bentonite mixture using an infiltration column[J]. Engineering Geology, 2018, 243: 18-25. doi: 10.1016/j.enggeo.2018.06.006
[37]	苏振妍. 颗粒膨润土材料持水性能及渗透性能研究[D]. 兰州: 兰州大学, 2019. SU Zhen-yan. The Water Retention and Permeability of Granular Bentonite Material for HLW Disposal[D]. Lanzhou: Lanzhou University, 2019. (in Chinese)
[38]	DIXON D, LUNDIN C, ÖRTENDAHL E, et al. Deep Repository–Engineered Barrier Systems: Half Scale Tests to Examine Water Uptake by Bentonite Pellets in a Block-Pellet Backfill System[R]. Stockholm: Svensk Kärnbränslehantering AB, 2008.
[39]	VAN GEET M, VOLCKAERT G, ROELS S. The use of microfocus X-ray computed tomography in characterising the hydration of a clay pellet/powder mixture[J]. Applied Clay Science, 2005, 29(2): 73-87. doi: 10.1016/j.clay.2004.12.007
[40]	MOLINERO-GUERRA A, AIMEDIEU P, BORNERT M, et al. Analysis of the structural changes of a pellet/powder bentonite mixture upon wetting by X-ray computed microtomography[J]. Applied Clay Science, 2018, 165: 164-169. doi: 10.1016/j.clay.2018.07.043
[41]	叶为民, 刘樟荣, 崔玉军, 等. 膨润土膨胀力时程曲线的形态特征及其模拟[J]. 岩土工程学报, 2020, 42(1): 29-36. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC202001006.htm YE Wei-min, LIU Zhang-rong, CUI Yu-jun, et al. Features and modelling of time-evolution curves of swelling pressure of bentonite[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(1): 29-36. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC202001006.htm
[42]	VILLAR M V. EB experiment Laboratory infiltration tests report[R]. Madrid: CIEMAT, 2012.
[43]	ZHANG Z, YE W M, LIU Z R, et al. Mechanical behavior of GMZ bentonite pellet mixtures over a wide suction range[J]. Engineering Geology, 2020, 264: 105383. doi: 10.1016/j.enggeo.2019.105383
[44]	PUSCH R, BLUEMLING P, JOHNSON L. Performance of strongly compressed MX-80 pellets under repository-like conditions[J]. Applied Clay Science, 2003, 23: 239-244. doi: 10.1016/S0169-1317(03)00108-X
[45]	ALONSO E E, ROMERO E, HOFFMANN C. Hydromechanical behaviour of compacted granular expansive mixtures: experimental and constitutive study[J]. Géotechnique, 2011, 61(4): 329-344. doi: 10.1680/geot.2011.61.4.329
[46]	ITO H. Compaction properties of granular bentonites[J]. Applied Clay Science, 2006, 31(1/2): 47-55.
[47]	GENS A, VALLEJÁN B, SÁNCHEZ M, et al. Hydromechanical behaviour of a heterogeneous compacted soil: experimental observations and modelling[J]. Géotechnique, 2011, 61(5): 367-386. doi: 10.1680/geot.SIP11.P.015

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