摘要(英) |
MX-80 bentonite was used for the erosion test. The turbidity of the liquid was measured from the water outlet of the device to estimate the erosion quality. The average radial expansion distance and the area of accessory minerals were measured by the image, analyze the influence of different aperture, water chemistry and water flow on the erosion of bentonite.
The most serious erosion was observed using deionized water in a large aperture (2.0 mm) and a high flow rate (1.0 mL/min) environment. 30.8% of the original weight has been lost at 93 days , And the ionic strength of 2.54 mM and 4.00 mM NaCl solution, the eroded mass measured in 63 days is less than 1.0% of the original weight. The ionic strength of groundwater is the key to the erosion of bentonite. In the test of deionized water with a flow rate 1.0 mL/min and a 0.2 mm aperture, the eroded mass measured at 93 days is equivalent to the loss of 3.68% of the original weight, so the eroded mass will decrease with the aperture. In the test of deionized water with a flow rate 0.2 mL/min and a 2.0 mm aperture, the eroded mass measured at 104 days is equivalent to the loss of 8.84% of the original weight. When a lower water flow rate is used, the eroded mass will reduce significantly.
Observe and analyze the image and the bentonite sample after the erosion test. It is believed that the formation of the accessory mineral ring is whether erosion occurs. If a large amount of montmorillonite is lost after bentonite erosion, the coarser particles staying in place will block the medium-sized and fine particles, These particles will be blocked by bridging. The bridging will jam each other in place, and eventually form a accessory mineral ring.
From the results, it is known that the large water flow and aperture will cause severe erosion. The impact of water chemistry is the most critical. In the test of 4.00 mM NaCl solution, buffer will maintain barrier function. |
參考文獻 |
王欣婷,(2003),「緩衝材料在深層處置場模擬近場環境下回脹行為基礎研究」,國立中央大學土木工程研究所碩士論文,中壢。
台灣電力公司,(2017),「我國用過核子燃料最終處置技術可行性評估報告」,台北。(TPC-SNFD2017-V1)
日本原子能研究開發機構(JAEA),(2008),「緩衝材の浸食現象評価-ベントナイトコロイドの生成挙動」,茨城縣。(JAEA-Research 2008-097)
莊文壽、洪錦雄、董家寶,(2000),「深層地質處置技術之研究」,核研季刊,第三十七期、第44-54頁。
陳文泉,(2004),「高放射性廢棄物深層地質處置緩衝材料之回脹行為研究」,國立中央大學土木工程研究所博士論文,中壢。
鄭百宏,(2014),「緩以膨潤土製作緩衝回填材料之性能評估」,國立台灣大學土木工程學系研究所碩士論文,台北。
Birgersson, M., Hedström, M., and Karnland, O. (2011) “Sol formation ability of Ca/Na-montmorillonite at low ionic strength.” Physics and Chemistry of the Earth, 36 (2011) 1572–1579
Huang, W.H., and Chen, W.C. (2004) “Swelling behavior of a buffer material under simulated near field environment.” Journal of Nuclear Science and Technology, 41(12), 1271-1279.
Hedström, M., Birgersson, M., Nilsson, U., and Karnland, O., (2011) “Role of cation mixing in the sol formation of Ca/Na-montmorillonite. ” Physics and Chemistry of the Earth, 36 (2011) 1564–1571
Juvankoski, M., Ikonen, K., and Jalonen, T. (2012) Buffer production line 2012: Design, production and initial state of the buffer. Posiva Oy, Eurajoki. (Posiva 2012-17)
Kiviranta, L. and Kumpulainen, S. (2011) Quality control and characterisation of bentonite materials. Posiva Oy, Eurajoki. (Working Report 2011-84)
Mitchell, J.K. (1993) Fundamentals of Soil Behavior, 2nd ed, Wiley, New York.
NWMO. (2010), Laboratory Bentonite Erosion Experiments in a Synthetic and a Natural Fracture, Nuclear Waste Management Organization(Canada), Toronto. (NWMO TR-2010-16)
Reid, C., Lunn, R., Mountassir, G.E., and Tarantino, A. (2015) “A mechanism for bentonite buffer erosion in a fracture with a naturally varying aperture.” Mineralogical Magazine, The Mineralogical Society of Great Britain & Ireland, Vol. 79(6), pp. 1485–1494.
SKB. (1983), Final Storage of Spent Nuclear Fuel – KBS-3, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden.
SKB. (2002), The buffer and backfill handbook part 2: materials and techniques, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden. (SKB TR-02-12)
SKB. (2006a), Montmorillonite stability with special respect to KBS-3 conditions, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden. (SKB TR-06-11)
SKB. (2006b), Physical and chemical stability of the bentonite buffer, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden. (SKB R-06-103)
SKB. (2009a), Bentonite erosion Laboratory studies, Swedish Nuclear Fuel and Waste Management Co. Stockholm,Sweden.(SKB TR-09-33)
SKB. (2009b), Bentonite erosion Final report, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden. (SKB TR-09-34)
SKB. (2009c), Mechanisms and models for bentonite erosion, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden. (SKB TR-09-35)
SKB. (2011a), Environmental Impact Statement, Interim storage, encapsulation and final disposal of spent nuclear fuel, March 2011, ISBN 978-91-978702-5-2.
SKB. (2011b), Long-term safety for the final repository for spent nuclear fuel at Forsmark, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden. (SKB TR-11-01)
SKB. (2019), Bentonite expansion, sedimentation and erosion in artificial fractures, Swedish Nuclear Fuel and Waste Management Co. Stockholm, Sweden. (SKB TR-19-08) |