在低放射性廢棄物最終處置場的服務期間長久，而混凝土和回填材料介面的交互作用時間是連續且長久，長期下來接觸介面的交互作用以及未來地下水的入侵，皆會造成回填材料內部微結構和障壁功能的改變，直接影響到原本預期的材料特性。
本研究內容主要分為兩個階段，在第一階段有兩個部分，第一部份以電滲加速試驗模擬處置場在長久未飽和狀態下，模擬混凝土襯砌及回填材料介面的交互作用，混凝土分別選用一般混凝土及低鹼混凝土，比較不同混凝土對回填材料的影響，回填材料是以 Volclay SPV 200 膨潤土取代 50 % 重量百分比的粒料；，以低鹼性混凝土作為混凝土襯砌，回填材料分別以膨潤土取代50% 及 30% 的粒料，比較碎石粒料的添加比例是否能減少混凝土對回填材料的影響。第二部份，以回脹壓力與水力傳導試驗針對處置場在飽和狀況下，了解地下水化學及pH值效應對電滲後回填材料回脹行為之影響。
研究結果顯示，在未飽和環境下混凝土襯砌與回填材料相互接觸經電滲加速試驗後，混凝土中鈣離子將會釋出，使得與其接觸的回填材料由接觸面開始，其鈣鈉比升高、pH值降低，且普通混凝土對回填材料的影響較低鹼性混凝土大。在飽和環境下，電滲後回填材料於NaCl 與 CaCl2 環境下，回脹壓力隨著陽離子濃度提升而降低，其中NaCl效應下對回脹壓力影響較大。電滲後回填材料於 pH值＜13 溶液中，對回脹壓力沒有明顯影響；當回填材料於高鹼系統中，高濃度氫氧根離子入侵至膨潤土內部，造成蒙脫石溶解，導致回脹壓力永久性降低。

Both concrete and backfill serve as engineered barriers for isolation of low-level radioactive wastes in a repository for radioactive wastes. As the disposal site is expected to serve a very long time, the interactions between the two barriers need to be evaluated under the potential unsaturated/saturated situations. This study aims at simulating the long-term scenario of engineered barrier materials and the corresponding effects of the scenario on the expected function of barrier materials in a final disposal site for low-level radioactive wastes.
In this research, a migration technique was applied to accelerate the migration of calcium ions from the pore solution of concrete so as to investigate the alteration of compacted bentonite in contact with the concrete. The backfill material was prepared by mixing 30-50% of Black Hills bentonite from Wyoming with 50-70% of Taitung area argillite to produce different ratios of sand-bentonite mixture as backfill. And the barrier concrete is a low-pH concrete having a binder comprised of 60% cement and 40% silica fume. After the migration test, backfill material was tested for swelling pressure to evaluate the effects of long-term contact. Finally, concrete barrier and backfill were both subjected to extended unsaturated situation as well as saturated situation for further evaluation. The backfill was treated with groundwater permeated through the concrete after the migration test so as to simulate the sequence of unsaturated and saturated scenarios that are expected to be experienced. Also, concrete barrier and backfill were both subjected to extended unsaturated situation as well as saturated situation for further evaluation. The backfill was treated with groundwater chemistry, pH environment after the migration test so as to simulate the sequence of unsaturated and saturated scenarios that are expected to be experienced. Results from the study show:(1) It was found from the accelerated migration test that the release of calcium from concrete in unsaturated situation results in reduction of swelling capacity of the contacting buffer. The shorter the distance to the interface, the more the increases in the ratio of calcium to sodium content in the backfill material, and the swelling pressure decreased as well. (2) in NaCl and CaCl2 solution, the swelling pressure of bentonite decreases with increasing cation concentration, and the effect of NaCl on swelling pressure is more pronounced; (3) at solutions with pH < 13, no significant reduction on swelling pressure was observed; (4) as illustrated by ICP analysis, backfill in NaOH [1.0M] solution shows decreases in montmorillonite and quartz minerals, while the Si4+ ions exhibits obvious increase.

參考文獻
王明光，(2001)，「環境土壤化學」，五南圖書出版。
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。
王俊堯，（2011），「低放射性廢棄物最終處置回填材料於近場環境下之長期穩定性研究」，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，(2009)，低放射性廢棄物最終處置設施，概念設計 (B版)。
台灣電力公司，(2010)，我國用過核子燃料最終處置初步技術可行性評估報告。
台灣電力公司，（2014），用過核子燃料最終處置計畫，潛在處置母岩特性調查與評估階段－2010 至 2013 年計畫整合報告。
台灣電力公司，(2015)，建議候選場址概念設計報告。
李冠宏，(2015)，「最終處置場近場環境對緩衝材料回脹壓力之影響」，國立中央大學土木工程研究所，碩士論文，中壢。
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」，博士論文，國立中央大學土木工程研究所，中壢。
張皓鈞，（2011），「高放廢棄物最終處置場緩衝材料與混凝土障壁的交互作用」，碩士論文，國立中央大學土木工程研究所，中壢。
張皓鈞，(2015)，「低放射性廢棄物最終處置場工程障壁材料於未飽和/飽和環境下之長期穩定性研究」，國立中央大學土木工程研究所博士論文，中壢。
趙杏媛、張有瑜，（1990），「黏土礦物與黏土礦物分析」，海洋出版社，北京。
洪昆煌、王明光、陳尊賢、賴朝明、何聖賓、李達源，（1996），「土壤化學」，國立編譯館。
經濟部低放射性廢棄物最終處置設施場址選擇小組，（2011），建議候選場址遴選報告。
單信瑜，1997），「放射性廢料處置場緩衝回填材料物性及化性之介紹」，核能研究所放射性廢料最終處置核種遷移與水文地質相關技術訓練研討會（第二期）講義。
萬鑫森，（1991），「基礎土壤物理學」，茂昌圖書。
劉東山、蔡昭明，（1993），「放射性廢料管理」，曉園出版社，台北市。
Abdullah, W.S., Alshibli, K.A., and Al-Zou'bi, M.S. (1999). “Influence of pore water chemistry on swelling behavior of compacted clays.” Applied Clay Science, 15, 447-462.
Alonso, M.C., Garcia Calvo, J. L., Walker C, Naito M., Pettersson, S., Puigdomenech, I., Cuñado, M.A., Vuorio M, Posiva, Weber, H., Ueda, H.,and Fujisaki, K. (2012). “Development of an accurate pH measurement methodology for the pore fluids of low pH cementitious materials.” SKB
Report R-12-02 Swedish Nuclear Fuel and Waste Management Company,
Stockholm, Sweden.
ASTM D422-63. (2007). “Standard test method for particle-size analysis of soils.” PA.
ASTM D584-10. (2010). “Standard test method for wool content of raw wool – laboratory scale.” PA.
ASTM D1141-98. (2013). “Standard practice for the preparation of sub-stitute ocean water.” PA.
ASTM D2216-10. (2010). “Standard test methods for laboratory deter-mination of water (moisture) content of soil and rock by mass.” PA.
ASTM D4318-10. (2010). “Standard test methods for liquid limit, plastic limit, and plasticity index of soils.” PA.
ASTM D4972-13. (2013). “Standard test method for pH of soils.” PA.
ASTM D5890-11. (2011). “Standard test method for swell index of clay mineral component of geosynthetic clay liners.” PA.
Bauer, A., Lanson, B., Ferrage, E., Emmerich, K., Taubald, H., Schild, D., and Velde, B. (2006). “The fate of smectite in KOH solutions.” American Mineralogist, 91(8-9), 1313-1322.
Bag, R. (2011). “Coupled thermo-hydro-mechanical-chemical behaviour of MX80 bentonite in geotechnical applications.” PhD Thesis, Cardiff University, Cardiff.
Bohn, H.L., McNeal, B.L., and O’Connor, G.A. (1985). Soil Chemistry, 2nd ed., John Wiley & Sons Inc., New York.
Chen, Y.G., Zhu, C.M., Ye, W.M., Cui, Y.J., and Chen, B. (2016). “Effects of solution concentration and vertical stress on the swelling behavior of compacted GMZ01 bentonite.” Applied Clay Science, 124-125, 11-20.
Claret, F., Bauer, A., Schäfer, T., Griffault, L., and Lanson, B. (2002). “Experimental investigation of the interaction of clays with high pH solutions: a case study from the Callovo-Oxfordian formation, Meuse-Haute Marne underground laboratory (France).” Clays and Clay Minerals, 50, 633-646.
Cuisinier, O., Masrouri, F., Pelletier, M., Villieras, F., and Mosser-Ruck, R. (2008). “Microstructure of a compacted soil submitted to an alkaline plume.” Applied Clay Science, 40, 159-170.
Delage, P., Marcial, D., Cui, Y.J., and Ruiz, X. (2006). “Ageing effects in the compacted bentonite: a microstructure approach.” Géotechnique, 56(4), 291-304.
Fernández, R., Rodríguez, M., Vigil de la Villa, R., and Cuevas, J. (2010). “Geochemical constraints on the stability of zeolites and C–S–H in the high pH reaction of bentonite.” Geochimica and Cosmochimica Acta, 74, 890-906.
Gomez-Esipna, R., and Villar, M.V. (2010). “Geochemical and minera-logical changes in compacted MX-80 bentonite submitted to heat and water gradients.” Applied Clay Science, 47, 400-408.
Grim, R. E., and Guven, N. (1978). Bentonites, Geology, Mineralogy, Properties and Uses, Elsevier, Amsterdam.
Han, W.S., Xia, M.F., Shen, L.T., and Bai, Y.L. (1997). “Statistical formulation and experimental determination of growth rate of micrometer cracks under impact loading.” International Journal of Solids & Structure, Vol.34, pp.2905-2925.Karnland (2007)
Karnland, O., Olsson, S., Nilsson, U., and Sellin, P. (2007). “Experi-mentally determined swelling pressures and geochemical interactions of compacted Wyoming bentonite with highly alkaline solutions.” Physics and Chemistry of the Earth, 32, 275-286.
Kaufhold, S., Dohrmann, R. (2011). “Stability of bentonites in salt solu-tions III – Calcium hydroxide.” Applied Clay Science, 51, 300-307.
Komine, H., Yasuhara, K., and Murakami, S. (2009). “Swelling cha-racteristics of bentonites in artificial seawater.” Can. Geotech. J., 46, 177-189.
Lambe, T.W. (1958). “The structure of compacted clay.” Journal of the Soil Mechanics and Foundations Division, 84(SM2), 1-35.
Lloret, A., Villar, M.V., Sanchez, M., Gens, A., Pintado, X., and Alonso, E.E. (2003). “Mechanical behaviour of heavily compacted bentonite under high suction changes.” Géotechnique, 53(1), 27-40.
Melkior, T., Mourzagh, D., Yahiaoui, S., Thoby, D., Alberto, J.C., Brouard, C., and Michau, N. (2004). “Diffusion of an alkaline fluid through clayey barriers and its effect on the diffusion properties of some chemical species.” Applied Clay Science, 26, 99-107.
Mishra, M., Schanz, T., and Tripathy, S. (2008). “A column device to study THM behaviour of expansive soils.” Proceddings of 12th International conference of International Association for Computer Methods in Advances in Geomechanics, 1149-1156.
Mitchell, J.K. (1993). Fundamentals of Soil Behavior, 2nd Edition, John Wiley & Sons Inc., New York.
Montes-H, G., Fritz, B., Clement, A., and Michau, N. (2005). “Modelling of geochemical reactions and experimental cation exchange in MX-80 bentonite.” J. Environ. Manage., 77, 35-46.
Pusch, R. (1980). “Swelling pressure of highly compacted bentonite.” SKB Technical Report TR-80-13, Stockholm.
Pusch, R. (1982). “Mineral-water interactions and their influence on the physical behaviour of highly compacted Na bentonite.” Canadian Geotechnical Journal, 19, 381-387.
Pusch, R., (2001). “Experimental study of the effect of high porewater salinity on the physical properties of a natural smectitic clay.” SKB Technical Report TR-01-07, Stockholm.
Pusch, R., and Moreno, L. (2001). “Saturation and permeation of buffer clay.” Proceedings of 6th international workshop on Key Issues in Waste Isolation Research, Paris, 71-81.
Pusch, R., Zwhar, H., Gerber, R., and Schomburg, J. (2003). “Interaction of cement and smectitic clay – theory and practice.” Applied Clay Science, 23, 203-210.
Sato, T., Kuroda, M., Yokoyama, K., and Nakayama, S. (2002). “Effect of pH on smectite dissolution rates under alkaline conditions.” Clays in Natural and Engineered Barriers for Radioactive Waste Confinement: International Meeting, Reims, France, 11-12.
Savage, D., Bateman, K., Hill, P., Hughes, C., Milodowski, A., Pearce, J., Rae, E., and Rochelle, C. (1992). “Rate and mechanism of the reaction of silicates with cement pore fluids.” Applied Clay Science, 7, 33-45.
Savage D., and Benbow S. (2007). “Low-pH Cements.” SKI Report 2007:32, Swedish Nuclear Power Inspectorate (SKI), Stockhoolm, Sweeden.
Savage D., and Benbow S. (2007). “Low-pH Cements.” SKI Report 2007:32, Seed, H. B., Woodware, R. J., and Lundgren, R. (1962). “Prediction of Swelling Potential for Compacted Clays.” Journal of the Soil Mechanics and Foundation Engineering , ASCE, Vol.88, pp.53-87.Swedish Nuclear Power Inspectorate (SKI), Stockhoolm, Sweeden.
Savage, D., Benbow, S., Watson, C., Takase, H., Ono, K., Oda, C., and Honda, A. (2010). “Natural systems evidence for the alteration of clay under alkaline conditions: an example from Searles Lake, California.” Applied Clay Science, 47, 72-81.
SKB TR11-01. (2011). “Long-term safety for the final repository for spent nuclear fuel at Forsmark: Main report of the SR-Site project Volume I.” SKB Technical Report TR-11-01, Svensk Kärnbränslehantering AB.
Takafumi S., and Yukikazu, T. (2008). ” Use of a migration technique to study alteration of compacted sand–bentonite mixture in contact with concrete.”
Yong, R.N., and Benno, P.W. (1975). Soil Properties and Behavior, Elsevier, NewYork.
Yong, R.N., Mohammed, A.M.O., Shooshapasha, I., and Onofrei, C. (1997). “Hydrothermal performance of unsaturated bentonite-sand buffer material.” Engineering Geology, 47, 351-365.
Zhu, C.M., Ye, W.M., Chen, Y.G., Chen, B., and Cui, Y.J. (2013). “Influence of salt solutions on the swelling pressure and hydraulic conductivity of compacted GMZ01 bentonite.” Engineering Geology, 166, 74-80.