Impact Analysis of Earthquake-Induced Cracks in Deep Geological Repositories for Nuclear Waste Fuel

Abstract

Based on the concept of deep geologic repositories, high-level radioactive waste will be stored in deep deposition holes away from the ground surface. The heat generated by the waste will induce both significant stress increments and ground water seepage in a multiple geologic barrier system. The long-term ability of a barrier system is significantly impacted by coupling between the thermal, hydrological, and mechanical processes. The stability of a system may also depend particularly upon unanticipated factors such as the development of post-earthquake macrocracks. Therefore, this study investigates the three-dimensional transient and long term thermo-hydro-mechanical behavior of a barrier system. The results can be used for future reference in practical engineering design.高放射性用過核燃料所產生之長期衰變熱會對生物圈造成極大衝擊，目前國際上多傾向以深層地質處置作為最終處置之方式。處置過程中，極可能因為地震或地層變動等不可預期之因素，在天然障壁中產生大形裂縫，由此伴隨的災損效應將會加速障壁之劣化。本研究依據我國深層地質處置的初步設計概念，針對天然障壁系統長期之熱-水力-力學耦合效應，利用依序耦合分析方法，考慮不同的裂縫尺寸，針對其可能引致之熱應力與地下水影響進行評估