用過核燃料中因放射性核種衰變產生的衰變熱，是影響處置設施安全的一項重要因素。深層地下處置法利用廢料包件、緩衝材料、回填材料、以及處置母岩所形成的多重障壁來達到阻隔及延緩核種向外遷移之目的，使得核種到達地面時，其放射性已衰變至對人體無害的程度。 研究內容針對核研所（2002）深層地質處置概念的初步設計尺寸進行模擬。利用ABAQUS分析在多孔處置場的空間配置之下，預期可獲得處置概念設計下溫度場隨時間及空間的變化情形，並且預估處置設施之最高溫及其發生時間。此模擬結果可確保處置設計概念之穩定性及安全性。 分析中針對原本設計間距尺寸面積6*40（短向*長向）M ，進行變動長向、短向間距尺寸，並與SKB溫度設計基準比較，藉以觀察多孔處置場中的內部處置孔間距的影響。結果顯示：以長向間距比較而言，6*60M 約略可符合要求；而以短向間距比較而言，8*40M 可以符合要求；若限定膨潤土內側低於水沸點100 C，則6*40M 即可符合要求。 Decay heat generated by the decay of radionuclides in spent nuclear fuels is one of the major consideration influencing the design and safety of a potential disposal facility. Deep geologic disposal achieves the isolation and retardation of nuclide migrating by multiple barrier (made up of waste package, buffer material, backfill material and host rock). In this way, before nuclide reaches ground, the decayed radioactivity will have no harm to human body. This study is performed according to the preliminary size design of INER (Institute of Nuclear Energy Research), 2002. It is aimed to obtain the distribution of temperature field with respect to space and time in a repository space environment by using the code ABAQUS. Also estimated is the highest temperature and its timing in the disposal environment. The result can be used to assess the stability and safety of facility design based on the disposal concept. The analytical results show the space influence of deposition hole inside the multiple deposition holes environment. By considering the original space design area 6*40(short direction* long direction)M² as a standard , we change long direction’s space and short direction’s space and compare their differences with SKB design criteria. For long direction’s space comparison, the area 6*60M² approximately can confirm the criteria. For short direction’s space comparison, the area 8*40M² can confirm the criteria. If we adopt the criteria of canister’s surface temperature lower than 100°C, then the area 6*40 M² can confirm the criteria.
